[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fK94Nev3_ZKkm6fn2zBr74YSyXRc_KKKHt6QP87EQ66U":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":284,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":347},[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},"Authors","authors","\u002Fauthors\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},"Tags","tags","\u002Ftags\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":67,"related":69,"comments":280},"coccidioides-immitis-posadasii-pathogenesis-diagnosis","Coccidioides (Valley Fever): Spherules, Arthroconidia, and Lab Diagnosis","\u003Cp>\u003Cem>Coccidioides \u003C\u002Fem>causes Valley fever. In tissue it forms a spherule packed with endospores, not a yeast, and in the environment it makes infectious arthroconidia. Its morphology, why it is a biohazard, and lab diagnosis.\u003C\u002Fp>",null,"Acharya Tankeshwar","2026-09-06",false,"mycology","A construction worker in Arizona develops fever, cough, and chest pain a couple of weeks after a dust storm blew through an excavation site. It looks like pneumonia, but antibiotics do nothing. The clue is not in the chest film but in the geography and the dust: he has inhaled the spores of a desert-soil fungus, and in his lungs those spores have swollen into large, round structures packed with tiny endospores. This is coccidioidomycosis, or Valley fever, and the fungus behind it, *Coccidioides*, is the one dimorphic fungus that does not become a yeast in the body. It becomes a spherule.\n\n*Coccidioides* is a thermally dimorphic fungus and the cause of coccidioidomycosis (Valley fever, or San Joaquin Valley fever). It is a member of the classic dimorphic fungi, but it breaks the usual rule in a way that is the single most tested fact about it: instead of converting from mold to yeast at body temperature, it converts from mold to a **spherule**, a large structure filled with endospores. For where it sits among the other dimorphic fungi, see the [dimorphic fungi overview](https:\u002F\u002Fmicrobeonline.com\u002Fnotable-dimorphic-fungi-and-their-properties\u002F).\n\n### Two species, one disease\n\n*Coccidioides* is now recognized as two species that are clinically identical and handled the same way: *Coccidioides immitis*, found mainly in California (the San Joaquin Valley), and *Coccidioides posadasii*, found elsewhere across the endemic range. Because they cause the same disease, look the same, and are managed the same way, they are usually discussed together simply as *Coccidioides*.\n\n## What Coccidioides looks like\n\n*Coccidioides* looks completely different in its two forms, and each has a diagnostic structure.\n\n**In the environment (mold form, 25 to 30°C).** In desert soil it grows as a mold with septate hyphae that break up into **arthroconidia**: small, thick-walled, barrel-shaped spores formed by fragmentation of the hyphae, classically alternating with empty (disjunctor) cells along the filament. These arthroconidia are light, airborne, and highly infectious. They are the form that infects people and the form that makes laboratory cultures dangerous.\n\n**In tissue (the spherule, 37°C).** Once inhaled, each arthroconidium rounds up and enlarges into a **spherule**: a large (typically 20 to 80 µm, sometimes up to 200 µm), thick-walled, round structure. The spherule fills with hundreds of small **endospores**. When the mature spherule ruptures, it releases the endospores, each of which can form a new spherule, and the cycle repeats in the tissue. This spherule-with-endospores is the diagnostic tissue form and the reason *Coccidioides* is the dimorphic fungus that does not make a yeast.\n\n**The exam-trap exception:** every other classic dimorphic fungus becomes a yeast in tissue. *Coccidioides* becomes a spherule packed with endospores. If you remember one thing, remember that *Coccidioides* is dimorphic (mold in the environment, spherule in tissue), but its tissue form is a spherule, not a yeast.\n\n### How people get Valley fever\n\nInfection follows **inhalation of arthroconidia** when arid soil is disturbed, by wind, dust storms, farming, construction, excavation, or archaeological digging. The organism lives in the alkaline desert soils of the endemic regions: the southwestern United States (Arizona, California's San Joaquin Valley, and neighboring states), northern Mexico, and parts of Central and South America. Outbreaks follow soil disturbance and dust storms, and cases rise in dry seasons after wet winters (a \"grow then blow\" pattern). It is not transmitted from person to person. Occupational and recreational soil exposure in an endemic area is the key epidemiological clue.\n\n## Pathogenesis\n\n*Coccidioides* is a primary pathogen: it can infect healthy people, not only the immunocompromised, although immunosuppression greatly increases the risk of severe and disseminated disease.\n\nThe sequence follows the two-form life cycle. Inhaled arthroconidia reach the alveoli and convert into spherules. As each spherule matures and ruptures, it releases endospores that spread locally and form new spherules, amplifying the infection in the lung. The host mounts a granulomatous inflammatory response. In most people, **cell-mediated immunity contains the infection**, and the disease is mild or self-limited. When cell-mediated immunity is weak, the organism disseminates through the blood to the skin, bones and joints, and, most seriously, the meninges.\n\nCertain groups are at markedly higher risk of dissemination: people with impaired cell-mediated immunity (HIV\u002FAIDS, transplant, high-dose steroids), pregnant women (especially in the third trimester), and, for reasons still studied, people of African and Filipino ancestry.\n\n### Clinical forms of coccidioidomycosis\n\n1. **Asymptomatic or primary pulmonary infection.** About 60% of infections are silent or mild. Symptomatic primary disease is a flu-like or pneumonia-like illness (fever, cough, chest pain, fatigue) developing 1 to 3 weeks after exposure. This is \"Valley fever.\" Some patients develop hypersensitivity signs such as **erythema nodosum** or **erythema multiforme**, and the combination of fever, joint aches, and erythema nodosum is sometimes called \"desert rheumatism.\"\n2. **Chronic pulmonary coccidioidomycosis.** A minority develop persistent pneumonia, lung nodules, or thin-walled cavities that can mimic tuberculosis or lung cancer.\n3. **Disseminated coccidioidomycosis.** In a small proportion, especially the high-risk groups above, the organism spreads beyond the lungs to the skin (verrucous lesions), bones and joints, and the meninges. **Coccidioidal meningitis is the most serious form**, is difficult to treat, and requires lifelong therapy.\n\n## Laboratory diagnosis\n\n**A critical safety warning first.** *Coccidioides* is one of the most hazardous fungi in the laboratory. The mold form's arthroconidia are extremely infectious by inhalation, and it is a recognized cause of laboratory-acquired infection and a select agent. If coccidioidomycosis is suspected, the laboratory must be informed, and any mold culture must be handled in a [biological safety cabinet](https:\u002F\u002Fmicrobeonline.com\u002Fbiological-safety-cabinet-bsc-types-working-mechanism\u002F), with work on confirmed or strongly suspected cultures done under BSL-3 conditions. Cultures must never be opened or examined on an open bench.\n\n**Direct microscopy and histopathology.** The diagnosis can be made rapidly by finding the **spherule filled with endospores** in sputum, other respiratory specimens, pus, or tissue, seen on a [KOH preparation](https:\u002F\u002Fmicrobeonline.com\u002Fkoh-preparation-test-principle-procedure-results-uses\u002F) or on stained tissue sections (PAS, Gomori methenamine silver). Seeing a mature endospore-filled spherule is diagnostic. A useful safety point: the **spherule (tissue form) is not infectious to handle**; it is the mold-form arthroconidia that are dangerous.\n\n**Culture.** *Coccidioides* grows within a few days to about two weeks on Sabouraud dextrose agar and routine fungal media at 25 to 30°C as a white to tan, cottony mold. Because this mold form is so hazardous, once growth suggestive of *Coccidioides* appears, the culture is handled with maximum caution and identified by nucleic acid probe, DNA sequencing, or antigen methods rather than by extensive manipulation. Converting the mold to the spherule form in the laboratory is difficult and is not routinely done.\n\n**Serology.** Antibody testing is central to diagnosis and follow-up. Early infection produces **IgM** (detected by tube precipitin or immunodiffusion), followed by **IgG** (detected by complement fixation). The **complement fixation (CF) titer is clinically important**: a high or rising CF titer suggests severe or disseminated disease, and CF antibody in the cerebrospinal fluid supports the diagnosis of coccidioidal meningitis. Enzyme immunoassays are widely used for screening.\n\n**Antigen and molecular tests.** A urine and serum *Coccidioides* antigen test is available and is most useful in severe or disseminated disease and in the immunocompromised, though it can cross-react with other endemic mycoses such as histoplasmosis. PCR on clinical specimens is increasingly available.\n\n**Skin test.** The coccidioidin or spherulin skin test indicates prior exposure and delayed-type hypersensitivity. Like the histoplasmin test, it is an epidemiological and prognostic tool (loss of skin-test reactivity in disseminated disease is a poor sign), not a routine diagnostic test.\n\n## Treatment\n\nTreatment depends on severity and site, and this section gives drug-of-choice and class-level guidance only.\n\nMild, uncomplicated primary pulmonary infection in a healthy person often resolves on its own and may need only observation. When treatment is required, an azole, usually fluconazole or itraconazole, is the drug of choice for mild to moderate disease. Severe or rapidly progressive pulmonary disease, disseminated disease, and infection in the immunocompromised are treated with a polyene, amphotericin B (liposomal), often followed by an azole. **Coccidioidal meningitis requires lifelong azole therapy** (high-dose fluconazole), because relapse is common if treatment stops. Specific doses and durations are decided by the treating clinician. No vaccine is available; prevention relies on reducing soil-dust exposure in endemic areas.\n\n## How to remember\n\n**Spherule, not yeast, is the whole point.** Every other classic dimorphic fungus becomes a yeast in tissue. *Coccidioides* becomes a spherule packed with endospores. This is the single most tested fact about it.\n\n**Arthroconidia in the air, spherules in the tissue.** In the desert soil (cold) the mold makes barrel-shaped arthroconidia that are inhaled. In the body (hot) they become spherules. Mold form infects, spherule form is the tissue diagnosis.\n\n**Dust and desert equals Valley fever.** Arid soil in the southwestern USA, disturbed by wind, farming, or construction. A pneumonia that will not respond to antibiotics in someone from Arizona or the San Joaquin Valley should raise coccidioidomycosis.\n\n**The arthroconidia are the biohazard, not the spherule.** The airborne mold-form arthroconidia cause laboratory-acquired infection, so cultures go in a safety cabinet. The tissue spherule is safe to handle.\n\n**Meningitis means lifelong treatment.** Coccidioidal meningitis is the most feared form and needs lifelong azole therapy because it relapses.\n\n## Key exam facts\n\n| Feature | Detail |\n| --- | --- |\n| Organism | *Coccidioides immitis* (California) and *C. posadasii* (elsewhere); thermally dimorphic |\n| Disease | Coccidioidomycosis (Valley fever, San Joaquin Valley fever) |\n| Tissue form | **Spherule** filled with endospores (not a yeast); 20 to 80 µm, up to 200 µm |\n| Mold form | Septate hyphae fragmenting into barrel-shaped **arthroconidia** (infectious) |\n| The exception | Only dimorphic fungus whose tissue form is a spherule, not a yeast |\n| Route | Inhalation of arthroconidia from disturbed arid soil |\n| Endemic area | Southwestern USA (Arizona, San Joaquin Valley), northern Mexico, Central\u002FSouth America |\n| Pathogen type | Primary pathogen (infects healthy people); worse if immunosuppressed |\n| Hypersensitivity signs | Erythema nodosum, erythema multiforme (\"desert rheumatism\") |\n| Most serious form | Coccidioidal meningitis (lifelong azole therapy) |\n| Biosafety | Highly hazardous mold; BSL-3; a select agent; arthroconidia are the risk |\n| Key serology | Complement fixation titer (high\u002Frising = severe\u002Fdisseminated; CSF CF for meningitis) |\n| Treatment | Fluconazole\u002Fitraconazole (mild-moderate); amphotericin B (severe\u002Fdisseminated); lifelong fluconazole for meningitis |\n\n## Where students get confused\n\n**Coccidioides does not form a yeast in tissue.** It forms a spherule packed with endospores. It is still dimorphic (mold in the environment, spherule in the body), but the tissue form is a spherule, which is exactly why it is the classic exception among the dimorphic fungi.\n\n**The spherule is safe to handle; the mold is not.** The tissue spherule is not the infectious form. The danger is the mold-form arthroconidia, which are airborne and cause laboratory-acquired infection. This reverses the intuition that the \"tissue form\" is the dangerous one.\n\n**Valley fever is not tuberculosis, even when it looks like it.** Chronic pulmonary coccidioidomycosis can produce cavities and a wasting illness that mimics TB. Geography and travel history (arid southwestern soil) are the discriminating clue.\n\n**It infects healthy people, not just the immunocompromised.** *Coccidioides* is a primary pathogen. Immunosuppression, pregnancy, and certain ancestries raise the risk of *dissemination*, but a healthy person can get primary Valley fever.\n\n**A falling skin test in disease is a bad sign, not a good one.** Loss of delayed-type hypersensitivity (skin-test reactivity) in a patient with coccidioidomycosis signals failing cell-mediated immunity and disseminated disease, the opposite of recovery.\n\n## References\n\n1. Tille PM. Bailey and Scott's Diagnostic Microbiology. 15th ed. St. Louis: Elsevier; 2022.\n2. Procop GW, Church DL, Hall GS, et al. Koneman's Color Atlas and Textbook of Diagnostic Microbiology. 7th ed. Philadelphia: Wolters Kluwer; 2017.\n3. Nguyen C, Barker BM, Hoover S, et al. Recent advances in our understanding of the environmental, epidemiological, immunological, and clinical dimensions of coccidioidomycosis. Clin Microbiol Rev. 2013;26(3):505-525. \u003Chttps:\u002F\u002Fdoi.org\u002F10.1128\u002FCMR.00005-13>\n4. Centers for Disease Control and Prevention. Valley Fever (Coccidioidomycosis). \u003Chttps:\u002F\u002Fwww.cdc.gov\u002Fvalley-fever\u002F>",[49,52,55,58,61,64],{"question":50,"answer":51},"\u003Cp>What is Valley fever?\u003C\u002Fp>","\u003Cp>Valley fever is coccidioidomycosis, an infection caused by inhaling the spores (arthroconidia) of the soil fungus \u003Cem>Coccidioides\u003C\u002Fem> in arid regions such as the southwestern United States. It usually causes a flu-like or pneumonia-like illness, and in a minority of people it spreads beyond the lungs.\u003C\u002Fp>",{"question":53,"answer":54},"\u003Cp>Why is \u003Cem>Coccidioides\u003C\u002Fem> not a typical dimorphic fungus?\u003C\u002Fp>","\u003Cp>Because in tissue it does not form a yeast. It converts from a soil mold into a spherule, a large round structure filled with endospores. It is still dimorphic (mold in the environment, spherule in the body), but the spherule instead of a yeast makes it the classic exception among dimorphic fungi.\u003C\u002Fp>",{"question":56,"answer":57},"\u003Cp>What is a spherule?\u003C\u002Fp>","\u003Cp>A spherule is the tissue form of \u003Cem>Coccidioides\u003C\u002Fem>: a large, thick-walled, round structure (20 to 80 µm, sometimes larger) packed with small endospores. When it ruptures it releases the endospores, each of which can form a new spherule. Seeing an endospore-filled spherule in a specimen is diagnostic of coccidioidomycosis.\u003C\u002Fp>",{"question":59,"answer":60},"\u003Cp>How is \u003Cem>Coccidioides\u003C\u002Fem> transmitted?\u003C\u002Fp>","\u003Cp>By inhaling airborne arthroconidia when dry desert soil is disturbed, for example by wind, dust storms, farming, or construction. It is not spread from person to person.\u003C\u002Fp>",{"question":62,"answer":63},"\u003Cp>Why is \u003Cem>Coccidioides\u003C\u002Fem> dangerous in the laboratory?\u003C\u002Fp>","\u003Cp>Its mold form produces arthroconidia that are easily aerosolized and highly infectious by inhalation, making it a well-known cause of laboratory-acquired infection and a select agent. Suspected cultures must be handled in a biosafety cabinet under BSL-3 precautions. The tissue spherule, by contrast, is not infectious to handle.\u003C\u002Fp>",{"question":65,"answer":66},"\u003Cp>How is coccidioidomycosis treated?\u003C\u002Fp>","\u003Cp>Mild disease in healthy people often resolves without treatment. When treatment is needed, azoles such as fluconazole or itraconazole are used for mild to moderate disease, and amphotericin B for severe or disseminated disease. Coccidioidal meningitis requires lifelong azole therapy because it tends to relapse.\u003C\u002Fp>",[68],"dimorphic-fungi",[70,92,124,148,176,204,232,253],{"slug":71,"title":72,"description":73,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":74,"lastUpdatedDate":44,"draft":45,"category":46,"image":42,"faq":75,"tags":91},"notable-dimorphic-fungi-and-their-properties","Dimorphic Fungi: Examples, Thermal Dimorphism, and Mnemonic","\u003Cp>Dimorphic fungi grow as mold in the environment and yeast in the body. See the six classic examples compared, why the 37°C switch is a virulence factor, their tissue forms, geography, and the mnemonic to remember them.\u003C\u002Fp>","2013-05-29",[76,79,82,85,88],{"question":77,"answer":78},"Why do dimorphic fungi change shape based on temperature?","\u003Cp>Thermal dimorphism is a virulence adaptation. Mold form (25-30°C) optimises environmental spore dispersal. Yeast form (35-37°C, body temp) is smaller, survives within macrophages, and resists immune clearance better, a deliberate survival strategy.\u003C\u002Fp>",{"question":80,"answer":81},"Why must dimorphic fungal cultures be handled in a biosafety cabinet?","\u003Cp>The mold form's airborne conidia are the infectious form for humans. Examining cultures on an open bench risks aerosolizing conidia and causing laboratory-acquired infection.\u003C\u002Fp>",{"question":83,"answer":84},"Which dimorphic fungi do NOT follow the typical mold-to-yeast pattern?","\u003Cp>\u003Cem>Coccidioides immitis\u003C\u002Fem> forms a spherule (20-200 μm, filled with endospores) instead of a true yeast. \u003Cem>Talaromyces marneffei\u003C\u002Fem> divides by fission (central septum) rather than budding. Both are common exam traps precisely because they break the general pattern.\u003C\u002Fp>",{"question":86,"answer":87},"Why is geographic\u002Ftravel history important when dimorphic fungal infection is suspected?","\u003Cp>Each organism has highly specific environmental niches: \u003Cem>Histoplasma\u003C\u002Fem> (Ohio\u002FMississippi valleys, bird\u002Fbat droppings), \u003Cem>Coccidioides \u003C\u002Fem>(SW USA arid soil), \u003Cem>Blastomyces\u003C\u002Fem> (Great Lakes\u002FOhio region), \u003Cem>Paracoccidioides\u003C\u002Fem> (rural Latin America), \u003Cem>Talaromyces\u003C\u002Fem> (Southeast Asia). Travel\u002Foccupational history dramatically narrows the differential before any test.\u003C\u002Fp>",{"question":89,"answer":90},"\u003Cp>Is \u003Cem>Sporothrix schenckii \u003C\u002Fem>a systemic or subcutaneous pathogen?\u003C\u002Fp>","\u003Cp>Primarily subcutaneous (sporotrichosis). Acquired by traumatic inoculation (rose thorns, splinters, so called 'rose gardener's disease'), typically remains localized with lymphocutaneous spread. Systemic dissemination is rare, occurring almost exclusively in severe immunocompromise.\u003C\u002Fp>",[68],{"slug":93,"title":94,"description":95,"seoTitle":42,"seoDescription":42,"author":96,"createdDate":97,"lastUpdatedDate":98,"draft":45,"category":99,"image":42,"faq":100,"tags":122},"biological-safety-cabinet-bsc-types-working-mechanism","Biological Safety Cabinet Classes I, II, and III: Which Class for Which Organism","How Class I, II, and III biosafety cabinets differ in airflow and what each actually protects, which class is required at each biosafety level, the four Class II types explained, and why a laminar airflow cabinet must never be used for infectious work.","Nisha Rijal","2019-12-05","2026-07-23","bacteriology",[101,104,107,110,113,116,119],{"question":102,"answer":103},"When do I need a biosafety cabinet, and when is open-bench work okay?","BSL1 work does not require a cabinet; open-bench work with proper handwashing and PPE is acceptable. BSL2 work requires a Class II cabinet for aerosol-generating procedures; routine non-aerosol work can be done on the open bench. BSL3 and BSL4 work require a cabinet (Class II or III depending on the organism). The biosafety level of your laboratory and the risk group of the organism determine what you need.",{"question":105,"answer":106},"What is the difference between Class I, Class II, and Class III cabinets?","Class I protects the worker and environment but not the product (room air flows over the work). Class II protects the worker, environment, and product (inward airflow, downward laminar flow, HEPA exhaust) and is the standard for BSL2\u002F3 work. Class III provides maximum containment with a totally enclosed cabinet and is used for RG4 agents at BSL4. The more you need to protect, the higher the class.",{"question":108,"answer":109},"Can I use a Class I cabinet for BSL2 work?","No. Using Class I for BSL2 (RG2 organisms) is a regulatory violation and a containment failure. Class II is required for BSL2 because RG2 organisms need product protection that Class I does not provide. Cost or equipment availability does not override this requirement.",{"question":111,"answer":112},"What is the difference between Type A2, Type B1, and Type B2 cabinets?","Type A2 recirculates 70% of air within the cabinet and exhausts 30% to the room; it is the workhorse for most BSL2\u002F3 work. Type B1 recirculates 30% and exhausts 70% to a hard duct; it is used when volatile chemicals or greater containment is needed. Type B2 exhausts 100% to a hard duct; it provides maximum containment but uses more energy. For most BSL2\u002F3 work, Type A2 is sufficient and is the standard choice.",{"question":114,"answer":115},"How often does a biosafety cabinet need to be certified?","Most regulations require annual recertification (some require every 6 months for heavily used cabinets). Certification verifies that the cabinet's airflow, HEPA filter integrity, and containment function are still adequate. Using a cabinet that hasn't been recently certified is a containment failure. Know the certification date before you work.",{"question":117,"answer":118},"What is the difference between a biosafety cabinet and a laminar airflow cabinet?","A BSC protects the worker from biohazards with inward airflow drawing aerosols away from the worker. A laminar airflow cabinet protects the product from contamination with outward airflow that pushes air toward the worker. Never use a laminar airflow cabinet for pathogenic work. For the full comparison, see Laminar Airflow Cabinet: Types and Working Principle.",{"question":120,"answer":121},"Is a Class II cabinet enough for all BSL3 work?","Class II is acceptable for most BSL3 organisms, but some highly hazardous RG3 agents may require Class III depending on institutional policy and the specific organism. Check your lab's SOPs and your biosafety officer's recommendations for agents on the borderline between Class II and Class III.",[123],"biosafety-levels",{"slug":125,"title":126,"description":127,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":128,"lastUpdatedDate":129,"draft":45,"category":46,"image":42,"faq":130,"tags":146},"koh-preparation-test-principle-procedure-results-uses","KOH Mount: Principle, Procedure, Results, Uses","\u003Cp>KOH preparation: principle, procedure, 10% concentration rationale, organism-specific findings (dermatophytes, \u003Cem>Candida\u003C\u002Fem>, Mucorales, \u003Cem>Coccidioides\u003C\u002Fem>), troubleshooting artifacts vs true fungal elements, and comparison with calcofluor white.\u003C\u002Fp>","2016-04-30","2026-08-21",[131,134,137,140,143],{"question":132,"answer":133},"Is KOH a stain?","No. KOH is a clearing agent, not a stain. It dissolves keratin and other tissue material so that the fungus, which resists the alkali, becomes visible against a cleared background. It does not color or bind the fungus the way true stains such as PAS, GMS, or calcofluor white do.",{"question":135,"answer":136},"Why is 10% KOH used for skin but 20% for nails?","The concentration has to be strong enough to dissolve keratin in a reasonable time without distorting the fungal elements. Skin scrapings clear quickly in 10% KOH. Nails are far more heavily keratinized, so they need 20% (sometimes with gentle warming) to clear in a practical timeframe.",{"question":138,"answer":139},"What is the most common false-positive in KOH microscopy?","The outlines of normal skin cell borders, sometimes called \"mosaic fungus.\" These can mimic pseudohyphae. The distinguishing feature is that true hyphae cross over cell borders, whereas the artifact follows the cell boundaries exactly and does not cross into neighboring cells.",{"question":141,"answer":142},"How can I tell true hyphae from a cotton fiber?","True hyphae have a consistent width, show true branching, and usually show septa (cross-walls). Cotton and textile fibers are typically wider, do not branch, have sharp broken ends, and often shine brightly (birefringent) under polarized light. When in doubt, add calcofluor white, fibers do not fluoresce the way chitin-containing fungi do.",{"question":144,"answer":145},"Does a positive KOH mount identify the fungal species?","No. KOH confirms that fungal elements are present and can suggest a broad category (for example, septate hyphae versus broad aseptate hyphae versus yeast with pseudohyphae), but it does not identify the species. Culture is needed for definitive identification.",[147],"fungal-diagnostics",{"slug":149,"title":150,"description":151,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":152,"lastUpdatedDate":44,"draft":45,"category":46,"image":42,"faq":153,"tags":175},"blastomyces-dermatitidis-pathogenesis-diagnosis","Blastomyces dermatitidis: Morphology, Pathogenesis, and Lab Diagnosis","\u003Cp>\u003Cem>Blastomyces dermatitidis\u003C\u002Fem> appears in tissue as a broad-based budding yeast with a thick, double-contoured cell wall (not a capsule). Learn its morphology, dimorphism, pathogenesis, how it differs from look-alikes, and lab diagnosis.\u003C\u002Fp>","2019-12-14",[154,157,160,163,166,169,172],{"question":155,"answer":156},"\u003Cp>What does \u003Cem>Blastomyces dermatitidis \u003C\u002Fem>look like under the microscope?\u003C\u002Fp>","\u003Cp>In tissue it is a large, round yeast (8 to 15 micrometers) with a single broad-based bud and a thick, double-contoured cell wall, and it is multinucleate. In the environment it is a mold with septate hyphae and oval \"lollipop\" conidia.\u003C\u002Fp>",{"question":158,"answer":159},"\u003Cp>Does \u003Cem>Blastomyces \u003C\u002Fem>have a capsule?\u003C\u002Fp>","\u003Cp>No. It has a thick, double-contoured cell wall that can look like a bright rim. The capsule is the feature of \u003Cem>Cryptococcus\u003C\u002Fem>, not \u003Cem>Blastomyces\u003C\u002Fem>. This is a common point of confusion.\u003C\u002Fp>",{"question":161,"answer":162},"\u003Cp>What is broad-based budding?\u003C\u002Fp>","\u003Cp>It describes a daughter yeast cell attached to the parent by a wide, flat base rather than a narrow neck. It is the defining microscopic feature of \u003Cem>Blastomyces dermatitidis\u003C\u002Fem>.\u003C\u002Fp>",{"question":164,"answer":165},"\u003Cp>How is \u003Cem>Blastomyces\u003C\u002Fem> different from \u003Cem>Cryptococcus\u003C\u002Fem>?\u003C\u002Fp>","\u003Cp>\u003Cem>Blastomyces\u003C\u002Fem> shows broad-based budding with a thick cell wall. \u003Cem>Cryptococcus\u003C\u002Fem> shows narrow-based budding with a wide clear capsule (seen as a halo on India ink). The budding base and the wall-versus-capsule distinction separate them.\u003C\u002Fp>",{"question":167,"answer":168},"\u003Cp>What is BAD-1?\u003C\u002Fp>","\u003Cp>BAD-1 (\u003Cem>Blastomyces\u003C\u002Fem> adhesin-1, formerly WI-1) is the main virulence factor. It binds the yeast to macrophages, blocks complement, and suppresses the immune response.\u003C\u002Fp>",{"question":170,"answer":171},"\u003Cp>What disease does \u003Cem>Blastomyces dermatitidis\u003C\u002Fem> cause?\u003C\u002Fp>","\u003Cp>Blastomycosis, which usually begins as a lung infection and can spread to the skin, bones, genitourinary tract, and central nervous system.\u003C\u002Fp>",{"question":173,"answer":174},"\u003Cp>Where is blastomycosis found?\u003C\u002Fp>","\u003Cp>It is endemic to North America, especially the Ohio and Mississippi River valleys, the Great Lakes region, and parts of Canada, with occasional cases elsewhere.\u003C\u002Fp>",[68],{"slug":177,"title":178,"description":179,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":180,"lastUpdatedDate":44,"draft":45,"category":46,"image":42,"faq":181,"tags":203},"histoplasma-capsulatum-properties-diseases-laboratory-diagnosis","Histoplasma capsulatum: Morphology, Pathogenesis, and Lab Diagnosis","\u003Cp>\u003Cem>Histoplasma capsulatum\u003C\u002Fem> is a dimorphic fungus identified by its tuberculate macroconidia and by small intracellular yeast in macrophages. Learn its morphology, why the name is a misnomer, pathogenesis, disease forms, and lab diagnosis.\u003C\u002Fp>","2016-06-24",[182,185,188,191,194,197,200],{"question":183,"answer":184},"\u003Cp>What is the diagnostic structure of \u003Cem>Histoplasma capsulatum\u003C\u002Fem>?\u003C\u002Fp>","\u003Cp>The tuberculate macroconidium: a large (8 to 15 μm), thick-walled, round spore covered with distinctive finger-like or knobby surface projections, seen in the mold form.\u003C\u002Fp>",{"question":186,"answer":187},"\u003Cp>What does \u003Cem>Histoplasma\u003C\u002Fem> look like in tissue?\u003C\u002Fp>","\u003Cp>Small (2 to 4 μm), oval, narrow-based budding yeast cells found inside macrophages and other mononuclear cells.\u003C\u002Fp>",{"question":189,"answer":190},"\u003Cp>What is the difference between microconidia and macroconidia in \u003Cem>Histoplasma\u003C\u002Fem>?\u003C\u002Fp>","\u003Cp>Microconidia are small (2 to 5 μm) and are the infectious particles that are inhaled. Macroconidia are large and tuberculate (knobby) and are used to identify the mold in culture.\u003C\u002Fp>",{"question":192,"answer":193},"\u003Cp>What are the other names for histoplasmosis?\u003C\u002Fp>","\u003Cp>Darling's disease, cave disease, and spelunker's disease.\u003C\u002Fp>",{"question":195,"answer":196},"\u003Cp>How does \u003Cem>Histoplasma \u003C\u002Fem>cause disease?\u003C\u002Fp>","\u003Cp>Inhaled microconidia reach the lungs and convert to yeast, which survive and multiply inside macrophages. Carried inside these cells, the yeast can spread to the bone marrow, liver, spleen, and other organs, especially when cell-mediated immunity is weak.\u003C\u002Fp>",{"question":198,"answer":199},"\u003Cp>How is histoplasmosis treated?\u003C\u002Fp>","\u003Cp>Mild disease in healthy people often needs no treatment. Moderate disease is treated with itraconazole, and severe or disseminated disease with liposomal amphotericin B, usually followed by itraconazole.\u003C\u002Fp>",{"question":201,"answer":202},"\u003Cp>How is \u003Cem>Histoplasma\u003C\u002Fem> distinguished from \u003Cem>Leishmania\u003C\u002Fem> in tissue?\u003C\u002Fp>","\u003Cp>Both are small and intracellular, but \u003Cem>Leishmania donovani\u003C\u002Fem> amastigotes have a kinetoplast, a small rod-shaped structure, which \u003Cem>Histoplasma\u003C\u002Fem> yeast cells lack.\u003C\u002Fp>",[68],{"slug":205,"title":206,"description":207,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":208,"lastUpdatedDate":209,"draft":45,"category":46,"image":42,"faq":210,"tags":231},"overview-of-sporotrichosis-rose-gardeners-disease-and-laboratory-diagnosis","Sporothrix schenckii (Rose Gardener's Disease): Pathogenesis, and Lab Diagnosis","\u003Cp>\u003Cem>Sporothrix schenckii \u003C\u002Fem>causes sporotrichosis (rose gardener's disease), appearing as cigar-shaped yeast in tissue and rosette conidia in the mold form. Learn its morphology, lymphocutaneous spread, cat-transmitted disease, and treatment.\u003C\u002Fp>","2013-08-01","2026-08-17",[211,214,217,220,223,226,229],{"question":212,"answer":213},"\u003Cp>What does \u003Cem>Sporothrix \u003C\u002Fem>look like under the microscope?\u003C\u002Fp>","\u003Cp>In tissue at body temperature it is a small (3 to 5 μm) cigar-shaped budding yeast. In the environment it is a mold with delicate hyphae and conidia arranged in a rosette or daisy pattern.\u003C\u002Fp>",{"question":215,"answer":216},"\u003Cp>What is cigar-shaped yeast?\u003C\u002Fp>","\u003Cp>It describes the elongated, cigar-like shape of the \u003Cem>Sporothrix\u003C\u002Fem> yeast cells seen in infected tissue. It is the identifying feature of \u003Cem>Sporothrix schenckii\u003C\u002Fem>.\u003C\u002Fp>",{"question":218,"answer":219},"\u003Cp>Why is it called rose gardener's disease?\u003C\u002Fp>","\u003Cp>Because it is classically acquired when the fungus is implanted into the skin by a thorn or plant material, such as from roses or sphagnum moss, so gardeners and florists are commonly affected.\u003C\u002Fp>",{"question":221,"answer":222},"\u003Cp>How does sporotrichosis spread in the body?\u003C\u002Fp>","\u003Cp>Most often as a lymphocutaneous infection: a nodule forms at the site of injury, and further nodules appear in a chain ascending along the lymphatic vessels.\u003C\u002Fp>",{"question":224,"answer":225},"\u003Cp>What is cat-transmitted sporotrichosis?\u003C\u002Fp>","\u003Cp>A zoonotic form caused mainly by \u003Cem>Sporothrix brasiliensis\u003C\u002Fem>, spread from infected cats through scratches and bites. It is common in Brazil, tends to be more severe, and affects cat owners and veterinarians.\u003C\u002Fp>",{"question":227,"answer":228},"\u003Cp>How is sporotrichosis diagnosed?\u003C\u002Fp>","\u003Cp>Culture is the gold standard, because the yeast is hard to see directly. The mold that grows is confirmed by converting it to the cigar-shaped yeast form at 37°C. PAS and silver stains can show the yeast in tissue.\u003C\u002Fp>",{"question":230,"answer":230},"",[68],{"slug":233,"title":234,"description":235,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":44,"lastUpdatedDate":44,"draft":45,"category":46,"image":42,"faq":236,"tags":252},"paracoccidioides-brasiliensis-pathogenesis-diagnosis","Paracoccidioides brasiliensis: Mariner's Wheel, Pathogenesis, and Lab Diagnosis","\u003Cp>\u003Cem>Paracoccidioides brasiliensis\u003C\u002Fem> causes paracoccidioidomycosis (South American blastomycosis). Its tissue yeast forms the diagnostic \"mariner's wheel\" of multiple peripheral buds. Morphology, why it favors men, and lab diagnosis.\u003C\u002Fp>",[237,240,243,246,249],{"question":238,"answer":239},"\u003Cp>What is the mariner's wheel in \u003Cem>Paracoccidioides\u003C\u002Fem>?\u003C\u002Fp>","\u003Cp>It is the diagnostic tissue form: a large central yeast cell surrounded by many small daughter buds, each attached by a narrow neck, so that the whole structure resembles a ship's steering wheel. Seeing it on microscopy of a lesion or sputum is enough to identify \u003Cem>Paracoccidioides brasiliensis\u003C\u002Fem>.\u003C\u002Fp>",{"question":241,"answer":242},"\u003Cp>How is \u003Cem>Paracoccidioides\u003C\u002Fem> different from \u003Cem>Blastomyces\u003C\u002Fem>?\u003C\u002Fp>","\u003Cp>Both were historically called \"blastomycosis\" (South American vs North American). The difference is the budding: \u003Cem>Paracoccidioides\u003C\u002Fem> makes multiple narrow-based buds around the cell (mariner's wheel), while \u003Cem>Blastomyces\u003C\u002Fem> makes a single broad-based bud.\u003C\u002Fp>",{"question":244,"answer":245},"\u003Cp>Why does paracoccidioidomycosis affect mostly men?\u003C\u002Fp>","\u003Cp>Men and women are infected at similar rates, but clinical disease is far more common in men. Estrogen inhibits the fungus's conversion from mold to the pathogenic yeast form, which largely protects women from progressing to disease.\u003C\u002Fp>",{"question":247,"answer":248},"\u003Cp>Where is paracoccidioidomycosis found?\u003C\u002Fp>","\u003Cp>In Central and South America, especially rural Brazil, and in Colombia, Venezuela, Argentina, and neighboring countries. It is associated with agricultural soil exposure and is acquired by inhaling conidia.\u003C\u002Fp>",{"question":250,"answer":251},"\u003Cp>How is paracoccidioidomycosis treated?\u003C\u002Fp>","\u003Cp>With itraconazole, or trimethoprim-sulfamethoxazole (co-trimoxazole) as an alternative, for mild to moderate disease, and amphotericin B for severe or disseminated disease. Treatment is long, often months to years, because relapse is common, and serology is used to monitor response.\u003C\u002Fp>",[68],{"slug":254,"title":255,"description":256,"seoTitle":42,"seoDescription":42,"author":257,"createdDate":258,"lastUpdatedDate":259,"draft":45,"category":46,"image":42,"faq":260,"tags":279},"yeast-structure-reproduction-and-uses","Yeast: Structure, Reproduction, and Uses","\u003Cp>Yeast structure, reproduction (budding, fission, sexual life cycles), and clinical relevance. How \u003Cem>Candida \u003C\u002Fem>and other pathogenic yeasts relate to general yeast biology, pseudohyphae formation, and why understanding budding matters for diagnosis.\u003C\u002Fp>","Sushmita Baniya","2023-11-09","2026-09-05",[261,264,267,270,273,276],{"question":262,"answer":263},"\u003Cp>How does yeast reproduce?\u003C\u002Fp>","\u003Cp>Yeast reproduces mainly asexually. Most yeasts bud: a small daughter cell grows out from the mother and pinches off. Some, like \u003Cem>Schizosaccharomyces\u003C\u002Fem>, divide by fission into two equal cells instead. Under stress, yeast can also reproduce sexually by forming ascospores.\u003C\u002Fp>",{"question":265,"answer":266},"\u003Cp>What is the most common mode of reproduction in yeast?\u003C\u002Fp>","\u003Cp>Budding (also called gemmation). It is the primary method in \u003Cem>Saccharomyces cerevisiae\u003C\u002Fem> and in the medically important yeasts such as \u003Cem>Candida\u003C\u002Fem> and \u003Cem>Cryptococcus\u003C\u002Fem>.\u003C\u002Fp>",{"question":268,"answer":269},"\u003Cp>Does yeast reproduce by budding or fission?\u003C\u002Fp>","\u003Cp>Both occur, but in different yeasts. Most yeasts bud. Fission is used mainly by \u003Cem>Schizosaccharomyces\u003C\u002Fem>, the fission yeast. If the two cells are equal in size it is fission; if one is a smaller offshoot of a larger mother, it is budding.\u003C\u002Fp>",{"question":271,"answer":272},"\u003Cp>What is the structure of a yeast cell?\u003C\u002Fp>","\u003Cp>A yeast cell is a single eukaryotic cell, 3 to 15 μm long, surrounded by a wall of beta-glucans, mannoproteins, and a little chitin. Beneath the wall is the plasma membrane and cytoplasm containing a nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, ribosomes, and a vacuole. Yeast has no chloroplasts and no flagella.\u003C\u002Fp>",{"question":274,"answer":275},"\u003Cp>What are the three types of yeast life cycle?\u003C\u002Fp>","\u003Cp>Haplobiontic (the dominant phase is haploid, as in \u003Cem>Schizosaccharomyces\u003C\u002Fem>), diplobiontic (the dominant phase is diploid, as in \u003Cem>Saccharomycodes ludwigii\u003C\u002Fem>), and haplodiplobiontic (both phases are prominent, as in \u003Cem>Saccharomyces cerevisiae\u003C\u002Fem>).\u003C\u002Fp>",{"question":277,"answer":278},"\u003Cp>Why does yeast reproduction matter clinically?\u003C\u002Fp>","\u003Cp>Because the same budding biology explains what pathogenic yeasts look like under the microscope. The presence or absence of a constriction distinguishes a bud from a pseudohypha from a true germ tube, and that distinction is the basis of the germ tube test used to identify \u003Cem>Candida albicans\u003C\u002Fem>.\u003C\u002Fp>",[],{"enabled":281,"threads":282,"total":283},true,[],0,[285,291,298,304,310,315,321,326,332,335,341],{"slug":286,"name":43,"description":287,"image":288,"body":289,"postCount":290},"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.*",509,{"slug":292,"name":293,"description":294,"image":295,"body":296,"postCount":297},"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.",88,{"slug":299,"name":257,"description":300,"image":301,"body":302,"postCount":303},"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":305,"name":306,"description":300,"image":307,"body":308,"postCount":309},"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":311,"name":312,"description":300,"image":42,"body":313,"postCount":314},"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":316,"name":317,"description":318,"image":42,"body":319,"postCount":320},"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":322,"name":323,"description":324,"image":42,"body":42,"postCount":325},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":327,"name":328,"description":300,"image":329,"body":330,"postCount":331},"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.",15,{"slug":333,"name":334,"description":324,"image":42,"body":42,"postCount":325},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":336,"name":96,"description":337,"image":338,"body":339,"postCount":340},"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.*",55,{"slug":342,"name":343,"description":344,"image":345,"body":346,"postCount":325},"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.",[348,355,361,365,370,375,379,383,387,392,396,401,405,410,415,420,424,428,433,438,442,446,450,454,457,461,465,469,474,479,484,488,492,497,501,505,509,513,516,520,524,528,532,535,539,544,547,551,556,560,564,568,572,576,580,585,589,593,597,601,605,609,613,617,621,625,629,633,636,640,643,646,649,652,655,658,661,664,667,670,673,676,679,682,685,688],{"slug":349,"name":350,"description":351,"image":352,"body":353,"postCount":354},"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":356,"name":357,"description":358,"image":42,"body":359,"postCount":360},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":362,"name":363,"description":364,"image":42,"body":42,"postCount":360},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",{"slug":366,"name":367,"description":368,"image":42,"body":42,"postCount":369},"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":371,"name":372,"description":373,"image":42,"body":42,"postCount":374},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":376,"name":377,"description":378,"image":42,"body":42,"postCount":360},"mycobacteria","Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":380,"name":381,"description":382,"image":42,"body":42,"postCount":360},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":384,"name":385,"description":386,"image":42,"body":42,"postCount":360},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":388,"name":389,"description":390,"image":42,"body":42,"postCount":391},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":393,"name":394,"description":395,"image":42,"body":42,"postCount":354},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":397,"name":398,"description":399,"image":42,"body":42,"postCount":400},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",22,{"slug":402,"name":403,"description":404,"image":42,"body":42,"postCount":354},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":406,"name":407,"description":408,"image":42,"body":42,"postCount":409},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":411,"name":412,"description":413,"image":42,"body":42,"postCount":414},"specimen-collection-transport","Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":416,"name":417,"description":418,"image":42,"body":42,"postCount":419},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",21,{"slug":421,"name":422,"description":42,"image":42,"body":423,"postCount":314},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":425,"name":426,"description":42,"image":42,"body":427,"postCount":409},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":429,"name":430,"description":431,"image":42,"body":432,"postCount":391},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":434,"name":435,"description":436,"image":42,"body":437,"postCount":314},"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":439,"name":440,"description":441,"image":42,"body":42,"postCount":314},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":443,"name":444,"description":445,"image":42,"body":42,"postCount":314},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":447,"name":448,"description":449,"image":42,"body":42,"postCount":314},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":451,"name":452,"description":453,"image":42,"body":42,"postCount":419},"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.",{"slug":123,"name":455,"description":456,"image":42,"body":42,"postCount":391},"Biosafety levels ","Articles related to Biosafety Levels",{"slug":458,"name":459,"description":460,"image":42,"body":42,"postCount":369},"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":462,"name":463,"description":464,"image":42,"body":42,"postCount":314},"pipette","Pipette","Posts related with Pipette. ",{"slug":466,"name":467,"description":468,"image":42,"body":42,"postCount":391},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":470,"name":471,"description":472,"image":42,"body":42,"postCount":473},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":475,"name":476,"description":477,"image":42,"body":42,"postCount":478},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":480,"name":481,"description":482,"image":42,"body":42,"postCount":483},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",3,{"slug":485,"name":486,"description":487,"image":42,"body":42,"postCount":391},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":489,"name":490,"description":491,"image":42,"body":42,"postCount":409},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":493,"name":494,"description":495,"image":42,"body":42,"postCount":496},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",23,{"slug":498,"name":499,"description":500,"image":42,"body":42,"postCount":314},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":502,"name":503,"description":504,"image":42,"body":42,"postCount":369},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":506,"name":507,"description":508,"image":42,"body":42,"postCount":409},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":510,"name":511,"description":512,"image":42,"body":42,"postCount":473},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":68,"name":514,"description":515,"image":42,"body":42,"postCount":314},"Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":517,"name":518,"description":519,"image":42,"body":42,"postCount":391},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":521,"name":522,"description":523,"image":42,"body":42,"postCount":369},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":525,"name":526,"description":527,"image":42,"body":42,"postCount":320},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":529,"name":530,"description":531,"image":42,"body":42,"postCount":391},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":533,"name":534,"description":42,"image":42,"body":42,"postCount":483},"haemophilus","Haemophilus",{"slug":536,"name":537,"description":538,"image":42,"body":42,"postCount":314},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":540,"name":541,"description":542,"image":42,"body":42,"postCount":543},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",13,{"slug":147,"name":545,"description":546,"image":42,"body":42,"postCount":354},"Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":548,"name":549,"description":550,"image":42,"body":42,"postCount":369},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":552,"name":553,"description":554,"image":42,"body":555,"postCount":314},"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":557,"name":558,"description":559,"image":42,"body":42,"postCount":320},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":561,"name":562,"description":563,"image":42,"body":42,"postCount":320},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":565,"name":566,"description":567,"image":42,"body":42,"postCount":314},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":569,"name":570,"description":571,"image":42,"body":42,"postCount":325},"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":573,"name":574,"description":575,"image":42,"body":42,"postCount":409},"bacterial-staining-technique","Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":577,"name":578,"description":579,"image":42,"body":42,"postCount":419},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":581,"name":582,"description":583,"image":42,"body":42,"postCount":584},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",11,{"slug":586,"name":587,"description":588,"image":42,"body":42,"postCount":369},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":590,"name":591,"description":592,"image":42,"body":42,"postCount":478},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":594,"name":595,"description":596,"image":42,"body":42,"postCount":374},"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":598,"name":599,"description":600,"image":42,"body":42,"postCount":483},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":602,"name":603,"description":604,"image":42,"body":42,"postCount":369},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":606,"name":607,"description":608,"image":42,"body":42,"postCount":391},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":610,"name":611,"description":612,"image":42,"body":42,"postCount":478},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":614,"name":615,"description":616,"image":42,"body":42,"postCount":369},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":618,"name":619,"description":620,"image":42,"body":42,"postCount":374},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":622,"name":623,"description":624,"image":42,"body":42,"postCount":314},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":626,"name":627,"description":628,"image":42,"body":42,"postCount":314},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":630,"name":631,"description":632,"image":42,"body":42,"postCount":391},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":634,"name":635,"description":42,"image":42,"body":42,"postCount":325},"colorimetric-assay","Colorimetric Assay ",{"slug":637,"name":638,"description":639,"image":42,"body":42,"postCount":369},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":641,"name":642,"description":42,"image":42,"body":42,"postCount":483},"blood-and-immune-cells","Blood and Immune Cells",{"slug":644,"name":645,"description":42,"image":42,"body":42,"postCount":369},"host-pathogen-interaction","Host Pathogen Interaction",{"slug":647,"name":648,"description":42,"image":42,"body":42,"postCount":478},"blood-culture","Blood Culture",{"slug":650,"name":651,"description":42,"image":42,"body":42,"postCount":478},"environmental-microbiology","Environmental microbiology ",{"slug":653,"name":654,"description":42,"image":42,"body":42,"postCount":391},"copromicroscopic-technique","Copromicroscopic Technique",{"slug":656,"name":657,"description":42,"image":42,"body":42,"postCount":483},"quality-control","Quality Control",{"slug":659,"name":660,"description":42,"image":42,"body":42,"postCount":391},"dermatophytes","Dermatophytes",{"slug":662,"name":663,"description":42,"image":42,"body":42,"postCount":483},"viral-hemorrhagic-fevers","Viral Hemorrhagic Fevers",{"slug":665,"name":666,"description":42,"image":42,"body":42,"postCount":478},"h2s-production","H2S Production",{"slug":668,"name":669,"description":42,"image":42,"body":42,"postCount":473},"water-quality-testing","Water Quality Testing",{"slug":671,"name":672,"description":42,"image":42,"body":42,"postCount":369},"virology-basics","Virology basics",{"slug":674,"name":675,"description":42,"image":42,"body":42,"postCount":478},"typing-methods","Typing Methods",{"slug":677,"name":678,"description":42,"image":42,"body":42,"postCount":483},"blotting-technique","Blotting Technique",{"slug":680,"name":681,"description":42,"image":42,"body":42,"postCount":478},"history-microbiology","History of Microbiology",{"slug":683,"name":684,"description":42,"image":42,"body":42,"postCount":314},"trematodes","Trematodes",{"slug":686,"name":687,"description":42,"image":42,"body":42,"postCount":478},"coccidian-parasites","Coccidian Parasites",{"slug":689,"name":690,"description":691,"image":42,"body":42,"postCount":354},"cell-structure","Cell Structure","\u003Cp>Articles related to Cell Structure. \u003C\u002Fp>"]