[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fxLN3MUwXCdr5RPjwZYIDpOj8CHyjOmngWTgoKXPtZbg":3,"$f4iUMl1DOzR-ukCyMohCiksME79awn2jl1gATaGEO4fY":36,"$f3Ft0rKFJHppdzE-vuveecxx1BUcg9iOlMLtyzf_MJDg":194,"$fucxFBm2ZjZfGSdmdRaSNGBI_F0jJme4f0GTvzUhQfL8":258},[4,8,12,16,20,24,28,32],{"title":5,"slug":6,"path":7},"About Microbeonline.com","about-microbeonline-com","\u002Fabout-microbeonline-com\u002F",{"title":9,"slug":10,"path":11},"About Me","about-me","\u002Fabout-microbeonline-com\u002Fabout-me\u002F",{"title":13,"slug":14,"path":15},"Advertise with Us","advertise-us","\u002Fadvertise-us\u002F",{"title":17,"slug":18,"path":19},"Privacy Policy","privacy-policy","\u002Fprivacy-policy\u002F",{"title":21,"slug":22,"path":23},"Authors","authors","\u002Fauthors\u002F",{"title":25,"slug":26,"path":27},"Microbes","microbes","\u002Fmicrobes\u002F",{"title":29,"slug":30,"path":31},"Books","recommended-books","\u002Frecommended-books\u002F",{"title":33,"slug":34,"path":35},"Tags","tags","\u002Ftags\u002F",{"type":37,"data":38},"blog",{"slug":39,"title":40,"description":41,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":44,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"body":48,"faq":49,"commentsClosed":46,"tags":50,"related":52,"comments":190},"salmonella-shigella-ss-agar-composition-principle-procedure-results","Salmonella-Shigella (SS) Agar: Composition, Principle, Colony Characteristics, and Limitations","\u003Cp>SS agar is a highly selective medium for \u003Cem>Salmonella\u003C\u002Fem> isolation from stool but despite its name, it inhibits most \u003Cem>Shigella\u003C\u002Fem> strains. Learn its principle, brilliant green mechanism, colony morphology, and when to use XLD or DCA instead.\u003C\u002Fp>",null,"Acharya Tankeshwar","2016-09-06","2026-08-14",false,"culture-media","A clinical microbiologist reviewing a stool culture protocol for a new district hospital is asked: \"Can we just use SS agar for all suspected enteric pathogen cases?\" The answer is \"no\".\n\nSalmonella-Shigella agar is excellent at what it does: suppressing coliforms and recovering *Salmonella* from heavily contaminated fecal specimens. But the same high selectivity that makes it good for *Salmonella* makes it inhibitory to *Shigella dysenteriae* and unreliable for *Shigella* species in general. A laboratory using SS agar as its only enteric selective medium will miss some of the most clinically important cases of bacillary dysentery.\n\nSalmonella-Shigella (SS) agar is used for selective isolation and differentiation of *Salmonella* and *Shigella*. It is used for the isolation, cultivation and differentiation of **gram-negative enteric microorganisms** from both clinical and non-clinical specimens such as from feces, urine, and suspected food items (fresh and canned foods). This medium is not recommended for the primary isolation of *Shigella* as some *Shigella* strains may not grow on SS agar due to a relatively high level of selectivity.\n\nOther less inhibitory media used for the isolation, cultivation and differentiation of gram-negative enteric microorganisms are:\n\n1. [Desoxycholate (DCA) Agar,](https:\u002F\u002Fmicrobeonline.com\u002Fdeoxycholate-citrate-agar-dca-preparation-uses-colony\u002F)\n2. [MacConkey Agar,](https:\u002F\u002Fmicrobeonline.com\u002Fmacconkey-agar-mac-composition-preparation-uses-and-colony-characteristics\u002F)\n3. [Eosin Methylene Blue (EMB) Agar,](https:\u002F\u002Fmicrobeonline.com\u002Feosin-methylene-blue-emb-agar-composition-uses-colony-characteristics\u002F)\n4. [Xylose Lysine Deoxycholate (XLD Agar)](https:\u002F\u002Fmicrobeonline.com\u002Fxylose-lysine-deoxycholate-xld-agar-composition-preparation-results-uses\u002F), and\n5. [Hektoen Enteric Agar](https:\u002F\u002Fmicrobeonline.com\u002Fhektoen-enteric-agar-composition-principle-uses\u002F)\n\n## Composition of Salmonella-Shigella (SS) Agar and their function\n\n| Ingredient | Amount (g\u002FL) | Function |\n| --- | --- | --- |\n| Beef extract | 5.0 | Nitrogen, vitamins, minerals |\n| Proteose peptone | 5.0 | Nitrogen, amino acids |\n| Lactose | 10.0 | Fermentable carbohydrate, lactose fermenters produce acid → red\u002Fpink colonies |\n| Bile salts mixture | 8.5 | Selective agent, inhibits Gram-positive organisms |\n| Sodium citrate | 8.5 | Selective agent, suppresses coliforms and Gram-positives |\n| Sodium thiosulfate | 8.5 | Selective agent; sulphur source; H₂S indicator (with ferric citrate) |\n| Ferric citrate | 1.0 | H₂S indicator. Reacts with H₂S → black iron sulfide precipitate |\n| **Brilliant green** | 0.00033 | **Primary selective agent**. Potent inhibitor of most Gram-negatives except *Salmonella* |\n| Neutral red | 0.025 | pH indicator. Red\u002Fpink in acid (lactose fermenters); colorless in neutral\u002Falkaline |\n| Agar | 13.5 | Solidifying agent |\n\n**Final pH:** 7.0 ± 0.2 at 25°C\n\n## Principle\n\nSS agar achieves its high selectivity through four synergistic inhibitory agents working simultaneously:\n\n**1. Bile salts**: inhibit Gram-positive organisms and suppress some Gram-negatives.\n\n**2. Sodium citrate**: inhibits Gram-positive organisms and suppresses most coliforms.\n\n**3. Sodium thiosulfate + ferric citrate** (H₂S **indicator system)**: the same system used in DCA: organisms producing H₂S from thiosulfate form black iron sulfide precipitate, giving *Salmonella* its characteristic black-centered colonies.\n\n**4. Brilliant green, the key selective agent that sets SS agar apart:** Brilliant green is a triphenylmethane dye with potent inhibitory activity against most Gram-negative bacteria, including the majority of coliforms. At the low concentration used in SS agar (0.00033 g\u002FL — just 0.33 mg per liter), it is bacteriostatic to most enterics while *Salmonella* species have inherent resistance. This allows *Salmonella* to grow where other organisms are suppressed.\n\n**Why *Shigella* is inhibited, the critical limitation:** *Shigella* species are more susceptible to brilliant green than *Salmonella*. At the concentration incorporated in SS agar, brilliant green inhibits *Shigella dysenteriae* almost completely, and suppresses growth of *S. flexneri* and *S. sonnei* to a variable but significant degree. This is the direct cause of the paradox embedded in the medium's name: the medium named for *Salmonella* and *Shigella* is poorly suited for *Shigella* isolation.\n\nSS agar combines brilliant green with a high bile salt content (roughly five times that of MacConkey agar). This combination makes it more inhibitory than MacConkey or DCA. The high selectivity maximizes suppression of competing flora in heavily contaminated specimens, but it comes at the cost of reduced *Shigella* recovery.\n\n**Differential mechanism:** Neutral red is the pH indicator. Lactose fermenters produce acid, turning colonies **red to pink**. Non-fermenters (*Salmonella*, *Shigella*, *Yersinia*) produce **colorless** colonies. H₂S producing species (*Salmonella*, some *Proteus*) develop **black centers**.\n\n![E coli Shigella Salmonella - Colony morphology ofE.coli, SalmonellaandShigellain Salmonella-Shigella Agar](\u002Fblogs\u002FE-coli-Shigella-Salmonella.jpg)Figure: Colony morphology of *E.coli, Salmonella* and *Shigella* in Salmonella-Shigella Agar\n\n## Preparation of the media\n\n1. Suspend 60 g of the medium in one liter of deionized or distilled water.\n2. Mix well.\n3. Heat with frequent agitation and boil for one minute.\n4. Sterilization in an autoclave is not necessary.\n5. Pour into plates\n6. Let the agar solidify and store it in the refrigerator (avoid freezing). Prepared culture media can be kept for at least a week in refrigeration. Note: Various commercial suppliers now supplies ready-to-use culture plates.\n\n## Culturing the sample\n\n1. Allow the plates to warm to room temperature and the agar surface to dry before inoculating.\n2. Heavily inoculate and streak the specimen as soon as possible after collection.\n3. If the specimen to be cultured is on a swab, roll the swab over a small area of the agar surface.\n4. Streak for isolation with a sterile loop.\n5. Incubate plates aerobically at 35-37°C 18-24 hours.\n6. Examine colonial morphology.\n\n## Results\n\n1. **Lactose fermenter**: If lactose fermentation occurs, the medium will turn red due to the acidic pH. e.g. *Escherichia coli, Klebsiella pneumoniae* gives red colonies.\n2. **Non-Lactose fermenter**: Salmonella, Shigella, and other non-lactose fermenters appear as transparent or translucent colorless colonies. Colonies of *Salmonella spp.* may appear with or without black centers (depending on the species isolated).\n\n## Colony Characteristics on SS Agar\n\n| Organism | Colony color | Black center | Notes |\n| --- | --- | --- | --- |\n| *Salmonella typhi* | Colorless | Yes (variable; may be small) | Lactose non-fermenter; H₂S positive; confirm with TSI + serology |\n| *Salmonella typhimurium* (non-typhi) | Colorless | Yes (prominent) | Classic *Salmonella* appearance on SS agar |\n| *Salmonella paratyphi A* | Colorless | **No** | H₂S negative, so colonies are colorless without a black center. This resembles Shigella and non-typhoidal Salmonella can be missed. Confirm with biochemical tests and serology. |\n| *Shigella sonnei* | Colorless (if grows) | No | **Variable growth, often inhibited or produces very small colonies** |\n| *Shigella flexneri* | Colorless (if grows) | No | Variable growth; more reliable on XLD or DCA |\n| *Shigella dysenteriae* | Often **no growth** | — | **Most inhibited species. SS agar is not suitable for *S. dysenteriae* isolation** |\n| *Escherichia coli* | **Pink to red** | No | Lactose fermenter; slightly inhibited but residual *E. coli* may still form pink colonies |\n| *Klebsiella pneumoniae* | **Pink, mucoid** | No | Lactose fermenter; mucoid capsule |\n| *Proteus mirabilis* | Colorless | Large black center | Strongly H2S positive; characteristic large central black dot; \"fishy\" odor; can mimic *Salmonella*, differentiate by urease test |\n| *Pseudomonas aeruginosa* | Irregular, slight growth | No | Partially inhibited; irregular colony edges |\n| Gram-positive bacteria | No growth | — | Completely inhibited by bile salts + brilliant green |\n\n> **Proteus vs Salmonella on SS agar:** Both produce colorless colonies with black centers. Key distinction: *Proteus* colonies are more glossy and translucent, often with a large central black dot; *Salmonella* colonies are more opaque. Always confirm with urease test (Proteus strongly positive) and TSI before reporting *Salmonella*.\n\n## When to Use SS Agar  and When Not To\n\n**Use SS agar when:**\n\n- Specimens are heavily contaminated with coliform flora (e.g., formed stool, rectal swabs) and maximum suppression of background flora is needed\n- *Salmonella* is the primary clinical concern (typhoid fever, non-typhoidal salmonellosis, food poisoning investigation)\n- Used alongside a less inhibitory medium, SS agar is best used as one plate in a two-plate battery, not as the sole medium\n\n**Do not use SS agar as the sole medium when:**\n\n- *Shigella* dysentery is the primary concern, *Shigella dysenteriae* and most other *Shigella* strains are inhibited\n- Specimens are from pediatric patients (children with bloody diarrhea, *Shigella* is a leading cause)\n- Investigating outbreaks of bacillary dysentery\n\n**Recommended two-medium battery for enteric stool culture:**\n\n| Clinical concern | Primary medium | Secondary medium |\n| --- | --- | --- |\n| Typhoid \u002F non-typhoidal *Salmonella* | SS agar (high selectivity for *Salmonella*) | MacConkey agar |\n| Dysentery (*Shigella* suspected) | XLD agar (best *Shigella* recovery) | MacConkey agar |\n| Broad enteric screen | XLD agar + MacConkey agar | DCA if available |\n| Cholera suspected | TCBS agar + APW enrichment | — |\n\n## How to Remember\n\n**SS agar, high selectivity is both its strength and its flaw:**\n\nThe key to understanding SS agar is the brilliant green dye. At the concentration used, brilliant green:\n\n- Suppresses nearly all coliforms → clean background, easy to read\n- Suppresses *Shigella* → misses the pathogen in the medium's own name\n- Does not suppress *Salmonella* → the medium's real target\n\n**Memory anchor \"SS agar should be called S agar\":** Despite being named Salmonella-*Shigella* agar, it is functionally a *Salmonella*-selective agar. Renaming it mentally as \"S agar\" is not just a memory trick, it prevents the clinical error of relying on SS agar alone when *Shigella* dysentery is suspected.\n\n**The enteric media selectivity spectrum:**\n\n| Selectivity | Medium | Best for |\n| --- | --- | --- |\n| Low | MacConkey agar | General GN screen; grows almost everything GN |\n| Moderate | DCA | *Salmonella* + *Shigella*; good for standard stool culture |\n| Moderate-high | XLD agar | Best *Shigella* recovery; three-step *Salmonella* differentiation |\n| High | SS agar | Maximum coliform suppression; *Salmonella* specialist; poor for *Shigella* |\n\n**Colony reading: two questions, three outcomes.**\n\n| Colony color | H₂S (black center) | Most likely organism |\n| --- | --- | --- |\n| Colorless | Yes | *Salmonella* (confirm with TSI + serology) |\n| Colorless | No | *Shigella* (if it grew) or *S. paratyphi A* |\n| Pink\u002Fred | No | *E. coli*, *Klebsiella*, coliform contaminants |\n\n**Precautions:**\n\nAs SS Agar media contains components of animal origin (absence of transmissible pathogenic agents cannot be ruled out) so treat it as potentially infectious, and handle observing the usual universal blood precautions. Do not ingest, inhale, or allow the media to come into contact with skin.\n\n## Where Students Get Confused\n\n**1. The name promises more than the medium delivers.** SS agar is named for both organisms but reliably recovers only Salmonella. Brilliant green inhibits most Shigella, and *Shigella dysenteriae* barely grows at all. If dysentery is the concern, SS agar alone will miss it. Use XLD or a less inhibitory medium alongside it.\n\n**2. *Proteus* can be mistaken for *Salmonella*.** Both are non-lactose fermenters that produce colorless colonies with black centers from H₂S. Do not report Salmonella on colony appearance alone. Proteus is strongly urease positive and Salmonella is urease negative, so a urease test and TSI separate them before serology.\n\n**3. *S.* Paratyphi A has no black center.** Most Salmonella produce the classic colorless colony with a black center. *S.* Paratyphi A is H₂S negative, so it is colorless without a black center and looks like Shigella or a plain non-fermenter. A black center is a useful clue when present, but its absence does not rule out Salmonella.\n\n**4. Coliforms are suppressed, not always absent.** Brilliant green and bile salts inhibit coliforms but do not always kill them. On prolonged incubation, residual *E. coli* or Klebsiella may grow as pink colonies. Read plates at 18 to 24 hours; late-appearing pink colonies are usually breakthrough coliforms, not the target pathogen.\n\n**References**\n\n- Tille PM. Bailey and Scott's Diagnostic Microbiology. 15th ed. St. Louis: Elsevier; 2022.\n- Cheesbrough M. District Laboratory Practice in Tropical Countries, Part 2. 2nd ed. Cambridge: Cambridge University Press; 2006.\n- World Health Organization. Guidelines for the Control of Shigellosis, Including Epidemics Due to Shigella dysenteriae Type 1. Geneva: WHO; 2005.\n- Mahon CR, Lehman DC, Manuselis G. Textbook of Diagnostic Microbiology. 6th ed. St. Louis: Elsevier; 2018.",[],[51],"bacterial-culture-media",[53,61,95,123,132,139,176,183],{"slug":54,"title":55,"description":56,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":57,"lastUpdatedDate":45,"draft":46,"category":47,"image":58,"faq":59,"tags":60},"deoxycholate-citrate-agar-dca-preparation-uses-colony","Deoxycholate Citrate Agar (DCA): Composition, Principle, Uses, and Colony Characteristics","\u003Cp>Deoxycholate Citrate Agar (DCA) is a selective and differential medium for isolating \u003Cem>Salmonella \u003C\u002Fem>and \u003Cem>Shigella \u003C\u002Fem>from stool. Learn its three-layer selectivity mechanism, colony morphology including H₂S producing \u003Cem>Salmonella\u003C\u002Fem>, and how it compares to SS agar and XLD agar.\u003C\u002Fp>","2018-11-30","https:\u002F\u002Fassets.microbeonline.com\u002Fblogs\u002Fsalmonella-in-deoxycholacte-citrate-agar-microbeonline.png",[],[51],{"slug":62,"title":63,"description":64,"seoTitle":65,"seoDescription":66,"author":43,"createdDate":67,"lastUpdatedDate":68,"draft":46,"category":47,"image":42,"faq":69,"tags":94},"macconkey-agar-mac-composition-preparation-uses-and-colony-characteristics","MacConkey Agar: Composition, Principle, Preparation, Uses, and Colony Characteristics","\u003Cp>MacConkey agar: composition, principle, uses, and detailed colony morphology of 20+ organisms including \u003Cem>E. coli, Klebsiella, Salmonella, Pseudomonas, Acinetobacter\u003C\u002Fem>, and more. Updated for clinical lab use.\u003C\u002Fp>","MacConkey Agar: Preparation, Colony Results, and Interpretation","Understand how MacConkey agar selects Gram-negative bacteria, differentiates lactose fermentation, and supports interpretation of common colony appearances.","2013-08-14","2026-08-22",[70,73,76,79,82,85,88,91],{"question":71,"answer":72},"What is the difference between lactose fermenters and non-lactose fermenters on MacConkey agar?","\u003Cp>Lactose fermenters produce acid which lowers the pH, turning the neutral red indicator pink\u002Fred. Strong fermenters like \u003Cem>E. coli \u003C\u002Fem>additionally precipitate bile salts, producing a darker pink halo. Non-lactose fermenters cannot metabolize lactose, so no acid is produced and colonies appear colorless.\u003C\u002Fp>",{"question":74,"answer":75},"\u003Cp>Why do \u003Cem>Klebsiella\u003C\u002Fem> colonies appear mucoid on MacConkey agar?\u003C\u002Fp>","\u003Cp>\u003Cem>Klebsiella\u003C\u002Fem> produces a thick polysaccharide capsule. During lactose fermentation, some lactose is used to synthesize additional capsular polysaccharide, resulting in large, wet-appearing, mucoid colonies that may string when touched with an inoculation loop.\u003C\u002Fp>",{"question":77,"answer":78},"\u003Cp>How do you differentiate \u003Cem>Salmonella\u003C\u002Fem> from \u003Cem>Shigella\u003C\u002Fem> on MacConkey agar?\u003C\u002Fp>","\u003Cp>Both appear as colorless non-lactose fermenting colonies and cannot be reliably differentiated by MacConkey alone. \u003Cem>Salmonella\u003C\u002Fem> colonies are typically convex, 2-3mm with smooth margins; Shigella are flatter, 1-2mm with irregular edges. Definitive differentiation requires biochemical testing or agglutination with specific antisera.\u003C\u002Fp>",{"question":80,"answer":81},"\u003Cp>Why does \u003Cem>Proteus\u003C\u002Fem> swarm on some media but not on MacConkey agar?\u003C\u002Fp>","MacConkey agar's bile salt content partially inhibits swarming by acting on the bacterial surface and reducing motility. The higher agar concentration also physically restricts movement. However, swarming is not completely eliminated and may still occur toward the plate periphery.",{"question":83,"answer":84},"Can fungi or yeast grow on MacConkey agar?","\u003Cp>Standard MacConkey agar does not support most fungi and yeasts. \u003Cem>Cryptococcus neoformans\u003C\u002Fem> has been reported to grow under certain conditions. For fungal isolation, Sabouraud dextrose agar (SDA) is the appropriate medium.\u003C\u002Fp>",{"question":86,"answer":87},"Why is MacConkey agar incubated at 35-37°C and not at room temperature?","35-37°C approximates human body temperature and is optimal for clinically important gram-negative pathogens, producing reliable colony morphology within 18-24 hours. Exception: Yersinia enterocolitica grows better at 25-28°C and should be incubated at room temperature for 48-72 hours.",{"question":89,"answer":90},"\u003Cp>What does a pink halo around \u003Cem>E. coli\u003C\u002Fem> colonies on MacConkey agar indicate?\u003C\u002Fp>","\u003Cp>The pink halo indicates strong acid production from vigorous lactose fermentation. The large amount of acid drops the local pH so significantly that bile salts precipitate out of solution, forming a visible turbid pink zone. This is specific to strong lactose fermenters and is a useful rapid indicator of \u003Cem>E. coli\u003C\u002Fem> in mixed cultures.\u003C\u002Fp>",{"question":92,"answer":93},"\u003Cp>Why is \u003Cem>Pseudomonas aeruginosa\u003C\u002Fem> described as a non-lactose fermenter on MacConkey agar?\u003C\u002Fp>","\u003Cp>\u003Cem>Pseudomonas aeruginosa\u003C\u002Fem> is an obligate aerobe that uses oxygen as its primary electron acceptor and does not ferment lactose. Its oxidative metabolism does not produce enough acid to change the neutral red indicator, so colonies remain colorless. Its blue-green pyocyanin pigment and sweet grape-like odor are more useful identifying features.\u003C\u002Fp>",[51],{"slug":96,"title":97,"description":98,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":99,"lastUpdatedDate":68,"draft":46,"category":47,"image":42,"faq":100,"tags":122},"eosin-methylene-blue-emb-agar-composition-uses-colony-characteristics","EMB Agar: Composition, Principle, and Colony Morphology","\u003Cp>How eosin and methylene blue produce the metallic green sheen, why \u003Cem>Klebsiella \u003C\u002Fem>ferments lactose without one, how to read EMB plates in reflected versus transmitted light, and when EMB beats MacConkey.\u003C\u002Fp>","2013-08-23",[101,104,107,110,113,116,119],{"question":102,"answer":103},"\u003Cp>Why does \u003Cem>E. coli\u003C\u002Fem> produce a metallic green sheen on EMB agar?\u003C\u002Fp>","\u003Cp>On the Levine EMB formulation used in most laboratories today, \u003Cem>E. coli\u003C\u002Fem> vigorously ferments lactose (the only sugar present), producing enough acid to sharply lower the pH at the colony surface. At this low pH, eosin Y and methylene blue precipitate in large quantities onto the colony. The densely packed dye crystals produce an iridescent metallic sheen, similar to a soap bubble, visible as green under reflected light. It is a direct indicator of vigorous acid production from lactose fermentation.\u003C\u002Fp>",{"question":105,"answer":106},"What is the difference between EMB and MacConkey agar?","\u003Cp>EMB (Levine): eosin Y + methylene blue dyes, contains lactose only, \u003Cem>E. coli\u003C\u002Fem> shows metallic green sheen. The original Holt-Harris-Teague EMB also contained sucrose, but Levine EMB is standard today. MacConkey: crystal violet + bile salts, contains lactose only, E. coli shows dark pink with bile precipitate halo.\u003C\u002Fp>",{"question":108,"answer":109},"\u003Cp>Why does \u003Cem>Klebsiella\u003C\u002Fem> produce mucoid colonies on EMB agar?\u003C\u002Fp>","\u003Cp>\u003Cem>Klebsiella\u003C\u002Fem> produces a thick polysaccharide capsule, using some fermented carbohydrate for capsule synthesis rather than acid production. Results in large, moist, dome-shaped mucoid colonies. On EMB they appear dark pink-brown and mucoid but without the metallic green sheen characteristic of \u003Cem>E. coli.\u003C\u002Fem>\u003C\u002Fp>",{"question":111,"answer":112},"Can gram-positive bacteria grow on EMB agar?","\u003Cp>No, eosin Y and methylene blue dyes are toxic to gram-positive organisms, penetrating gram-positive cell walls and disrupting membrane function. Most \u003Cem>Staphylococcus, Streptococcus\u003C\u002Fem>, and \u003Cem>Enterococcus\u003C\u002Fem> species are completely inhibited. EMB is not suitable when gram-positive pathogens are suspected.\u003C\u002Fp>",{"question":114,"answer":115},"What is the significance of EMB agar in water quality testing?","\u003Cp>EMB is FDA-BAM approved for \u003Cem>E. coli\u003C\u002Fem> detection in food and water. The metallic green sheen provides rapid, reliable presumptive fecal coliform identification. In the membrane filter technique, a measured water volume is filtered and the membrane placed on EMB, apperance of metallic green sheen colonies at 24–48 hours are counted as presumptive fecal coliforms.\u003C\u002Fp>",{"question":117,"answer":118},"\u003Cp>Why are \u003Cem>Salmonella\u003C\u002Fem> and \u003Cem>Shigella\u003C\u002Fem> colorless on EMB agar?\u003C\u002Fp>","\u003Cp>Both are non-lactose fermenters. Without acid production, the pH does not fall and dyes remain soluble rather than precipitating onto colonies. Colorless colonies on EMB suggest non-lactose fermenters but cannot distinguish \u003Cem>Salmonella\u002FShigella \u003C\u002Fem>from \u003Cem>Proteus\u003C\u002Fem> or \u003Cem>Pseudomonas, \u003C\u002Fem>for which TSI and specific antisera required.\u003C\u002Fp>",{"question":120,"answer":121},"What does a dark pink colony without metallic sheen indicate on EMB?","\u003Cp>Moderate lactose or sucrose fermentation, enough acid for dye precipitation but not enough for metallic sheen. Most typically \u003Cem>Klebsiella pneumoniae\u003C\u002Fem> (large, mucoid, dark pink-brown) and \u003Cem>Enterobacter\u003C\u002Fem> species. \u003Cem>E. coli\u003C\u002Fem> (metallic sheen) vs \u003Cem>Klebsiella \u003C\u002Fem>(dark, no sheen) is one of the most useful differential observations on EMB.\u003C\u002Fp>",[51],{"slug":124,"title":125,"description":126,"seoTitle":42,"seoDescription":42,"author":127,"createdDate":128,"lastUpdatedDate":129,"draft":46,"category":47,"image":42,"faq":130,"tags":131},"xylose-lysine-deoxycholate-xld-agar-composition-preparation-results-uses","XLD Agar: Composition, Principle, Colony Characteristics, and Uses","XLD (Xylose Lysine Deoxycholate) agar is the best single medium for isolating Salmonella and Shigella from stool. Learn its three-step differentiation mechanism, why Salmonella produces red colonies with black centres, and how XLD compares to DCA and SS agar.","Nisha Rijal","2015-04-22","2026-07-16",[],[],{"slug":133,"title":134,"description":135,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":136,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"faq":137,"tags":138},"hektoen-enteric-agar-composition-principle-uses","Hektoen Enteric (HE) Agar: Composition, Principle, Colony Characteristics, and Uses","\u003Cp>Hektoen Enteric (HE) Agar is a selective and differential medium for \u003Cem>Salmonella\u003C\u002Fem> and \u003Cem>Shigella\u003C\u002Fem> with better \u003Cem>Shigella\u003C\u002Fem> recovery than SS agar. Learn its green-medium principle, three-carbohydrate differentiation, H₂S indicator system, and colony colors.\u003C\u002Fp>","2015-01-27",[],[51],{"slug":140,"title":141,"description":142,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":143,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"faq":144,"tags":175},"cled-agar-composition-uses-typical-colony-characteristics","CLED Agar: Composition, Principle, Uses, and Colony Characteristics","\u003Cp>CLED (Cystine-Lactose-Electrolyte-Deficient) agar is the preferred single medium for urine culture. Learn its composition, why it inhibits Proteus swarming, colony colors of key uropathogens, and how it compares to MacConkey and blood agar.\u003C\u002Fp>","2015-03-16",[145,148,151,154,157,160,163,166,169,172],{"question":146,"answer":147},"What does CLED stand for?","Cystine-Lactose-Electrolyte-Deficient. Each element is functional: cystine supports cystine-dependent dwarf-colony coliforms that might otherwise be missed, lactose provides the fermentable carbohydrate that drives color differentiation, and electrolyte deficiency prevents Proteus from swarming across the plate.",{"question":149,"answer":150},"Is CLED agar selective or differential?","Differential only. It contains no inhibitory agents, so Gram-positive organisms, Gram-negative organisms, and yeasts all grow. Differentiation comes from bromothymol blue responding to acid production from lactose fermentation, turning colonies yellow, while non-fermenters remain blue or blue-green.",{"question":152,"answer":153},"Why is CLED agar preferred for urine culture?","\u003Cp>It does in one plate what blood agar and MacConkey do in two. It grows all common uropathogens including Gram-positives and \u003Cem>Candida\u003C\u002Fem>, differentiates lactose fermenters by color, prevents \u003Cem>Proteus\u003C\u002Fem> swarming from obscuring the plate, and supports quantitative colony counting with a calibrated loop. The result is lower cost and less bench space without losing diagnostic information.\u003C\u002Fp>",{"question":155,"answer":156},"How does CLED agar prevent Proteus swarming?","\u003Cp>\u003Cem>Proteus\u003C\u002Fem> swarming requires differentiation from short vegetative rods into elongated, hyperflagellated swarmer cells, and that switch depends on adequate electrolyte concentration. CLED omits added sodium chloride, keeping electrolytes below the triggering threshold. \u003Cem>Proteus\u003C\u002Fem> grows normally and produces translucent blue colonies, but stays as discrete colonies rather than spreading in waves.\u003C\u002Fp>",{"question":158,"answer":159},"What color are lactose fermenters on CLED agar?","\u003Cp>Yellow. Acid from lactose fermentation lowers the pH and shifts bromothymol blue from green toward yellow. \u003Cem>E. coli\u003C\u002Fem> gives opaque yellow colonies with a deeper yellow center; \u003Cem>Klebsiella\u003C\u002Fem> gives large, markedly mucoid yellow colonies. Non-fermenters such as \u003Cem>Proteus \u003C\u002Fem>and \u003Cem>Pseudomonas\u003C\u002Fem> remain blue or blue-green.\u003C\u002Fp>",{"question":161,"answer":162},"Why should CLED plates not be incubated beyond 24 hours?","Continued acid production by dominant lactose fermenters can eventually turn the whole medium yellow. Once that happens, blue non-fermenting colonies present in smaller numbers can no longer be distinguished against the background, and a mixed infection may be read as a pure growth.",{"question":164,"answer":165},"Can Candida grow on CLED agar?","\u003Cp>Yes. \u003Cem>Candida albicans\u003C\u002Fem> produces white to cream, raised, opaque yeast-like colonies, and may show foot-like projections at the colony margin with prolonged incubation. This is an advantage over MacConkey, where \u003Cem>Candida\u003C\u002Fem> grows poorly, and it matters in catheterized and diabetic patients where candiduria is common.\u003C\u002Fp>",{"question":167,"answer":168},"What colony count is significant in urine culture?","For voided midstream urine from a symptomatic patient, 10⁵ CFU\u002FmL or more indicates significant bacteriuria, and counts below 10⁴ usually suggest contamination. The thresholds shift with specimen type and clinical context: counts as low as 10² CFU\u002FmL can be significant in catheter specimens and in symptomatic men, and any growth from a suprapubic aspirate is significant. Growth of three or more species generally indicates contamination rather than polymicrobial infection.",{"question":170,"answer":171},"What is the difference between CLED agar and MacConkey agar?","\u003Cp>MacConkey is selective and differential; it contains bile salts and crystal violet that inhibit Gram-positive organisms, and lactose with neutral red for differentiation. CLED is differential only, with no inhibitors, so it grows Gram-positives and yeasts as well. Both suppress \u003Cem>Proteus\u003C\u002Fem> swarming, MacConkey through bile salts and CLED through electrolyte deficiency. For urine culture, CLED's ability to recover Gram-positive uropathogens on the same plate is the main advantage.\u003C\u002Fp>",{"question":173,"answer":174},"\u003Cp>Why can not CLED agar be used for all specimen types?\u003C\u002Fp>","\u003Cp>It contains no blood, so hemolysis cannot be assessed, and it does not support fastidious organisms. \u003Cem>Haemophilus\u003C\u002Fem> and \u003Cem>Neisseria\u003C\u002Fem> will not grow on it, so genital specimens where gonorrhea is suspected need chocolate agar or a selective medium such as Thayer-Martin alongside. CLED is designed for urine, and it is excellent there.\u003C\u002Fp>",[51],{"slug":177,"title":178,"description":179,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":180,"lastUpdatedDate":45,"draft":46,"category":47,"image":42,"faq":181,"tags":182},"buffered-charcoal-yeast-extract-bcye-agar-composition-uses-colony-characteristics","Buffered Charcoal Yeast Extract (BCYE) Agar: Composition, Principle, Uses, and Colony Characteristics","\u003Cp>BCYE agar is the only medium that grows \u003Cem>Legionella pneumophila\u003C\u002Fem>, requiring L-cysteine and iron for growth. Learn its six-component principle, why charcoal is essential, how growth on BCYE but not blood agar confirms Legionella, and how selective BCYE variants work.\u003C\u002Fp>","2013-09-08",[],[51],{"slug":184,"title":185,"description":186,"seoTitle":42,"seoDescription":42,"author":43,"createdDate":187,"lastUpdatedDate":68,"draft":46,"category":47,"image":42,"faq":188,"tags":189},"mannitol-salt-agar-msa-composition-uses-and-colony-characteristics","Mannitol Salt Agar (MSA): Principle, Composition, Uses, and Colony Characteristics","\u003Cp>Mannitol Salt Agar (MSA) is a selective and differential medium for isolating \u003Cem>Staphylococcus aureus.\u003C\u002Fem> Learn its principle, composition, colony colors of \u003Cem>S. aureus\u003C\u002Fem> vs CONS, and why \u003Cem>Enterococcus\u003C\u002Fem> and \u003Cem>Micrococcus\u003C\u002Fem> can give false-positive results.\u003C\u002Fp>","2013-08-13",[],[51],{"enabled":191,"threads":192,"total":193},true,[],0,[195,201,208,215,221,226,232,237,243,246,252],{"slug":196,"name":43,"description":197,"image":198,"body":199,"postCount":200},"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.*",491,{"slug":202,"name":203,"description":204,"image":205,"body":206,"postCount":207},"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.",79,{"slug":209,"name":210,"description":211,"image":212,"body":213,"postCount":214},"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":216,"name":217,"description":211,"image":218,"body":219,"postCount":220},"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":222,"name":223,"description":211,"image":42,"body":224,"postCount":225},"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":227,"name":228,"description":229,"image":42,"body":230,"postCount":231},"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":233,"name":234,"description":235,"image":42,"body":42,"postCount":236},"guest-author","Guest Author","Guest Author \u002F Contributor",1,{"slug":238,"name":239,"description":211,"image":240,"body":241,"postCount":242},"srijana-khanal","Srijana Khanal","https:\u002F\u002Fassets.microbeonline.com\u002Fauthors\u002Fsrijana-khanal-1.png","Srijana Khanal is a microbiology educator with nearly a decade of teaching experience, including her role as faculty in the Microbiology Department at National College, NIST. \n\nHer time in the classroom has given her a clear sense of where students struggle and what explanations actually work, a perspective that directly shapes how she writes.\n\nHer academic interests span Immunology, Genetics, Basic Sciences, and Research Methodology, and she brings the same rigor to her writing that she brought to teaching. Alongside academic writing, she has a passion for creative writing -- an instinct that shows in her ability to make dense scientific material readable without sacrificing accuracy.\n\nShe contributes to Microbeonline to extend her teaching reach beyond the classroom, helping medical and laboratory science students across the region build a stronger foundation in microbiology.",15,{"slug":244,"name":245,"description":235,"image":42,"body":42,"postCount":236},"dr-poonam-acharya","Dr. Poonam Acharya",{"slug":247,"name":127,"description":248,"image":249,"body":250,"postCount":251},"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.*",55,{"slug":253,"name":254,"description":255,"image":256,"body":257,"postCount":236},"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.",[259,266,272,277,282,287,291,295,299,304,308,313,317,322,327,332,336,340,345,350,354,358,362,366,370,374,378,382,387,392,396,400,404,408,412,416,420,424,428,432,436,440,444,448,452,456,460,464,469,473,477,481,485,489,493,497,501,505,509,513,517,521,525,529,533,537,541,545,548,552,555,558,561,564,567,570,573,576,579,582,585,588,591],{"slug":260,"name":261,"description":262,"image":263,"body":264,"postCount":265},"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":267,"name":268,"description":269,"image":42,"body":270,"postCount":271},"microscopy","Microscopy","Microscope types, components, and microscopy techniques","These are list of blog posts related to microscopy. ",12,{"slug":273,"name":274,"description":275,"image":42,"body":42,"postCount":276},"gram-positive-cocci","Gram-Positive Cocci","Staphylococcus, Streptococcus, Enterococcus, Micrococcus — organisms, diseases, and identification tests",11,{"slug":278,"name":279,"description":280,"image":42,"body":42,"postCount":281},"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":283,"name":284,"description":285,"image":42,"body":42,"postCount":286},"gram-positive-rods","Gram-Positive Rods","Bacillus, Clostridium, Listeria, Corynebacterium, Actinomyces and related organisms",8,{"slug":288,"name":289,"description":290,"image":42,"body":42,"postCount":271},"mycobacteria","Mycobacteria","Mycobacterium tuberculosis, leprosy, atypical mycobacteria, and acid-fast organism diagnosis",{"slug":292,"name":293,"description":294,"image":42,"body":42,"postCount":271},"anaerobic-bacteriology","Anaerobic Bacteriology","Anaerobic organisms, anaerobic culture methods, and anaerobic infection diagnosis",{"slug":296,"name":297,"description":298,"image":42,"body":42,"postCount":271},"enterobacteriaceae","Enterobacteriaceae","Identification, differentiation, and clinical significance of Enterobacteriaceae family members",{"slug":300,"name":301,"description":302,"image":42,"body":42,"postCount":303},"spirochetes","Spirochetes","Treponema, Leptospira, Borrelia and spirochetal infections",7,{"slug":305,"name":306,"description":307,"image":42,"body":42,"postCount":265},"food-microbiology","Food Microbiology","Food-borne pathogens, food safety, spoilage, and preservation",{"slug":309,"name":310,"description":311,"image":42,"body":42,"postCount":312},"antimicrobial-susceptibility-testing","Antimicrobial Susceptibility Testing","Methods for testing antibiotic susceptibility in clinical microbiology",22,{"slug":314,"name":315,"description":316,"image":42,"body":42,"postCount":265},"antimicrobials-moa-amr","Antimicrobials (MOA & AMR)","Mechanisms, detection, and clinical significance of antimicrobial resistance",{"slug":318,"name":319,"description":320,"image":42,"body":42,"postCount":321},"sterilization-disinfection","Sterilization and Disinfection","Methods of sterilization and disinfection in healthcare and laboratory settings",10,{"slug":323,"name":324,"description":325,"image":42,"body":42,"postCount":326},"specimen-collection-transport","Specimen Collection and Transport","Collection, handling, and transport of clinical specimens for microbiological testing",27,{"slug":328,"name":329,"description":330,"image":42,"body":42,"postCount":331},"bacterial-structure-physiology","Bacterial Structure and Physiology","Bacterial cell structure, growth, physiology, and environmental factors affecting growth",21,{"slug":333,"name":334,"description":42,"image":42,"body":335,"postCount":225},"horizontal-gene-transfer","Horizontal Gene Transfer","Articles related to **Horizontal Gene Transfer**",{"slug":337,"name":338,"description":42,"image":42,"body":339,"postCount":321},"chromatography","Chromatography","Information about chromatographic techniques.",{"slug":341,"name":342,"description":343,"image":42,"body":344,"postCount":303},"electrophoresis","Electrophoresis","Information about Electrophoresis Techniques ","Detailed information  about Electrophoresis Techniques ",{"slug":346,"name":347,"description":348,"image":42,"body":349,"postCount":225},"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":351,"name":352,"description":353,"image":42,"body":42,"postCount":225},"bacteriophage","Bacteriophage","Description about Bacteriophage.",{"slug":355,"name":356,"description":357,"image":42,"body":42,"postCount":225},"malaria","Malaria","It is the collections of articles regarding malarial disease. ",{"slug":359,"name":360,"description":361,"image":42,"body":42,"postCount":225},"anaerobic-culture-techniques","Anaerobic Culture Techniques","Posts related with Anaerobic Culture Techniques.",{"slug":363,"name":364,"description":365,"image":42,"body":42,"postCount":331},"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.",{"slug":367,"name":368,"description":369,"image":42,"body":42,"postCount":303},"biosafety-levels","Biosafety levels ","Articles related to Biosafety Levels",{"slug":371,"name":372,"description":373,"image":42,"body":42,"postCount":281},"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":375,"name":376,"description":377,"image":42,"body":42,"postCount":225},"pipette","Pipette","Posts related with Pipette. ",{"slug":379,"name":380,"description":381,"image":42,"body":42,"postCount":303},"bacteriology-mcqs","Bacteriology MCQs","This sections lists MCQs in Bacteriology.",{"slug":383,"name":384,"description":385,"image":42,"body":42,"postCount":386},"parasitology-mcqs","Parasitology MCQs","This section lists MCQs in Parasitology.",2,{"slug":388,"name":389,"description":390,"image":42,"body":42,"postCount":391},"virology-mcqs","Virology MCQs","This is the collections of Multiple Choice Questions in Virology.",4,{"slug":393,"name":394,"description":395,"image":42,"body":42,"postCount":281},"mcqs-in-microbiology","MCQs in Microbiology","This section lists the collections of Multiple Choice Questions in General Microbiology Topics. ",{"slug":397,"name":398,"description":399,"image":42,"body":42,"postCount":303},"immunology-mcqs","Immunology MCQs","In this section; we are posting collections of Multiple Choice Questions about Immunology. ",{"slug":401,"name":402,"description":403,"image":42,"body":42,"postCount":321},"microbial-curiosities","Microbial Curiosities","In this clusters, we are posting interesting and unique information about Microorganisms. ",{"slug":51,"name":405,"description":406,"image":42,"body":42,"postCount":407},"Bacterial Culture Media","Posts related to Bacterial Culture Media. ",23,{"slug":409,"name":410,"description":411,"image":42,"body":42,"postCount":225},"fungal-culture-media","Fungal Culture Media","Posts related to Fungal Culture Media.",{"slug":413,"name":414,"description":415,"image":42,"body":42,"postCount":281},"motility-test","Motility Test","This lists the procedure regarding various tests methods for bacterial motility.",{"slug":417,"name":418,"description":419,"image":42,"body":42,"postCount":321},"bacterial-enumeration","Bacterial enumeration","These posts are related to isolation and enumeration of bacteria. ",{"slug":421,"name":422,"description":423,"image":42,"body":42,"postCount":386},"gram-positive-coccobacillus","Gram-positive coccobacillus","List of Gram Positive Coccobacilli",{"slug":425,"name":426,"description":427,"image":42,"body":42,"postCount":391},"dimorphic-fungi","Dimorphic Fungi","This is about various dimorphic fungi. ",{"slug":429,"name":430,"description":431,"image":42,"body":42,"postCount":303},"bacterial-classification","Bacterial Classification","These posts are related with various approaches used for the classification of Bacteria. ",{"slug":433,"name":434,"description":435,"image":42,"body":42,"postCount":281},"immunofluorescence","Immunofluorescence ","Various Tests related to Immunofluorescence ",{"slug":437,"name":438,"description":439,"image":42,"body":42,"postCount":231},"antibody-mediated-immunity","Antibody-mediated Immunity","This clusters links the articles that are sharing insights about Antibody-mediated immunity. ",{"slug":441,"name":442,"description":443,"image":42,"body":42,"postCount":303},"hypersensitivity","Hypersensitivity","Articles related to Hypersensitivity.",{"slug":445,"name":446,"description":42,"image":42,"body":42,"postCount":447},"haemophilus","Haemophilus",3,{"slug":449,"name":450,"description":451,"image":42,"body":42,"postCount":391},"sexually-transmitted-infections-stis","Sexually transmitted infections (STIs)","This is the clusters of infections that are transmitted sexually. ",{"slug":453,"name":454,"description":455,"image":42,"body":42,"postCount":271},"adaptive-immunity","Adaptive Immunity","Blog posts related to B Cell Immunity and T Cell Immunity.",{"slug":457,"name":458,"description":459,"image":42,"body":42,"postCount":265},"fungal-diagnostics","Fungal Diagnostics","Various methods used for the Diagnosis of Fungal Infections. ",{"slug":461,"name":462,"description":463,"image":42,"body":42,"postCount":281},"laboratory-storage-and-preservation","Laboratory Storage and Preservation","Articles about Laboratory Storage of Antimicrobial Disk, Test organisms and Equipment used for this process. ",{"slug":465,"name":466,"description":467,"image":42,"body":468,"postCount":225},"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":470,"name":471,"description":472,"image":42,"body":42,"postCount":231},"laboratory-glassware","Laboratory Glassware","Posts about Laboratory Glassware. ",{"slug":474,"name":475,"description":476,"image":42,"body":42,"postCount":231},"helminths","Helminths","In this section, we are covering properties, life cycle, pathogenesis and laboratory diagnosis of Helminths\u002FHelminthic infestations. ",{"slug":478,"name":479,"description":480,"image":42,"body":42,"postCount":286},"protozoan-parasite","Protozoan Parasite","In this cluster, we are covering protozoan parasites. ",{"slug":482,"name":483,"description":484,"image":42,"body":42,"postCount":236},"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":486,"name":487,"description":488,"image":42,"body":42,"postCount":321},"bacterial-staining-technique","Bacterial Staining Technique","Lists of various staining techniques that are used to stain bacteria. ",{"slug":490,"name":491,"description":492,"image":42,"body":42,"postCount":331},"enzyme-tests","Enzyme Tests","\u003Cp>Various Biochemical Test that are based on enzymatic activity of the microorganisms. \u003C\u002Fp>",{"slug":494,"name":495,"description":496,"image":42,"body":42,"postCount":276},"carbohydrate-utilization","Carbohydrate Utilization","\u003Cp>Various biochemical tests which are related to Carbohydrate fermentation or Utilization\u003C\u002Fp>",{"slug":498,"name":499,"description":500,"image":42,"body":42,"postCount":281},"susceptibility-based-id","Susceptibility-based ID","\u003Cp>These are susceptibility based identification test such as optochin sensitivity, bacitracin sensitivity etc. \u003C\u002Fp>",{"slug":502,"name":503,"description":504,"image":42,"body":42,"postCount":391},"microbial-metabolism","Microbial Metabolism","\u003Cp>Tests about Microbial Metabolism. \u003C\u002Fp>",{"slug":506,"name":507,"description":508,"image":42,"body":42,"postCount":286},"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":510,"name":511,"description":512,"image":42,"body":42,"postCount":447},"atypical-pneumonia","Atypical Pneumonia","\u003Cp>Organisms responsible for Atypical Pneumonia. \u003C\u002Fp>",{"slug":514,"name":515,"description":516,"image":42,"body":42,"postCount":281},"antigen","Antigen","\u003Cp>Various articles related to Antigens.\u003C\u002Fp>",{"slug":518,"name":519,"description":520,"image":42,"body":42,"postCount":303},"innate-immunity","Innate Immunity","\u003Cp>Articles related to Innate Immunity. \u003C\u002Fp>",{"slug":522,"name":523,"description":524,"image":42,"body":42,"postCount":391},"respiratory-tract-infection","Respiratory Tract Infection","\u003Cp>In this cluster, you can see various etiological agents that causes respiratory tract infection. \u003C\u002Fp>",{"slug":526,"name":527,"description":528,"image":42,"body":42,"postCount":281},"torch-infection","TORCH Infection","\u003Cp>In this section; you can find articles related with TOCH infection. \u003C\u002Fp>",{"slug":530,"name":531,"description":532,"image":42,"body":42,"postCount":286},"microbiology-for-beginners","Microbiology for Beginners","\u003Cp>These articles are very basic articles, which will share general concepts in Microbiology. \u003C\u002Fp>",{"slug":534,"name":535,"description":536,"image":42,"body":42,"postCount":225},"dna-replication","DNA Replication","\u003Cp>Articles related to DNA and Replication of DNA. \u003C\u002Fp>",{"slug":538,"name":539,"description":540,"image":42,"body":42,"postCount":303},"genetic-code","Genetic Code","\u003Cp>Articles related to Genetic Code.\u003C\u002Fp>",{"slug":542,"name":543,"description":544,"image":42,"body":42,"postCount":303},"molecular-technique","Molecular Technique","\u003Cp>Posts related to Molecular Techniques. \u003C\u002Fp>",{"slug":546,"name":547,"description":42,"image":42,"body":42,"postCount":236},"colorimetric-assay","Colorimetric Assay ",{"slug":549,"name":550,"description":551,"image":42,"body":42,"postCount":281},"pharmaceutical-microbiology","Pharmaceutical Microbiology","\u003Cp>Various articles related to Pharmaceutical Microbiology\u003C\u002Fp>",{"slug":553,"name":554,"description":42,"image":42,"body":42,"postCount":447},"blood-and-immune-cells","Blood and Immune Cells",{"slug":556,"name":557,"description":42,"image":42,"body":42,"postCount":281},"host-pathogen-interaction","Host Pathogen Interaction",{"slug":559,"name":560,"description":42,"image":42,"body":42,"postCount":391},"blood-culture","Blood Culture",{"slug":562,"name":563,"description":42,"image":42,"body":42,"postCount":391},"environmental-microbiology","Environmental microbiology ",{"slug":565,"name":566,"description":42,"image":42,"body":42,"postCount":303},"copromicroscopic-technique","Copromicroscopic Technique",{"slug":568,"name":569,"description":42,"image":42,"body":42,"postCount":447},"quality-control","Quality Control",{"slug":571,"name":572,"description":42,"image":42,"body":42,"postCount":303},"dermatophytes","Dermatophytes",{"slug":574,"name":575,"description":42,"image":42,"body":42,"postCount":447},"viral-hemorrhagic-fevers","Viral Hemorrhagic Fevers",{"slug":577,"name":578,"description":42,"image":42,"body":42,"postCount":391},"h2s-production","H2S Production",{"slug":580,"name":581,"description":42,"image":42,"body":42,"postCount":386},"water-quality-testing","Water Quality Testing",{"slug":583,"name":584,"description":42,"image":42,"body":42,"postCount":281},"virology-basics","Virology basics",{"slug":586,"name":587,"description":42,"image":42,"body":42,"postCount":391},"typing-methods","Typing Methods",{"slug":589,"name":590,"description":42,"image":42,"body":42,"postCount":447},"blotting-technique","Blotting Technique",{"slug":592,"name":593,"description":42,"image":42,"body":42,"postCount":391},"history-microbiology","History of Microbiology"]