[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$f8KejLBl5X_J_BHtHJ2goJZorFkCbng1fLIV0MPB6wMc":32,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":146},[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":55,"related":57},"procedure-hanging-drop-method-test-bacterial-motility","Hanging Drop Method: Principle, Procedure & How to Read True Motility","Step-by-step hanging drop technique — how to tell true motility from Brownian movement and passive drift, plus its real use in flagging cholera and ruling out Bacillus anthracis.",null,"Acharya Tankeshwar","2014-08-03","2026-07-18",false,"bacteriology","The hanging drop method is a wet-mount technique used to observe **living, unstained bacteria** moving freely in a suspended drop of broth culture. It is the classic direct method for distinguishing genuinely motile organisms from those that only appear to move.\n\n![](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FHanging-Drop-Technique.png)Figure: Hanging Drop Technique\n\n## Why It Matters\n\nWhen a patient presents with sudden, profuse rice-watery stool during a suspected cholera outbreak, a hanging drop prep can give a presumptive answer in minutes — long before culture results are back. *Vibrio cholerae* shows a distinctive **darting motility**: fast, erratic, shooting-star-like movement that looks visibly different from the slower, purposeful motility of typical Enterobacteriaceae. In an outbreak setting, that visual alone is often enough to start oral rehydration and alert public health authorities while confirmatory culture is still pending.\n\nThe same basic technique also plays a role in a very different, high-stakes scenario: distinguishing *Bacillus anthracis* from its close, harmless relatives in the *B. cereus* group. True *B. anthracis* is classically **nonmotile**, while *B. cereus* and most other *Bacillus* species are motile — so a quick motility check is one of the first practical steps in ruling anthrax in or out when a concerning *Bacillus* isolate turns up, well before more specialized confirmatory testing is run.\n\nAnd on the obstetric\u002Fneonatal side: *Listeria monocytogenes* shows a characteristic **tumbling motility** in hanging drop preps from overnight broth culture — a useful clue in suspected listerial meningitis or perinatal infection workups.\n\n## Principle\n\nIn a true hanging drop, the culture drop hangs freely from the coverslip with no pressure or compression from above — unlike a standard wet mount, where the coverslip presses directly onto the slide. That free-hanging environment is what allows organisms to move naturally and lets you reliably tell apart three different things that can all *look* like motion under the microscope:\n\n| Movement type | What it looks like | What it means |\n| --- | --- | --- |\n| **True motility** | Organisms actively change position relative to *each other* — purposeful, directional | Genuinely motile organism |\n| **Brownian movement** | Organisms jiggle or vibrate in place but stay in the same position relative to one another | Not motility — molecular bombardment by water molecules, seen in motile and nonmotile organisms alike |\n| **Passive\u002Fconvectional drift** | The entire field drifts uniformly in one direction together | Not motility — usually evaporation or temperature currents in the fluid, not the organism's own movement |\n\n## Materials Required\n\n1. Glass slides with a concave depression (or a regular slide with a paraffin\u002Fadhesive-tape ring to create one)\n2. Petroleum jelly (vaseline) or another sticky sealant\n3. [Inoculating loop](https:\u002F\u002Fmicrobeonline.com\u002Finoculating-loop-types-and-uses\u002F)\n4. Coverslip\n5. [Microscope](https:\u002F\u002Fmicrobeonline.com\u002Fparts-of-microscope-and-their-functions\u002F) — ideally with oil immersion capability for closer inspection once organisms are located\n6. [Bunsen burner](https:\u002F\u002Fmicrobeonline.com\u002Fbunsen-burner-parts-principle-and-applications\u002F)\n7. A **young, actively growing broth culture** (4–6 hours for fast growers, or as fresh as practical for the organism) — see the culture-age note below\n\n## Quality Control\n\n| Organism | Expected result |\n| --- | --- |\n| *Proteus mirabilis* or *E. coli* | Motile (positive control) |\n| *Klebsiella pneumoniae* or *Shigella sonnei* | Nonmotile (negative control) |\n\nTechnologist competency should also be periodically validated using a known motile organism that moves subtly, such as *Listeria monocytogenes*, in a broth assay. Subtle motility is a good test of whether a technologist is reading the slide correctly, not just whether the slide was prepared correctly. (Note that most clinically important enterococci, including *E. faecalis* and *E. faecium*, are nonmotile; only *E. gallinarum* and *E. casseliflavus* are motile, so \"enterococci\" is not a reliable motile control.)\n\n## Procedure\n\nThe procedure has two stages: preparing the sealed hanging-drop slide, then locating and reading the organisms under the microscope.\n\n### Slide Preparation\n\n![](https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002FHanging-drop-method.jpg)Figure: Slide Preparation for Hanging Drop Method\n\n1. If using a flat slide, apply a paraffin or adhesive-tape ring to create a circular concavity. (Skip this step if using a true depression slide.)\n2. Hold a clean coverslip by its edges and dab petroleum jelly on its corners with a toothpick.\n3. Place a **light** loopful of fresh broth culture in the center of the coverslip — it should not look visibly turbid. A heavy inoculum overcrowds the field, making it impossible to track individual cells and increasing the chance of convection currents that can mimic motility.\n4. Invert the concave slide over the drop so the petroleum jelly seals the coverslip to the slide around the concavity.\n5. Turn the slide right-side up so the coverslip is on top, and let organisms settle for about a minute.\n\n### Microscopic Observation\n\n1. Position the slide so an edge of the drop sits under the low-power objective.\n2. Lower the objective to its lowest position and **close the diaphragm.** This isn't an arbitrary step — unstained bacteria are nearly transparent and have very little contrast against the surrounding fluid. Closing the diaphragm reduces stray light and dramatically improves your ability to actually see them.\n3. Raise the objective slowly until the edge of the drop appears as an irregular line crossing the field, then center it.\n4. Swing in the high-dry objective without changing the focus height, and fine-adjust until the edge appears as a thick, dark line.\n5. Look just inside that line for small, dark or faintly greenish rods or spheres — these are the bacteria. (Remember: high-dry magnifies a little less than half of oil immersion.)\n6. Adjust the diaphragm as needed to maximize visibility.\n7. Observe cell morphology and grouping, then assess motility using the true-motility-vs-Brownian-vs-drift distinction above.\n8. If you need a closer look once organisms are located, oil immersion can be applied directly on top of the coverslip — most labs read motility reliably at high-dry, but oil immersion can help confirm subtler patterns like *Listeria* tumbling.\n9. Dispose of the slide and coverslip per your institution's biohazard protocol (see Safety note below) — don't reuse a depression slide without proper decontamination.\n\n### Where people actually get confused (students and bench staff alike)\n\n- **Brownian movement will be visible on every slide, motile or not.** Its presence doesn't confirm motility, and its absence doesn't rule it out — what matters is whether organisms change position *relative to each other* over time.\n- **Convection drift at the edge of the drop can fool you.** Evaporation at the drop's margin creates currents that sweep the whole field in one direction together. If everything in view is moving the same way at the same speed, that's drift, not motility — read closer to the center of the drop, not right at the edge.\n- **Culture age matters more than people expect.** Many organisms lose motility as a culture ages past log phase — flagella can be shed or expression downregulated in stationary phase. A nonmotile-looking result from an old culture may be a false negative, not a true one. Always use the youngest practical culture.\n- **An incomplete petroleum-jelly seal lets the drop dry out before you finish reading it** — if the drop is visibly shrinking or the edges look ragged partway through observation, the seal likely failed; remake the prep rather than trying to interpret a drying sample.\n- ***Vibrio cholerae* and *Campylobacter* darting motility can look almost too fast to be real** — tiny dots flickering in and out of the field. That's the expected appearance, not a preparation error.\n\n## Safety Note\n\nThis test is frequently performed on organisms that may include high-risk pathogens; *V. cholerae* in outbreak settings, or *Bacillus* species being screened in a possible anthrax-exclusion context. Handle suspect isolates under your institution's biosafety protocol (appropriate containment level, no unnecessary aerosol generation), and dispose of slides and coverslips in a biohazard sharps\u002Fwaste stream — soaking used depression slides in a disinfectant (e.g., a phenolic disinfectant) before reuse, or discarding flat slides outright, rather than simply washing and reusing without decontamination.\n\n## Result Interpretation Summary\n\n| Observation | Interpretation |\n| --- | --- |\n| Organisms change position relative to each other, directionally | True motility — **positive** |\n| Organisms jiggle in place, stay in the same relative position | Brownian movement only — **negative** |\n| Entire field drifts uniformly together | Passive\u002Fconvectional drift — **not a valid reading, re-examine** |\n| Fast, erratic, \"darting\" movement | Consistent with *Vibrio cholerae* \u002F *Campylobacter* pattern |\n| Tumbling motion, especially from overnight culture | Consistent with *Listeria monocytogenes* |\n| No movement at all, even Brownian artifact ruled out | Nonmotile |\n\nFor any organism that reads negative on initial wet mount, [repeat after further incubation in broth, or confirm by tube method](https:\u002F\u002Fmicrobeonline.com\u002Ftests-bacterial-motility-procedure-results\u002F):\n\n- Nonfermenting Gram-negative rods: incubate at 30°C for 24 hours before re-testing\n- *Listeria monocytogenes* and other subtly motile organisms: sub-culture into fresh broth and incubate at room temperature (20–25°C) for 8–24 hours before re-testing, since flagellar expression and tumbling motility are strongest below body temperature and are suppressed at 35–37°C\n- Most other organisms: incubate at their usual optimal growth temperature, typically 35°C\n\n**References**\n\n1. Jordan, E. O., Caldwell, M. E., & Reiter, D. (1934). Bacterial Motility. *Journal of Bacteriology, 27*(2), 165–174. \u003Chttps:\u002F\u002Fdoi.org\u002F10.1128\u002Fjb.27.2.165-174.1934>\n2. Luna, V. A., Peak, K. K., Veguilla, W. O., Reeves, F., Heberlein-Larson, L., Cannons, A. C., Amuso, P., & Cattani, J. (2005). Use of two selective media and a broth motility test can aid in identification or exclusion of *Bacillus anthracis*. *Journal of Clinical Microbiology, 43*(9), 4336–4341. \u003Chttps:\u002F\u002Fdoi.org\u002F10.1128\u002FJCM.43.9.4336-4341.2005>\n3. Tille, P. M. (2022). *Bailey & Scott's Diagnostic Microbiology* (15th ed.). Elsevier.\n4. Koneman, E. W., et al. (2017). *Koneman's Color Atlas and Textbook of Diagnostic Microbiology* (7th ed.). Wolters Kluwer.",[46,49,52],{"question":47,"answer":48},"How do I tell true motility from Brownian movement?","True motility means organisms change position relative to each other over time — purposeful, directional movement. Brownian movement is jiggling in place; the organisms stay in the same relative position to one another even though they appear to vibrate. Brownian movement appears on every slide regardless of whether the organism is motile.",{"question":50,"answer":51},"My drop dried out before I finished reading it — what went wrong?","Almost always an incomplete petroleum-jelly seal. If the drop looks like it's shrinking or the edges look ragged partway through observation, remake the prep with a more complete seal rather than trying to interpret a drying sample.",{"question":53,"answer":54},"Can hanging drop be used to help rule out anthrax?","Yes, as one early step. Bacillus anthracis is classically nonmotile, while closely related B. cereus group members are typically motile — so a quick motility check helps distinguish a concerning isolate before specialized confirmatory testing, per Luna et al. (2005), cited in the References.",[56],"motility-test",[58,76,96,112],{"slug":59,"title":60,"description":61,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":62,"lastUpdatedDate":63,"draft":42,"category":64,"image":38,"faq":65,"tags":75},"sulfide-indole-motility-sim-medium","Sulfide Indole Motility (SIM) Test: Principle, Procedure & Result Interpretation","SIM medium principle, procedure, and how to read sulfide, indole, and motility correct including why it catches weak H2S producers that TSI and KIA miss.","2022-10-10","2026-07-28","biochemical-tests",[66,69,72],{"question":67,"answer":68},"Why does SIM detect H2S that TSI\u002FKIA misses?","SIM is semisolid, which lets H2S gas diffuse through the whole tube rather than staying trapped at one interface like it does on a TSI or KIA slant. Weak producers like Salmonella Typhi can show clear diffuse blackening on SIM while barely registering on TSI.",{"question":70,"answer":71},"I can't tell if my tube is motile because the H2S blackening covers everything — what do I report?","If sulfide production is dense enough to obscure a clear read of the surrounding medium, the accepted convention is to record it as motility-positive rather than guessing negative from an unclear tube.",{"question":73,"answer":74},"Can I add Kovac's reagent first and read motility after?","No. Always read motility and H2S first. Adding reagent is the last, irreversible step; doing it early can make the earlier readings unreliable.",[56],{"slug":77,"title":78,"description":79,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":80,"lastUpdatedDate":81,"draft":42,"category":64,"image":38,"faq":82,"tags":95},"tests-bacterial-motility-procedure-results","Tests for Bacterial Motility: Methods, How to Read Them, and Where They Fool You","A practical guide to testing bacterial motility: hanging drop, semisolid stab, and SIM\u002FMIU. When to use each, how to read a stab tube, and the false positives (mucoid Klebsiella) and false negatives (flagellar shock, strict aerobes) that catch people.","2015-10-19","2026-07-15",[83,86,89,92],{"question":84,"answer":85},"How do you read a semisolid motility tube?","Stab the organism down the centre of a semisolid agar tube and incubate. Hold the tube to the light and look at the stab line. A motile organism spreads away from the stab and clouds the surrounding medium; a non-motile organism grows only along the stab line, leaving the medium clear. Adding triphenyltetrazolium chloride (TTC) makes this easier to read, because bacteria reduce the colourless TTC to a red compound, so growth and spread appear red.",{"question":87,"answer":88},"Why can a non-motile organism give a false-positive motility result?","Mucoid strains, especially of Klebsiella pneumoniae, can seep between the agar and the glass wall of the tube, producing a cloudy appearance that mimics motile spread. Using a tube with adequate depth and reading the density of growth in the central stab, rather than just overall cloudiness, helps avoid this error.",{"question":90,"answer":91},"Why might a motile organism like Pseudomonas look non-motile in a stab tube?","Pseudomonas and Vibrio are strict aerobes and do not grow well down the oxygen-poor depth of a stab tube. Their spread may be limited to the top few millimetres even though they are motile, so a clear deep stab can be misread as non-motile. For these organisms, confirm motility by microscopy such as a hanging drop preparation.",{"question":93,"answer":94},"Does temperature affect bacterial motility tests?","Yes. Some organisms only produce flagella at lower temperatures. Listeria monocytogenes and Yersinia enterocolitica are motile at around 20 to 25 degrees Celsius but non-motile at 35 to 37 degrees Celsius. Testing these at body temperature can give a false-negative motility result, so a parallel tube incubated at room temperature is used when these organisms are suspected.",[56],{"slug":97,"title":98,"description":99,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":100,"lastUpdatedDate":81,"draft":42,"category":43,"image":38,"faq":101,"tags":111},"motility-patterns-of-bacteria","Motility Patterns of Bacteria: Tumbling, Darting, Swarming, and the Key Exceptions","Which bacteria show which motility pattern; tumbling (Listeria), darting (Vibrio), swarming (Proteus), corkscrew (Campylobacter, spirochetes) — plus the temperature and strain exceptions that trip up identification.","2013-05-03",[102,105,108],{"question":103,"answer":104},"What are the main types of bacterial motility patterns?","Common named patterns include tumbling motility (Listeria), darting or shooting-star motility (Vibrio cholerae and Campylobacter), swarming motility (Proteus), corkscrew or flexion-extension motility (spirochetes such as Treponema, Borrelia, and Leptospira), gliding motility (Mycoplasma), and stately slow motility (Clostridium). The pattern is often a fast presumptive clue to the organism's identity.",{"question":106,"answer":107},"Which bacteria are important non-motile exceptions?","Key non-motile organisms include Klebsiella pneumoniae, Shigella, and Acinetobacter. A high-yield exception is Bacillus anthracis, which is non-motile while most other Bacillus species are motile. On the Gram-positive side, most cocci are non-motile, so the motile enterococci (Enterococcus gallinarum and E. casseliflavus) are the notable exception.",{"question":109,"answer":110},"Why is Listeria motile at 25°C but not at 37°C?","Listeria monocytogenes produces the flagella responsible for its characteristic tumbling motility mainly at lower temperatures, around 18 to 25 degrees Celsius. At 35 to 37 degrees Celsius, flagellar expression is reduced, so the organism appears non-motile or only minimally motile. In a semisolid tube at 25 degrees it also produces a characteristic umbrella-shaped growth near the top.",[56],{"slug":113,"title":114,"description":115,"seoTitle":38,"seoDescription":38,"author":39,"createdDate":116,"lastUpdatedDate":117,"draft":42,"category":118,"image":38,"faq":119,"tags":144},"bacterial-flagella-structure-importance-and-examples-of-flagellated-bacteria","Bacterial Flagella: Arrangement Types, Motility Patterns, and What They Mean at the Bench","Bacterial flagella: structure (filament, hook, basal body), types of flagellar arrangement with mnemonics, how flagella rotate, clinical significance in pathogenesis, identification, and motility patterns. With memory aids and exam tips.","2013-04-28","2026-07-24","general-microbiology",[120,123,126,129,132,135,138,141],{"question":121,"answer":122},"What is the difference between monotrichous, lophotrichous, amphitrichous, and peritrichous flagella?","Atrichous: no flagella (Klebsiella, Shigella). Monotrichous: single flagellum at one pole (Vibrio cholerae, Pseudomonas). Lophotrichous: tuft at one pole (Helicobacter pylori). Amphitrichous: flagella at both poles (Alcaligenes). Peritrichous: flagella distributed over entire cell surface (E. coli, Salmonella, Proteus). Mnemonic: 'A Monkey Lives Peacefully, Always' — Atrichous, Monotrichous, Lophotrichous, Peritrichous, Amphitrichous.",{"question":124,"answer":125},"What are the three structural components of a bacterial flagellum?","Filament — long helical extracellular portion composed of flagellin protein subunits. Hook — short flexible coupling between filament and basal body. Basal body — the motor embedded in the cell wall and membrane. Gram-negative bacteria have three ring systems (L, P, MS rings); gram-positive bacteria have only two rings (no outer membrane to anchor an L ring).",{"question":127,"answer":128},"Why do all motile Enterobacteriaceae have peritrichous flagella?","Peritrichous flagellation is phylogenetically conserved in Enterobacteriaceae — encoded in the core genome. Non-motile exceptions to memorise: Klebsiella, Shigella, and Yersinia pestis. Mnemonic: 'KSY — Keep Still, You!' All other motile Enterobacteriaceae are peritrichous.",{"question":130,"answer":131},"How do H antigens differ from O antigens in Salmonella serotyping?","O antigens are somatic LPS antigens — heat-stable, alcohol-resistant. H antigens are flagellar (flagellin protein) antigens — heat-labile, alcohol-labile. In the Widal test, anti-H antibodies appear later (day 10-12) and persist longer than anti-O antibodies (day 6-8), sometimes for years after infection or vaccination — making elevated H titers alone less specific for current active infection.",{"question":133,"answer":134},"What makes Helicobacter pylori flagella different from other bacteria?","H. pylori has lophotrichous flagella (4-7 at one pole) that are sheathed — covered by a membrane extension of the outer membrane. This sheathing: protects flagellin from acid degradation in the stomach (pH 1-2); masks flagellin from TLR5 recognition, reducing innate immune response and enabling chronic colonisation. Flagella-deficient H. pylori mutants cannot penetrate gastric mucus and cannot colonise the stomach.",{"question":136,"answer":137},"What is the difference between true bacterial motility and Brownian movement?","Brownian movement is random, non-directional vibration of all microscopic particles caused by water molecule bombardment — no net displacement. True bacterial motility is directional — the organism progressively moves from point A to point B. In wet preparations: observe whether the organism changes position relative to surrounding debris. Debris also shows Brownian movement but does not show directional travel.",{"question":139,"answer":140},"Why does Proteus mirabilis swarm on blood agar but not on MacConkey or CLED?","On blood agar, Proteus differentiates from swimmer cells to hyperflagellated swarm cells (up to 500 flagella per cell) that spread in concentric rings. MacConkey: bile salts inhibit flagellar function and swarming differentiation. CLED: low electrolyte concentration suppresses the proton-motive force driving the flagellar motor. Both media are preferred for urine cultures to prevent swarming from obscuring other organisms.",{"question":142,"answer":143},"What is chemotaxis and how do bacterial flagella enable it?","Chemotaxis is movement toward attractants and away from repellents via the run-and-tumble mechanism. Counterclockwise flagellar rotation = bundled flagella = smooth run. Clockwise rotation = bundle flies apart = tumble and reorientation. Chemoreceptors bias the ratio — detecting increasing attractant concentration decreases tumbling frequency and lengthens runs, producing net movement up the concentration gradient without any nervous system.",[145,56],"bacterial-structure-physiology",[147,153,160,165,169,173,178,183,187,191],{"slug":148,"name":39,"description":149,"image":150,"body":151,"postCount":152},"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":154,"name":155,"description":156,"image":157,"body":158,"postCount":159},"ashma-shrestha","Ashma Shrestha","SEO Copywriter and Science Communicator\nKathmandu, Nepal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fashma-shrestha.png","Ashma Shrestha holds a Master of Science in Medical Microbiology from the Institute of Science and Technology (IOST), Tribhuvan University, Nepal, where she developed a strong foundation in virology, molecular biology, and diagnostic microbiology.\n\nShe now works as an SEO Copywriter at Resolution Digital, where she combines her scientific training with research-driven content strategy. She is certified in Google Analytics and Google Business Profile (GBP), and brings a data-informed approach to science communication writing content that is not only accurate but structured to reach and serve the students who need it most.\n\nAt microbeonline, Ashma contributes articles primarily in virology and molecular biology, areas she finds most compelling for their mechanistic depth and their growing clinical relevance. Her writing reflects the same standard the site is built on: factual rigor, clear explanation of the *why* behind microbiology concepts, and content that helps students move from memorization to genuine understanding.\n\nShe is passionate about making complex microbiological concepts accessible without sacrificing accuracy; a skill that sits at the intersection of her scientific training and her professional work in content and SEO.",81,{"slug":161,"name":162,"description":163,"image":38,"body":38,"postCount":164},"sushmita-baniya","Sushmita Baniya","Author \u002F Contributor",32,{"slug":166,"name":167,"description":163,"image":38,"body":38,"postCount":168},"samikshya-acharya","Samikshya Acharya",20,{"slug":170,"name":171,"description":163,"image":38,"body":38,"postCount":172},"alisha-tripathi","Alisha Tripathi",6,{"slug":174,"name":175,"description":176,"image":38,"body":38,"postCount":177},"aastha-shrestha","Aastha Shrestha"," Author \u002F Contributor",9,{"slug":179,"name":180,"description":181,"image":38,"body":38,"postCount":182},"guest-author","Guest Author","Guest Author \u002F Contributor",2,{"slug":184,"name":185,"description":163,"image":38,"body":38,"postCount":186},"srijana-khanal","Srijana Khanal",18,{"slug":188,"name":189,"description":181,"image":38,"body":38,"postCount":190},"dr-poonam-acharya","Dr. Poonam Acharya",1,{"slug":192,"name":193,"description":163,"image":38,"body":194,"postCount":195},"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]