[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$fgzY66NNr84vZMDeFakQfPwdmmhaY_v-X6Ok4xobit_E":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":264,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":329},[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},"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",{"title":33,"slug":34,"path":35},"Utilization Tests for Bacterial Identification","utilization-tests","\u002Futilization-tests\u002F",{"type":37,"data":38},"blog",{"slug":39,"title":40,"description":41,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":44,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"body":48,"faq":49,"commentsClosed":46,"tags":71,"related":73,"comments":260},"mycobacterium-overview","Mycobacterium: The Acid-Fast Bacteria and the Diseases They Cause","\u003Cp>What makes \u003Cem>Mycobacterium\u003C\u002Fem> unique: a waxy, mycolic-acid cell wall that makes these bacteria acid-fast, slow-growing, and hard to treat. An overview of tuberculosis, leprosy, and the atypical mycobacteria, and how they are diagnosed.\u003C\u002Fp>",null,"Acharya Tankeshwar","2026-08-06","2026-08-09",false,"bacteriology","A laboratory receives a sputum sample and applies a Gram stain, but the bacteria barely take up the dye. Only the Ziehl-Neelsen method, which uses hot carbol fuchsin to drive the stain in, finally colors them red, and then, even when washed with acid-alcohol, they keep the color. That single stubborn property, being acid-fast, identifies the sample containing *Mycobacterium*, and it comes from a cell wall unlike almost any other bacterium's: **thick, waxy, and built from mycolic acid.**\n\nThat waxy wall is the key to the entire genus. It is why mycobacteria stain as they do, why they grow so slowly, why they survive drying and disinfectants, why they resist many antibiotics, and why the diseases they cause, tuberculosis, leprosy, and others, are chronic and hard to cure. This page is the overview of the genus: what makes mycobacteria unique, how they are classified, and how they are diagnosed.\n\n## The waxy cell wall: the key to the whole genus\n\n*Mycobacterium* is a genus of rod-shaped bacteria defined by one extraordinary feature: a **cell wall extremely rich in lipids, above all mycolic acids**, long, waxy fatty acids that form a thick, hydrophobic (water-repelling) outer layer. Almost everything about mycobacteria follows from this wall.\n\n- **They are acid-fast.** The waxy wall resists ordinary stains, including the Gram stain. Special methods (Ziehl-Neelsen, or fluorescent auramine) use heat or strong reagents to drive dye into the cell, and once stained, the cell resists decolorization even by acid-alcohol. This property, holding the stain against acid, is called **acid-fastness**, and it is the single defining laboratory feature of the genus. (Because they stain so poorly by Gram, mycobacteria are often called \"neither Gram-positive nor Gram-negative,\" though structurally they are closer to Gram-positive.)\n- **They grow slowly.** The waxy wall makes nutrient uptake slow, so mycobacteria divide slowly, *M. tuberculosis* every 15 to 20 hours (versus 20 minutes for *E. coli*), which is why cultures take **weeks**, not days.\n- **They are environmentally tough.** The wall resists drying, acids, alkalis, and many disinfectants, which is why *M. tuberculosis* survives in dried sputum and airborne droplet nuclei, and why laboratories can use harsh chemicals to decontaminate specimens without killing the mycobacteria.\n- **They resist many antibiotics.** The wall is a barrier that keeps many drugs out, which is part of why mycobacterial infections need multiple drugs for long periods.\n- **They cause chronic, granulomatous disease.** Because they survive inside macrophages and are cleared only slowly, the body walls them off in **granulomas**, producing the slow, chronic diseases typical of the genus.\n\nIf you remember one thing about mycobacteria, remember the waxy mycolic-acid wall. It explains the staining, the slow growth, the toughness, the drug resistance, and the chronic disease, all at once.\n\n## General properties of mycobacteria\n\n- **Rod-shaped**, often slightly curved, sometimes beaded on staining.\n- **Aerobic** and **non-motile**, **non-spore-forming**, **non-capsulated**.\n- **Acid-fast** (the defining feature).\n- **Slow-growing** (most species), requiring enriched media such as **Lowenstein-Jensen (LJ) medium** and weeks of incubation. A minority (some atypical species) grow faster.\n- **Catalase-positive** (variably), and identified by growth characteristics and biochemical tests, or now by molecular methods.\n\n## How the mycobacteria are classified\n\nThe genus contains many species, grouped by the disease they cause and their laboratory behavior.\n\nThe Mycobacterium tuberculosis complex\n\nA group of closely related species that cause **tuberculosis**, chiefly:\n\n- ***Mycobacterium tuberculosis***: the main cause of human TB.\n- ***Mycobacterium bovis***: cattle TB, transmissible to humans (historically via unpasteurized milk); the source of the **BCG vaccine** strain.\n\nTuberculosis is covered on the [*Mycobacterium tuberculosis* and tuberculosis](https:\u002F\u002Fmicrobeonline.com\u002Fmycobacterium-tuberculosis\u002F) page.\n\n**Mycobacterium leprae**\n\n***Mycobacterium leprae*** causes **leprosy (Hansen's disease)**. It is unique in that it **cannot be grown on any artificial culture medium** (it is even more fastidious than the rest of the genus) and grows best at cooler body temperatures, which is why leprosy affects the skin, peripheral nerves, and cooler areas of the body. *M. leprae* is covered on the [leprosy](https:\u002F\u002Fmicrobeonline.com\u002Fintroduction-transmission-pathogenesis-and-lab-diagnosis-of-leprosy-hansens-disease\u002F) page.\n\n**Non-tuberculous (atypical) mycobacteria**\n\nThe **non-tuberculous mycobacteria (NTM)**, also called atypical or environmental mycobacteria, are a large group found in soil and water that occasionally cause disease, often in people with damaged lungs or weakened immunity. They were classically sorted into four **Runyon groups** by pigment production and growth rate:\n\n- **Group I, photochromogens** (pigment only in light), e.g. *M. kansasii*.\n- **Group II, scotochromogens** (pigment in dark or light), e.g. *M. scrofulaceum*.\n- **Group III, non-chromogens** (no pigment), e.g. *M. avium* complex (MAC).\n- **Group IV, rapid growers** (grow in under 7 days), e.g. *M. fortuitum*, *M. abscessus*.\n\nThese organisms are covered in detail on the [atypical mycobacteria](https:\u002F\u002Fmicrobeonline.com\u002Fshort-notes-atypical-mycobacterial-infections\u002F) page.\n\n## The medically important mycobacteria at a glance\n\n| Group | Key species | Disease | Article |\n| --- | --- | --- | --- |\n| *M. tuberculosis* complex | *M. tuberculosis*, *M. bovis* | Tuberculosis | [Tuberculosis](https:\u002F\u002Fmicrobeonline.com\u002Fmycobacterium-tuberculosis\u002F) |\n| *M. leprae* | *M. leprae* | Leprosy (Hansen's disease) | [Leprosy](https:\u002F\u002Fmicrobeonline.com\u002Fintroduction-transmission-pathogenesis-and-lab-diagnosis-of-leprosy-hansens-disease\u002F) |\n| Non-tuberculous (atypical) | *M. avium* complex, *M. kansasii*, *M. abscessus*, others | Lung, lymph node, skin, disseminated (often opportunistic) | [Atypical mycobacteria](https:\u002F\u002Fmicrobeonline.com\u002Fshort-notes-atypical-mycobacterial-infections\u002F) |\n\n## How mycobacteria are diagnosed\n\nBecause mycobacteria are slow-growing and acid-fast, their diagnosis uses a distinctive set of methods. This article gives the logic; for detailed method, result and interpretation check the given link for each method.\n\n- **Acid-fast staining (microscopy).** The first and fastest step: staining sputum or tissue to see acid-fast bacilli directly, by the [Ziehl-Neelsen technique](https:\u002F\u002Fmicrobeonline.com\u002Fziehl-neelsen-technique-principle-procedure-reporting\u002F) (hot method) or the more sensitive fluorescent [auramine-rhodamine stain](https:\u002F\u002Fmicrobeonline.com\u002Fauramine-rhodamine-fluorochrome-staining-principle-procedure-results-limitations\u002F). Microscopy is quick and cheap but needs many organisms to be positive, so a negative smear does not exclude TB.\n- **Culture.** The reference standard for confirmation, on solid media such as [Lowenstein-Jensen medium](https:\u002F\u002Fmicrobeonline.com\u002Fpreparation-uses-lowenstein-jensen-lj-medium\u002F) or in faster liquid systems. Culture is sensitive and allows drug-susceptibility testing, but is **slow** (weeks) because the organisms grow slowly.\n- **Molecular tests.** Nucleic acid amplification, above all [GeneXpert MTB\u002FRIF](https:\u002F\u002Fmicrobeonline.com\u002Fgenexpert-mtbrif-assay-principle-procedure-results-interpretations\u002F), detects *M. tuberculosis* DNA and rifampicin resistance directly from sputum in hours, transforming rapid TB diagnosis.\n- **Species identification.** [Biochemical methods](https:\u002F\u002Fmicrobeonline.com\u002Fkey-biochemical-methods-used-to-distinguish-mycobacterial-group\u002F) and molecular methods distinguish *M. tuberculosis* from the atypical mycobacteria.\n- **Immunological tests.** The [tuberculin skin test (Mantoux)](https:\u002F\u002Fmicrobeonline.com\u002Ftuberculin-skin-test-mauntoux-testprinciple-procedure-results-limitations\u002F) and interferon-gamma release assays (IGRAs) detect the immune response to TB, indicating infection (latent or active) but not proving active disease.\n\nThe full TB diagnostic workflow, how these fit together in practice, is on the [*M. tuberculosis* lab diagnosis](https:\u002F\u002Fmicrobeonline.com\u002Fmycobacterium-tuberculosis-lab-diagnosis\u002F) page.\n\n## Why mycobacterial infections are hard to treat\n\nTwo principles apply across the genus, and both come back to the biology above:\n\n- **Multiple drugs, for a long time.** The waxy wall and slow growth, plus the organism's ability to persist inside cells, mean single drugs fail and short courses relapse. TB and leprosy are treated with **combinations of drugs for months**, far longer than ordinary bacterial infections.\n- **Drug resistance is a major problem.** Because treatment is long, resistance develops when it is incomplete, giving rise to **multidrug-resistant TB (MDR-TB)** and worse. This is why supervised, complete, combination therapy is central to TB control.\n\n## How to remember\n\n**The waxy wall explains everything.** Mycolic acid makes the wall thick and waxy, and that one fact explains why mycobacteria are acid-fast (hold stain against acid), slow-growing (nutrients get in slowly), tough (survive drying and disinfectants), drug-resistant (barrier keeps drugs out), and chronic (walled off in granulomas). Learn the wall, and the genus follows.\n\n**Acid-fast is the signature.** They resist the Gram stain but hold a stain against acid decolorization, that's \"acid-fast.\" If a rod is acid-fast, think *Mycobacterium* first.\n\n**Three buckets.** The medically important mycobacteria split into three: the TB complex (*M. tuberculosis*, *M. bovis*), *M. leprae* (leprosy, can't be cultured), and the atypical\u002Fenvironmental ones (opportunists, Runyon groups). Three buckets cover the genus.\n\n**Leprae won't grow.** *M. leprae* is the one you cannot culture on any medium, and it likes cool body sites (skin, nerves). If a question says \"cannot be grown in the lab,\" think *M. leprae*.\n\n**Slow to grow, long to treat.** Slow growth means cultures take weeks and treatment takes months with multiple drugs. Slow bug, long therapy.\n\n## Key exam facts in one table\n\n| Fact | Detail |\n| --- | --- |\n| Genus feature | Waxy, mycolic-acid-rich cell wall |\n| Defining lab property | Acid-fast (resists decolorization by acid-alcohol) |\n| Staining | Ziehl-Neelsen (hot), auramine-rhodamine (fluorescent); poorly Gram-stained |\n| Growth | Slow (weeks); most need enriched media (LJ) |\n| TB complex | *M. tuberculosis*, *M. bovis* (BCG from *M. bovis*) |\n| Leprosy | *M. leprae*; cannot be cultured; cool body sites |\n| Atypical (NTM) | Environmental; Runyon groups I–IV; often opportunistic |\n| Environmental resistance | Survives drying, acids, alkalis, many disinfectants |\n| Key molecular test | GeneXpert MTB\u002FRIF (detects TB + rifampicin resistance in hours) |\n| Culture reference | Lowenstein-Jensen medium; liquid systems faster |\n| Immune test | Tuberculin (Mantoux) skin test; IGRA |\n| Treatment principle | Multiple drugs, months; resistance (MDR-TB) a major concern |\n\n## Where students get confused\n\n**\"Neither Gram-positive nor Gram-negative.\"** Mycobacteria stain poorly by Gram because of their waxy wall, so they are identified by acid-fast staining instead. Structurally they are closer to Gram-positive, but in practice you never rely on the Gram stain for them.\n\n**Acid-fast means holding stain against acid, not being an acid.** The term describes the cell keeping its stain when washed with acid-alcohol, because of the waxy wall, not the organism being acidic. This confuses many students constantly.\n\n**M. leprae cannot be cultured.** Unlike *M. tuberculosis* (slow but culturable on LJ), *M. leprae* grows on no artificial medium at all. Expecting a leprosy culture result is a mistake.\n\n**Slow growth is a diagnostic problem.** Because cultures take weeks, a negative early culture does not exclude TB, and rapid methods (smear, GeneXpert) are needed for timely decisions. Students underestimate how slow the culture is.\n\n**Atypical mycobacteria are not TB.** The non-tuberculous mycobacteria are environmental organisms causing largely opportunistic disease, and are treated differently from TB. A positive acid-fast smear is not automatically tuberculosis.\n\n**References**\n\n1. Tille, P. M. (2022). *Bailey & Scott's Diagnostic Microbiology* (15th ed.). Elsevier.\n2. Procop, G. W., et al. (2017). *Koneman's Color Atlas and Textbook of Diagnostic Microbiology* (7th ed.). Wolters Kluwer.\n3. Murray, P. R., Rosenthal, K. S., & Pfaller, M. A. (2020). *Medical Microbiology* (9th ed.). Elsevier.\n4. World Health Organization. (current). *Global Tuberculosis Report*. WHO.",[50,53,56,59,62,65,68],{"question":51,"answer":52},"\u003Cp>What makes \u003Cem>Mycobacterium\u003C\u002Fem> different from other bacteria?\u003C\u002Fp>","\u003Cp>Its cell wall is extremely rich in waxy lipids called mycolic acids. This waxy wall makes mycobacteria acid-fast, slow-growing, resistant to drying and disinfectants, and hard to treat, and it is the reason they cause chronic diseases such as tuberculosis and leprosy.\u003C\u002Fp>",{"question":54,"answer":55},"\u003Cp>What does \"acid-fast\" mean?\u003C\u002Fp>","\u003Cp>It means the organism keeps its stain even when washed with acid-alcohol. Because of their waxy wall, mycobacteria resist ordinary staining, but once stained by special methods (like Ziehl-Neelsen), they hold the color against acid decolorization. Acid-fastness is the defining laboratory feature of the genus.\u003C\u002Fp>",{"question":57,"answer":58},"\u003Cp>Why do mycobacteria grow so slowly?\u003C\u002Fp>","\u003Cp>Because their waxy wall slows the uptake of nutrients, so the cells divide slowly, \u003Cem>M. tuberculosis\u003C\u002Fem> about once every 15 to 20 hours. This is why mycobacterial cultures take weeks rather than days.\u003C\u002Fp>",{"question":60,"answer":61},"\u003Cp>What diseases do mycobacteria cause?\u003C\u002Fp>","\u003Cp>The main ones are tuberculosis (\u003Cem>M. tuberculosis\u003C\u002Fem> complex), leprosy (\u003Cem>M. leprae\u003C\u002Fem>), and a range of opportunistic infections caused by the non-tuberculous (atypical) mycobacteria, which live in soil and water.\u003C\u002Fp>",{"question":63,"answer":64},"\u003Cp>Why can't \u003Cem>Mycobacterium leprae \u003C\u002Fem>be grown in the laboratory?\u003C\u002Fp>","\u003Cp>\u003Cem>M. leprae\u003C\u002Fem> is so dependent on host cells that it grows on no artificial culture medium. It is studied using animal models (such as the mouse footpad and the armadillo). It also prefers cooler body temperatures, which is why leprosy affects the skin and peripheral nerves.\u003C\u002Fp>",{"question":66,"answer":67},"\u003Cp>Why does tuberculosis need several drugs for months?\u003C\u002Fp>","\u003Cp>Because the waxy wall and slow growth make mycobacteria hard to kill, and the organism can persist inside cells. Single drugs fail and short courses relapse, so treatment uses a combination of drugs for months. Incomplete treatment leads to drug resistance, including multidrug-resistant TB.\u003C\u002Fp>",{"question":69,"answer":70},"\u003Cp>Are all acid-fast bacteria tuberculosis?\u003C\u002Fp>","\u003Cp>No. A positive acid-fast smear shows a \u003Cem>Mycobacterium\u003C\u002Fem> (or a related acid-fast organism), but it could be tuberculosis, an atypical mycobacterium, or others. Further tests, culture and molecular methods, identify the exact species.\u003C\u002Fp>",[72],"mycobacteria",[74,104,135,164,182,199,207,252],{"slug":75,"title":76,"description":77,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":44,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"faq":78,"tags":103},"mycobacterium-tuberculosis","Mycobacterium tuberculosis and Tuberculosis: Pathogenesis, Clinical Disease, and Diagnosis","\u003Cp>How \u003Cem>Mycobacterium tuberculosis \u003C\u002Fem>causes tuberculosis: why it survives inside macrophages, how the granuloma leads to latent and active TB, the clinical picture, drug-resistant TB, and how TB is diagnosed.\u003C\u002Fp>",[79,82,85,88,91,94,97,100],{"question":80,"answer":81},"\u003Cp>How does Mycobacterium tuberculosis cause disease?\u003C\u002Fp>","\u003Cp>It is inhaled and engulfed by alveolar macrophages, but instead of being killed it survives inside them by blocking the macrophage's killing machinery. The immune system walls it off in structures called granulomas, which contain the infection but also shelter living organisms that can reactivate later.\u003C\u002Fp>",{"question":83,"answer":84},"\u003Cp>What is the difference between latent and active TB?\u003C\u002Fp>","\u003Cp>Latent TB means the organism is present but walled off by the immune system: the person is infected, has a positive tuberculin or IGRA test, but is not ill and not infectious. Active TB means the organism has broken out and is causing disease; pulmonary active TB is infectious.\u003C\u002Fp>",{"question":86,"answer":87},"\u003Cp>Is latent TB contagious?\u003C\u002Fp>","\u003Cp>No. Only active pulmonary or laryngeal TB spreads through the air. People with latent TB do not transmit the organism.\u003C\u002Fp>",{"question":89,"answer":90},"\u003Cp>Why does tuberculosis affect the upper lungs?\u003C\u002Fp>","\u003Cp>Because \u003Cem>M. tuberculosis\u003C\u002Fem> is a strict aerobe and prefers the most oxygen-rich parts of the lung, which are the upper lobes. This is where reactivation TB typically causes cavities.\u003C\u002Fp>",{"question":92,"answer":93},"\u003Cp>Why does TB treatment take so many months and so many drugs?\u003C\u002Fp>","\u003Cp>Because the organism grows slowly, survives inside cells, and lies dormant in granulomas, so it cannot be cleared quickly. Several drugs are given together for months. Using one drug or stopping early causes relapse and drug resistance.\u003C\u002Fp>",{"question":95,"answer":96},"\u003Cp>What is MDR-TB?\u003C\u002Fp>","\u003Cp>Multidrug-resistant TB is tuberculosis resistant to at least isoniazid and rifampicin, the two most important first-line drugs. It needs longer treatment with more toxic second-line drugs. It arises mainly from incomplete or improper treatment.\u003C\u002Fp>",{"question":98,"answer":99},"\u003Cp>What is the Ghon complex?\u003C\u002Fp>","\u003Cp>The combination of the initial lung lesion of primary TB plus the involved draining lymph node. It is the pathological hallmark of primary (first-time) tuberculosis infection.\u003C\u002Fp>",{"question":101,"answer":102},"\u003Cp>Does the BCG vaccine prevent tuberculosis?\u003C\u002Fp>","\u003Cp>BCG mainly protects young children against the severe forms of TB (miliary TB and TB meningitis). Its protection against adult pulmonary TB is variable, so it does not reliably prevent the common adult form.\u003C\u002Fp>",[72],{"slug":105,"title":106,"description":107,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":108,"lastUpdatedDate":44,"draft":46,"category":47,"image":42,"faq":109,"tags":134},"introduction-transmission-pathogenesis-and-lab-diagnosis-of-leprosy-hansens-disease","Leprosy (Hansen's Disease): Why the Immune Response Decides Tuberculoid vs Lepromatous","\u003Cp>How\u003Cem> Mycobacterium leprae\u003C\u002Fem> causes leprosy, why the strength of cell-mediated immunity decides whether disease is tuberculoid or lepromatous, how it damages nerves, and how the slit-skin smear and lepromin test are used.\u003C\u002Fp>","2012-05-15",[110,113,116,119,122,125,128,131],{"question":111,"answer":112},"\u003Cp>What causes leprosy?\u003C\u002Fp>","\u003Cp>\u003Cem>Mycobacterium leprae\u003C\u002Fem>, a slow-growing acid-fast bacterium. It mainly infects the skin and peripheral nerves, preferring the cooler parts of the body, and it cannot be grown on any artificial laboratory medium.\u003C\u002Fp>",{"question":114,"answer":115},"\u003Cp>Why does leprosy have two very different forms?\u003C\u002Fp>","\u003Cp>Because the form depends on the patient's cell-mediated immunity. Strong immunity produces tuberculoid leprosy (few lesions, few bacilli); weak immunity produces lepromatous leprosy (many lesions, many bacilli). The same organism causes both.\u003C\u002Fp>",{"question":117,"answer":118},"\u003Cp>Is leprosy highly contagious?\u003C\u002Fp>","\u003Cp>No. Most people are naturally immune. Transmission requires prolonged close contact with an untreated multibacillary patient, mainly through nasal droplets, and patients become non-infectious soon after starting treatment.\u003C\u002Fp>",{"question":120,"answer":121},"\u003Cp>Why is nerve damage the main problem in leprosy?\u003C\u002Fp>","\u003Cp>Because \u003Cem>M. leprae\u003C\u002Fem> infects the Schwann cells of peripheral nerves, and the resulting nerve damage causes loss of sensation. Injuries and burns then go unnoticed, leading to ulcers, deformity, and disability. Treating the infection does not reverse established nerve damage, so early treatment is essential.\u003C\u002Fp>",{"question":123,"answer":124},"\u003Cp>How is leprosy diagnosed?\u003C\u002Fp>","\u003Cp>Mainly clinically (a skin patch with loss of sensation, or a thickened peripheral nerve) supported by a slit-skin smear stained with a modified Ziehl-Neelsen method to show acid-fast bacilli, and by skin or nerve biopsy. \u003Cem>M. leprae\u003C\u002Fem> cannot be cultured, so culture is not used.\u003C\u002Fp>",{"question":126,"answer":127},"\u003Cp>What is the lepromin test used for?\u003C\u002Fp>","\u003Cp>To determine the type of leprosy and assess prognosis, not to diagnose it. It is positive in tuberculoid leprosy (strong immunity) and negative in lepromatous leprosy (weak immunity).\u003C\u002Fp>",{"question":129,"answer":130},"\u003Cp>How is leprosy treated?\u003C\u002Fp>","\u003Cp>With multidrug therapy combining dapsone, rifampicin, and clofazimine, given for a period that depends on the type of leprosy. It is curable, and early treatment prevents the nerve damage that causes long-term disability.\u003C\u002Fp>",{"question":132,"answer":133},"\u003Cp>Why can't Mycobacterium leprae be grown in the laboratory?\u003C\u002Fp>","\u003Cp>It is so dependent on host cells that it grows on no artificial medium or cell culture. It is propagated only in the footpads of mice or in nine-banded armadillos, and it divides very slowly (about once every 14 days).\u003C\u002Fp>",[72],{"slug":136,"title":137,"description":138,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":139,"lastUpdatedDate":140,"draft":46,"category":47,"image":42,"faq":141,"tags":163},"short-notes-atypical-mycobacterial-infections","Non-Tuberculous (Atypical) Mycobacteria: The Diseases, the Runyon Groups, and When to Suspect Them","\u003Cp>The non-tuberculous (atypical) mycobacteria: environmental organisms that cause lung disease, lymphadenitis, skin infections, and disseminated disease, how they differ from TB, and the Runyon classification.\u003C\u002Fp>","2014-11-07","2026-08-12",[142,145,148,151,154,157,160],{"question":143,"answer":144},"\u003Cp>What are non-tuberculous (atypical) mycobacteria?\u003C\u002Fp>","\u003Cp>All the mycobacteria except the \u003Cem>M. tuberculosis\u003C\u002Fem> complex and \u003Cem>M. leprae\u003C\u002Fem>. They are environmental organisms found in soil and water that usually cause disease only in people with damaged lungs, weakened immunity, or broken skin. They are also called atypical, environmental, or MOTT.\u003C\u002Fp>",{"question":146,"answer":147},"\u003Cp>How are NTM different from tuberculosis?\u003C\u002Fp>","\u003Cp>NTM come from the environment rather than from other people and do not spread person to person. They are often opportunistic, and a positive culture may reflect harmless colonization rather than disease, so it must be interpreted clinically. TB, by contrast, spreads between people and is almost always significant when isolated.\u003C\u002Fp>",{"question":149,"answer":150},"\u003Cp>What diseases do NTM cause?\u003C\u002Fp>","\u003Cp>Four main patterns: chronic lung disease (mainly MAC and \u003Cem>M. kansasii\u003C\u002Fem>), cervical lymphadenitis in children (\u003Cem>M. scrofulaceum\u003C\u002Fem>, MAC), skin and soft-tissue infection after water exposure or trauma (\u003Cem>M. marinum\u003C\u002Fem>, \u003Cem>M. ulcerans\u003C\u002Fem>, rapid growers), and disseminated disease in the severely immunocompromised (MAC in advanced AIDS).\u003C\u002Fp>",{"question":152,"answer":153},"\u003Cp>What is the Runyon classification?\u003C\u002Fp>","\u003Cp>A laboratory scheme that sorts NTM by growth rate and pigment: photochromogens (pigment in light), scotochromogens (pigment even in the dark), non-chromogens (no pigment), and rapid growers (colonies in under 7 days). It is being replaced by molecular identification but remains a common exam topic.\u003C\u002Fp>",{"question":155,"answer":156},"\u003Cp>What is fish-tank granuloma?\u003C\u002Fp>","\u003Cp>A skin infection caused by \u003Cem>Mycobacterium marinum\u003C\u002Fem>, acquired from contact with aquariums or swimming pools. It causes nodular skin lesions at the site of a minor injury, which can spread in a line up the arm along the lymphatics.\u003C\u002Fp>",{"question":158,"answer":159},"\u003Cp>What is Buruli ulcer?\u003C\u002Fp>","\u003Cp>A destructive skin and soft-tissue ulcer caused by \u003Cem>Mycobacterium ulcerans\u003C\u002Fem>. Its toxin, mycolactone, destroys tissue and numbs the area, so the ulcer is characteristically painless despite being large. It is the third most common mycobacterial disease worldwide after TB and leprosy.\u003C\u002Fp>",{"question":161,"answer":162},"\u003Cp>Why is a positive NTM culture sometimes ignored?\u003C\u002Fp>","\u003Cp>Because NTM are everywhere in the environment and can colonize the airways or contaminate a sample without causing disease. A single positive culture may not mean infection, so doctors look for repeated positive cultures plus compatible symptoms and imaging before treating.\u003C\u002Fp>",[72],{"slug":165,"title":166,"description":167,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":168,"lastUpdatedDate":140,"draft":46,"category":169,"image":42,"faq":170,"tags":180},"ziehl-neelsen-technique-principle-procedure-reporting","Ziehl-Neelsen Staining: Principle, Procedure, Grading, and Interpretation","The hot ZN acid-fast staining method step by step, why mycolic acid holds carbol fuchsin against acid-alcohol, WHO smear grading from scanty to 3+, and what a negative smear does and does not rule out in TB.","2013-12-06","staining-techniques",[171,174,177],{"question":172,"answer":173},"Why does Ziehl-Neelsen staining require heat while other staining techniques do not?","\u003Cp>Mycobacteria have a cell wall rich in mycolic acids, long-chain fatty acids that make the wall waxy, hydrophobic, and impermeable to most dyes at room temperature. Heat acts as a mordant by disrupting this waxy barrier and allowing carbol fuchsin to penetrate the cell wall. Once inside, the stain is held so tightly by the mycolic acids that even acid-alcohol, one of the strongest decolorizers used in microbiology, cannot remove it. This is why the stain is called 'acid-fast',  the organisms hold fast to the dye even after acid treatment.\u003C\u002Fp>",{"question":175,"answer":176},"How is an AFB smear graded and what does the grade mean clinically?","\u003Cp>AFB smears are graded using the WHO\u002FIUATLD scale: No AFB seen (after examining 300 fields); Scanty: 1-9 AFB per 100 fields (report exact count and request repeat); 1+: 10-99 AFB per 100 fields; 2+: 1-10 AFB per field in at least 50 fields; 3+: more than 10 AFB per field in at least 20 fields. Higher grades indicate greater organism burden and greater infectiousness. Grade is recorded at treatment initiation and at months 2, 5, and 6 to monitor bacteriological response. Conversion from positive to negative smear during treatment indicates therapeutic response.\u003C\u002Fp>",{"question":178,"answer":179},"What is the difference between Ziehl-Neelsen and Kinyoun (cold) acid-fast staining?","\u003Cp>Both methods use carbolfuchsin as the primary stain and acid-alcohol for decolorization, but they differ in how the dye penetrates the mycobacterial cell wall. Ziehl-Neelsen uses heat (the hot technique), the slide is steamed to drive the dye through the waxy cell wall. Kinyoun's cold technique achieves penetration without heat by increasing the concentration of both carbolfuchsin and phenol and incorporating a wetting agent (Triton X-100 or similar). The results are equivalent. Kinyoun is preferred where open flames are unsafe or inconvenient, and for partial acid-fast organisms (Nocardia, Cryptosporidium) where lower decolorizer concentrations are needed.\u003C\u002Fp>",[181,72],"bacterial-staining-technique",{"slug":183,"title":184,"description":185,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":186,"lastUpdatedDate":187,"draft":46,"category":169,"image":42,"faq":188,"tags":198},"auramine-rhodamine-fluorochrome-staining-principle-procedure-results-limitations","Auramine-Rhodamine Fluorochrome Staining: Principle, Procedure, and Results","Auramine-rhodamine is a WHO-recommended fluorochrome stain for detecting acid-fast bacilli, which is more sensitive than Ziehl-Neelsen and faster to screen. Learn the Truant method procedure, results grading, and when to confirm with ZN staining.","2015-04-03","2026-08-02",[189,192,195],{"question":190,"answer":191},"Why is auramine-rhodamine staining more sensitive than Ziehl-Neelsen for detecting acid-fast bacilli?","Auramine-rhodamine allows smear screening at 250x or 400x magnification — compared to 1,000x oil immersion required for ZN staining. At lower magnification, a much larger area of the slide can be examined per unit time (3-5 minutes vs 15-20 minutes per slide). This means more of the smear is examined, increasing the chance of detecting paucibacillary specimens. Studies consistently show auramine-rhodamine detects approximately 10% more positive cases than ZN in direct smear microscopy, which is why WHO recommends it as the preferred method where fluorescence microscopy is available.",{"question":193,"answer":194},"What is the two-step workflow for auramine-rhodamine results?","Positive auramine-rhodamine results should be confirmed by ZN staining of the same slide, as fluorescence artefacts (dust, fibres, non-AFB structures) can occasionally give false-positive fluorescence. Negative auramine-rhodamine results require examination of the minimum required number of fields before reporting — at 200-250x this is typically 30-100 fields. In high-suspicion patients, a negative fluorochrome result should prompt ZN confirmation and repeat specimen collection, as the minimum detection threshold for smear microscopy (approximately 5,000-10,000 AFB\u002FmL) means culture is more sensitive than any smear method.",{"question":196,"answer":197},"Can auramine-rhodamine staining detect organisms other than mycobacteria?","Yes. A modified fluorochrome method using a weaker decolouriser (0.5% sulphuric acid instead of 3% acid-alcohol) detects partially acid-fast organisms including Cryptosporidium parvum, Cyclospora cayetanensis, and Isospora belli oocysts in stool specimens, and Nocardia species in respiratory or wound specimens. These organisms share a partial acid-fast property with mycobacteria. The oocysts appear as bright yellow-orange fluorescent structures against a dark background. This application requires the modified decolouriser — the standard 3% acid-alcohol used for TB smears will over-decolourise these weakly acid-fast organisms.",[181,72],{"slug":200,"title":201,"description":202,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":203,"lastUpdatedDate":45,"draft":46,"category":204,"image":42,"faq":205,"tags":206},"preparation-uses-lowenstein-jensen-lj-medium","Löwenstein-Jensen (LJ) Medium: Principle, Preparation, Uses, and Colony Characteristics","\u003Cp>Löwenstein-Jensen (LJ) medium is the standard solid culture medium for \u003Cem>Mycobacterium tuberculosis.\u003C\u002Fem> Learn its principle, preparation by inspissation, colony characteristics of\u003Cem> M. tuberculosis\u003C\u002Fem> and NTM, and how LJ compares to MGIT liquid culture.\u003C\u002Fp>","2016-04-29","culture-media",[],[72],{"slug":208,"title":209,"description":210,"seoTitle":211,"seoDescription":42,"author":43,"createdDate":212,"lastUpdatedDate":213,"draft":46,"category":47,"image":42,"faq":214,"tags":251},"genexpert-mtbrif-assay-principle-procedure-results-interpretations","GeneXpert MTB\u002FRIF: How to Read the Result and What to Do Next","Semi-quantitative grades, probe-level RIF calls, error codes, and the traps: why a \"RIF resistance detected\" result still needs confirmation and why \"not detected\" never rules out TB.","GeneXpert MTB\u002FRIF Assay: Principle, Procedure, Results, and Interpretation","2016-01-04","2026-07-25",[215,218,221,224,227,230,233,236,239,242,245,248],{"question":216,"answer":217},"Does GeneXpert detect isoniazid resistance?","No. The assay reads only the rpoB gene and reports rifampicin resistance. Isoniazid resistance requires a line probe assay, targeted sequencing, or phenotypic DST. Because rifampicin resistance usually co-exists with isoniazid resistance, a positive RIF result is used as a marker for probable MDR-TB, but it is an inference, not a measurement.",{"question":219,"answer":220},"Can GeneXpert replace sputum smear microscopy and culture?","It replaces smear microscopy as the initial diagnostic test under current WHO guidance. It does not replace culture. Culture is still needed for phenotypic drug susceptibility testing, genotyping, detection of non-tuberculous mycobacteria, and confirmation of cure.",{"question":222,"answer":223},"What does \"MTB detected, trace\" mean?","It means the multicopy IS6110 or IS1081 targets were detected but rpoB was essentially unread, so bacillary load is at the very bottom of the assay's range and rifampicin resistance cannot be reported. In children, people living with HIV, and extrapulmonary specimens, trace counts as bacteriological confirmation of TB. In previously treated adults it should be repeated on a fresh specimen, because it may represent residual DNA from cured disease.",{"question":225,"answer":226},"Why does the report say \"very low\" or \"high\"?","That is the semi-quantitative grade, derived from the cycle threshold of the first rpoB probe to bind. It estimates bacillary load, which relates to infectiousness, to how reliable the rifampicin call is, and to the likelihood that a weak positive represents old rather than active disease.",{"question":228,"answer":229},"What is the difference between Invalid and Error?","Invalid means the Sample Processing Control failed: something about the specimen, usually inhibitors or inadequate processing, prevented a trustworthy result. Repeat with a new specimen. Error means the run aborted on an instrument or cartridge fault, most often a failed probe check or a pressure problem. Repeat with a new cartridge.",{"question":231,"answer":232},"Can a GeneXpert result be falsely positive for rifampicin resistance?","Yes. The assay infers resistance from a probe failing to bind, not from reading the mutation, so silent mutations and non-resistance-conferring polymorphisms in the RRDR are reported as resistance. False positives are most common on paucibacillary specimens. This is why a positive result should be confirmed by a line probe assay, targeted sequencing, or phenotypic DST, while treatment is started in parallel.",{"question":234,"answer":235},"Can GeneXpert miss rifampicin resistance?","Yes. Approximately 5% of rifampicin-resistant strains carry mutations outside the 81-bp RRDR. These leave all probes binding normally and are reported as susceptible.",{"question":237,"answer":238},"How long does the GeneXpert MTB\u002FRIF test take?","Under two hours from loading. The standard Xpert MTB\u002FRIF run is about 112 minutes; Xpert Ultra is faster at roughly 65 to 87 minutes. Specimen preparation adds about 15 to 20 minutes before loading.",{"question":240,"answer":241},"Can GeneXpert be used on non-sputum specimens?","Yes. WHO endorses its use on CSF, lymph node aspirate and tissue, gastric aspirate, nasopharyngeal aspirate, and stool, with sensitivity varying by specimen type. It is strongly recommended as the initial test in suspected TB meningitis. Sensitivity is lowest in pleural fluid.",{"question":243,"answer":244},"Can GeneXpert be used to monitor response to treatment?","No. It detects DNA from both living and dead bacilli, so it can remain positive for months in patients who are responding well. Smear microscopy and culture are used for treatment monitoring.",{"question":246,"answer":247},"Does a positive GeneXpert distinguish M. tuberculosis from M. bovis?","No. It detects the M. tuberculosis complex as a group and cannot separate M. tuberculosis, M. bovis, M. africanum, or BCG. Species-level identification requires culture-based methods.",{"question":249,"answer":250},"Is a biological safety cabinet required to run GeneXpert?","Specimen manipulation before the 15-minute inactivation step should be done in a Class II BSC where available. After that step the cartridge is closed and the risk is minimal. WHO permits Xpert testing at the same biosafety level as direct sputum smear microscopy in settings without a BSC.",[72],{"slug":253,"title":254,"description":254,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":255,"lastUpdatedDate":256,"draft":46,"category":257,"image":42,"faq":258,"tags":259},"key-biochemical-methods-used-to-distinguish-mycobacterial-group","Biochemical Tests to identify Mycobacteria, NTM","2013-07-22","2026-07-04","biochemical-tests",[],[72],{"enabled":261,"threads":262,"total":263},true,[],0,[265,271,278,285,291,296,302,307,313,316,323],{"slug":266,"name":43,"description":267,"image":268,"body":269,"postCount":270},"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.*",468,{"slug":272,"name":273,"description":274,"image":275,"body":276,"postCount":277},"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":279,"name":280,"description":281,"image":282,"body":283,"postCount":284},"sushmita-baniya","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":286,"name":287,"description":281,"image":288,"body":289,"postCount":290},"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":292,"name":293,"description":281,"image":42,"body":294,"postCount":295},"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":297,"name":298,"description":299,"image":42,"body":300,"postCount":301},"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":303,"name":304,"description":305,"image":42,"body":42,"postCount":306},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":308,"name":309,"description":281,"image":310,"body":311,"postCount":312},"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.",17,{"slug":314,"name":315,"description":305,"image":42,"body":42,"postCount":306},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":317,"name":318,"description":319,"image":320,"body":321,"postCount":322},"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":324,"name":325,"description":326,"image":327,"body":328,"postCount":306},"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.",[330,337,343,348,353,358,361,365,369,374,378,383,387,392,397,401,405,409,414,419,423,427,431,436,440,444,448,452,457,462,466,470,474,478,482,486,490,494,498,502,506,510,514,518,522,526,530,534,539,543,547,551,555,558,562,566,570,574,578,582,586,590,594,598,602,606,610,614,617,621],{"slug":331,"name":332,"description":333,"image":334,"body":335,"postCount":336},"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":338,"name":339,"description":340,"image":42,"body":341,"postCount":342},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":344,"name":345,"description":346,"image":42,"body":42,"postCount":347},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",11,{"slug":349,"name":350,"description":351,"image":42,"body":42,"postCount":352},"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":354,"name":355,"description":356,"image":42,"body":42,"postCount":357},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":72,"name":359,"description":360,"image":42,"body":42,"postCount":347},"Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":362,"name":363,"description":364,"image":42,"body":42,"postCount":347},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":366,"name":367,"description":368,"image":42,"body":42,"postCount":342},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":370,"name":371,"description":372,"image":42,"body":42,"postCount":373},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":375,"name":376,"description":377,"image":42,"body":42,"postCount":336},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":379,"name":380,"description":381,"image":42,"body":42,"postCount":382},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",21,{"slug":384,"name":385,"description":386,"image":42,"body":42,"postCount":357},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":388,"name":389,"description":390,"image":42,"body":42,"postCount":391},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":393,"name":394,"description":395,"image":42,"body":42,"postCount":396},"specimen-collection-transport","Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":398,"name":399,"description":400,"image":42,"body":42,"postCount":382},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",{"slug":402,"name":403,"description":42,"image":42,"body":404,"postCount":295},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":406,"name":407,"description":42,"image":42,"body":408,"postCount":391},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":410,"name":411,"description":412,"image":42,"body":413,"postCount":373},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":415,"name":416,"description":417,"image":42,"body":418,"postCount":295},"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":420,"name":421,"description":422,"image":42,"body":42,"postCount":295},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":424,"name":425,"description":426,"image":42,"body":42,"postCount":295},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":428,"name":429,"description":430,"image":42,"body":42,"postCount":295},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":432,"name":433,"description":434,"image":42,"body":42,"postCount":435},"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":437,"name":438,"description":439,"image":42,"body":42,"postCount":373},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":441,"name":442,"description":443,"image":42,"body":42,"postCount":352},"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":445,"name":446,"description":447,"image":42,"body":42,"postCount":295},"pipette","Pipette","Posts related with Pipette. ",{"slug":449,"name":450,"description":451,"image":42,"body":42,"postCount":357},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":453,"name":454,"description":455,"image":42,"body":42,"postCount":456},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":458,"name":459,"description":460,"image":42,"body":42,"postCount":461},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":463,"name":464,"description":465,"image":42,"body":42,"postCount":352},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",{"slug":467,"name":468,"description":469,"image":42,"body":42,"postCount":357},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":471,"name":472,"description":473,"image":42,"body":42,"postCount":301},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":475,"name":476,"description":477,"image":42,"body":42,"postCount":382},"bacterial-culture-media","Bacterial Culture Media","Posts related to Bacterial Culture Media. ",{"slug":479,"name":480,"description":481,"image":42,"body":42,"postCount":295},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":483,"name":484,"description":485,"image":42,"body":42,"postCount":352},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":487,"name":488,"description":489,"image":42,"body":42,"postCount":391},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":491,"name":492,"description":493,"image":42,"body":42,"postCount":456},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":495,"name":496,"description":497,"image":42,"body":42,"postCount":461},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":499,"name":500,"description":501,"image":42,"body":42,"postCount":373},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":503,"name":504,"description":505,"image":42,"body":42,"postCount":352},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":507,"name":508,"description":509,"image":42,"body":42,"postCount":301},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":511,"name":512,"description":513,"image":42,"body":42,"postCount":373},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":515,"name":516,"description":42,"image":42,"body":42,"postCount":517},"haemophilus","Haemophilus",3,{"slug":519,"name":520,"description":521,"image":42,"body":42,"postCount":461},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":523,"name":524,"description":525,"image":42,"body":42,"postCount":342},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",{"slug":527,"name":528,"description":529,"image":42,"body":42,"postCount":336},"fungal-diagnostics","Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":531,"name":532,"description":533,"image":42,"body":42,"postCount":352},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":535,"name":536,"description":537,"image":42,"body":538,"postCount":295},"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":540,"name":541,"description":542,"image":42,"body":42,"postCount":357},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":544,"name":545,"description":546,"image":42,"body":42,"postCount":295},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":548,"name":549,"description":550,"image":42,"body":42,"postCount":295},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":552,"name":553,"description":554,"image":42,"body":42,"postCount":306},"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":181,"name":556,"description":557,"image":42,"body":42,"postCount":391},"Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":559,"name":560,"description":561,"image":42,"body":42,"postCount":290},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":563,"name":564,"description":565,"image":42,"body":42,"postCount":347},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",{"slug":567,"name":568,"description":569,"image":42,"body":42,"postCount":352},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":571,"name":572,"description":573,"image":42,"body":42,"postCount":461},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":575,"name":576,"description":577,"image":42,"body":42,"postCount":357},"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":579,"name":580,"description":581,"image":42,"body":42,"postCount":517},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":583,"name":584,"description":585,"image":42,"body":42,"postCount":352},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":587,"name":588,"description":589,"image":42,"body":42,"postCount":373},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":591,"name":592,"description":593,"image":42,"body":42,"postCount":461},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":595,"name":596,"description":597,"image":42,"body":42,"postCount":352},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":599,"name":600,"description":601,"image":42,"body":42,"postCount":373},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":603,"name":604,"description":605,"image":42,"body":42,"postCount":295},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":607,"name":608,"description":609,"image":42,"body":42,"postCount":373},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":611,"name":612,"description":613,"image":42,"body":42,"postCount":352},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":615,"name":616,"description":42,"image":42,"body":42,"postCount":306},"colorimetric-assay","Colorimetric Assay ",{"slug":618,"name":619,"description":620,"image":42,"body":42,"postCount":352},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":622,"name":623,"description":42,"image":42,"body":42,"postCount":517},"blood-and-immune-cells","Blood and Immune Cells"]