[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fh72glt30-uHb4mfFWUXceo9A8dmWNX6zmti_DKmDt1s":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":296,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":360},[4,8,12,16,20,24,28,32],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"title":33,"slug":34,"path":35},"Utilization Tests for Bacterial Identification","utilization-tests","\u002Futilization-tests\u002F",{"type":37,"data":38},"blog",{"slug":39,"title":40,"description":41,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":44,"lastUpdatedDate":44,"draft":45,"category":46,"image":42,"body":47,"faq":48,"commentsClosed":45,"tags":70,"related":72,"comments":292},"throat-swab-collection-transport-lab-diagnosis","Throat Swab: Collection, Transport, and Lab Diagnosis","\u003Cp>How to take a throat swab that actually samples the tonsils and posterior pharynx, why the tongue and cheeks must be avoided, which test needs which swab, why children need a backup culture, and how to transport it.\u003C\u002Fp>",null,"Acharya Tankeshwar","2026-08-13",false,"bacteriology","The throat swab looks like the simplest specimen in the lab, and it is the one most often taken wrong. The target for the common question, Group A strep, sits on the tonsils and the back of the throat. The tongue, the cheeks, and the saliva are covered in commensal bacteria that mean nothing. A swab that touches those and misses the tonsils gives a clean-looking specimen that is actually useless. **Almost every throat-swab error is a sampling error, so that is where this article puts its weight.**\n\nA throat swab is collected mainly to diagnose bacterial pharyngitis or tonsillitis, most often caused by *Streptococcus pyogenes* (Group A beta-hemolytic *Streptococcus*). Less often it is used for *Corynebacterium diphtheriae*, *Neisseria gonorrhoeae* (pharyngeal), *Arcanobacterium haemolyticum*, or, on request, other organisms. For the organism detail and full workup, each links to its dedicated page. This page is about the specimen.\n\n## How to take a throat swab correctly\n\n\u003Cfigure>\n\u003Cimg src=\"https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fthroat-swab-open-mouth-schematic.png\" alt=\"Swab target zones for a throat swab. Sample both tonsils and the posterior pharyngeal wall (teal). Avoid the tongue, cheeks, lips, and uvula (coral), which carry commensal flora that contaminate the specimen\" width=\"2720\" height=\"2160\" draggable=\"false\" contenteditable=\"false\">\u003Cfigcaption>Swab target zones for a throat swab. Sample both tonsils and the posterior pharyngeal wall (teal). Avoid the tongue, cheeks, lips, and uvula (coral), which carry commensal flora that contaminate the specimen\u003C\u002Ffigcaption>\n\u003C\u002Ffigure>\n\nThe single skill that decides the result is sampling the right surface. The technique:\n\n1. Wash hands, put on gloves and a mask (this procedure provokes coughing).\n2. Seat the patient facing a good light, head tilted back.\n3. Ask the patient to open wide and say \"aah.\" This lifts the soft palate and uvula and reduces gagging.\n4. Depress the tongue with a tongue depressor so you can see the tonsillar fossae and the posterior pharynx clearly.\n5. Rub the swab firmly over both tonsils (or tonsillar beds if the tonsils were removed) and the posterior pharyngeal wall, targeting any inflamed areas, exudate, or white patches.\n6. Do not touch the tongue, the cheeks, the teeth, the uvula, or the lips on the way in or out. Contact with those surfaces contaminates the swab with mouth flora.\n7. Withdraw and place the swab straight into transport medium.\n\nThe core rule: **swab the tonsils and the back of the throat, and nothing else.** Firm contact with the right surface matters more than gentleness; a timid swab that avoids the gag reflex often misses the target.\n\n## Which test decides the swab and the workflow\n\nHow the throat swab is handled depends on which test the clinic or lab runs.\n\n| Test | What it needs | Key point |\n| --- | --- | --- |\n| Rapid antigen detection test (RADT) | A dedicated swab, point of care | Fast (minutes); high specificity but lower sensitivity, so a negative may need backup |\n| Molecular test (NAAT, LAMP) | A swab in the kit's tube | High sensitivity and specificity; can replace backup culture |\n| Throat culture (blood agar) | Swab in Amies or Stuart's transport medium | The reference method; also gives the isolate for typing and susceptibility |\n\n**The backup-culture rule is the clinically important one.** RADT can miss true cases. In children and adolescents, a negative RADT should be confirmed by a throat culture or a molecular test, because a missed Group A strep can lead to rheumatic fever. In adults, a negative RADT usually does not need backup culture, because Group A strep pharyngitis and rheumatic fever are far less common. A positive RADT is reliable and does not need confirmation at any age.\n\nThis is why the two-swab habit is useful: one swab for the rapid test and one held in transport medium, so a backup culture can be set up from the second swab without recalling the patient.\n\n### Two swabs, and when one is enough\n\nThe convention for culture is two swabs from the same pass: one to make the smear if microscopy is requested (for example Albert or Gram stain when diphtheria is suspected), and one for culture. Where a rapid test is used, one swab serves the RADT and a second is held for a possible backup culture. If only one swab is available, it goes to culture, since culture cannot be repeated without bringing the patient back.\n\n## Transport\n\nThroat swabs are not fragile the way genital or CSF specimens are, but the target can still dry out and die.\n\n- Transport at room temperature and get it to the lab as soon as possible.\n- If a delay beyond about 2 hours is expected, place the swab in Amies or Stuart's transport medium so it does not dry.\n- Use a Dacron or rayon swab. Do not use calcium alginate if a molecular test may be run, since it can inhibit the reaction. Plain cotton is acceptable for routine culture but is a poorer choice for NAAT.\n- If a viral cause is being investigated (for example influenza), send the swab in viral transport medium instead, or use the test kit's own tube.\n\nRefrigeration is generally unnecessary for a routine throat swab in transport medium; room temperature with prompt transport is the norm.\n\n### When a throat swab is the wrong specimen\n\n- **Suspected epiglottitis:** do not swab the throat. Provoking the gag reflex can precipitate airway obstruction. This is an airway emergency, not a specimen decision.\n- **Nasopharyngeal pathogens** (*Bordetella pertussis*, respiratory viruses for some assays): the nasopharyngeal swab, not the throat swab, is the correct specimen. See the nasopharyngeal swab page.\n- **Lower respiratory infection:** a throat swab does not sample the lung. Sputum or a lower-respiratory specimen is needed.\n\n### Children versus adults: what actually differs\n\nThe collection technique is the same, but two things differ by age and matter clinically:\n\n- **Backup culture:** required after a negative RADT in children and adolescents, not routinely in adults.\n- **When to test at all:** testing is generally not recommended in children under 3 years unless there is a risk factor (such as an older sibling with strep), because Group A strep pharyngitis and rheumatic fever are uncommon at that age, and carriage is common. This is a testing-decision difference, not a collection-technique difference.\n\n## What the lab does with the specimen\n\nThe oropharynx carries a heavy normal flora, so the laboratory's job is to find the pathogen against a crowded background rather than to identify everything that grows.\n\n**Direct examination.** A routine Gram stain is not usually helpful for a throat swab, because the normal flora makes it hard to interpret and Group A *Streptococcus* cannot be distinguished from commensal streptococci on a smear. A Gram stain or specific stain is used only for particular questions, such as suspected Vincent's angina (fusiform bacilli and spirochetes) or when diphtheria is suspected, where an Albert or methylene blue stain shows the characteristic metachromatic granules of *Corynebacterium diphtheriae*.\n\n**The test forks three ways.** How the specimen is handled depends on which test is run:\n\n- **Rapid antigen detection test (RADT):** performed directly on the swab at the point of care, detecting the Group A *Streptococcus* carbohydrate antigen in minutes. High specificity, lower sensitivity.\n- **Molecular test (NAAT):** detects Group A *Streptococcus* nucleic acid with high sensitivity and specificity; can stand in for a backup culture.\n- **Throat culture:** the swab is plated on blood agar, the reference method, which also yields the isolate for any further testing.\n\n**Culture media and reading.** For culture, the swab is inoculated onto sheep blood agar and incubated at 35 to 37 degrees C, often anaerobically or with a CO2 environment, which enhances the beta-hemolysis of *Streptococcus pyogenes*. The read targets one thing in most cases:\n\n- Small, translucent colonies surrounded by a clear zone of **beta-hemolysis** are the suspect Group A *Streptococcus* colonies picked out from the mixed flora.\n- These are confirmed presumptively by **bacitracin susceptibility** and the **PYR test** (Group A *Streptococcus* is bacitracin-susceptible and PYR-positive), which separate it from other beta-hemolytic streptococci.\n- Because the throat is full of commensals, the lab reports the pathogen sought (chiefly Group A *Streptococcus*), not the entire mixed growth, unless a specific other pathogen was requested.\n\n**Interpretation, and the backup rule from the read side.** The clinical backup-culture rule carries straight through to the bench:\n\n- A negative RADT in a child or adolescent is followed by a throat culture or molecular test, because RADT can miss true cases and a missed Group A *Streptococcus* can lead to rheumatic fever.\n- A negative RADT in an adult is usually not cultured.\n- A positive RADT is reliable and needs no confirmation at any age.\n- Group A *Streptococcus* is essentially always susceptible to penicillin, so routine susceptibility testing is not performed on it; testing is reserved for penicillin-allergic patients, where macrolide susceptibility is checked.\n\n## **Identification and antimicrobial susceptibility testing**\n\nThe organisms sought from a throat swab, and the approach to each:\n\n- ***Streptococcus pyogenes* (Group A *Streptococcus*)**: beta-hemolytic, bacitracin-susceptible, PYR-positive gram-positive cocci in chains; the main target. See the *Streptococcus pyogenes* page.\n- ***Corynebacterium diphtheriae***: suspected clinically (pseudomembrane); requires special media (Tinsdale or tellurite) and toxigenicity testing, so the lab must be told in advance. See the diphtheria page.\n- **Groups C and G beta-hemolytic streptococci**: also cause pharyngitis; beta-hemolytic but bacitracin-resistant or PYR-negative, separating them from Group A. See the relevant spoke.\n- ***Arcanobacterium haemolyticum***: pharyngitis with a rash in adolescents and young adults; slow-growing, narrow-zone beta-hemolysis. See the relevant spoke.\n- ***Neisseria gonorrhoeae* (pharyngeal)**: when a sexual history indicates; needs selective medium or NAAT, and does not grow on routine throat culture. See the *Neisseria gonorrhoeae* page.\n\n## How to Remember\n\n**Throat swab errors are sampling errors.** The target is on the tonsils and the back of the throat. The tongue, cheeks, and saliva are full of commensals that mean nothing. Hit the target, avoid everything else. If you remember only one thing, remember where to rub.\n\n**Say \"aah\" to lift the curtain.** The \"aah\" raises the soft palate and uvula and opens the view to the tonsils, and it dampens the gag reflex. Light, tongue depressor, \"aah,\" swab.\n\n**Firm beats gentle.** A timid swab that dodges the gag reflex usually misses the tonsils. Good contact with the right surface is the whole point.\n\n**Kids get a backup, adults usually don't.** A negative rapid test in a child or adolescent needs a backup culture or molecular test, because of rheumatic fever risk. In adults a negative rapid test usually stands. A positive rapid test is trusted at any age.\n\n**Two swabs saves a second visit.** One for the rapid test, one held in transport medium for the backup culture. If you only have one, culture wins.\n\n## Key exam facts in one table\n\n| Point | Fact |\n| --- | --- |\n| Main target | *Streptococcus pyogenes* (Group A beta-hemolytic *Streptococcus*) |\n| Sample site | Both tonsils and the posterior pharynx |\n| Avoid | Tongue, cheeks, teeth, uvula, lips, saliva |\n| Patient maneuver | Head back, say \"aah,\" tongue depressor |\n| RADT | Fast, specific, less sensitive |\n| Negative RADT in children\u002Fadolescents | Backup throat culture or molecular test (rheumatic fever risk) |\n| Negative RADT in adults | Backup culture not routinely needed |\n| Positive RADT | Reliable, no confirmation needed |\n| Culture medium | Blood agar; bacitracin disc for presumptive Group A |\n| Transport medium | Amies or Stuart's if delay >2 hours |\n| Transport temperature | Room temperature, prompt |\n| Swab material | Dacron or rayon; not calcium alginate for NAAT |\n| Number of swabs | Two (RADT plus backup, or smear plus culture); if one, culture first |\n| Do NOT swab | Suspected epiglottitis (airway risk) |\n| Wrong specimen for | *Bordetella pertussis* and pertussis (use nasopharyngeal swab) |\n| Testing under age 3 | Generally not recommended without risk factors |\n\n## Where Students Get Confused\n\n**\"The swab looked clean and well-coated, so it is a good specimen, right?\"** Not necessarily. A swab coated with saliva and tongue flora looks fine but has missed the target. Quality is about where you sampled (tonsils and posterior pharynx), not how wet the swab is.\n\n**\"Why avoid the tongue and cheeks when they are right there?\"** Because they are covered in harmless commensal bacteria. Touching them dilutes the specimen with organisms that mean nothing and can obscure or crowd out the pathogen on culture.\n\n**\"A rapid test was negative, so strep is ruled out?\"** In an adult, usually yes. In a child or adolescent, no, the rapid test can miss true cases, so a negative result needs a backup culture or molecular test because of the risk of rheumatic fever. A positive rapid test, however, is trusted at any age.\n\n**\"Can I use a throat swab to diagnose whooping cough?\"** No. *Bordetella pertussis* lives in the nasopharynx, not the oropharynx. A nasopharyngeal swab or aspirate is required; a throat swab will miss it.\n\n**\"The child has severe sore throat and drooling, should I swab quickly?\"** No. Drooling, distress, and difficulty breathing suggest epiglottitis, where provoking the gag reflex can obstruct the airway. That is an emergency; do not swab.\n\n**\"Why two swabs for one test?\"** So a backup culture can be set up from the second swab if the rapid test is negative, without bringing the patient back. It also lets one swab make a smear while the other goes to culture.\n\n### References and further reading\n\n1. Tille PM. *Bailey & Scott's Diagnostic Microbiology.* 15th ed. St. Louis: Elsevier; 2022.\n2. Leber AL, editor. *Clinical Microbiology Procedures Handbook.* 4th ed. Washington, DC: ASM Press; 2016. DOI: 10.1128\u002F9781683670438.CMPH\n3. Shulman ST, Bisno AL, Clegg HW, et al. Clinical Practice Guideline for the Diagnosis and Management of Group A Streptococcal Pharyngitis. Infectious Diseases Society of America.",[49,52,55,58,61,64,67],{"question":50,"answer":51},"\u003Cp>Where exactly should a throat swab be taken from?\u003C\u002Fp>","\u003Cp>From both tonsils (or the tonsillar beds) and the posterior pharyngeal wall, targeting any inflamed areas or exudate. Avoid the tongue, cheeks, teeth, uvula, and lips, which carry commensal flora that contaminate the specimen.\u003C\u002Fp>",{"question":53,"answer":54},"\u003Cp>Why does the patient say \"aah\" during collection?\u003C\u002Fp>","\u003Cp>Saying \"aah\" lifts the soft palate and uvula, opening the view to the tonsils and posterior pharynx, and it reduces the gag reflex. Combined with a tongue depressor and good light, it lets you sample the right surface.\u003C\u002Fp>",{"question":56,"answer":57},"\u003Cp>If a rapid strep test is negative, is a culture still needed?\u003C\u002Fp>","\u003Cp>In children and adolescents, yes. A negative rapid antigen test should be confirmed by a throat culture or molecular test, because a missed Group A strep can lead to rheumatic fever. In adults, a negative rapid test usually does not need a backup culture. A positive rapid test is reliable at any age.\u003C\u002Fp>",{"question":59,"answer":60},"\u003Cp>How should a throat swab be transported?\u003C\u002Fp>","\u003Cp>At room temperature, as soon as possible. If a delay beyond about 2 hours is expected, place the swab in Amies or Stuart's transport medium to prevent drying. Use a Dacron or rayon swab, and avoid calcium alginate if a molecular test may be run.\u003C\u002Fp>",{"question":62,"answer":63},"\u003Cp>Can a throat swab diagnose whooping cough?\u003C\u002Fp>","\u003Cp>No. \u003Cem>Bordetella pertussis\u003C\u002Fem> lives in the nasopharynx, so a nasopharyngeal swab or aspirate is required. A throat swab will miss it.\u003C\u002Fp>",{"question":65,"answer":66},"\u003Cp>When should a throat swab not be taken?\u003C\u002Fp>","\u003Cp>When epiglottitis is suspected (severe sore throat with drooling and breathing difficulty), because provoking the gag reflex can obstruct the airway. That is an emergency requiring airway management, not a swab.\u003C\u002Fp>",{"question":68,"answer":69},"\u003Cp>Why are two swabs often collected?\u003C\u002Fp>","\u003Cp>One serves the rapid test and the other is held in transport medium for a backup culture, so the patient does not have to return. Alternatively, one makes a smear while the other goes to culture. If only one swab is available, it goes to culture first.\u003C\u002Fp>",[71],"specimen-collection-transport",[73,102,140,170,199,227,235,265],{"slug":74,"title":75,"description":76,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":77,"lastUpdatedDate":78,"draft":45,"category":46,"image":42,"faq":79,"tags":101},"eye-specimens-collection-transport-lab-diagnosis","Eye Specimens: Collection and Transport (Conjunctival Swab, Corneal Scraping)","\u003Cp>Why you swab both eyes even when one looks normal, how the specimen changes from conjunctivitis to a corneal ulcer, why eye samples are inoculated at the bedside, and when to think fungus or \u003Cem>Acanthamoeba.\u003C\u002Fem>\u003C\u002Fp>","2026-08-15","2026-08-14",[80,83,86,89,92,95,98],{"question":81,"answer":82},"\u003Cp>Why should both eyes be swabbed when only one is infected?\u003C\u002Fp>","\u003Cp>The apparently normal eye acts as a control for the conjunctiva's normal flora, helping distinguish a true pathogen from a commensal. It is also frequently infected before it shows symptoms, particularly in newborns and in viral and chlamydial conjunctivitis. Use a separate swab for each eye and label them left and right.\u003C\u002Fp>",{"question":84,"answer":85},"\u003Cp>What is the difference between a conjunctival swab and a corneal scraping?\u003C\u002Fp>","\u003Cp>A conjunctival swab samples the surface for conjunctivitis. A corneal scraping samples the corneal tissue at the edge of an ulcer for keratitis, because the pathogen sits within the cornea where a surface swab cannot reach. Scrapings are collected by an ophthalmologist.\u003C\u002Fp>",{"question":87,"answer":88},"\u003Cp>Why are eye specimens inoculated onto media at the bedside?\u003C\u002Fp>","\u003Cp>Eye specimens are scanty and can dry out and lose their few organisms in transit. Inoculating blood and chocolate agar (and Sabouraud if fungus is suspected) at the patient's side recovers far more than a swab that has to travel to the lab.\u003C\u002Fp>",{"question":90,"answer":91},"\u003Cp>Why must specimens be collected before eye drops are given?\u003C\u002Fp>","\u003Cp>Topical antibiotics suppress the organisms, and topical anesthetics are themselves bacteriostatic and lower the yield. If drops were already given, a negative culture may reflect suppression rather than true absence of infection, so note any prior treatment on the request.\u003C\u002Fp>",{"question":93,"answer":94},"\u003Cp>When should fungal or Acanthamoeba keratitis be suspected, and how does that change the specimen?\u003C\u002Fp>","\u003Cp>In contact lens wearers with keratitis. Submit the contact lens, its case, and the cleaning solution along with the corneal scraping, and request special media: non-nutrient agar for \u003Cem>Acanthamoeba\u003C\u002Fem> and Sabouraud agar with a KOH or calcofluor-white preparation for fungi.\u003C\u002Fp>",{"question":96,"answer":97},"\u003Cp>What organisms are targeted in a newborn with conjunctivitis?\u003C\u002Fp>","\u003Cp>\u003Cem>Neisseria gonorrhoeae\u003C\u002Fem> and \u003Cem>Chlamydia trachomatis\u003C\u002Fem>. Gonococcal specimens follow the fragile-organism rules (bedside inoculation, no refrigeration), and Giemsa staining is used to look for chlamydial inclusion bodies. Both eyes are sampled.\u003C\u002Fp>",{"question":99,"answer":100},"\u003Cp>Should eye specimens be refrigerated if there is a delay?\u003C\u002Fp>","\u003Cp>No. Fragile organisms such as \u003Cem>Neisseria gonorrhoeae\u003C\u002Fem> and \u003Cem>Haemophilus\u003C\u002Fem> do not tolerate cold. If a swab must travel, use Amies transport medium at room temperature and deliver it quickly; bedside inoculation is better still.\u003C\u002Fp>",[71],{"slug":103,"title":104,"description":105,"seoTitle":106,"seoDescription":42,"author":107,"createdDate":108,"lastUpdatedDate":109,"draft":45,"category":110,"image":42,"faq":111,"tags":139},"eswab-types-and-uses","Liquid-Based Swab Transport Systems (eSwab): Types, Uses, and Limitations","How liquid Amies transport systems like eSwab let one collection serve culture, Gram stain, and PCR, which formats exist, and the specimens they are not suitable for.","Liquid-Based Swab Transport Systems: How eSwab Works and When to Use It","Sushmita Baniya","2022-11-03","2026-07-23","lab-equipment",[112,115,118,121,124,127,130,133,136],{"question":113,"answer":114},"What is eSwab and what does the E stand for?","eSwab is a liquid-based swab transport system consisting of a nylon flocked swab and 1 mL of liquid Amies medium in a sterile screw-cap tube. The E stands for elute, referring to the sample releasing off the swab into the liquid rather than remaining trapped in the fibers.",{"question":116,"answer":117},"Can I use eSwab for viral specimens such as influenza or SARS-CoV-2?","No. Liquid Amies is a bacterial maintenance medium and lacks the protein stabilizers and antimicrobials that viral transport medium provides. Viral specimens require viral transport medium or universal transport medium. The two systems look very similar, so check the medium stated on the label rather than relying on the appearance of the swab.",{"question":119,"answer":120},"How long do organisms survive in a liquid Amies system?","Up to 48 hours at either room temperature (20 to 25°C) or refrigerator temperature (4 to 8°C), validated against CLSI standard M40-A2. Neisseria gonorrhoeae is the exception and should be processed within 24 hours, since it is the most fragile of the commonly transported pathogens.",{"question":122,"answer":123},"How many tests can be run from one eSwab collection?","Because the specimen becomes a liquid suspension, it can be divided into aliquots, typically up to ten from the 1 mL supplied. One collection can therefore serve Gram stain, culture, rapid antigen testing, and molecular assays, whereas a dry swab is usually spent on the first test performed.",{"question":125,"answer":126},"Why is the device sterilized by gamma irradiation?","Sterilization during manufacture ensures the tube and swab arrive sterile and ready to use, and it destroys any residual nucleic acid in the device. That matters for molecular testing, because contaminating DNA in a collection device could produce a false positive. It happens before the swab ever meets a patient and has no effect on the specimen collected later.",{"question":128,"answer":129},"What is the difference between liquid Amies and gel Amies?","Gel Amies holds the specimen within the swab fibers, so it must be eluted at the bench and only part is recovered. Liquid Amies elutes the sample at the moment of collection, recovering far more of it and allowing multiple aliquots. Gel remains cheaper and adequate for a routine single-request bacterial swab; liquid earns its cost for multi-test requests, fastidious organisms, and molecular or automated workflows.",{"question":131,"answer":132},"Is a liquid-based swab as good as a tissue sample?","No. For anaerobic culture, deep wounds, and fungal infection, tissue or aspirated fluid remains the preferred specimen. Liquid-based systems substantially improve what a swab can deliver, but they do not make a swab equivalent to tissue.",{"question":134,"answer":135},"What is the breakpoint on the swab shaft?","A scored line that allows the shaft to be snapped cleanly once the swab is inside the tube, so the cap seals properly and the collector's fingers never enter the tube. Bend the shaft against the tube rim at the mark, holding the tube away from your face.",{"question":137,"answer":138},"Which eSwab format should I use for a pediatric or nasopharyngeal sample?","The single minitip format, which has a smaller flocked tip suited to narrow or small collection sites, pediatric patients, and urethral sampling. The single regular format suits routine adult collection from throat, wound, ear, eye, and genital sites.",[71],{"slug":141,"title":142,"description":143,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":144,"lastUpdatedDate":145,"draft":45,"category":146,"image":42,"faq":147,"tags":169},"sample-collections-for-laboratory-diagnosis-of-fungal-infections","Sample Collection for Fungal Infections: Which Specimen, How to Collect and Transport","\u003Cp>Which specimen to collect for a suspected fungal infection by site, how to collect skin, nail, hair, blood, CSF, respiratory, urine, and tissue correctly, and the transport rule.\u003C\u002Fp>","2021-04-03","2026-08-17","mycology",[148,151,154,157,160,163,166],{"question":149,"answer":150},"\u003Cp>Why is a skin scraping better than a swab for a suspected fungal infection?\u003C\u002Fp>","\u003Cp>The fungus lives in the keratin at the advancing edge of the lesion, not loose on the surface. A swab collects surface debris and often misses the fungus, while scraping the growing margin with a slide edge or scalpel collects the living organism. Swabs give more false-negative results for dermatophyte infections.\u003C\u002Fp>",{"question":152,"answer":153},"\u003Cp>Should fungal specimens be refrigerated if there is a delay?\u003C\u002Fp>","\u003Cp>Almost never. Skin, nail, hair, CSF, blood, and tissue are kept at room temperature. Only urine is refrigerated (at 4°C) if processing is delayed beyond 2 hours. The rule is: warm for nearly all fungal specimens, refrigerate only urine.\u003C\u002Fp>",{"question":155,"answer":156},"\u003Cp>How should nail specimens be collected?\u003C\u002Fp>","\u003Cp>From beneath the nail plate, sampling the softened subungual material from the nail bed, because that is where the fungus grows. If that is not possible, scrape away the surface of the nail and collect shavings from the deeper portions. A surface clipping alone is a poor specimen.\u003C\u002Fp>",{"question":158,"answer":159},"\u003Cp>Why must hairs be plucked rather than cut?\u003C\u002Fp>","\u003Cp>The infection is at the hair root and the base of the shaft. Cutting the hair leaves the diagnostic part on the scalp. Hairs are plucked with forceps so the root is included, and a Wood lamp can help identify which hairs to sample.\u003C\u002Fp>",{"question":161,"answer":162},"\u003Cp>Where on a ringworm lesion should the scraping be taken?\u003C\u002Fp>","\u003Cp>From the raised, red, advancing margin. The center of the lesion is often healing and holds little live fungus, while the active edge is where the fungus is growing.\u003C\u002Fp>",{"question":164,"answer":165},"\u003Cp>Can tissue for fungal culture be placed in formalin?\u003C\u002Fp>","\u003Cp>No. Formalin kills the fungus and makes culture impossible. Send fresh tissue kept moist in sterile saline for culture, and a separate portion in formalin only if histopathology is also requested.\u003C\u002Fp>",{"question":167,"answer":168},"\u003Cp>Why is a 24-hour urine sample not accepted for fungal culture?\u003C\u002Fp>","\u003Cp>Pooling urine over 24 hours lets contaminating bacteria overgrow, which obscures the fungus. A fresh first early-morning sample is preferred, refrigerated if there is a delay.\u003C\u002Fp>",[71],{"slug":171,"title":172,"description":173,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":174,"lastUpdatedDate":175,"draft":45,"category":46,"image":42,"faq":176,"tags":198},"key-points-laboratory-diagnosis-lower-respiratory-tract-infections","Sputum Sample: Collection, Transport, Staining, and Culture","\u003Cp>How to collect a good sputum sample, why the first morning specimen matters, the ideal-to-compromise order when a patient cannot expectorate, the cell criteria that decide accept or reject, and correct transport timing.\u003C\u002Fp>","2013-09-04","2026-08-12",[177,180,183,186,189,192,195],{"question":178,"answer":179},"\u003Cp>Why is the first morning sputum sample preferred?\u003C\u002Fp>","\u003Cp>Secretions pool in the lower airways overnight, so the first deep cough of the day gives the most concentrated lower-airway material. For tuberculosis this raises the bacillary yield.\u003C\u002Fp>",{"question":181,"answer":182},"\u003Cp>How does the laboratory decide a sputum sample is really sputum and not saliva?\u003C\u002Fp>","\u003Cp>It screens a Gram-stained smear under low power. A good expectorated sample has more than 25 neutrophils and fewer than 10 squamous epithelial cells per low power field. Many squamous cells indicate saliva, and the sample is rejected. This screen applies to expectorated sputum only.\u003C\u002Fp>",{"question":184,"answer":185},"\u003Cp>Why is induced sputum sometimes rejected even though it is a valid sample?\u003C\u002Fp>","\u003Cp>Induced sputum is watery and cell-poor, so it fails the squamous-cell screen that is designed for expectorated samples. If it is labeled as induced, the lab bypasses that screen and processes it. Unlabeled, it can be wrongly rejected.\u003C\u002Fp>",{"question":187,"answer":188},"\u003Cp>What sample is used when a patient cannot cough up sputum?\u003C\u002Fp>","\u003Cp>Step up the invasiveness only as far as needed: induced sputum first, then endotracheal or tracheostomy aspirate in intubated patients, then bronchoscopy with BAL for immunocompromised or non-resolving cases. In young children, gastric aspirate (for TB) or bronchoscopy is often used because children swallow their sputum.\u003C\u002Fp>",{"question":190,"answer":191},"\u003Cp>How quickly must sputum reach the laboratory, and can it be refrigerated?\u003C\u002Fp>","\u003Cp>Process within 1 to 2 hours at room temperature. If delayed, refrigerate at 2 to 8 degrees C for up to 24 hours, except when a fastidious organism such as pneumococcus or \u003Cem>Haemophilus influenzae\u003C\u002Fem> is suspected, since cold lowers their recovery.\u003C\u002Fp>",{"question":193,"answer":194},"\u003Cp>Why might a hospitalized patient's gram-negative growth be ignored?\u003C\u002Fp>","\u003Cp>Intubated and hospitalized patients are colonized by gram-negative and nosocomial flora within days. A few colonies without matching clinical signs usually mean colonization, not infection, so identification and susceptibility testing would not change treatment.\u003C\u002Fp>",{"question":196,"answer":197},"\u003Cp>What concentration of saline is used for sputum induction?\u003C\u002Fp>","\u003Cp>Nebulized hypertonic saline, 3% to 7% NaCl. Normal saline (0.9%) is too dilute to irritate the airway and trigger a productive cough.\u003C\u002Fp>",[71],{"slug":200,"title":201,"description":202,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":203,"lastUpdatedDate":44,"draft":45,"category":46,"image":42,"faq":204,"tags":226},"collection-storage-and-transport-of-fecal-specimens-stool-for-microbiological-investigations","Stool Sample: Collection and Transport","\u003Cp>How to collect a stool sample correctly, how many samples and when, the rectal-swab compromise and when it is used, which transport medium or preservative to choose for bacteria versus parasites, and the storage rules that differ between them.\u003C\u002Fp>","2013-02-03",[205,208,211,214,217,220,223],{"question":206,"answer":207},"\u003Cp>How many stool samples are needed to look for parasites?\u003C\u002Fp>","\u003Cp>Three samples collected on separate days, because parasites are shed intermittently and a single stool can be falsely negative. For bacterial culture, one fresh sample in the acute phase is usually enough.\u003C\u002Fp>",{"question":209,"answer":210},"\u003Cp>When is a rectal swab acceptable instead of passed stool?\u003C\u002Fp>","\u003Cp>When passed stool cannot be obtained, for example in neonates or severely debilitated patients. The swab must be inserted past the anal sphincter and be visibly stained with feces, then placed in Cary-Blair. It is suitable for bacterial culture but not for parasite examination or C. difficile toxin testing.\u003C\u002Fp>",{"question":212,"answer":213},"\u003Cp>Which transport medium should a stool sample go into?\u003C\u002Fp>","\u003Cp>For enteric bacteria, Cary-Blair is the medium of choice. For parasites, use a preservative instead: formalin for concentration methods and PVA or a single-vial fixative for permanent stains. Bacteria and parasites need different chemistry.\u003C\u002Fp>",{"question":215,"answer":216},"\u003Cp>Can a delayed stool sample always be refrigerated?\u003C\u002Fp>","\u003Cp>Only for bacterial culture and for cysts and ova. An unpreserved liquid stool intended for trophozoite examination must not be refrigerated, since cold kills the motile trophozoites. Examine it fresh within about 30 minutes or fix it immediately.\u003C\u002Fp>",{"question":218,"answer":219},"\u003Cp>How much stool should be collected?\u003C\u002Fp>","\u003Cp>About 5 mL if the stool is liquid, or 2 grams (roughly two bean-sized portions) if formed. Sample any blood or mucus specifically, since pathogens concentrate there in dysentery.\u003C\u002Fp>",{"question":221,"answer":222},"\u003Cp>Why should stool not be collected from a bedpan?\u003C\u002Fp>","\u003Cp>Bedpans may contain residual disinfectant that kills pathogens, and the sample can be contaminated with urine. Collect directly into a clean, dry, wide-mouth container.\u003C\u002Fp>",{"question":224,"answer":225},"\u003Cp>When are stool cultures positive in typhoid fever?\u003C\u002Fp>","\u003Cp>Mainly from the second to third week of illness onward. In the first week, blood culture is the higher-yield test.\u003C\u002Fp>",[71],{"slug":228,"title":229,"description":230,"seoTitle":231,"seoDescription":42,"author":43,"createdDate":109,"lastUpdatedDate":175,"draft":45,"category":232,"image":42,"faq":233,"tags":234},"nasopharyngeal-swab-collection-procedure","Nasopharyngeal Swab Collection: Procedure, Depth, and Common Mistakes","Step-by-step nasopharyngeal and oropharyngeal swab collection, how deep the swab should go and how to tell, which swabs are unacceptable, and how to store the specimen so the result stays valid.","Nasopharyngeal and Oropharyngeal Swab Collection: Procedure and Technique","virology",[],[71],{"slug":236,"title":237,"description":238,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":175,"lastUpdatedDate":78,"draft":45,"category":46,"image":42,"faq":239,"tags":264},"specimen-collection-diagnosis-urinary-tract-infection","Urine Culture: Sample Collection, Transport and Lab Diagnosis ","\u003Cp>The organisms that cause UTI, how to collect and culture urine correctly, and how to read colony counts to separate real infection from contamination.\u003C\u002Fp>",[240,243,246,249,252,255,258,261],{"question":241,"answer":242},"\u003Cp>When should urine be sent for culture, and when should it not?\u003C\u002Fp>","\u003Cp>Send it only when there is real clinical suspicion of UTI: suspected pyelonephritis (loin pain and fever), UTI in men, recurrent UTI, pregnancy, or failed empiric treatment. Culturing every patient risks detecting asymptomatic bacteriuria, which usually does not need treatment.\u003C\u002Fp>",{"question":244,"answer":245},"\u003Cp>Which collection method gives the least contaminated sample?\u003C\u002Fp>","\u003Cp>Suprapubic aspiration, because the needle enters the bladder directly and bypasses the urethra. It is reserved for infants, young children, or cases where other methods fail. For routine adults, the clean-catch midstream sample is the practical standard despite its higher contamination risk.\u003C\u002Fp>",{"question":247,"answer":248},"\u003Cp>Why can urine never be cultured from a catheter drainage bag?\u003C\u002Fp>","\u003Cp>Bacteria multiply in the bag, so the count no longer reflects what is in the bladder. For a catheterized patient, clamp the tubing above the port, disinfect the port, and aspirate fresh urine through it.\u003C\u002Fp>",{"question":250,"answer":251},"\u003Cp>What does the calibrated loop actually do, and why does the angle matter so much?\u003C\u002Fp>","\u003Cp>It delivers a fixed, reproducible volume of urine (commonly 1 microlitre) so that counting colonies gives an estimate of CFU per mL. The result depends entirely on picking up that exact volume, so the loop must be held vertical and dipped only a few millimetres. A tilted or over-dipped loop delivers the wrong volume and invalidates the count.\u003C\u002Fp>",{"question":253,"answer":254},"\u003Cp>Why is \u003Cem>Staphylococcus aureus\u003C\u002Fem> in the urine treated differently from other organisms?\u003C\u002Fp>","\u003Cp>\u003Cem>S. aureus\u003C\u002Fem> usually reaches the kidney through the bloodstream rather than by ascending the urethra. So\u003Cem> S. aureus\u003C\u002Fem> in urine raises the question of a bloodstream infection, and any count from a suprapubic or catheter specimen can be significant rather than dismissed as a low count.\u003C\u002Fp>",{"question":256,"answer":257},"\u003Cp>Is \u003Cem>Staphylococcus saprophyticus\u003C\u002Fem> a contaminant like other coagulase-negative staphylococci?\u003C\u002Fp>","\u003Cp>No. Most coagulase-negative staphylococci in urine are skin contaminants, but \u003Cem>S. saprophyticus\u003C\u002Fem> is a genuine uropathogen in young women and should not be dismissed in a symptomatic patient.\u003C\u002Fp>",{"question":259,"answer":260},"\u003Cp>How quickly must urine reach the laboratory?\u003C\u002Fp>","\u003Cp>Within 1 to 2 hours at room temperature. If delayed, refrigerate at 2 to 8 degrees C for up to 24 hours, or use a boric acid preservative tube. Urine left warm overgrows and can turn a contaminant or a low count into a falsely significant result.\u003C\u002Fp>",{"question":262,"answer":263},"\u003Cp>Why is nitrofurantoin a poor choice for pyelonephritis?\u003C\u002Fp>","\u003Cp>It reaches good concentrations in the bladder urine but poor levels in the kidney tissue (renal parenchyma). That makes it effective for lower UTI (cystitis) but inadequate for a kidney infection. Fosfomycin is avoided in pyelonephritis for the same reason.\u003C\u002Fp>",[71],{"slug":266,"title":267,"description":268,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":77,"lastUpdatedDate":78,"draft":45,"category":46,"image":42,"faq":269,"tags":291},"tissue-biopsy-specimen-collection-transport","Tissue and Biopsy Specimens: Collection, Transport, and Processing","\u003Cp>Why tissue is the reference-standard specimen for deep infection, why the microbiology portion must be split off before formalin or decalcification, when to mince instead of grind, and how one small biopsy is divided across bacterial, AFB, fungal, and histology testing.\u003C\u002Fp>",[270,273,276,279,282,285,288],{"question":271,"answer":272},"\u003Cp>Why is tissue considered the best specimen for deep infections?\u003C\u002Fp>","\u003Cp>A biopsy samples the organisms actually invading the tissue rather than the flora on the surface, so it is the reference-standard specimen for deep, chronic, and serious infections such as osteomyelitis and deep abscesses. This is why the pus, wound, and sterile-fluid pages point to tissue when it can be obtained.\u003C\u002Fp>",{"question":274,"answer":275},"\u003Cp>Why must tissue for culture never be placed in formalin?\u003C\u002Fp>","\u003Cp>Formalin kills all organisms, making culture impossible. The microbiology portion must be separated into a sterile container before any part of the specimen touches formalin. Once tissue is fixed, it can be used only for histopathology.\u003C\u002Fp>",{"question":277,"answer":278},"\u003Cp>How is a single small biopsy divided across several tests?\u003C\u002Fp>","\u003Cp>The fresh microbiology portions (bacterial, mycobacterial, and fungal) are taken first, kept moist in a sterile container, and only then is the remaining piece placed in formalin for histopathology. When volume is limited, the clinician and laboratory prioritize together based on the most likely diagnosis.\u003C\u002Fp>",{"question":280,"answer":281},"\u003Cp>Why is tissue minced instead of ground when mucormycosis is suspected?\u003C\u002Fp>","\u003Cp>The hyphae of \u003Cem>Mucorales\u003C\u002Fem> molds are broad, non-septate, and fragile. Grinding shatters them and produces a false-negative culture even when the fungus is visible on histology. Mincing the tissue preserves viable hyphae, so suspected mucormycosis must be flagged for the laboratory.\u003C\u002Fp>",{"question":283,"answer":284},"\u003Cp>Why can bone sent for histology not also be cultured?\u003C\u002Fp>","\u003Cp>Bone for histopathology is decalcified in acid, which kills organisms just as formalin does. The culture portion of a bone specimen must be split off fresh before any fixation or decalcification, or nothing viable remains to grow.\u003C\u002Fp>",{"question":286,"answer":287},"\u003Cp>How should tissue be kept during transport?\u003C\u002Fp>","\u003Cp>In a sterile, leak-proof container with only a few drops of sterile saline to keep it moist, not submerged. Deliver it promptly, use an anaerobic transport system if anaerobes are suspected, and flag any suspected TB, fungal, or \u003Cem>Mucorales\u003C\u002Fem> infection on the request.\u003C\u002Fp>",{"question":289,"answer":290},"\u003Cp>Should tissue specimens be refrigerated if delayed?\u003C\u002Fp>","\u003Cp>A short delay at refrigeration temperature is acceptable for routine bacterial culture, but not when fastidious organisms are suspected. Keep those at room temperature and transport quickly.\u003C\u002Fp>",[71],{"enabled":293,"threads":294,"total":295},true,[],0,[297,303,310,316,322,327,333,338,344,347,354],{"slug":298,"name":43,"description":299,"image":300,"body":301,"postCount":302},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",468,{"slug":304,"name":305,"description":306,"image":307,"body":308,"postCount":309},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",78,{"slug":311,"name":107,"description":312,"image":313,"body":314,"postCount":315},"sushmita-baniya","Author \u002F Contributor","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsushmita-baniya-1.png","Sushmita Baniya holds an M.Sc. in Medical Microbiology from Tribhuvan University (National College), with a research focus in Genetics and Molecular Biology. She is actively involved in teaching and research in the field of microbiology.",26,{"slug":317,"name":318,"description":312,"image":319,"body":320,"postCount":321},"samikshya-acharya","Samikshya Acharya","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsamikshya-acharya.jpeg","Samikshya Sharma completed her postgraduate studies in Medical Microbiology at the Central Department of Microbiology, Tribhuvan University, Nepal. She contributes to Microbeonline with the goal of making foundational and clinical microbiology concepts clear and useful for students in medical, laboratory science, and allied health programs.",20,{"slug":323,"name":324,"description":312,"image":42,"body":325,"postCount":326},"alisha-tripathi","Alisha Tripathi","Alisha Tripathi holds an M.Sc. in Medical Microbiology from National College, Tribhuvan University. With over a year of teaching experience, her academic interests span Molecular Biology, Immunology, and Genetics.",6,{"slug":328,"name":329,"description":330,"image":42,"body":331,"postCount":332},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor","Aastha Shrestha is a Biotechnology graduate with an M.Sc. from National College, Tribhuvan University. Her academic interests center on Molecular Biology and Immunology; two fields that are increasingly converging in modern diagnostic and clinical microbiology. \n\nShe contributes to Microbeonline with the goal of making complex concepts in these areas approachable and exam-relevant for students across medical, biotechnology, and laboratory science programs.",9,{"slug":334,"name":335,"description":336,"image":42,"body":42,"postCount":337},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":339,"name":340,"description":312,"image":341,"body":342,"postCount":343},"srijana-khanal","Srijana Khanal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsrijana-khanal-1.png","Srijana Khanal is a microbiology educator with nearly a decade of teaching experience, including her role as faculty in the Microbiology Department at National College, NIST. \n\nHer time in the classroom has given her a clear sense of where students struggle and what explanations actually work, a perspective that directly shapes how she writes.\n\nHer academic interests span Immunology, Genetics, Basic Sciences, and Research Methodology, and she brings the same rigor to her writing that she brought to teaching. Alongside academic writing, she has a passion for creative writing -- an instinct that shows in her ability to make dense scientific material readable without sacrificing accuracy.\n\nShe contributes to Microbeonline to extend her teaching reach beyond the classroom, helping medical and laboratory science students across the region build a stronger foundation in microbiology.",17,{"slug":345,"name":346,"description":336,"image":42,"body":42,"postCount":337},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":348,"name":349,"description":350,"image":351,"body":352,"postCount":353},"nisha-rijal","Nisha Rijal","Microbiologist and AMR Specialist Kathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fnisha-rijal-1.png","Nisha Rijal is a microbiologist with nearly 15 years of frontline diagnostic and surveillance experience at the National Public Health Laboratory (NPHL), national reference laboratory under the Department of Health Services, Nepal. She currently works as an AMR Support Officer at the World Health Organization (WHO), Nepal, where her work focuses on strengthening antimicrobial resistance surveillance systems and translating AMR data into actionable public health response.\n\nHer research, published in peer-reviewed journals and cited over 220 times, spans some of the most clinically significant infectious disease challenges in Nepal and South Asia: antimicrobial resistance trends in *Vibrio cholerae* across an 11-year national surveillance dataset, sero-epidemiology of scrub typhus in patients with acute febrile illness, lower respiratory tract infections in HIV-positive patients, and gonococcal resistance surveillance. She was a contributor to Nepal's National Antimicrobial Resistance Containment Action Plan, a foundational policy document for AMR governance in Nepal. You can find list of [Nisha Rijal's article here in Google Scholar.](https:\u002F\u002Fscholar.google.com\u002Fcitations?user=N-Ruq54AAAAJ&hl=en)\n\nThis depth of experience is visible in her writing at Microbeonline. Her 53 published articles cover bacteriology, parasitology, mycology, immunology, and laboratory techniques, and are consistently among the most detailed and clinically grounded content on the site. She brings to every article the same standard that national reference laboratory work demands: methodological precision, awareness of real diagnostic constraints, and an understanding of what results actually mean for patient care in resource-limited settings.\n\nHer areas of particular expertise include antimicrobial susceptibility testing and resistance mechanism detection, quality assurance in clinical microbiology, and laboratory-based infectious disease surveillance.\n\n---\n\n*Nisha Rijal contributes to Microbeonline in a personal capacity. Her views and writing do not represent the positions of the World Health Organization or any other institution.*",54,{"slug":355,"name":356,"description":357,"image":358,"body":359,"postCount":337},"padma-shrestha","Padma Shrestha","Author","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fpadma-shrestha.png","Padma Shrestha is from Kathmandu, Nepal. She has completed Masters degree in Medical microbiology from Tribhuvan University. She has great interest in Microbiology and Molecular Biology.",[361,368,374,379,384,389,393,397,401,406,410,415,419,424,428,432,436,440,445,450,454,458,462,467,471,475,479,483,488,493,497,501,505,509,513,517,521,525,529,533,537,541,545,549,553,557,561,565,570,574,578,582,586,590,594,598,602,606,610,614,618,622,626,630,634,638,642,646,649,653],{"slug":362,"name":363,"description":364,"image":365,"body":366,"postCount":367},"gram-negative-cocci","Gram-Negative Cocci and Coccobacilli","Neisseria, Moraxella, Haemophilus and related gram-negative coccal organisms","https:\u002F\u002Fassets.microbeonline.com\u002Ftags\u002Fgram-negative-cocci.png","# Gram Negative Cocci\n\nNeisseria gonorrhoeae, Neisseria meningitides, Moraxella catarrhalis, and other Neisseria spp. are clinically relevant gram-negative cocci.\n\nN. gonorrhoeae is the leading cause of sexually transmitted disease whereas N. meningitides is a leading cause of fatal bacterial meningitis.",14,{"slug":369,"name":370,"description":371,"image":42,"body":372,"postCount":373},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":375,"name":376,"description":377,"image":42,"body":42,"postCount":378},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",11,{"slug":380,"name":381,"description":382,"image":42,"body":42,"postCount":383},"gram-negative-rods","Gram-Negative Rods (Other than Enterobacteriaceae)","\u003Cp>Gram negative rods other than members of Enterobacteriaceae family such as  Pseudomonas, Acinetobacter and related organisms\u003C\u002Fp>",5,{"slug":385,"name":386,"description":387,"image":42,"body":42,"postCount":388},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":390,"name":391,"description":392,"image":42,"body":42,"postCount":378},"mycobacteria","Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":394,"name":395,"description":396,"image":42,"body":42,"postCount":378},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":398,"name":399,"description":400,"image":42,"body":42,"postCount":373},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":402,"name":403,"description":404,"image":42,"body":42,"postCount":405},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":407,"name":408,"description":409,"image":42,"body":42,"postCount":367},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":411,"name":412,"description":413,"image":42,"body":42,"postCount":414},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",21,{"slug":416,"name":417,"description":418,"image":42,"body":42,"postCount":388},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":420,"name":421,"description":422,"image":42,"body":42,"postCount":423},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":71,"name":425,"description":426,"image":42,"body":42,"postCount":427},"Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":429,"name":430,"description":431,"image":42,"body":42,"postCount":414},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",{"slug":433,"name":434,"description":42,"image":42,"body":435,"postCount":326},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":437,"name":438,"description":42,"image":42,"body":439,"postCount":423},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":441,"name":442,"description":443,"image":42,"body":444,"postCount":405},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":446,"name":447,"description":448,"image":42,"body":449,"postCount":326},"pcr-techniques","PCR Techniques","Information about various types of Polymerase Chain Reaction Techniques ","More detailed information about various types of Polymerase Chain Reaction Techniques ",{"slug":451,"name":452,"description":453,"image":42,"body":42,"postCount":326},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":455,"name":456,"description":457,"image":42,"body":42,"postCount":326},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":459,"name":460,"description":461,"image":42,"body":42,"postCount":326},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":463,"name":464,"description":465,"image":42,"body":42,"postCount":466},"immunoassays","Immunoassays","You will get information about all the diagnostic tests that rely on the specific binding between an antigen and an antibody to detect or quantify a substance.",19,{"slug":468,"name":469,"description":470,"image":42,"body":42,"postCount":405},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":472,"name":473,"description":474,"image":42,"body":42,"postCount":383},"environmental-factors","Environmental Factors ","In this case we are talking about growth requirements of microorganisms with deep dive in environmental factors that affect the growth. ",{"slug":476,"name":477,"description":478,"image":42,"body":42,"postCount":326},"pipette","Pipette","Posts related with Pipette. ",{"slug":480,"name":481,"description":482,"image":42,"body":42,"postCount":388},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":484,"name":485,"description":486,"image":42,"body":42,"postCount":487},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":489,"name":490,"description":491,"image":42,"body":42,"postCount":492},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":494,"name":495,"description":496,"image":42,"body":42,"postCount":383},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",{"slug":498,"name":499,"description":500,"image":42,"body":42,"postCount":388},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":502,"name":503,"description":504,"image":42,"body":42,"postCount":332},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":506,"name":507,"description":508,"image":42,"body":42,"postCount":414},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",{"slug":510,"name":511,"description":512,"image":42,"body":42,"postCount":326},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":514,"name":515,"description":516,"image":42,"body":42,"postCount":383},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":518,"name":519,"description":520,"image":42,"body":42,"postCount":423},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":522,"name":523,"description":524,"image":42,"body":42,"postCount":487},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":526,"name":527,"description":528,"image":42,"body":42,"postCount":492},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":530,"name":531,"description":532,"image":42,"body":42,"postCount":405},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":534,"name":535,"description":536,"image":42,"body":42,"postCount":383},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":538,"name":539,"description":540,"image":42,"body":42,"postCount":332},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":542,"name":543,"description":544,"image":42,"body":42,"postCount":405},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":546,"name":547,"description":42,"image":42,"body":42,"postCount":548},"haemophilus","Haemophilus",3,{"slug":550,"name":551,"description":552,"image":42,"body":42,"postCount":492},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":554,"name":555,"description":556,"image":42,"body":42,"postCount":373},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",{"slug":558,"name":559,"description":560,"image":42,"body":42,"postCount":367},"fungal-diagnostics","Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":562,"name":563,"description":564,"image":42,"body":42,"postCount":383},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":566,"name":567,"description":568,"image":42,"body":569,"postCount":326},"laboratory-heating-equipment","Laboratory Heating Equipment","A guide to laboratory heating equipment, including hot plates, water baths, Bunsen burners, incubators, and dry baths, and how to choose the right one for each task.","Laboratory heating equipment covers the instruments that warm, melt, incubate, or sterilize samples and media in a microbiology laboratory. Each one delivers heat differently. \n\nA hot plate gives high, direct, dry heat; a water bath gives gentle, even, wet heat up to about 100°C; a Bunsen burner gives an open flame for rapid, very high heat; an incubator holds cultures at a steady temperature over hours or days; and a dry bath heats small tubes without water. Choosing the right one depends on the temperature you need, how precise it must be, and whether the sample can tolerate direct or open-flame heat.\n\nThe articles below cover each piece of heating equipment in detail, including its parts, working principle, uses, and the mistakes that most often go wrong at the bench.",{"slug":571,"name":572,"description":573,"image":42,"body":42,"postCount":388},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":575,"name":576,"description":577,"image":42,"body":42,"postCount":326},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":579,"name":580,"description":581,"image":42,"body":42,"postCount":326},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":583,"name":584,"description":585,"image":42,"body":42,"postCount":337},"tests-for-gram-positive-cocci","Biochemical Tests for Gram Positive Cocci","This is the lists of Biochemical Tests that are used for Gram Positive Cocci. ",{"slug":587,"name":588,"description":589,"image":42,"body":42,"postCount":423},"bacterial-staining-technique","Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":591,"name":592,"description":593,"image":42,"body":42,"postCount":321},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":595,"name":596,"description":597,"image":42,"body":42,"postCount":378},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",{"slug":599,"name":600,"description":601,"image":42,"body":42,"postCount":383},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":603,"name":604,"description":605,"image":42,"body":42,"postCount":492},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":607,"name":608,"description":609,"image":42,"body":42,"postCount":388},"substrate-utilization","Substrate Utilization","\u003Cp>The test in which a non-sugar carbon\u002Fnitrogen source is used or degraded (citrate, malonate, decarboxylases, indole, PAD).\u003C\u002Fp>",{"slug":611,"name":612,"description":613,"image":42,"body":42,"postCount":548},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":615,"name":616,"description":617,"image":42,"body":42,"postCount":383},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":619,"name":620,"description":621,"image":42,"body":42,"postCount":405},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":623,"name":624,"description":625,"image":42,"body":42,"postCount":492},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":627,"name":628,"description":629,"image":42,"body":42,"postCount":383},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":631,"name":632,"description":633,"image":42,"body":42,"postCount":405},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":635,"name":636,"description":637,"image":42,"body":42,"postCount":326},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":639,"name":640,"description":641,"image":42,"body":42,"postCount":405},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":643,"name":644,"description":645,"image":42,"body":42,"postCount":383},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":647,"name":648,"description":42,"image":42,"body":42,"postCount":337},"colorimetric-assay","Colorimetric Assay ",{"slug":650,"name":651,"description":652,"image":42,"body":42,"postCount":383},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":654,"name":655,"description":42,"image":42,"body":42,"postCount":548},"blood-and-immune-cells","Blood and Immune Cells"]