[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fRs-W9Wi9078QJ7KhFYVX-AUFaZMrkc0w-GfQz6S3bGU":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":145},[4,8,12,16,20,24,28],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Abbreviations","abbreviations","\u002Fabbreviations\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"type":33,"data":34},"blog",{"slug":35,"title":36,"description":37,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":40,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"body":44,"faq":45,"tags":61,"related":63},"dermatophyte-test-medium-dtm-composition-preparation-and-uses","Dermatophyte Test Medium (DTM): Composition, Preparation, and the Pathogens It Can Miss","Why a clean, unchanged DTM tube after two weeks doesn't always mean no fungal infection, the color-change logic explained, and the one ingredient that can silently suppress a true pathogen along with the contaminants.",null,"Acharya Tankeshwar","2021-01-30","2026-07-13",false,"mycology","**The negative result that wasn't actually negative**\n\nA patient with a stubborn, discolored, thickened toenail has a nail clipping sent for fungal culture. The lab plates the sample onto Dermatophyte Test Medium, a convenient single-tube screen: red means dermatophyte, unchanged means probably not. Two weeks later, the tube is still yellow. No color change, no growth reported. Dermatophyte testing negative.\n\nBut the true cause of this infection was never a dermatophyte at all. It was a non-dermatophyte mold, one that happens to be sensitive to cycloheximide, the same antifungal DTM relies on to keep saprophytic contaminants from overgrowing the plate. DTM didn't fail here. It worked exactly as designed, suppressing an unwanted organism before it could interfere with the reading. The problem is that \"unwanted contaminant\" and \"genuine pathogen sensitive to the same drug\" can look identical to this medium: both simply don't grow.\n\nThis is exactly why DTM is a screening tool, not a final answer, and why understanding what it can silently suppress matters as much as understanding what it's designed to detect.\n\n![Dermatophyte Test Medium Culture Plate - Dermatophyte Test Medium (DTM) Image source:labm.com](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FDermatophyte-test-medium.jpg)Figure: Dermatophyte Test Medium (DTM) Image source:labm.com\n\nDermatophyte Test Medium (DTM) is a specialized selective and differential medium used in medical mycology to differentiate dermatophytes (ringworm) from other fungi. Taplin and colleagues developed it by modifying [Sabouraud Dextrose Agar (SDA)](https:\u002F\u002Fmicrobeonline.com\u002Fsabouraud-dextrose-agar-sda-principle-composition-uses-colony-morphology\u002F).\n\nDTM uses phenol red as a pH indicator. The medium is yellow at pH below 6.8, turning pink at pH ≥ 8.2 in the presence of alkaline metabolites produced by [dermatophytes](https:\u002F\u002Fmicrobeonline.com\u002Fdermatophytes-tinea-and-lab-diagnosis\u002F) (*Epidermophyton*, *Microsporum*, and *Trichophyton* spp.). Contaminating saprophytes, if they grow, don't produce these alkaline byproducts within the testing window, typical saprotrophic fungi ferment carbohydrates into acidic byproducts instead, so the medium stays yellow. Culture results should be reported within two weeks of incubation; prolonged incubation increases the risk of false positives, since even slow-growing saprophytes can eventually shift the medium alkaline given enough time.\n\n### Composition\n\n| Ingredient | Amount (per liter) |\n| --- | --- |\n| Soy Peptone | 10.0 gm |\n| Dextrose | 10.0 gm |\n| Cycloheximide | 0.5 gm |\n| Chloramphenicol | 0.05 gm |\n| Gentamicin sulfate | 0.1 g |\n| Phenol Red | 0.2 gm |\n| Agar | 20.0 gm |\n\n**Functions of each ingredient:**\n\n- Soy peptone provides nitrogenous and carbonaceous compounds essential for microbial growth.\n- Dextrose serves as the energy source for metabolism.\n- Chloramphenicol acts as a broad-spectrum antibacterial, inhibiting a wide range of Gram-positive and Gram-negative bacteria.\n- Cycloheximide, an antifungal agent, inhibits saprophytic fungi, but see the safety note below, this same inhibition can extend to some pathogenic fungi.\n- Phenol red is the pH indicator.\n\nThe medium's own baseline pH, around 5.6, favors fungal growth generally. This is a separate fact from the phenol red indicator's own color-change thresholds (yellow below pH 6.8, pink at pH ≥ 8.2); the first describes the medium's starting condition, the second describes what the indicator dye does as dermatophytes shift that pH upward through their metabolism.\n\n### Preparation of Media\n\nDepending on the requirements, individual laboratories either prepare DTM from dehydrated powder supplied by the commercial manufacturer, or prepared plates or tubes can also be purchased. Theoretically, it can be made in the laboratory using individual ingredients, which is rarely done in most laboratories.\n\n### Methods of Inoculation and Incubation\n\nSuitable samples for DTM include plucked hair, skin scrapings, or nail clippings.\n\n- Allow DTM to equilibrate to room temperature before sample inoculation. Make sure the agar surface is dry.\n- Place the sample centrally on the surface of the medium and press it gently to ensure firm contact.\n- Allow the cap on the tube to remain loose to ensure gaseous exchange during incubation.\n- Incubate at 25°C for up to 2 weeks in ambient air.\n\n### Culture Results\n\nDermatophytes produce white or buff-colored growth within 5–10 days along with a red-colored medium; definitive identification requires additional testing; color change appearing only after two weeks is likely a contaminating saprophyte rather than a true positive.\n\n![ - Dermatophyte test medium (Left- uninoculated vial, middle and right vials showing growth compatible withTrichophyton mentagrophytes(Image source: Jorge Oliveira)](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fdermatophyte-test-medium-DTM.png)Figure: Dermatophyte test medium (Left- uninoculated vial, middle and right vials showing growth compatible with *Trichophyton mentagrophytes* (Image source: Jorge Oliveira)\n\n**HOW TO REMEMBER**\n\n***Anchor for the color logic: \"red flags alkaline.\"*** *Dermatophytes shift the medium alkaline as they metabolize, turning it pink\u002Fred. Saprophytes, still fermenting sugars into acid, leave it yellow. Red is the signal to take seriously; unchanged doesn't automatically mean \"nothing's there.\"*\n\n### Why DTM Can Miss the Real Pathogen\n\nCycloheximide is a double-edged design choice. It's specifically there to suppress fast-growing saprophytic contaminants that would otherwise overrun the plate before a slower-growing dermatophyte gets a chance to be detected. But cycloheximide sensitivity isn't limited to saprophytes: several clinically relevant fungi are also inhibited by it. A sample containing a genuine, cycloheximide-sensitive pathogen will simply fail to grow on DTM, indistinguishable, from the tube alone, from a clean, truly negative result.\n\n**This is exactly why DTM should never be the only medium used when a broader fungal differential is clinically relevant.** Pairing it with a cycloheximide-free medium (such as plain Sabouraud dextrose agar without added antifungals) protects against exactly the failure mode illustrated in the hook above.\n\n**HOW TO REMEMBER**\n\n***Anchor for cycloheximide's double edge: \"the bouncer that turns away a few honest guests too.\"*** *Cycloheximide is there to keep saprophytic gatecrashers off the plate, but it can't tell the difference between an unwanted contaminant and a legitimate, cycloheximide-sensitive pathogen. Both get turned away at the door, and both look identical from the outside: no growth at all.*\n\n### Limitations\n\nDTM is a screening test only; saprophytic fungi and yeast may also grow and produce alkaline metabolites, especially from soil-contaminated samples like foot or nail specimens; DTM should not be used as the sole means of dermatophyte identification.\n\n## Key exam facts in one table\n\n| Fact | Detail |\n| --- | --- |\n| Developed by | Taplin and colleagues, by modifying Sabouraud Dextrose Agar |\n| Indicator | Phenol red: yellow below pH 6.8, pink at pH ≥ 8.2 |\n| Baseline medium pH | \\~5.6, favors general fungal growth |\n| Positive result | White\u002Fbuff growth with red\u002Fpink medium, within 5–10 days |\n| Key antifungal ingredient | Cycloheximide, suppresses saprophytes but also some pathogenic fungi |\n| Other antimicrobials | Chloramphenicol and gentamicin (broad-spectrum antibacterial coverage) |\n| Reporting window | Within 2 weeks; longer incubation risks false positives from slow-growing saprophytes |\n| Major limitation | Screening test only; a cycloheximide-sensitive true pathogen can produce a false negative indistinguishable from a true negative |\n| Best practice | Never use DTM as the sole medium; pair with a cycloheximide-free medium for a complete differential |\n\n## Where Students Get Confused\n\n- **Assuming an unchanged (yellow) tube after two weeks always means no fungal infection.** A cycloheximide-sensitive true pathogen can be suppressed just as effectively as an unwanted saprophyte, producing an identical \"no growth\" result.\n- **Treating a color change alone as a confirmed diagnosis.** DTM is presumptive and screening-level only; definitive dermatophyte identification requires additional testing.\n- **Confusing the medium's baseline pH (\\~5.6, favoring growth) with the indicator's color-change threshold (≥8.2, signaling a positive read).** These are two different pH facts serving two different purposes.\n- **Assuming longer incubation is always safer.** Past the two-week window, the risk shifts toward false positives, since slow-growing saprophytes can eventually produce alkaline byproducts too.\n\n**References and further readings**\n\n1. Acharya T., Hare J. (2022) Sabouraud Agar and Other Fungal Growth Media. In: Gupta V.K., Tuohy M. (eds) Laboratory Protocols in Fungal Biology. Fungal Biology. Springer, Cham. [https:\u002F\u002Fdoi.org\u002F10.1007\u002F978-3-030-83749-5_2](https:\u002F\u002Flink.springer.com\u002Fbook\u002F10.1007\u002F978-3-030-83749-5)\n2. Taplin, D., Zaias, N., Rebell, G., & Blank, H. (1969). Isolation and recognition of dermatophytes on a new medium (DTM). *Archives of Dermatology*.",[46,49,52,55,58],{"question":47,"answer":48},"What is Dermatophyte Test Medium (DTM) used for?","Screening for dermatophytes (ringworm-causing fungi) in samples like hair, skin scrapings, or nail clippings, using a color change from yellow to red\u002Fpink as the presumptive positive signal.",{"question":50,"answer":51},"Why does DTM turn red when dermatophytes grow?","Dermatophyte metabolism shifts the medium's pH alkaline, and the phenol red indicator turns pink at pH ≥ 8.2. Saprophytic fungi, by contrast, ferment sugars into acid and leave the medium yellow.",{"question":53,"answer":54},"Can DTM give a false negative result?","Yes. Cycloheximide, included to suppress saprophytic contaminants, can also suppress genuine pathogenic fungi that happen to be cycloheximide-sensitive, producing a \"no growth\" result indistinguishable from a true negative.",{"question":56,"answer":57},"Should DTM be used as the only fungal culture medium?","No. It should be paired with a cycloheximide-free medium whenever a broader fungal differential is clinically relevant, to avoid missing a cycloheximide-sensitive true pathogen.",{"question":59,"answer":60},"Why should DTM results be read within two weeks?","Because incubation beyond two weeks increases the risk of false positives, as slow-growing saprophytic fungi can eventually produce alkaline byproducts too.",[62],"fungal-culture-media",[64,79,93,100,113],{"slug":65,"title":66,"description":67,"seoTitle":38,"seoDescription":38,"author":68,"createdDate":69,"lastUpdatedDate":41,"draft":42,"category":70,"image":38,"faq":71,"tags":78},"czapek-dox-agar-principle-composition-colony-characteristics","Czapek Dox Agar: Composition, Principle, and Colony Characteristics of Aspergillus and Penicillium","Czapek Dox agar is a synthetic medium with sucrose as the sole carbon source and nitrate as the sole nitrogen source — used for identification of Aspergillus, Penicillium, and other environmental fungi.","Sushmita Baniya","2022-06-11","culture-media",[72,75],{"question":73,"answer":74},"What makes Czapek Dox agar different from Sabouraud dextrose agar for fungal identification?","Czapek Dox agar is a synthetic (chemically defined) medium with sucrose as the sole carbon source and sodium nitrate as the sole nitrogen source — providing minimal, standardised nutrition. Sabouraud dextrose agar contains peptone as a complex nitrogen source, supporting more luxuriant growth. On Czapek Dox, the nutritional restriction reveals phenotypic differences in colony texture, colour, and growth rate that are suppressed on richer media. This makes Czapek Dox particularly useful for taxonomic characterisation of Aspergillus and Penicillium species, where colony morphology on a defined medium is part of the formal species description. It is not used for primary isolation from clinical specimens as it does not support fastidious organisms.",{"question":76,"answer":77},"Which fungi are best identified on Czapek Dox agar?","Czapek Dox agar is primarily used for identification of Aspergillus and Penicillium species — both common environmental moulds that may cause opportunistic infections in immunocompromised patients. On Czapek Dox, Aspergillus fumigatus produces characteristic blue-grey to grey-green colonies, A. flavus produces yellow-green colonies with granular texture, and A. niger produces dense black colonies. Penicillium species produce characteristic blue-green powdery colonies with the brush-like conidiophore arrangement visible on LPCB mount. The standardised composition ensures reproducible colony morphology that matches published species descriptions used in formal identification.",[62],{"slug":80,"title":81,"description":82,"seoTitle":38,"seoDescription":38,"author":83,"createdDate":84,"lastUpdatedDate":41,"draft":42,"category":70,"image":38,"faq":85,"tags":92},"bird-seed-agar-principle-composition-uses","Bird Seed Agar (Niger Seed Agar): Composition, Uses, and Cryptococcus Identification","Bird seed agar selectively detects Cryptococcus neoformans by its brown-black melanin production from caffeic acid. Learn the principle, composition, colony appearance, and how it differentiates C. neoformans from other Cryptococcus species.","Nisha Rijal","2018-10-31",[86,89],{"question":87,"answer":88},"How does bird seed agar identify Cryptococcus neoformans?","Bird seed agar (Niger seed\u002FStaib medium) contains caffeic acid derived from Guizotia abyssinica (Niger seeds). Cryptococcus neoformans possesses the enzyme laccase (phenol oxidase), which oxidises caffeic acid to melanin. This melanin deposits in the cell wall, producing distinctive brown-black colonies within 72 hours to 5 days at 30°C. Most other pathogenic yeasts — including all Candida species — lack laccase and remain white or cream coloured. The brown-black colony colour on bird seed agar is essentially diagnostic for Cryptococcus neoformans or C. gattii (both possess laccase) in the clinical laboratory.",{"question":90,"answer":91},"Can bird seed agar differentiate Cryptococcus neoformans from Cryptococcus gattii?","No — both C. neoformans and C. gattii produce laccase and give identical brown-black colonies on bird seed agar. They cannot be differentiated by this medium alone. Differentiation requires CanaVanine-Glycine-Bromothymol blue (CGB) agar: C. gattii grows on CGB agar and turns the medium blue (produces ammonia from glycine), while C. neoformans does not grow on CGB. This distinction matters clinically because C. gattii primarily infects immunocompetent hosts (unlike C. neoformans which predominantly causes disease in immunocompromised patients), affects different geographic areas, and may respond differently to antifungal therapy.",[62],{"slug":94,"title":95,"description":96,"seoTitle":38,"seoDescription":38,"author":83,"createdDate":97,"lastUpdatedDate":41,"draft":42,"category":70,"image":38,"faq":98,"tags":99},"sabouraud-dextrose-agar-sda-principle-composition-uses-colony-morphology","Sabouraud Dextrose Agar (SDA): Composition, Principle, Uses, and Colony Morphology","Sabouraud Dextrose Agar (SDA) is the standard medium for fungal isolation. Learn its composition, how its acidic pH selects for fungi, colony morphology of dermatophytes and yeasts, cycloheximide modification, and clinical uses.","2015-07-05",[],[62],{"slug":101,"title":102,"description":103,"seoTitle":38,"seoDescription":38,"author":83,"createdDate":104,"lastUpdatedDate":41,"draft":42,"category":70,"image":38,"faq":105,"tags":112},"potato-dextrose-agar-pda-principle-composition-colony-characteristics","Potato Dextrose Agar (PDA): Composition, Preparation, Uses, and Fungal Colony Characteristics","Potato dextrose agar promotes sporulation in fungi that fail to produce conidia on richer media. Learn the composition, why potato infusion induces sporulation, typical colony characteristics of dermatophytes, and how PDA compares to Sabouraud agar.","2015-06-01",[106,109],{"question":107,"answer":108},"Why does potato dextrose agar induce better sporulation than Sabouraud dextrose agar in some fungi?","PDA provides a nutritionally restricted environment — the potato infusion is low in amino acids and complex growth factors compared to the peptone-rich Sabouraud agar. This nutritional restriction creates metabolic stress that triggers fungi to reproduce by sporulation as a survival mechanism. On richer media like blood agar or BHI, the same fungi grow lush vegetative mycelium without sporulating. The 2% dextrose in PDA provides sufficient carbon for sustained growth, while the restricted nitrogen from potato infusion delivers the stress signal. This is why PDA is the preferred medium for inducing sporulation in dermatophytes that fail to produce diagnostic conidia on standard media.",{"question":110,"answer":111},"What is the diagnostic significance of red\u002Fwine-coloured reverse pigment on PDA?","A characteristic red to wine-red reverse pigment on the underside of colonies on PDA is highly characteristic of Trichophyton rubrum — the most common cause of tinea pedis (athlete's foot), tinea unguium (onychomycosis), and tinea corporis worldwide. This red reverse pigment is more prominently expressed on PDA than on Sabouraud agar, making PDA subculture valuable for confirming T. rubrum identity when reverse pigment is absent or faint on primary isolation plates. In combination with the microscopic appearance (thin-walled pencil-shaped macroconidia and tear-drop microconidia) and clinical presentation, the red reverse on PDA is an important identification feature.",[62],{"slug":114,"title":115,"description":116,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":117,"lastUpdatedDate":118,"draft":42,"category":70,"image":38,"faq":119,"tags":144},"common-fungal-culture-media-uses","Common Fungal Culture Media and Their Uses in Clinical Mycology","A complete guide to fungal culture media — non-selective, selective, and differential media used in clinical mycology, with incubation temperatures, specimen types, cycloheximide sensitivity chart, and links to individual media articles.","2014-01-26","2026-07-18",[120,123,126,129,132,135,138,141],{"question":121,"answer":122},"Why must cycloheximide-containing media never be used alone?","Cycloheximide inhibits Cryptococcus neoformans, Aspergillus, Fusarium, and some Candida species. Always pair Mycosel or DTM with a cycloheximide-free medium.",{"question":124,"answer":125},"What is the difference between SDA and BHI for fungal isolation?","SDA (pH 5.6, high glucose): dermatophytes and subculture. BHI: richer, supports both mold and yeast phases of fastidious dimorphic fungi (Histoplasma, Blastomyces, Coccidioides) from primary specimens.",{"question":127,"answer":128},"How do you identify Candida species on CHROMagar?","C. albicans = green; C. tropicalis = blue-grey; C. krusei = pink flat spreading; C. glabrata = pink-mauve small. Different colored colonies immediately reveal mixed Candida infections.",{"question":130,"answer":131},"Why is Niger seed agar specific for Cryptococcus?","Cryptococcus produces laccase that oxidizes caffeic compounds to melanin = brown colonies. No other common clinical yeast produces laccase. Definitive Cryptococcus identification test.",{"question":133,"answer":134},"Why do fungi require longer incubation?","Fungi grow much slower — 1-4 weeks vs 18-48 hours for bacteria. Dimorphic fungi may take 2-4 weeks. Hold cultures minimum 4 weeks before reporting negative.",{"question":136,"answer":137},"What are the limitations of DTM?","False positives occur after 14 days as saprophytes eventually turn medium red. Positive = red color within 10-14 days. DTM is presumptive only — confirm by microscopy.",{"question":139,"answer":140},"What is the purpose of Tween 80 in cornmeal agar?","Reduces surface tension to enhance chlamydospore, pseudohyphae, and hyphae formation. C. albicans and C. dubliniensis produce terminal chlamydospores not seen in other Candida species.",{"question":142,"answer":143},"Which media for CSF with suspected Cryptococcus meningitis?","Niger seed agar + BHI or SABHI (non-selective). Never use cycloheximide media — Cryptococcus is sensitive. Perform India ink preparation in parallel.",[62],[146,152,159,163,167,171,176,181,185,189],{"slug":147,"name":39,"description":148,"image":149,"body":150,"postCount":151},"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.*",432,{"slug":153,"name":154,"description":155,"image":156,"body":157,"postCount":158},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",81,{"slug":160,"name":68,"description":161,"image":38,"body":38,"postCount":162},"sushmita-baniya","Author \u002F Contributor",32,{"slug":164,"name":165,"description":161,"image":38,"body":38,"postCount":166},"samikshya-acharya","Samikshya Acharya",20,{"slug":168,"name":169,"description":161,"image":38,"body":38,"postCount":170},"alisha-tripathi","Alisha Tripathi",6,{"slug":172,"name":173,"description":174,"image":38,"body":38,"postCount":175},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",10,{"slug":177,"name":178,"description":179,"image":38,"body":38,"postCount":180},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":182,"name":183,"description":161,"image":38,"body":38,"postCount":184},"srijana-khanal","Srijana Khanal",18,{"slug":186,"name":187,"description":179,"image":38,"body":38,"postCount":188},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":190,"name":83,"description":161,"image":38,"body":191,"postCount":192},"nisha-rijal","**Nisha Rijal** is a microbiologist and quality assurance specialist. She served for nearly 12 years as a microbiologist at the National Public Health Laboratory (NPHL), Nepal's national reference laboratory, and continues to work as a consultant microbiologist in international public health organization. ",51]