[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fFFsDAbWElXwQZp_IoDexYZvqCl9pUEdgTCofoXrVq80":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":90},[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":46,"related":48},"pathogenic-microbes-characteristics-pigments-production","Pigment-Producing Bacteria and Fungi: Colors, Compounds, and Clinical Significance","Pigment production helps identify bacteria at the bench and reflects their virulence mechanisms. Learn which organisms produce which colors, the compounds responsible, and what those pigments actually do in infection.",null,"Acharya Tankeshwar","2016-04-13","2026-07-12",false,"general-microbiology","A microbiologist spots bright red colonies on a MacConkey plate from a urinary catheter specimen. A burn nurse notices blue-green staining soaking through a wound dressing. A bacteriologist sees orange-tinged colonies from a neonatal blood culture. In each case, colour is not cosmetic — it is a diagnostic clue, sometimes the first one available before any identification test is run.\n\nMany pathogenic bacteria and fungi produce pigments as metabolic byproducts or as deliberate virulence tools. These pigments fall into two broad categories:\n\n- **Water-soluble pigments** that diffuse into the surrounding medium and can colour the agar, the specimen, or infected tissue (e.g. *Pseudomonas* pyocyanin staining wound dressings green)\n- **Water-insoluble pigments** that remain within or on the colony itself, giving characteristic colony colour (e.g. *Serratia marcescens* red colonies, *S. aureus* golden colonies)\n\nBeyond their diagnostic utility, many bacterial pigments are active virulence factors — interfering with immune clearance, generating oxidative stress in host tissue, or protecting the organism from phagocytosis. Understanding what a pigment is and what it does distinguishes a microbiologist who can identify an organism from one who understands why that organism behaves the way it does in a patient.\n\n## Quick Reference: Pigment-Producing Pathogens\n\n| Organism | Pigment Name | Colour | Solubility | Medium Where Best Seen | Clinical Significance |\n| --- | --- | --- | --- | --- | --- |\n| *Pseudomonas aeruginosa* | Pyocyanin | Blue-green | Water-soluble | Mueller-Hinton, blood agar | Green wound dressings, blue-green sputum in CF; virulence factor |\n| *Pseudomonas aeruginosa* | Pyoverdin (fluorescein) | Yellow-green fluorescent | Water-soluble | King's medium A\u002FB | Fluorescence under UV; iron-scavenging siderophore |\n| *Serratia marcescens* | Prodigiosin | Bright red | Water-insoluble | Nutrient agar, blood agar at room temp | Red colonies; hospital outbreaks; historical biowarfare agent |\n| *Staphylococcus aureus* | Staphyloxanthin | Golden-yellow | Water-insoluble | Blood agar | Golden colonies; antioxidant virulence factor protecting from neutrophil killing |\n| *Chromobacterium violaceum* | Violacein | Blue-violet | Water-insoluble | Blood agar, nutrient agar | Fatal septicaemia in immunocompromised; tropical pathogen |\n| *Streptococcus agalactiae* (GBS) | Granadaene | Orange-red | Water-insoluble | Granada medium (serum starch agar, anaerobic) | Neonatal sepsis pathogen; orange pigment aids identification |\n| *Porphyromonas gingivalis* | Iron porphyrin (micro-oxo bis-haem) | Black | Water-insoluble | Blood agar (5–7 days) | Periodontal disease; black colonies after prolonged incubation |\n| *Prevotella melaninogenica* | Melanin-like | Black-brown | Water-insoluble | Blood agar (prolonged incubation) | Oral and respiratory anaerobe; black pigment from haem degradation |\n| *Mycobacterium kansasii* | Carotenoids | Yellow (light-induced) | Water-insoluble | Löwenstein-Jensen medium | Runyon Group I photochromogen; NTM lung disease |\n| *Mycobacterium scrofulaceum* | Carotenoids | Yellow-orange (dark) | Water-insoluble | Löwenstein-Jensen medium | Runyon Group II scotochromogen; cervical lymphadenitis |\n| *Cryptococcus neoformans* | Melanin | Brown-black | Water-insoluble | Birdseed (Niger seed) agar | Rapid ID on birdseed agar; melanin protects from phagocytosis |\n| *Aspergillus fumigatus* | Melanin-like (conidial) | Blue-grey\u002Fgreen | Water-insoluble | Sabouraud agar | Conidial pigment aids immune evasion |\n| *Talaromyces marneffei* | Unknown red pigment | Red, diffusible | Water-soluble | Sabouraud dextrose agar | Diffusible red pigment into agar = key ID feature; AIDS-defining infection |\n\n### Pseudomonas species\n\n![Pseudomonas aeruginosa growing on Mueller Hinton Agar - Pseudomonas aeruginosa(green color) growing onMueller Hinton Agar](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FPseudomonas-aeruginosa-growing-on-Mueller-Hinton-Agar-300x195.jpg)Figure: *Pseudomonas aeruginosa* (green color) growing on Mueller Hinton Agar\n\n*Pseudomonas aeruginosa* is a leading bacterial pathogen in hospital settings and for immunocompromised patients (those with underlying conditions such as neutropenia, burns, or cystic fibrosis). *P. aeruginosa (aeruginosa, which derives from a Latin word denoting the color of copper rust)* produces a green fluorescent pigment (fluorescein\u002Fpyoverdin) and a blue pigment (pyocyanin). These pigments impart a greenish hue to the sputum of cystic fibrosis patients with a chronic lung infection, giving colonies and infected wound dressings a greenish-blue coloration.\n\n*P. aeruginosa* is usually recognized by the pigments it produces and the distinctive smell of cultures. When the culture is left at room temperature, pigment color becomes more intense.  A minority of strains are non-pigment producing. Other species of Pseudomonas (such as *P.fluorescens* and *P. putida*) also produce pigments.\n\n*P. aeruginosa* produces at least four pigments, of which two are clinically most important:\n\n**Pyocyanin** (blue-green) is a phenazine compound and a genuine virulence factor, not merely a colour. It:\n\n- Generates reactive oxygen species (ROS) directly in host tissue, causing oxidative damage to respiratory epithelium\n- Impairs mucociliary clearance — relevant to why *P. aeruginosa* establishes chronic infection in cystic fibrosis lungs\n- Inhibits the normal function of neutrophils and macrophages\n- The name comes from Greek: *pyo* (pus) + *cyan* (blue) — blue pus\n\n**Pyoverdin** (yellow-green, fluorescent under UV) is a siderophore — an iron-chelating molecule that scavenges iron from the host environment. Since iron is essential for bacterial growth and the host actively withholds it as a defence mechanism (nutritional immunity), pyoverdin gives *P. aeruginosa* a significant survival advantage in iron-limited tissue.\n\n**Diagnostic note:** King's medium A enhances pyocyanin production; King's medium B enhances pyoverdin. In resource-limited settings, Mueller-Hinton agar at room temperature is commonly used and usually shows adequate pigmentation. A minority of strains (mucoid strains in CF patients) produce little or no pigment.\n\n### Serratia marcescens\n\n![Red colored colonies of Serratia marcescens in MacConkey Agar (Source University of Maryland) - Red colored colonies ofSerratia marcescensin MacConkey Agar(Source University of Maryland)](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FRed-colored-colonies-of-Serratia-marcescens-in-MacConkey-Agar-300x225.jpg)Figure: Red colored colonies of Serratia marcescens in MacConkey Agar(Source University of Maryland)\n\n*Serratia marcescens* (mnemonic: *Mars is red*) is notable for its production of a bright **red pigment** called “prodigiosin”. Some strains produce a red pigment in [nutrient agar](\u002Fnutrient-agar-composition-preparation-uses\u002F) at room temperature\n\n**Prodigiosin** is a tripyrrole red pigment produced optimally at room temperature (25–28°C) but not at 37°C — which is why *Serratia* colonies from clinical specimens incubated at 37°C may appear white or pale pink, leading to misidentification. If you suspect *Serratia* and see non-pigmented colonies, subculture to room temperature incubation.\n\n**Clinical and historical significance:**\n\n- *Serratia marcescens* was historically considered a harmless saprophyte and its red pigment was used as a biological marker. In 1950, the US Navy conducted a secret experiment releasing *S. marcescens* over San Francisco Bay to simulate a biological warfare attack — subsequently linked to cases of *Serratia* bacteraemia in local hospitals. The experiment was kept classified for decades.\n- Today *Serratia* is a significant nosocomial pathogen, particularly in ICUs, causing UTIs, bacteraemia, and pneumonia in catheterised and ventilated patients. It is intrinsically resistant to ampicillin and first-generation cephalosporins due to an inducible AmpC beta-lactamase.\n- Red-pigmented colonies on MacConkey or blood agar from a hospital patient should prompt consideration of *Serratia* and a review of infection control implications.\n\n### Staphylococcus aureus\n\n*Staphylococcus aureus* (aureus = “golden”, Latin) produces multiple carotenoid pigments, one being golden-yellow pigment (Staphyloxanthin). When cultured on [sheep blood agar](\u002Fblood-agar-composition-preparation-uses-and-types-of-hemolysis\u002F), *S. aureus* can be differentiated from other beta-hemolytic cocci by elaboration of golden pigment. The pigment is less pronounced in young colonies.\n\n**Staphyloxanthin** is not merely a laboratory curiosity — it is a carotenoid virulence factor with a specific immune-evasion function. Its golden colour is incidental to its primary role: neutralising reactive oxygen species generated by neutrophils during the oxidative burst.\n\nWhen neutrophils engulf *S. aureus*, they deploy hydrogen peroxide and hypochlorite to kill the bacterium. Staphyloxanthin acts as an antioxidant, quenching these ROS and allowing *S. aureus* to survive inside phagosomes. Mutant *S. aureus* strains lacking staphyloxanthin (and therefore appearing white rather than golden) are significantly less virulent in animal models.\n\n**Practical point:** Golden pigment is best seen on blood agar after 24–48 hours at 37°C. Young colonies and some clinical strains may appear pale yellow rather than distinctly golden. MRSA strains do not lose their pigment — golden colonies with beta-haemolysis should still prompt MRSA screening in appropriate clinical contexts.\n\n### *Chromobacterium violaceum*\n\n*Chromobacterium violaceum* is a Gram-negative, facultatively anaerobic bacillus found in soil and water in tropical and subtropical regions — Southeast Asia, South Asia, Central and South America, and parts of Africa. It is rare but memorable because of two features: its striking blue-violet pigment and its capacity to cause rapidly fatal septicaemia.\n\n**Violacein** is the purple-blue pigment responsible for the organism's name and its unmistakable colony appearance. It is produced from tryptophan via the *vio* biosynthetic pathway and has demonstrated antibacterial, antifungal, antiparasitic, and antitumour properties in laboratory studies — making it a subject of pharmaceutical research.\n\n**Clinical significance:** Most infections follow skin exposure to contaminated water or soil, often through minor wounds. In healthy individuals, infection is usually localised — skin nodules or lymphadenitis. In immunocompromised patients (particularly those with chronic granulomatous disease, CGD), *C. violaceum* can disseminate rapidly, causing multiple liver abscesses, lung involvement, and septicaemia with high mortality. CGD patients are specifically vulnerable because *C. violaceum* resists killing by the defective NADPH oxidase pathway.\n\n**Laboratory recognition:** Violet-pigmented colonies on blood agar are virtually diagnostic. Non-pigmented variants exist but are rare. The organism is oxidase-positive and produces HCN (hydrogen cyanide).\n\n![Characteristics pigment production by Chromobacterium violaceum - Characteristics pigment production byChromobacterium violaceum](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fchromobacterium-violaceum.jpg)Figure: Characteristics pigment production by *Chromobacterium violaceum*\n\n**Group B Streptococcus**\n\nGroup B Streptococcus (GBS), the leading etiologic cause of severe neonatal bacterial infection, expresses an orange-red pigment, called granadaene.This orange pigment is produced by [*Streptococcus agalactiae*](\u002Fstreptococcus-agalactiae-gbs-properties-pathogenesis-diagnosis\u002F) when cultured on serum starch agar anaerobically.\n\n### Iron porphyrin of Porphyromonas gingivalis\n\n*Porphyromonas gingivalis* is a gram-negative anaerobic bacilli, which is implicated in the pathogenesis of certain forms of periodontal disease. Arginine- and lysine-specific gingipain proteases of *P. gingivalis* degrade hemoglobin to release iron (III) protoporphyrin IX, which is dimerized to form the micro-oxo bis-haem-containing black pigment of the organism.\n\n### Nontuberculous Mycobacteria\n\nThe genus *Mycobacterium* includes many bacteria that produce pigments. The **Runyon classification system** groups mycobacteria based on growth rate and pigment production in the presence of light or dark. *M. tuberculosi*s is a nonchromogen, i.e. it does not produce pigment in light or darkness\n\nFor the full Runyon classification of NTM based on pigment production and growth rate, see our detailed article on [atypical mycobacterial infections](\u002Fshort-notes-atypical-mycobacterial-infections\u002F).\n\n## Fungal Pathogens That Produce Pigments\n\n### *Cryptococcus neoformans* — Melanin\n\n*Cryptococcus neoformans* produces **melanin** from diphenolic substrates (L-DOPA, catecholamines) via the enzyme laccase. This melanin production has direct clinical relevance:\n\n- **Virulence:** Melanin protects the organism from oxidative killing by macrophages and from amphotericin B — the mechanism is thought to involve melanin binding to the drug, reducing its bioavailability within the cell\n- **Rapid identification:** **Birdseed (Niger seed) agar** contains caffeic acid as a substrate; *Cryptococcus* colonies appear brown-black within 3–5 days, distinguishing them from non-melanin-producing yeasts. This is particularly useful in resource-limited settings where molecular identification is unavailable\n- *C. gattii* also produces melanin and is identified the same way\n\n### *Aspergillus fumigatus* — Conidial Melanin\n\n*A. fumigatus* conidia (spores) are coated with a melanin-like pigment that gives them their characteristic blue-grey colour. This pigment:\n\n- Inhibits complement activation on the conidial surface\n- Impairs phagolysosomal acidification after phagocytosis by macrophages\n- Confers resistance to UV damage\n\nMutant *A. fumigatus* strains with white (unpigmented) conidia are significantly less virulent in animal models.\n\n### *Talaromyces marneffei* — Diffusible Red Pigment\n\nFormerly *Penicillium marneffei*, this thermally dimorphic fungus is an important AIDS-defining opportunistic infection in Southeast Asia and southern China. Its **diffusible red pigment** — which stains the surrounding agar red on Sabouraud dextrose agar at 25°C — is a key identification feature distinguishing it from other *Talaromyces\u002FPenicillium* species, most of which do not produce this pigment.\n\nAt 37°C it grows as a yeast-like form (intracellular, found in macrophages on bone marrow or tissue biopsy); at 25°C it grows as a mould producing the red pigment. This thermal dimorphism plus the red pigment is essentially diagnostic.\n\n## Pigments as Virulence Factors — Beyond Identification\n\nThe diagnostic utility of pigments is well known. Less often taught is that several of these pigments are not metabolic waste products — they are active weapons:\n\n| Pigment | Organism | Virulence Mechanism |\n| --- | --- | --- |\n| Pyocyanin | *P. aeruginosa* | Generates ROS; impairs mucociliary clearance; inhibits phagocyte function |\n| Pyoverdin | *P. aeruginosa* | Iron scavenging (siderophore); competes with host iron-binding proteins |\n| Staphyloxanthin | *S. aureus* | Antioxidant; quenches neutrophil ROS; promotes survival in phagosomes |\n| Melanin | *C. neoformans* | Resists oxidative killing; may reduce amphotericin B efficacy |\n| Melanin | *A. fumigatus* | Inhibits complement; impairs phagolysosomal killing |\n| Violacein | *C. violaceum* | Cytotoxic to host cells; may contribute to tissue destruction in septicaemia |\n| Granadaene | *S. agalactiae* | Haemolytic activity; damages host cell membranes |\n\nThe practical implication: organisms with pigment-based virulence mechanisms are often harder to clear with the immune system alone. *C. neoformans* meningitis requires prolonged antifungal therapy partly because melanin-coated cells in the CNS are well protected. *S. aureus* bacteraemia recurs partly because staphyloxanthin-expressing organisms survive within phagocytes.\n\n## How to Remember: Bacterial Pigments\n\n**Colour-organism pairs — the exam-tested ones:**\n\n- **Green-blue** = *Pseudomonas aeruginosa* (pyocyanin — think \"pyo\" = pus, \"cyan\" = blue)\n- **Bright red** = *Serratia marcescens* (prodigiosin — mnemonic: *Mars is red*, *Serratia* = *S*, like *Scarlet*)\n- **Golden yellow** = *Staphylococcus aureus* (aureus = gold in Latin — the name tells you)\n- **Blue-violet** = *Chromobacterium violaceum* (violaceum = violet in Latin — again, the name tells you)\n- **Orange-red** = *Streptococcus agalactiae* GBS (granadaene — think \"Granada\" in Spain, red terracotta)\n- **Black** = *Porphyromonas gingivalis* and *Prevotella melaninogenica* (both oral anaerobes, both black on blood agar after prolonged incubation)\n- **Brown-black** = *Cryptococcus neoformans* on birdseed agar (melanin)\n- **Diffusible red** = *Talaromyces marneffei* on Sabouraud agar at 25°C\n\n**Runyon classification quick memory — \"Photo, Scoto, Non, Fast\":**\n\n- **Photo**chromogen = colour in LIGHT only (*M. kansasii*)\n- **Scoto**chromogen = colour in DARK too (*M. scrofulaceum*)\n- **Non**chromogen = no colour (*M. avium* complex, MTB)\n- **Fast** grower = colonies in <7 days (*M. fortuitum*)\n\n## Key Exam Facts in One Table\n\n| Organism | Pigment | Colour | Key Exam Point |\n| --- | --- | --- | --- |\n| *P. aeruginosa* | Pyocyanin + pyoverdin | Blue-green | Pyocyanin is a virulence factor (ROS generation); pigment = water-soluble |\n| *Serratia marcescens* | Prodigiosin | Bright red | Only at room temperature (25–28°C); absent at 37°C — white colonies possible |\n| *S. aureus* | Staphyloxanthin | Golden-yellow | Carotenoid antioxidant; protects from neutrophil killing |\n| *Chromobacterium violaceum* | Violacein | Blue-violet | Tropical pathogen; fatal septicaemia in CGD; from tryptophan |\n| *S. agalactiae* (GBS) | Granadaene | Orange-red | Seen on Granada\u002Fserum starch agar anaerobically; haemolytic |\n| *P. gingivalis* | Iron porphyrin | Black | Needs prolonged incubation (5–7 days); periodontal pathogen |\n| *M. kansasii* | Carotenoid | Yellow (light only) | Runyon Group I photochromogen |\n| *M. scrofulaceum* | Carotenoid | Yellow-orange (dark and light) | Runyon Group II scotochromogen; cervical lymphadenitis |\n| *M. tuberculosis* | None | Non-pigmented | Nonchromogen — important negative |\n| *C. neoformans* | Melanin | Brown-black on birdseed agar | Laccase enzyme; virulence factor; rapid ID on Niger seed agar |\n| *A. fumigatus* | Conidial melanin | Blue-grey conidia | Immune evasion; white mutants less virulent |\n| *T. marneffei* | Unknown red | Diffusible red into agar | At 25°C only; AIDS-defining; dimorphic |\n\n**References**\n\n1. Madigan MT, Bender KS, Buckley DH, Sattley WM, Stahl DA. Brock Biology of Microorganisms. 16th ed. Pearson; 2021.\n2. Lau YL, Yuen KY, Lee CW, Chan CF. Chromobacterium violaceum septicemia in children. Pediatr Infect Dis J. 1995;14(6):479–483.\n3. Clauditz A, Resch A, Wieland KP, Peschel A, Götz F. Staphyloxanthin plays a role in the fitness of *Staphylococcus aureus* and its ability to cope with oxidative stress. Infect Immun. 2006;74(8):4950–4953. \u003Chttps:\u002F\u002Fdoi.org\u002F10.1128\u002FIAI.00204-06>\n4. Chai LY, Denning DW, Warn P. *Candida tropicalis* in human disease. Crit Rev Microbiol. 2010;36(4):282–298.\n5. Nosanchuk JD, Casadevall A. The contribution of melanin to microbial pathogenesis. Cell Microbiol. 2003;5(4):203–223. \u003Chttps:\u002F\u002Fdoi.org\u002F10.1046\u002Fj.1462-5822.2003.00268.x>\n6. Reyes-Lamothe R, Sherratt DJ. The bacterial cell cycle, chromosome inheritance and cell growth. Nat Rev Microbiol. 2019;17(8):467–478.\n7. Edenborough FM. Pseudomonas aeruginosa in cystic fibrosis — the battle continues. J R Soc Med. 2001;94(Suppl 40):3–8.\n8. Pitt TL. Serratia marcescens — clinical significance and epidemiology. J Hosp Infect. 1994;27(2):87–90.",[],[47],"microbial-curiosities",[49,56,62,69,76,83],{"slug":50,"title":51,"description":51,"seoTitle":38,"seoDescription":38,"author":52,"createdDate":53,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":54,"tags":55},"microbes-in-art-agar-art-competition","Microbes in Art: Agar Art Competition","Ashma Shrestha","2023-06-27",[],[47],{"slug":57,"title":58,"description":58,"seoTitle":38,"seoDescription":38,"author":52,"createdDate":59,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":60,"tags":61},"microbes-in-space-their-survival-and-importance","Microbes in Space: Their Survival and Importance","2023-06-23",[],[47],{"slug":63,"title":64,"description":64,"seoTitle":38,"seoDescription":38,"author":52,"createdDate":65,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":66,"tags":67},"extremophiles-their-types-and-applications","Extremophiles: Their Types and Applications","2023-06-11",[],[68,47],"environmental-factors",{"slug":70,"title":71,"description":72,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":73,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":74,"tags":75},"pathogenic-microbes-characteristics-smell-good-bad","Characteristic Smell of Bacteria and Fungi: A Clinical and Laboratory Guide","Bacteria and fungi produce distinctive volatile compounds that can aid identification at the bedside and bench. Learn which organisms smell of grapes, burnt chocolate, bleach, or soil — and why it matters clinically.","2016-10-17",[],[47],{"slug":77,"title":78,"description":79,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":80,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":81,"tags":82},"roles-medical-microbiologist","Roles of a Medical Microbiologist: Clinical, Laboratory, and Advisory Functions","What does a medical microbiologist actually do? From specimen management and AST to infection control and AMR stewardship — a practical guide for students and early-career laboratory professionals.","2013-09-10",[],[47],{"slug":84,"title":85,"description":86,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":87,"lastUpdatedDate":41,"draft":42,"category":43,"image":38,"faq":88,"tags":89},"funny-and-unusual-names-of-infectious-diseases-and-the-stories-behind-them","Funny and Unusual Names of Infectious Diseases And the Stories Behind Them","Why is chickenpox called chickenpox? What makes Q fever a Q? Who was Darling, and why does a fungal disease carry his name? The surprising stories behind infectious disease names — and what they teach you about the diseases themselves.","2013-08-10",[],[47],[91,97,103,108,112,116,121,126,130,134],{"slug":92,"name":39,"description":93,"image":94,"body":95,"postCount":96},"acharya-tankeshwar","Editor-in-chief","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Ftankeshwar-acharya-author-microbeonline.jpg","***Tankeshwar Acharya, MSc (Medical Microbiology)***\n\n*Tankeshwar Acharya is an Assistant Professor in the Department of Microbiology at Patan Academy of Health Sciences (PAHS), Nepal, where he has been teaching and practicing clinical microbiology for over 14 years. He is the founder of Microbe Online, one of the leading free microbiology education resources on the web, covering bacteriology, mycology, parasitology, immunology, and clinical laboratory diagnostics written from direct experience in both the classroom and the diagnostic laboratory.*",433,{"slug":98,"name":52,"description":99,"image":100,"body":101,"postCount":102},"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":104,"name":105,"description":106,"image":38,"body":38,"postCount":107},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":109,"name":110,"description":106,"image":38,"body":38,"postCount":111},"samikshya-acharya","Samikshya Acharya",20,{"slug":113,"name":114,"description":106,"image":38,"body":38,"postCount":115},"alisha-tripathi","Alisha Tripathi",6,{"slug":117,"name":118,"description":119,"image":38,"body":38,"postCount":120},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",10,{"slug":122,"name":123,"description":124,"image":38,"body":38,"postCount":125},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":127,"name":128,"description":106,"image":38,"body":38,"postCount":129},"srijana-khanal","Srijana Khanal",18,{"slug":131,"name":132,"description":124,"image":38,"body":38,"postCount":133},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":135,"name":136,"description":106,"image":38,"body":137,"postCount":138},"nisha-rijal","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]