[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fAeBiyff_Xjkz71_EhbitE2fEcsinq3kIBvhONpGJrwM":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":157},[4,8,12,16,20,24,28],{"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",{"type":33,"data":34},"blog",{"slug":35,"title":36,"description":37,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":40,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"body":44,"faq":45,"tags":61,"related":63},"amies-transport-medium","Amies Transport Medium: Composition, Uses, and Why It Replaced Stuart's Medium","Why a fragile gonococcus swab can die before it ever reaches the lab, the design fix that made Amies better than Stuart's medium, and when to choose the charcoal-free version instead.",null,"Nisha Rijal","2019-12-03","2026-07-05",false,"culture-media","**The infection that dies before the culture even starts**\n\nA patient at a genitourinary clinic has a urethral swab taken for suspected gonorrhea. *Neisseria gonorrhoeae* is notoriously fragile outside the body, sensitive to drying, temperature swings, and delay. If that swab sits on a counter for even a few hours without proper transport conditions, the organism can die before it ever reaches the lab. The culture comes back negative, not because the infection wasn't there, but because it never survived the trip. The patient, still infected, may go untreated, and any contact-tracing that depended on a positive result never happens.\n\nThis is exactly the problem **Amies transport medium** exists to solve: keeping a fragile organism alive and stable between collection and processing, without letting it multiply, dry out, or die in the meantime. Getting this medium's design and its handling rules right isn't a formality. It's the difference between a true infection reaching the lab intact and a true infection quietly disappearing en route.\n\nAmies transport medium is a widely used, effective semisolid medium for transporting swab specimens to the microbiology laboratory. Placing a swab in a moist transport medium prevents drying and death of the organism during transit.\n\nAmies is a modification of Stuart’s medium in which glycerophosphate is replaced by an inorganic phosphate buffer and charcoal is added. This modification prolongs the viability and thus increases the isolation of anaerobes, delicate bacterial pathogens like *Neisseria gonorrhoeae*, *Haemophilus influenzae*, *Neisseria meningitidis*, and *Haemophilus ducreyi*. For delays as long as 24 hours, Amies medium with charcoal can be used.\n\n## Principle\n\n![ - Amies transport medium](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FAmies-Transport-medium-Swab-and-medium.jpg)Figure: Amies transport medium\n\nThe presence of sodium thioglycollate and a small amount of agar creates a reduced environment which favors the growth of a wide variety of pathogens. The use of charcoal in transport media neutralizes toxic materials in the specimen or on the swab and facilitates the growth of sensitive bacterial pathogens such as *Neisseria gonorrhoeae*.\n\nCalcium, magnesium, potassium, and sodium salts help the survival of pathogens and also control the permeability of bacterial cells. Phosphate buffer maintains the pH of the medium.\n\n### Why Amies Replaced Stuart's Medium\n\nAmies is a modification of the older Stuart's transport medium, and the change wasn't cosmetic. Stuart's medium used **glycerophosphate** as a buffering component, but glycerophosphate can also serve as a carbon source, meaning some organisms could actually use it to keep multiplying during transport. That's the opposite of what a transport medium is supposed to do: **a transport medium's job is to pause the situation, not let it keep writing itself.** Uncontrolled multiplication during transport can distort what the lab eventually recovers, overrepresenting fast growers and underrepresenting the organism that actually matters.\n\nAmies replaced glycerophosphate with an inorganic phosphate buffer, removing that accidental carbon source, and added charcoal. The result: organisms are held in a stable, non-multiplying, non-dying state for far longer than plain saline or a dry swab would allow.\n\n***GUIDE TO REMEMBER:  Anchor for the Stuart's-to-Amies fix: \"take away the snack.\"*** *Stuart's medium accidentally gave some organisms a carbon source (glycerophosphate) they could use to keep multiplying. Amies took that snack away, which is the entire reason it replaced Stuart's medium rather than just being a minor variant of it.*\n\n### With Charcoal vs. Without Charcoal\n\nThis distinction matters and is easy to get backwards:\n\n- **Amies with charcoal** is the standard choice for most specimens. Charcoal absorbs toxic fatty acids and other bacterial metabolic byproducts that would otherwise damage sensitive organisms during transport, extending viability for delicate pathogens like *N. gonorrhoeae*, *Haemophilus influenzae*, *N. meningitidis*, and *H. ducreyi*.\n- **Amies without charcoal** is preferred specifically for **Mycoplasma and Ureaplasma** recovery. The same charcoal that protects most fastidious organisms actually interferes with recovery of these two, so the charcoal-free version is used whenever they're a specific concern.\n\n***GUIDE TO REMEMBER: Anchor for charcoal vs. charcoal-free: \"charcoal is a sponge for troublemakers, but Mycoplasma doesn't like the couch.\"*** *Charcoal soaks up toxic byproducts that would otherwise hurt most fastidious organisms, but it also happens to inhibit Mycoplasma and Ureaplasma recovery specifically, which is exactly why the charcoal-free version exists for those two.*\n\n### Handling Rules, and Why They Matter\n\nTransport specimens to the laboratory as soon as possible, ideally within 6 hours, and no later than 24 hours, maintaining a cold chain. **Do not freeze.** Freezing causes ice crystals to form inside bacterial cells, rupturing them; this is a direct cause of specimen death, not a precaution taken \"just in case.\" Refrigeration slows metabolism without destroying the cells; freezing kills them outright.\n\n## Composition of Amies transport medium\n\nFinal pH (at 25°C) 7.2±0.2\n\n| Ingredients | Gms\u002Fliter |\n| --- | --- |\n| Sodium chloride | 3.0 |\n| Potassium chloride | 0.2 |\n| Calcium chloride | 0.1 |\n| Magnesium chloride | 0.1 |\n| Monopotassium phosphate | 0.2 |\n| Disodium phosphate | 1.150 |\n| Sodium thioglycollate | 1.0 |\n| Charcoal | 10.0 |\n| Agar | 4.0 |\n\n## Preparation of Amies Transport medium\n\nAmies transport medium is best prepared from ready to use dehydrated powder, available from most suppliers of culture media.\n\n**pH of medium**: This should be within the range of pH 7.0-7.4 at room temperature.\n\n**Shelf-life**: Up to 9 months providing there is no change in the volume or appearance of the medium to suggest contamination or an alteration of its pH.\n\n## Inoculation of the Medium\n\nClinics and ward staff should be advised to check the expiry date before using the medium. Specimen collected on a sterile cotton wool swab should be immersed into the medium, cutting off the swab stick to allow the bottle top to be replaced tightly.\n\n1. Insert the swab (with cotton tip downwards) into the medium to one-third of the medium depth.\n2. Cut off or break the swab stick if longer than the tube.\n3. Screw the cap firmly in a way that the swab is forced to the bottom of the medium.\n4. Transport to the laboratory as soon as possible or preferably within 6 hours (maximum up to 24 hours) maintaining a cold chain (do not freeze).\n\n## Uses of Amies Transport Medium\n\nAmies transport medium is used for the collection, transport, and preservation of microbiological specimens, especially throat, vaginal, and wound swab samples. It is routinely used for the transport of specimens from collection centers (or health centers) to the microbiology laboratory.\n\n1. **Sputum:**  Transfer a purulent part of the sputum to a cotton-wool swab, and insert it in a container of Amies transport medium. Amies medium ensures the survival of pathogens such as *S.pneumoniae* and *H. influenzae* and also avoids the overgrowth of fast-multiplying commensals.\n2. **Pus:** Collect the pus specimen using a sterile cotton-wool swab. When pus is not discharged, use a sterile cotton swab to collect a sample from the infected site. Insert it in a container of Amies transport medium, breaking off the swab stick to allow the bottle top to be replaced tightly.\n3. **Nasopharyngeal specimen:** To identify carriers of *N.meningitidis*, a nasopharyngeal swab specimen is collected and transported to the laboratory in Amies or Stuart’s medium or plated directly onto medium and transported in a CO2 containing the system. Amies medium is also used in suspected *Bordetella pertussis* and *Corynebacterium diphtheriae* cases.\n4. **Urogenital swab:** Amies medium is the most efficient medium for transporting urethral, cervical, and vaginal swabs. It ensures the survival of *Haemophilus ducreyi* (which causes soft chancre) and delicate organisms like *Neisseria gonorrhoeae.*\n\n## Key exam facts in one table\n\n| Fact | Detail |\n| --- | --- |\n| Type of medium | Semisolid transport medium (not a growth medium) |\n| Modified from | Stuart's transport medium |\n| Key change from Stuart's | Glycerophosphate (a potential carbon source) replaced with an inorganic phosphate buffer |\n| Role of charcoal | Absorbs toxic fatty acids\u002Fmetabolic byproducts, extending viability of fastidious organisms |\n| Amies with charcoal | Standard choice; used for *N. gonorrhoeae*, *H. influenzae*, *N. meningitidis*, *H. ducreyi*, and most routine swabs |\n| Amies without charcoal | Preferred for *Mycoplasma* and *Ureaplasma*, since charcoal inhibits their recovery |\n| Transport time | As soon as possible, ideally within 6 hours, maximum 24 hours |\n| Temperature rule | Maintain a cold chain; refrigerate, never freeze |\n| Why not freeze | Ice crystal formation ruptures bacterial cells, killing the organism outright |\n\n## Where Students Get Confused\n\n- **Treating Amies as just \"a slightly different version\" of Stuart's medium.** The specific change, removing glycerophosphate as an accidental carbon source, is the whole point; without it, the same overgrowth problem Stuart's medium had would return.\n- **Assuming charcoal is always the better choice.** It's better for most fastidious organisms, but it specifically works against recovery of *Mycoplasma* and *Ureaplasma*, the one case where charcoal-free is the correct choice.\n- **Assuming colder is always safer for transport.** Refrigeration is correct; freezing kills the organism via ice crystal formation, the opposite of the intended effect.\n- **Treating a transport medium as if it were a growth medium.** Its job is to keep organisms alive without letting them multiply, not to support active growth the way a culture medium does.\n\n**Reference and further reading**\n\n1. MacFaddin J.F., 1985, Media For Isolation-Cultivation-Identification-Maintenance of Medical Bacteria, Vol. 1, Williams and Wilkins, Baltimore. Revision: 04\u002F 2018\n2. Jorgensen,J.H., Pfaller , M.A., Carroll, K.C., Funke, G., Landry, M.L., Richter, S.S and Warnock., D.W. (2015) Manual of Clinical Microbiology, 11th Edition. Vol. 1\n3. Monica Cheesbrough District laboratory Practice in Tropical countries (Part II)\n4. Koneman, E. W. et al. *Color Atlas and Textbook of Diagnostic Microbiology* (5th ed.).\n5. World Health Organization guidance on specimen collection and transport for STI diagnosis.",[46,49,52,55,58],{"question":47,"answer":48},"What is Amies transport medium used for?","Preserving swab specimens, such as throat, wound, vaginal, and genital swabs, in a stable, non-multiplying state during transport to the microbiology laboratory.",{"question":50,"answer":51},"Why did Amies medium replace Stuart's medium?","Stuart's medium used glycerophosphate as a buffer, but some organisms could use it as a carbon source and keep multiplying during transport. Amies replaced it with an inorganic phosphate buffer to remove that problem.",{"question":53,"answer":54},"When should Amies without charcoal be used instead of the charcoal version?","Specifically for Mycoplasma and Ureaplasma recovery, since charcoal, helpful for most other fastidious organisms, actually inhibits recovery of these two.",{"question":56,"answer":57},"Can Amies transport medium be frozen for longer storage?","No. Freezing causes ice crystals to rupture bacterial cells, killing the organism. Refrigeration, not freezing, is the correct way to slow deterioration during transport.",{"question":59,"answer":60},"How long can a specimen sit in Amies medium before processing?","Ideally within 6 hours, and no later than 24 hours, maintaining a cold chain throughout.",[62],"specimen-collection-transport",[64,73,80,87,93,100,126,142],{"slug":65,"title":66,"description":66,"seoTitle":38,"seoDescription":38,"author":67,"createdDate":68,"lastUpdatedDate":69,"draft":42,"category":70,"image":38,"faq":71,"tags":72},"blood-collection-tubes","Blood Collection Tubes: Significance of Color Coding","Acharya Tankeshwar","2023-01-26","2026-07-19","lab-equipment",[],[62],{"slug":74,"title":75,"description":75,"seoTitle":38,"seoDescription":38,"author":67,"createdDate":76,"lastUpdatedDate":41,"draft":42,"category":77,"image":38,"faq":78,"tags":79},"rejection-criteria-for-microbiological-specimens","Microbiology Sample Collection Guidelines and Rejection Criteria","2021-05-04","bacteriology",[],[62],{"slug":81,"title":82,"description":82,"seoTitle":38,"seoDescription":38,"author":67,"createdDate":83,"lastUpdatedDate":41,"draft":42,"category":84,"image":38,"faq":85,"tags":86},"sample-collections-for-laboratory-diagnosis-of-fungal-infections","Sample Collections for Lab Diagnosis of Fungal Infections","2021-04-03","mycology",[],[62],{"slug":88,"title":89,"description":89,"seoTitle":38,"seoDescription":38,"author":67,"createdDate":90,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":91,"tags":92},"viral-transport-media-vtm","Viral Transport Media (VTM): Preparation, Uses","2020-03-23",[],[62],{"slug":94,"title":95,"description":95,"seoTitle":38,"seoDescription":38,"author":67,"createdDate":96,"lastUpdatedDate":97,"draft":42,"category":77,"image":38,"faq":98,"tags":99},"pus-sample-collection-staining-culture","Pus Sample: Collection, Processing, Staining and Culture","2019-02-07","2026-07-08",[],[62],{"slug":101,"title":102,"description":103,"seoTitle":38,"seoDescription":38,"author":67,"createdDate":104,"lastUpdatedDate":41,"draft":42,"category":105,"image":38,"faq":106,"tags":125},"lab-diagnosis-intestinal-parasitic-infections","Laboratory Diagnosis of Intestinal Parasitic Infections: Methods, Specimen Handling, and When to Use Each Test","Complete guide to laboratory diagnosis of intestinal parasites — stool collection, O&P examination, concentration techniques, permanent stains, culture, serology, and PCR with a decision table and specimen exceptions for pinworm and Schistosoma.","2018-11-13","parasitology",[107,110,113,116,119,122],{"question":108,"answer":109},"What is the O&P examination for intestinal parasites?","The Ova and Parasite (O&P) examination is the standard laboratory protocol for diagnosing intestinal parasitic infections. It consists of four sequential steps: macroscopic examination of the stool, direct saline and iodine wet mount (for motile trophozoites and helminth eggs), a concentration technique (formal-ether sedimentation or Kato-Katz), and a permanent stained smear (trichrome or iron-haematoxylin) when protozoan identification is required. Each step detects organisms that the others may miss.",{"question":111,"answer":112},"Why must liquid stool be examined within 30 minutes?","Liquid stool from patients with acute diarrhoea may contain trophozoites of Entamoeba histolytica or Giardia lamblia. Trophozoites are motile and identifiable by their characteristic movement, but they disintegrate rapidly after passage. After 30 minutes, motility is lost and trophozoites degenerate, making identification unreliable. Formed stool (containing cysts and eggs, which are more stable) can be examined within 24 hours.",{"question":114,"answer":115},"Why is pinworm not diagnosed from a routine stool O&P examination?","Enterobius vermicularis (pinworm) females migrate from the rectum to the perianal skin at night to deposit eggs. These eggs are rarely shed into the stool in detectable numbers. The correct diagnostic method is the cellophane (Scotch) tape test: transparent adhesive tape is pressed against the perianal skin early in the morning before bathing and applied to a glass slide for microscopic examination. This has far higher sensitivity than stool O&P for pinworm diagnosis.",{"question":117,"answer":118},"What stain is used to diagnose Cryptosporidium in stool?","Cryptosporidium parvum oocysts are acid-fast and are not detected by routine direct wet mount or trichrome staining. A modified acid-fast stain (modified Ziehl-Neelsen or Kinyoun) is required — oocysts appear as pink-red spheres against a blue background. The same stain detects Cyclospora cayetanensis and Cystoisospora belli. This stain must be specifically requested and is especially important in HIV\u002FAIDS patients with unexplained chronic diarrhoea.",{"question":120,"answer":121},"What is the difference between formal-ether sedimentation and Kato-Katz technique?","Formal-ether sedimentation concentrates cysts, eggs, and larvae from a stool sample using formalin fixation and ethyl acetate, suitable for detecting all intestinal parasites including protozoa (but not trophozoites). Kato-Katz uses a large, standardised stool volume pressed through a mesh screen onto a slide for quantitative helminth egg detection — it gives eggs per gram (EPG) of stool, useful for measuring infection intensity and treatment response. Kato-Katz detects helminth eggs only and cannot identify protozoa.",{"question":123,"answer":124},"How many stool specimens are needed to diagnose giardiasis?","A minimum of three stool specimens collected on separate days is recommended for most intestinal parasites. For Giardia lamblia and Entamoeba histolytica, six specimens are preferred because cyst shedding is intermittent — a single specimen misses up to 30% of infections. If clinical suspicion remains high after negative results, stool antigen EIA for Giardia offers higher sensitivity than repeated microscopy.",[62],{"slug":127,"title":128,"description":129,"seoTitle":38,"seoDescription":38,"author":67,"createdDate":130,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":131,"tags":141},"alkaline-peptone-water-apw-principle-preparation-uses","Alkaline Peptone Water (APW): Composition, Principle, Preparation, and Uses in Vibrio Enrichment","Alkaline Peptone Water (APW) is the standard enrichment broth for Vibrio cholerae isolation. Learn its pH selectivity principle, why vibrios form a pellicle at the surface, how to subculture onto TCBS agar, and when APW is used versus Cary-Blair transport medium.","2016-09-10",[132,135,138],{"question":133,"answer":134},"Why does Vibrio cholerae form a pellicle at the surface of APW, and why is only the surface subcultured onto TCBS?","V. cholerae is both motile (single polar flagellum) and aerophilic — it preferentially grows in oxygenated environments. When inoculated into APW and incubated at 37°C, V. cholerae actively swims toward the air-liquid interface where oxygen concentration is highest, accumulating there and forming a thin film called a pellicle after 4–6 hours. Competing organisms that survive the alkaline pH but lack directed motility toward the surface tend to remain distributed throughout the broth or settle to the bottom. Inoculating TCBS agar from the surface pellicle only — by touching the inoculating loop to the surface without mixing or shaking the broth — transfers V. cholerae-enriched material while leaving the sediment of competing organisms behind. Mixing the broth before subculture defeats the purpose of this spatial separation and reduces the sensitivity of the enrichment step.",{"question":136,"answer":137},"Why is APW suitable for Vibrio enrichment but unsuitable for Salmonella, Shigella, or Campylobacter?","APW's selectivity is based entirely on its alkaline pH (8.6–9.0). This pH range is optimal for V. cholerae and selectively suppresses most intestinal commensals. However, it also inhibits the growth of other clinically important enteric pathogens: Salmonella and Shigella grow optimally at pH 7.0–7.4 and are significantly inhibited at pH 8.6–9.0; Campylobacter is microaerophilic and also pH-sensitive, with optimal growth at pH 6.5–7.5. If a specimen for broad enteric workup (including Salmonella, Shigella, or Campylobacter) is placed into APW for transport, these organisms will be progressively killed by the alkaline pH while V. cholerae multiplies. The specimen will arrive at the laboratory as effectively Vibrio-only material, making it impossible to detect co-infecting pathogens or to perform a comprehensive enteric culture. Cary-Blair transport medium, which is pH-neutral to mildly alkaline and contains no selective enrichment mechanism, preserves all enteric pathogens simultaneously.",{"question":139,"answer":140},"When is APW enrichment unnecessary, and why?","APW enrichment is unnecessary when the specimen contains very high numbers of V. cholerae — specifically in acute cholera during the first few days of illness. A patient with acute cholera is passing liquid 'rice-water' stool containing 10⁷ to 10⁹ V. cholerae per milliliter. At these concentrations, V. cholerae vastly outnumbers competing flora even before enrichment, and direct plating onto TCBS agar will produce abundant yellow colonies without any pre-enrichment step. Proceeding with APW enrichment in this situation delays the result by 6–8 hours unnecessarily. APW enrichment is specifically valuable for the four situations where organism counts are low: convalescent patients (illness >5 days, declining shedding), asymptomatic carriers, environmental water and food samples, and rectal swab specimens (which transfer fewer organisms than fresh liquid stool).",[62],{"slug":143,"title":144,"description":145,"seoTitle":38,"seoDescription":38,"author":67,"createdDate":130,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":146,"tags":156},"cary-blair-transport-medium-composition-preparation-uses"," Cary-Blair Transport Medium: Composition, Principle, Preparation, and Uses","Cary-Blair is the medium of choice for transporting enteric pathogens including Vibrio cholerae, Salmonella, Shigella, and Campylobacter. Learn its principle, semisolid composition, survival times for key organisms, and how it compares to Stuart's, Amies, and APW.",[147,150,153],{"question":148,"answer":149},"Why does Cary-Blair medium use sodium thioglycollate when other transport media do not?","Sodium thioglycollate is a reducing agent that lowers the oxidation-reduction (redox) potential of Cary-Blair medium, creating a microaerobic to anaerobic microenvironment within the semisolid matrix. This is specifically important for two groups of pathogens: (1) Campylobacter species, which are microaerophilic and are killed by prolonged exposure to atmospheric oxygen concentrations — the reduced environment extends their viability during transport; and (2) any facultative anaerobes present in the specimen whose viability is compromised by reactive oxygen species accumulation at room temperature. Stuart's and Amies media do not contain thioglycollate, which is why they show inferior Campylobacter recovery compared to Cary-Blair for specimens with anticipated transport delays beyond 2 hours.",{"question":151,"answer":152},"Why is Cary-Blair medium alkaline (pH 8.4), and how does this protect the specimen?","The alkaline pH of 8.4 in Cary-Blair medium serves two protective functions. First, it creates conditions that specifically favour Vibrio cholerae survival — V. cholerae grows optimally at pH 8.0–9.6 and survives transport far better in alkaline than neutral conditions. This is why Cary-Blair is the medium of choice for cholera specimen transport and is superior to Stuart's and Amies media (both pH 7.3) for this specific organism. Second, the alkaline pH acts as a buffer against the metabolic acid production that would otherwise occur as organisms undergo limited metabolic activity during transport. Even minimal metabolism of substrates in the specimen produces organic acids; at pH 7.3, these acids accumulate and can drop the local pH to levels lethal to acid-sensitive organisms such as Shigella. The alkaline starting pH provides a substantial buffer capacity that maintains a safe pH range throughout the transport period.",{"question":154,"answer":155},"How long do different enteric pathogens survive in Cary-Blair medium, and what are the practical implications?","Survival times in Cary-Blair medium vary significantly by organism, which has direct implications for transport planning: Salmonella and Shigella survive for at least 48 hours and typically several days; Vibrio cholerae survives for at least 48 hours, with Cary-Blair's alkaline pH providing superior conditions compared to other transport media; Yersinia enterocolitica and Y. pestis survive for 48+ hours; Campylobacter species survive for only up to 6 hours, making same-day transport essential — specimens for Campylobacter culture collected in Cary-Blair must reach the laboratory within 6 hours, or be refrigerated to slow all bacterial activity. The practical implication for field collection: Cary-Blair is suitable for overnight transport for Salmonella and Shigella, but not for Campylobacter. If Campylobacter is specifically suspected and same-day transport is not possible, campy thioglycollate medium is the alternative.",[62],[158,164,171,176,180,184,189,194,198,202],{"slug":159,"name":67,"description":160,"image":161,"body":162,"postCount":163},"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.*",433,{"slug":165,"name":166,"description":167,"image":168,"body":169,"postCount":170},"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.",81,{"slug":172,"name":173,"description":174,"image":38,"body":38,"postCount":175},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":177,"name":178,"description":174,"image":38,"body":38,"postCount":179},"samikshya-acharya","Samikshya Acharya",20,{"slug":181,"name":182,"description":174,"image":38,"body":38,"postCount":183},"alisha-tripathi","Alisha Tripathi",6,{"slug":185,"name":186,"description":187,"image":38,"body":38,"postCount":188},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",10,{"slug":190,"name":191,"description":192,"image":38,"body":38,"postCount":193},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":195,"name":196,"description":174,"image":38,"body":38,"postCount":197},"srijana-khanal","Srijana Khanal",18,{"slug":199,"name":200,"description":192,"image":38,"body":38,"postCount":201},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":203,"name":39,"description":174,"image":38,"body":204,"postCount":205},"nisha-rijal","**Nisha Rijal** is a microbiologist and quality assurance specialist. She served for nearly 12 years as a microbiologist at the National Public Health Laboratory (NPHL), Nepal's national reference laboratory, and continues to work as a consultant microbiologist in international public health organization. ",51]