Antibiotics

  • Bacitracin
  • Chloramphenicol
  • Erythromycin
  • Kanamycin
  • Nalidixic Acid
  • Nitrofurantoin
  • Novobiocin
  • Optochin
  • Penicillin
  • Streptomycin
  • Sulfamethoxazole
  • Tetracycline

Biochemical tests

  • Acid from glucose
  • Adonitol fermentation test
  • Antibiotic susceptibility tests
  • Arabinose fermentation test
  • Arabitol fermentation test
  • Arginine dihydrolase test
  • Bacitracin susceptibility test
  • Catalase test
  • Cellobiose fermentation test
  • Citrate utilization test
  • Coagulase test
  • Deoxyribonuclease (DNase) test
  • Dulcitol fermentation test
  • Esculin hydrolysis test
  • Fructose fermentation test
  • Galactose fermentation test
  • Gas from glucose
  • Gelatin hydrolysis test
  • Glucose fermentation
  • Glycerol fermentation test
  • Growth in KCN (potassium cyanide)
  • Growth on 6.5% NaCl
  • Growth on 7.5% NaCl
  • Growth on bile salts test
  • Hand Hygiene and Infection Control
  • Hemolysis on blood agar
  • Hydrogen sulfide (H2S) production test
  • Indole production test
  • Inositol fermentation
  • Kirby-Bauer Antibiotic Susceptibility Test
  • Lactose fermentation test
  • Lipase test (using corn oil)
  • Lysine decarboxylase test
  • Malonate utilization test
  • Maltose fermentation test
  • Mannitol fermentation test
  • Mannose fermentation test
  • Melezitose fermentation test
  • Melibiose fermentation test
  • Methyl red test
  • Motility test
  • myo-Inositol fermentation test
  • Nitrate reductase test
  • Novobiocin susceptibility test
  • OF glucose test
  • Optochin susceptibility test
  • Ornithine decarboxylase test
  • Oxidase test
  • Phenylalanine deaminase test
  • Raffinose fermentation test
  • Rhamnose fermentation test
  • Ribose fermentation test
  • Salicin fermentation test
  • Sorbitol fermentation test
  • Starch hydrolysis test
  • Sucrose fermentation test
  • Trehalose fermentation test
  • Urea hydrolysis test (Christiansen’s)
  • Voges-Proskauer test
  • Xylitol fermentation test
  • Xylose fermentation test

Gram negative bacilli

  • Buttiauxella agrestis
  • Cedecea davisae
  • Cedecea lapagei
  • Cedecea neteri
  • Citrobacter amalonaticus
  • Citrobacter amalonaticus biogroup 1
  • Citrobacter freundii
  • Citrobacter koseri
  • Cronobacter sakazakii
  • Edwardsiella hoshinae
  • Edwardsiella ictaluri
  • Edwardsiella tarda (wild type)
  • Edwardsiella tarda biogroup 1
  • Enterobacter aerogenes
  • Enterobacter amnigenus biogroup 1
  • Enterobacter amnigenus biogroup 2
  • Enterobacter cancerogenus
  • Enterobacter cloacae
  • Enterobacter gergoviae
  • Escherichia coli
  • Escherichia fergusonii
  • Escherichia hermannii
  • Escherichia vulneris
  • Ewingella americana
  • Hafnia alvei
  • Klebsiella oxytoca
  • Klebsiella pneumoniae subspecies ozaenae
  • Klebsiella pneumoniae subspecies pneumoniae
  • Klebsiella pneumoniae subspecies rhinoscleromatis
  • Kluyvera ascorbata
  • Kluyvera intermedia
  • Leclercia adecarboxylata
  • Mollerella wisconsinsis
  • Morganella morganii subspecies morganii
  • Morganella morganii subspecies sibonii
  • Proteus mirabilis
  • Proteus myxofaciens
  • Proteus penneri
  • Proteus vulgaris
  • Providencia alcalifaciens
  • Providencia rettgeri
  • Providencia rustigianii
  • Providencia stuartii
  • Rahnella aquatilis
  • Raoultella ornithinolytica
  • Raoultella terrigena
  • Salmonella bongori
  • Salmonella enterica
  • Salmonella enterica subspecies arizonae
  • Salmonella enterica subspecies enterica
  • Salmonella enterica subspecies houtenae
  • Salmonella enterica subspecies paratyphi
  • Salmonella enterica subspecies salamae
  • Salmonella typhi
  • Serratia ficaria
  • Serratia fonticola
  • Serratia marcescens
  • Serratia odorifera biogroup 1
  • Serratia plymuthica
  • Serratia proteamaculans subspecies proteamaculans
  • Serratia rubidaea
  • Shigella dysenteriae
  • Shigella flexneri
  • Shigella sonnei
  • Shimwellia blattae
  • Tatumella ptyseos
  • Yersinia enterocolitica
  • Yersinia frederiksenii
  • Yersinia kristensenii
  • Yersinia pestis
  • Yersinia pseudotuberculosis

Gram positive cocci

  • Dermacoccus nishinomiyaensis
  • Enterococcus avium
  • Enterococcus faecalis
  • Enterococcus faecium
  • Enterococcus gallinarum
  • Kocuria kristinae
  • Kocuria rosea
  • Kocuria varians
  • Kytococcus sedentarius
  • Lactococcus lactis
  • Lactococcus raffinolactis
  • Macrococcus caseolyticus
  • Micrococcus luteus
  • Micrococcus lylae
  • Nesterenkonia halobia
  • Rothia mucilaginosa
  • Staphylococcus aureus
  • Staphylococcus auricularis
  • Staphylococcus capitis
  • Staphylococcus caprae
  • Staphylococcus carnosus
  • Staphylococcus chromogenes
  • Staphylococcus cohnii ssp. cohnii
  • Staphylococcus cohnii ssp. urealyticum
  • Staphylococcus epidermidis
  • Staphylococcus gallinarum
  • Staphylococcus haemolyticus
  • Staphylococcus hominis
  • Staphylococcus hyicus
  • Staphylococcus intermedius
  • Staphylococcus lentus
  • Staphylococcus saccharolyticus
  • Staphylococcus saprophyticus
  • Staphylococcus sciuri
  • Staphylococcus simulans
  • Staphylococcus warneri
  • Staphylococcus xylosus
  • Streptococcus acidominimus
  • Streptococcus agalactiae
  • Streptococcus bovis
  • Streptococcus criceti
  • Streptococcus equi
  • Streptococcus equinus
  • Streptococcus ferus
  • Streptococcus iniae
  • Streptococcus mutans
  • Streptococcus pneumoniae
  • Streptococcus pyogenes
  • Streptococcus ratti
  • Streptococcus salivarius
  • Streptococcus sanguinis
  • Streptococcus sobrinus
  • Streptococcus uberis

Media

  • 6.5% NaCl broth
  • Arginine dihydrolase broth
  • Bile esculin agar slant
  • Blood agar
  • Christiansen’s urea broth
  • DNase agar with methyl green plate
  • Lysine decarboxylase broth
  • Malonate broth
  • Mannitol salt agar
  • MRVP broth
  • Mueller Hinton Agar
  • Nitrate broth with Durham tube
  • Nutrient agar plate
  • Nutrient broth
  • Nutrient gelatin
  • OF glucose broth
  • Ornithine decarboxylase broth
  • Phenol red adonitol broth
  • Phenol red arabinose broth
  • Phenol red arabitol broth
  • Phenol red cellobiose broth
  • Phenol red dulcitol broth
  • Phenol red fructose (levulose) broth
  • Phenol red galactose broth
  • Phenol red glucose (dextrose) broth with Durham tube
  • Phenol red glycerol broth
  • Phenol red inositol broth
  • Phenol red lactose broth
  • Phenol red maltose broth
  • Phenol red mannitol broth
  • Phenol red mannose broth
  • Phenol red melezitose broth
  • Phenol red melibiose broth
  • Phenol red raffinose broth
  • Phenol red rhamnose broth
  • Phenol red ribose broth
  • Phenol red salicin broth
  • Phenol red sorbitol broth
  • Phenol red sucrose (saccharose) broth
  • Phenol red trehalose broth
  • Phenol red xylitol broth
  • Phenol red xylose broth
  • Phenylalanine agar slant
  • Potassium cyanide (KCN) broth
  • Rabbit plasma
  • Simmons’ citrate agar slant
  • Spirit blue agar plate
  • Starch agar
  • Triple sugar iron agar slant
  • Tryptone broth

Reagents, Chemicals, Stains

  • Ammonium Sulfate (saturated)
  • Barritt’s A reagent
  • Barritt’s B reagent
  • Crystal Violet
  • Ferric chloride (10%) reagent
  • Gram’s Decolorizer
  • Gram’s Iodine
  • HCl 0.1N reagent
  • Hydrogen peroxide
  • Iodine reagent
  • Kovac’s reagent
  • Methyl red reagent
  • Nitrate A reagent
  • Nitrate B reagent
  • Oxidase reagent
  • Rabbit Plasma
  • Safranine

Hydrogen sulfide (H2S) production test

About this test

What is the purpose of the test?

This test determines whether the microbe reduces sulfur-containing compounds to sulfides during the process of metabolism.

How is the hydrogen sulfide production determined?  

If sulfide is produced, it combines with iron compounds to produce FeS, a black precipitate .

What medium is used?  

Several media containing iron compounds allow detection of hydrogen sulfide production. One medium used is Sulfide-Indole-Motility (SIM) medium . This is a nutrient medium allowing the detection of three different traits in bacteria: (1) it contains sulfates to serve as the substrate for detecting sulfide production; (2) it has abundant tryptophan as a substrate for indole production; and (3) its content of 0.5% agar is sufficient to allow bacterial motility, thereby allowing detection of motility. SIM is not supported by VirtualUnknown(C) Microbiology.  A second medium is triple sugar iron agar (TSIA), which is also used to detect the ability of the microbe to ferment up to three sugars. In either case, the chemistry of the test and its interpretation are the same.  VirtualUnknown Microbiology uses TSIA for detecting H2S production.

How is the test performed?  

An inoculum from a pure culture is transferred aseptically to a sterile triple sugar iron agar (TSIA) slant. The inoculated tube is incubated at 35-37 C for 24 hours and the results are determined. Present in TSIA is an iron compound . The iron ions (Fe2+) have a high affinity (strong attraction) for sulfide ions. The result is that H2S combines with the iron to make FeS, a black compound. In tubes of TSIA containing bacteria producing hydrogen sulfide, the agar turns black from the FeS.  Please note that this medium is also useful for monitoring fermentation properties of the unknown microbe. Three sugars are found in TSIA: glucose, sucrose, and lactose. If any of the sugars can be used, the microbe will accumulate acidic byproducts. In a positive test, the pH indicator in the medium changes color from its normal red to yellow, indicating acid production. For more information on how to interpret these changes, refer to the discussion of TSIA agar slants .

What reagents are required?  

None. 

Performing this test in the VUMIE Online lab

Inoculation of Medium

1. Select the TSIA slant medium.  

2. Using an inoculating wire, complete the process of a tube-to-tube aseptic transfer to inoculate the medium by streaking the slant and stabbing the butt of the medium.

Incubation of the Inoculated Medium

3. Place the inoculated tube into the 35-37 C incubator.  

4. Press the New Day button to move forward 24 hours.

Determination of Test Results

5. Incubate this test for only 24 hours.  

6. Retrieve the incubated culture from the incubator.

7. Observe test result. If regions of the agar have been turned black, the organism is producing hydrogen sulfide. Other, unrelated results can also be seen. Cracks in the agar indicate gas production from the fermentation of sugars. If the red agar has been turned yellow, acids are being produced from at lease one of the sugars contained within.  

8. Record test result.  

Uninoculated TSIA Slant:

Incubated TSIA Slant positive for H2S production (presence of black precipitate)

Incubated TSIA Slant negative for H2S production (no black precipitate)


VUMIE is the flight simulator of microbiology labs.

Learn more about VUMIE
Updated on November 1, 2022
Acid from glucose

Powered by BetterDocs