[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$flpkK8ewOrGZgmL2g-NrjrAHcrrpsXJ68Oqo4fq-sloM":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":128,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":192},[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":49,"related":51,"comments":124},"trichophyton-species-identification","Trichophyton: Species, Identification, and Microscopic Appearance","\u003Cp>The \u003Cem>Trichophyton\u003C\u002Fem> species that matter in the lab: colony and microscopic appearance, pencil-shaped macroconidia, endothrix vs ectothrix hair invasion, and how to tell\u003Cem> T. rubrum\u003C\u002Fem> from \u003Cem>T. mentagrophytes.\u003C\u002Fem>\u003C\u002Fp>",null,"Acharya Tankeshwar","2026-08-22",false,"mycology","Two culture plates sit on the bench. Both grew a white-to-buff mold from skin scrapings. Both are *Trichophyton*, the most common dermatophyte genus. But one is *Trichophyton rubrum* and the other is *Trichophyton mentagrophytes*, and the difference is not academic: it changes which follow-up tests you run and confirms which species is driving infection in your patient.\n\nTurn one plate over and the answer starts to appear as a deep red pigment bleeding into the agar. This is the everyday *Trichophyton* problem, and this article is about recognizing each species down the microscope and on the plate.\n\n\u003Cfigure>\n\u003Cimg src=\"https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fmicroscopic-observation-.png\" alt=\"Figure: Morphological characteristics of Trichophyton and Microsporum species\" width=\"1920\" height=\"1080\" draggable=\"false\" contenteditable=\"false\">\u003Cfigcaption>Figure: Morphological characteristics of Trichophyton and Microsporum species\u003C\u002Ffigcaption>\n\u003C\u002Ffigure>\n\n*Trichophyton* is the genus that infects all three keratinized tissues: skin, hair, and nails. That range is why it turns up in nearly every kind of tinea infection. For how *Trichophyton* fits alongside *Microsporum* and *Epidermophyton*, and the full laboratory workflow, see the [dermatophytes lab diagnosis](https:\u002F\u002Fmicrobeonline.com\u002Fdermatophytes-tinea-and-lab-diagnosis\u002F) article.\n\n## What defines the genus Trichophyton\n\n*Trichophyton* is identified in the laboratory by a consistent set of features:\n\n- **Tissues infected:** skin, hair, and nails (all three). This distinguishes it from *Microsporum* (no nails) and *Epidermophyton* (no hair).\n- **Microconidia:** abundant, and the more useful identifying feature for the genus. They are borne along the sides of the hyphae or in clusters.\n- **Macroconidia:** few, thin-walled, smooth, and pencil- or cigar-shaped when present. In many isolates they are scarce or absent, so identification leans on the microconidia.\n- **Hair invasion:** *Trichophyton* species can invade hair by either the endothrix pattern (inside the shaft) or the ectothrix pattern (outside the shaft), depending on the species.\n\nThe contrast to keep in mind: *Microsporum* is defined by its large, thick-walled, spindle-shaped macroconidia, while *Trichophyton* leans on abundant microconidia and produces macroconidia that are thin-walled and sparse. If a slide is dominated by microconidia with few thin-walled macroconidia, think *Trichophyton*.\n\n## Endothrix versus ectothrix: reading hair invasion\n\nWhen *Trichophyton* infects hair, the pattern of invasion is visible on [KOH microscopy](https:\u002F\u002Fmicrobeonline.com\u002Fkoh-preparation-test-principle-procedure-results-uses\u002F) and helps point to the species.\n\n- **Endothrix (inside the shaft).** Spores form inside the hair shaft, which weakens it so the hair breaks at the scalp surface. This produces the black-dot pattern of tinea capitis. *T. tonsurans* and *T. violaceum* are the classic endothrix species.\n- **Ectothrix (outside the shaft).** Spores coat the outside of the hair shaft. *T. mentagrophytes* shows ectothrix invasion.\n- **Favic (hyphae and air spaces).** Hairs infected with *T. schoenleinii* show hyphae and characteristic air spaces within the shaft, the pattern seen in favus.\n\n**Endothrix ends at the scalp.** Growth inside the shaft weakens it, the hair snaps flush with the skin, and each stub shows as a black dot.\n\n## The Trichophyton species that matter\n\n### Trichophyton rubrum\n\nThe single most common dermatophyte worldwide, and the one to know best. It infects skin and nails most often, and is the leading cause of tinea corporis, tinea pedis (moccasin type), and tinea unguium.\n\n- **Colony:** velvety or downy, white to pinkish on the surface, with a characteristic **deep red pigment on the reverse** (the underside of the plate). The red reverse is the classic clue.\n- **Microscopy:** abundant tear-drop or peg-shaped **microconidia** arranged along the sides of the hyphae. Macroconidia are few, long, thin-walled, and **pencil-shaped** when present.\n- **Key tests:** does not perforate hair (**hair perforation test negative**) and does not hydrolyze urea ([urease test](https:\u002F\u002Fmicrobeonline.com\u002Furease-test-principle-procedure-interpretation-and-urease-positive-organsims\u002F) negative). These separate it from *T. mentagrophytes*.\n\n### Trichophyton mentagrophytes\n\nThe second most common dermatophyte, and the species most often confused with *T. rubrum*. It is a frequent cause of inflammatory tinea, including tinea pedis and tinea barbae, and some forms are zoophilic (acquired from animals).\n\n- **Colony:** white to tan (cream), cottony or granular\u002Fpowdery. Reverse pigment is variable, usually absent or tan, not the deep red of *T. rubrum*.\n- **Microscopy:** abundant **round microconidia in grape-like clusters**, and **cigar-shaped macroconidia**, sometimes with coiled or spiral hyphae. Some isolates show a terminal thread on the macroconidia.\n- **Key tests:** perforates hair (hair perforation test **positive**, wedge-shaped) and hydrolyzes urea (urease **positive** within 2 to 4 days). Both tests are positive, which is the quickest way to separate it from *T. rubrum*.\n\n### Trichophyton tonsurans\n\nA major cause of black-dot tinea capitis, especially in children, and a common cause of scalp outbreaks.\n\n- **Colony:** flat, powdery to velvety, cream to yellow or brown, often with central folds or furrows.\n- **Microscopy:** abundant microconidia of varying size and shape (\"balloon\" forms), borne on stalks at right angles to the hyphae. Macroconidia are rare and irregular.\n- **Hair invasion:** endothrix, producing the black-dot pattern. Does not fluoresce under Wood's lamp.\n- **Note:** growth is enhanced by thiamine, a feature used in some identification schemes.\n\n### Trichophyton schoenleinii\n\nThe cause of favus, a chronic scarring form of tinea capitis with honeycomb-like yellow crusts.\n\n- **Colony:** slow growing, waxy, heaped, cream to brownish, often cracking the agar.\n- **Microscopy:** microconidia and macroconidia are usually absent. The identifying features are swollen hyphal tips that branch like antlers, called **favic chandeliers**, along with chlamydospores.\n- **Hair invasion:** favic pattern with hyphae and air spaces in the shaft.\n\n### Trichophyton violaceum\n\nA cause of endothrix black-dot tinea capitis, more common in parts of Africa, the Middle East, and Asia.\n\n- **Colony:** very slow growing, waxy or heaped, with a distinctive **violet to purple pigment**.\n- **Microscopy:** distorted, irregular hyphae; conidia are rare or absent, so the colony color and slow growth carry the identification.\n- **Hair invasion:** endothrix.\n\n### Trichophyton verrucosum\n\nA zoophilic species acquired from cattle, causing inflammatory tinea (including kerion and tinea barbae) in farm and rural settings.\n\n- **Colony:** very slow growing, small, heaped, white to cream, waxy.\n- **Growth:** grows best at 37°C (warmer than the usual 25 to 30°C), and growth is enhanced by thiamine and inositol.\n- **Microscopy:** conidia usually absent; chlamydospores in chains (\"chains of pearls\") are characteristic.\n\n## Trichophyton species at a glance\n\n| Species | Colony (surface \u002F reverse) | Microscopy | Hair \u002F clinical clue |\n| --- | --- | --- | --- |\n| *T. rubrum* | Velvety white; **deep red reverse** | Tear-drop microconidia along hyphae; few pencil-shaped macroconidia | Most common overall; nails, feet, body |\n| *T. mentagrophytes* | Cottony\u002Fgranular cream; reverse tan\u002Fvariable | Round microconidia in **grape-like clusters**; cigar macroconidia; spiral hyphae | Inflammatory tinea; hair + urease **positive** |\n| *T. tonsurans* | Powdery cream-brown, folded | Varied microconidia at right angles; rare macroconidia | Black-dot tinea capitis (endothrix) |\n| *T. schoenleinii* | Waxy, heaped, cracks agar | **Favic chandeliers**, chlamydospores; conidia absent | Favus |\n| *T. violaceum* | Waxy, **violet-purple**, very slow | Distorted hyphae; conidia rare | Black-dot tinea capitis (endothrix) |\n| *T. verrucosum* | Small, waxy, white; grows at 37°C | Chlamydospore chains; conidia absent | Zoophilic (cattle); kerion, tinea barbae |\n\n\u003Cfigure>\n\u003Cimg src=\"https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FTrichophyton-and-Microsporum.png\" alt=\"Trichophyton and microsporum\" width=\"1920\" height=\"1080\" draggable=\"false\" contenteditable=\"false\">\u003Cfigcaption>Figure: Colony characteristics of Trichophyton and Microsporum\u003C\u002Ffigcaption>\n\u003C\u002Ffigure>\n\n## Differentiating T. rubrum from T. mentagrophytes\n\nThese two are the most frequently isolated dermatophytes, and separating them is the most common *Trichophyton* identification problem in the laboratory. Four features agree with each other, so you rarely need all four.\n\n| Feature | *T. rubrum* | *T. mentagrophytes* |\n| --- | --- | --- |\n| Reverse pigment on SDA | Deep red | Absent or tan, variable |\n| Microconidia | Tear-drop, along the hyphae | Round, in grape-like clusters |\n| Hair perforation test | Negative | Positive (wedge-shaped) |\n| Urease (urea hydrolysis) | Negative | Positive in 2 to 4 days |\n\nThe memory anchor from the hub applies here: *T. mentagrophytes* is the \"active\" one. It perforates hair and splits urea. *T. rubrum* does neither and shows off its red reverse pigment instead. **\"Mentagrophytes moves, rubrum rests and reddens.\"** The full procedures are in the **hair perforation tes**t and [urease test](https:\u002F\u002Fmicrobeonline.com\u002Furease-test-principle-procedure-interpretation-and-urease-positive-organsims\u002F) articles.\n\n## How to Remember\n\n**Trichophyton = tricho = hair, and it takes all three tissues.** The genus name comes from the Greek for hair (*thrix*), and it is the one genus that infects skin, hair, and nails. If a dermatophyte is in a nail, it is not *Microsporum*; if it is *Trichophyton*, it can be anywhere.\n\n**Micro over macro.** *Trichophyton* is the microconidia genus: abundant microconidia, few thin-walled macroconidia. *Microsporum* is the opposite: big thick-walled macroconidia carry its identity. Same first syllable, opposite conidia emphasis, so learn them as a pair.\n\n**Mentagrophytes moves, rubrum rests and reddens.** The two-species problem in one line: *mentagrophytes* is positive on hair perforation and urease; *rubrum* is negative on both and shows the red reverse.\n\n**Pencil versus cigar.** *T. rubrum* macroconidia are long and pencil-shaped; *T. mentagrophytes* macroconidia are cigar-shaped. Both are thin-walled, unlike the thick spindle macroconidia of *Microsporum*.\n\n## Key exam facts\n\n| Fact | Detail |\n| --- | --- |\n| Tissues infected | Skin, hair, nail (all three) |\n| Genus-defining conidia | Abundant microconidia; few thin-walled macroconidia |\n| Most common species overall | *Trichophyton rubrum* |\n| *T. rubrum* reverse | Deep red |\n| *T. rubrum* macroconidia | Few, pencil-shaped |\n| *T. mentagrophytes* | Hair perforation and urease both positive |\n| Black-dot tinea capitis (endothrix) | *T. tonsurans*, *T. violaceum* |\n| Favus | *T. schoenleinii* (favic chandeliers) |\n| Grows best at 37°C | *T. verrucosum* (zoophilic, cattle) |\n| Wood's lamp | Most *Trichophyton* do not fluoresce (*T. schoenleinii* dull green) |\n\n## Where Students Get Confused\n\n**There is no \"Trichophyton gypseum.\"** *Gypseum* is a *Microsporum* species (*Microsporum gypseum*), a geophilic mould from soil. It is a common mix-up because the species names blur together, but the genus is *Microsporum*. If you see \"gypseum,\" think soil and *Microsporum*, not *Trichophyton*.\n\n**Microconidia are the genus clue, not macroconidia.** Students expect macroconidia to identify *Trichophyton* because macroconidia identify *Microsporum*. For *Trichophyton* it is the reverse: macroconidia are often scarce or absent, and the abundant microconidia carry the identification.\n\n**Endothrix and ectothrix are patterns, not species.** *T. mentagrophytes* is ectothrix and *T. tonsurans* is endothrix, but the terms describe where the spores sit on KOH microscopy, not the organism's name. You report the pattern from the hair; the species comes from culture.\n\n**The red reverse of T. rubrum is on the underside.** The surface of a *T. rubrum* colony is usually white to pinkish. The diagnostic deep red is the pigment diffusing into the agar, seen by turning the plate over. Students looking only at the surface miss it.\n\n**Colony color is a clue, not a confirmation.** *T. violaceum* is genuinely violet and *T. rubrum* has a red reverse, but colony color alone never names a dermatophyte. It narrows the field; microscopy and differential tests confirm.\n\n## References\n\n- Chander J. Textbook of Medical Mycology. 4th ed. Jaypee Brothers Medical Publishers; 2018.\n- Tille PM. Bailey and Scott's Diagnostic Microbiology. 15th ed. Elsevier; 2022.\n- Procop GW, Church DL, Hall GS, et al. Koneman's Color Atlas and Textbook of Diagnostic Microbiology. 7th ed. Wolters Kluwer; 2017.\n- Larone DH. Larone's Medically Important Fungi: A Guide to Identification. 6th ed. ASM Press; 2018.\n- Su H, Packeu A, Ahmed SA, et al. Species distinction in the Trichophyton rubrum complex. J Clin Microbiol. 2019;57(9):e00352-19. \u003Chttps:\u002F\u002Fdoi.org\u002F10.1128\u002FJCM.00352-19>",[],[50],"dermatophytes",[52,81,105],{"slug":53,"title":54,"description":55,"seoTitle":42,"seoDescription":42,"author":56,"createdDate":57,"lastUpdatedDate":44,"draft":45,"category":46,"image":42,"faq":58,"tags":80},"dermatophytes-tinea-and-lab-diagnosis","Dermatophytes: Lab Diagnosis and How to Tell the Three Genera Apart","\u003Cp>How the laboratory identifies dermatophytes: KOH microscopy, SDA culture, Wood's lamp, and the differential tests that separate look-alike \u003Cem>Trichophyton, Microsporum\u003C\u002Fem>, and \u003Cem>Epidermophyton\u003C\u002Fem> species.\u003C\u002Fp>","Sushmita Baniya","2022-08-21",[59,62,65,68,71,74,77],{"question":60,"answer":61},"\u003Cp>What are dermatophytes?\u003C\u002Fp>","\u003Cp>Dermatophytes are a group of fungi that feed on keratin, the tough protein found in skin, hair, and nails. They cause the skin infections known as tinea or ringworm. The three medically important genera are \u003Cem>Trichophyton\u003C\u002Fem>, \u003Cem>Microsporum\u003C\u002Fem>, and \u003Cem>Epidermophyton\u003C\u002Fem>.\u003C\u002Fp>",{"question":63,"answer":64},"\u003Cp>What is the difference between dermatophytes and dermatophytosis?\u003C\u002Fp>","\u003Cp>Dermatophytes are the fungi. Dermatophytosis is the infection they cause. Dermatophytosis is also called tinea or ringworm, and it is named by body site, such as tinea capitis on the scalp or tinea pedis on the feet.\u003C\u002Fp>",{"question":66,"answer":67},"\u003Cp>How are the three dermatophyte genera different?\u003C\u002Fp>","\u003Cp>They differ in which tissue they invade. \u003Cem>Trichophyton\u003C\u002Fem> infects skin, hair, and nails. \u003Cem>Epidermophyton\u003C\u002Fem> infects skin and nails but not hair. \u003Cem>Microsporum\u003C\u002Fem> infects skin and hair but not nails. The tissue involved is often the first clue to the genus.\u003C\u002Fp>",{"question":69,"answer":70},"\u003Cp>How are dermatophyte infections diagnosed in the laboratory?\u003C\u002Fp>","\u003Cp>The main steps are a KOH wet mount of skin, hair, or nail to look for fungal elements, followed by culture on Sabouraud dextrose agar to grow and identify the fungus. Colony appearance and the shape of macroconidia and microconidia under lactophenol cotton blue identify the genus, and differential tests separate similar species.\u003C\u002Fp>",{"question":72,"answer":73},"\u003Cp>How do you tell Trichophyton rubrum from Trichophyton mentagrophytes?\u003C\u002Fp>","\u003Cp>By a small set of tests that agree with each other. \u003Cem>T. mentagrophytes\u003C\u002Fem> perforates hair in the hair perforation test and hydrolyzes urea (urease positive). \u003Cem>T. rubrum\u003C\u002Fem> does neither and instead shows a deep red pigment on the reverse of the colony.\u003C\u002Fp>",{"question":75,"answer":76},"\u003Cp>Why does ringworm form a ring?\u003C\u002Fp>","\u003Cp>The fungus grows outward from the point where it started, spreading in a circle through the outer skin. The active edge advances while the center begins to clear, which produces the ring shape with a raised border. There is no worm involved.\u003C\u002Fp>",{"question":78,"answer":79},"\u003Cp>Does a negative Wood's lamp rule out a fungal infection?\u003C\u002Fp>","\u003Cp>No. Only some dermatophytes fluoresce under Wood's lamp, mainly certain \u003Cem>Microsporum\u003C\u002Fem> species on the scalp. Most \u003Cem>Trichophyton\u003C\u002Fem> species do not fluoresce, so a negative result does not exclude tinea. KOH microscopy and culture are still needed.\u003C\u002Fp>",[50],{"slug":82,"title":83,"description":84,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":85,"lastUpdatedDate":86,"draft":45,"category":46,"image":42,"faq":87,"tags":103},"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",[88,91,94,97,100],{"question":89,"answer":90},"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":92,"answer":93},"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":95,"answer":96},"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":98,"answer":99},"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":101,"answer":102},"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.",[104],"fungal-diagnostics",{"slug":106,"title":107,"description":108,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":109,"lastUpdatedDate":110,"draft":45,"category":111,"image":42,"faq":112,"tags":122},"urease-test-principle-procedure-interpretation-and-urease-positive-organsims","Urease Test: Principle, Procedure, Interpretation & Urease-Positive Organisms","\u003Cp>Urease test principle and procedure: including the PUNCH mnemonic, the rapid-vs-delayed reading windows, and why \u003Cem>H. pylori\u003C\u002Fem> gastric biopsies use this exact reaction.\u003C\u002Fp>","2012-12-29","2026-08-13","biochemical-tests",[113,116,119],{"question":114,"answer":115},"Why did my Enterobacter test negative in broth but positive on agar?","\u003Cp>Stuart's broth has a higher buffering capacity than Christensen's agar, which can mask the weaker, delayed urease activity of organisms like \u003Cem>Enterobacter\u003C\u002Fem>. The agar is more sensitive for delayed producers, if results disagree, trust the agar reading.\u003C\u002Fp>",{"question":117,"answer":118},"\u003Cp>My urea agar turned pink overnight even though I expected a negative, what happened?\u003C\u002Fp>","Check what medium you used. If it's peptone-rich, peptone hydrolysis alone can raise the pH and mimic a positive reaction, independent of true urease activity.",{"question":120,"answer":121},"How is the urease test used to diagnose H. pylori?","\u003Cp>A crushed gastric biopsy sample is placed directly into urease broth. If \u003Cem>H. pylori\u003C\u002Fem> is present, its urease rapidly hydrolyzes urea and turns the broth pink within minutes to hours, this is the basis of the rapid urease (CLO) test performed during endoscopy.\u003C\u002Fp>",[123],"enzyme-tests",{"enabled":125,"threads":126,"total":127},true,[],0,[129,135,142,148,154,159,165,170,176,179,186],{"slug":130,"name":43,"description":131,"image":132,"body":133,"postCount":134},"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.*",477,{"slug":136,"name":137,"description":138,"image":139,"body":140,"postCount":141},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",78,{"slug":143,"name":56,"description":144,"image":145,"body":146,"postCount":147},"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":149,"name":150,"description":144,"image":151,"body":152,"postCount":153},"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":155,"name":156,"description":144,"image":42,"body":157,"postCount":158},"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":160,"name":161,"description":162,"image":42,"body":163,"postCount":164},"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":166,"name":167,"description":168,"image":42,"body":42,"postCount":169},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":171,"name":172,"description":144,"image":173,"body":174,"postCount":175},"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":177,"name":178,"description":168,"image":42,"body":42,"postCount":169},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":180,"name":181,"description":182,"image":183,"body":184,"postCount":185},"nisha-rijal","Nisha Rijal","Microbiologist and AMR Specialist Kathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fnisha-rijal-1.png","Nisha Rijal is a microbiologist with nearly 15 years of frontline diagnostic and surveillance experience at the National Public Health Laboratory (NPHL), national reference laboratory under the Department of Health Services, Nepal. She currently works as an AMR Support Officer at the World Health Organization (WHO), Nepal, where her work focuses on strengthening antimicrobial resistance surveillance systems and translating AMR data into actionable public health response.\n\nHer research, published in peer-reviewed journals and cited over 220 times, spans some of the most clinically significant infectious disease challenges in Nepal and South Asia: antimicrobial resistance trends in *Vibrio cholerae* across an 11-year national surveillance dataset, sero-epidemiology of scrub typhus in patients with acute febrile illness, lower respiratory tract infections in HIV-positive patients, and gonococcal resistance surveillance. She was a contributor to Nepal's National Antimicrobial Resistance Containment Action Plan, a foundational policy document for AMR governance in Nepal. You can find list of [Nisha Rijal's article here in Google Scholar.](https:\u002F\u002Fscholar.google.com\u002Fcitations?user=N-Ruq54AAAAJ&hl=en)\n\nThis depth of experience is visible in her writing at Microbeonline. Her 53 published articles cover bacteriology, parasitology, mycology, immunology, and laboratory techniques, and are consistently among the most detailed and clinically grounded content on the site. She brings to every article the same standard that national reference laboratory work demands: methodological precision, awareness of real diagnostic constraints, and an understanding of what results actually mean for patient care in resource-limited settings.\n\nHer areas of particular expertise include antimicrobial susceptibility testing and resistance mechanism detection, quality assurance in clinical microbiology, and laboratory-based infectious disease surveillance.\n\n---\n\n*Nisha Rijal contributes to Microbeonline in a personal capacity. Her views and writing do not represent the positions of the World Health Organization or any other institution.*",54,{"slug":187,"name":188,"description":189,"image":190,"body":191,"postCount":169},"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.",[193,200,206,211,216,221,225,229,233,238,242,247,251,256,261,265,269,273,278,283,287,291,295,300,304,308,312,316,321,326,330,334,338,343,347,351,355,359,363,367,371,375,379,383,387,391,394,398,403,407,411,415,419,423,426,430,434,438,442,446,450,454,458,462,466,470,474,478,481,485,488,491,494,497,500,503,505,508,511],{"slug":194,"name":195,"description":196,"image":197,"body":198,"postCount":199},"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":201,"name":202,"description":203,"image":42,"body":204,"postCount":205},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":207,"name":208,"description":209,"image":42,"body":42,"postCount":210},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",11,{"slug":212,"name":213,"description":214,"image":42,"body":42,"postCount":215},"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":217,"name":218,"description":219,"image":42,"body":42,"postCount":220},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":222,"name":223,"description":224,"image":42,"body":42,"postCount":210},"mycobacteria","Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":226,"name":227,"description":228,"image":42,"body":42,"postCount":210},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":230,"name":231,"description":232,"image":42,"body":42,"postCount":205},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":234,"name":235,"description":236,"image":42,"body":42,"postCount":237},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":239,"name":240,"description":241,"image":42,"body":42,"postCount":175},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":243,"name":244,"description":245,"image":42,"body":42,"postCount":246},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",21,{"slug":248,"name":249,"description":250,"image":42,"body":42,"postCount":164},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":252,"name":253,"description":254,"image":42,"body":42,"postCount":255},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":257,"name":258,"description":259,"image":42,"body":42,"postCount":260},"specimen-collection-transport","Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":262,"name":263,"description":264,"image":42,"body":42,"postCount":246},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",{"slug":266,"name":267,"description":42,"image":42,"body":268,"postCount":158},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":270,"name":271,"description":42,"image":42,"body":272,"postCount":255},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":274,"name":275,"description":276,"image":42,"body":277,"postCount":237},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":279,"name":280,"description":281,"image":42,"body":282,"postCount":158},"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":284,"name":285,"description":286,"image":42,"body":42,"postCount":158},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":288,"name":289,"description":290,"image":42,"body":42,"postCount":158},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":292,"name":293,"description":294,"image":42,"body":42,"postCount":158},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":296,"name":297,"description":298,"image":42,"body":42,"postCount":299},"immunoassays","Immunoassays","You will get information about all the diagnostic tests that rely on the specific binding between an antigen and an antibody to detect or quantify a substance.",19,{"slug":301,"name":302,"description":303,"image":42,"body":42,"postCount":237},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":305,"name":306,"description":307,"image":42,"body":42,"postCount":215},"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":309,"name":310,"description":311,"image":42,"body":42,"postCount":158},"pipette","Pipette","Posts related with Pipette. ",{"slug":313,"name":314,"description":315,"image":42,"body":42,"postCount":220},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":317,"name":318,"description":319,"image":42,"body":42,"postCount":320},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":322,"name":323,"description":324,"image":42,"body":42,"postCount":325},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":327,"name":328,"description":329,"image":42,"body":42,"postCount":215},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",{"slug":331,"name":332,"description":333,"image":42,"body":42,"postCount":220},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":335,"name":336,"description":337,"image":42,"body":42,"postCount":164},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":339,"name":340,"description":341,"image":42,"body":42,"postCount":342},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",22,{"slug":344,"name":345,"description":346,"image":42,"body":42,"postCount":158},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":348,"name":349,"description":350,"image":42,"body":42,"postCount":215},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":352,"name":353,"description":354,"image":42,"body":42,"postCount":255},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":356,"name":357,"description":358,"image":42,"body":42,"postCount":320},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":360,"name":361,"description":362,"image":42,"body":42,"postCount":325},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":364,"name":365,"description":366,"image":42,"body":42,"postCount":237},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":368,"name":369,"description":370,"image":42,"body":42,"postCount":215},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":372,"name":373,"description":374,"image":42,"body":42,"postCount":164},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":376,"name":377,"description":378,"image":42,"body":42,"postCount":237},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":380,"name":381,"description":42,"image":42,"body":42,"postCount":382},"haemophilus","Haemophilus",3,{"slug":384,"name":385,"description":386,"image":42,"body":42,"postCount":325},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":388,"name":389,"description":390,"image":42,"body":42,"postCount":205},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",{"slug":104,"name":392,"description":393,"image":42,"body":42,"postCount":199},"Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":395,"name":396,"description":397,"image":42,"body":42,"postCount":215},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":399,"name":400,"description":401,"image":42,"body":402,"postCount":158},"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":404,"name":405,"description":406,"image":42,"body":42,"postCount":164},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":408,"name":409,"description":410,"image":42,"body":42,"postCount":158},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":412,"name":413,"description":414,"image":42,"body":42,"postCount":237},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":416,"name":417,"description":418,"image":42,"body":42,"postCount":169},"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":420,"name":421,"description":422,"image":42,"body":42,"postCount":255},"bacterial-staining-technique","Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":123,"name":424,"description":425,"image":42,"body":42,"postCount":246},"Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":427,"name":428,"description":429,"image":42,"body":42,"postCount":210},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",{"slug":431,"name":432,"description":433,"image":42,"body":42,"postCount":215},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":435,"name":436,"description":437,"image":42,"body":42,"postCount":325},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":439,"name":440,"description":441,"image":42,"body":42,"postCount":220},"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":443,"name":444,"description":445,"image":42,"body":42,"postCount":382},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":447,"name":448,"description":449,"image":42,"body":42,"postCount":215},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":451,"name":452,"description":453,"image":42,"body":42,"postCount":237},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":455,"name":456,"description":457,"image":42,"body":42,"postCount":325},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":459,"name":460,"description":461,"image":42,"body":42,"postCount":215},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":463,"name":464,"description":465,"image":42,"body":42,"postCount":237},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":467,"name":468,"description":469,"image":42,"body":42,"postCount":158},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":471,"name":472,"description":473,"image":42,"body":42,"postCount":237},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":475,"name":476,"description":477,"image":42,"body":42,"postCount":215},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":479,"name":480,"description":42,"image":42,"body":42,"postCount":169},"colorimetric-assay","Colorimetric Assay ",{"slug":482,"name":483,"description":484,"image":42,"body":42,"postCount":215},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":486,"name":487,"description":42,"image":42,"body":42,"postCount":382},"blood-and-immune-cells","Blood and Immune Cells",{"slug":489,"name":490,"description":42,"image":42,"body":42,"postCount":215},"host-pathogen-interaction","Host Pathogen Interaction",{"slug":492,"name":493,"description":42,"image":42,"body":42,"postCount":325},"blood-culture","Blood Culture",{"slug":495,"name":496,"description":42,"image":42,"body":42,"postCount":325},"environmental-microbiology","Environmental microbiology ",{"slug":498,"name":499,"description":42,"image":42,"body":42,"postCount":158},"copromicroscopic-technique","Copromicroscopic Technique",{"slug":501,"name":502,"description":42,"image":42,"body":42,"postCount":382},"quality-control","Quality Control",{"slug":50,"name":504,"description":42,"image":42,"body":42,"postCount":325},"Dermatophytes",{"slug":506,"name":507,"description":42,"image":42,"body":42,"postCount":382},"viral-hemorrhagic-fevers","Viral Hemorrhagic Fevers",{"slug":509,"name":510,"description":42,"image":42,"body":42,"postCount":325},"h2s-production","H2S Production",{"slug":512,"name":513,"description":42,"image":42,"body":42,"postCount":320},"water-quality-testing","Water Quality Testing"]