Bacteria identification (sharing)

Created by Jan Bobek

GPC

Gram positive

catalase test

https://asm.org/protocols/catalase-test-protocol

+

clusters

https://www.atsu.edu/faculty/chamberlain/mosdoh/gramstainingrules.htm

coagulase test

https://bio.libretexts.org/@api/deki/files/61590/coagulase_positive_negative_tube.png?revision=2&size=bestfit&width=670&height=435

http://faculty.collin.edu/dcain/ccccd%20micro/Rapid%20staph.jpg

+

Staphylococcus aureus on blood agar (beta hemolysis)

https://www.microbiologyinpictures.com/bacteria%20photos/staphylococcus%20aureus%20photos/staphylococcus%20aureus%20033.jpg

-

cytochrome oxidase test

https://i0.wp.com/microbeonline.com/wp-content/uploads/2012/12/Mechanism-of-the-Cytochrome-Oxidase-Reaction.png?ssl=1

+

Micrococcus

(Bacitracin S)

https://phil.cdc.gov//PHIL_Images/17967/17967_lores.jpg

-

CNS (Bacitracin R)

Novobiocin

1. Positive control = Staphylococcus saprophyticus
2. Negative control = Staphylococcus epidermidis

http://microbesinfo.com/wp-content/uploads/2014/01/40991869_m.jpg

Resistant

S. saprophyticus

https://www.medical-labs.net/wp-content/uploads/2014/03/Staphylococcus-saprophyticus-570x485.jpg

Sensitive

other CNS

-

chains

https://en.wikipedia.org/wiki/Streptococcus_pyogenes

Hemolysis

https://www.britannica.com/science/hemolysis

beta

Beta hemolytic Streptococcus species, Streptococcus pyogenes (transmitted light) (Lancefield group A)

Buxton (2005) Blood Agar Plates and Hemolysis Protocols. American Society for Microbiology, 1-9.https://asm.org/getattachment/7ec0de2b-bb16-4f6e-ba07-2aea25a43e76/protocol-2885.pdf

CAMP

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ7QqX2a9xZYqMrobQH5gp_AckpUg3w53qqbw&s

+

GBS: STAG

Bacitracin R

-

GAS

Latex agglutination test

Streptococcus pyogenes (Bacitracin S)

Streptococcus dysgalactiae

Streptococcus canis

alpha

Alpha-hemolytic Streptococcus species “Viridans group” streptococci, including species such as the Streptococcus mutans, mitis, and salivarius groups display alpha hemolysis.

Buxton (2005) Blood Agar Plates and Hemolysis Protocols. American Society for Microbiology, 1-9.https://asm.org/getattachment/7ec0de2b-bb16-4f6e-ba07-2aea25a43e76/protocol-2885.pdf

Bile-Esculin test

Veena, V. & Paramasivan, Poornima & Parvatham, R. & Sivapriyadharsini, & Kalaiselvi, K.. (2011). Isolation and characterization of β-glucosidase producing bacteria from different sources. African Journal of Biotechnology. 10. 14907-14912. 10.5897/Ajb09.314.

gamma

"Gamma Streptococcus" or Enterococcus faecalis (24 hours, non-hemolytic). "Gamma streptococcus" are usually non-hemolytic after 24 hours of incubation, but many eventually display weak alpha hemolysis. (The genus Enterococcus was once a part of the Streptococcus genus, and was considered a "gamma Streptococcus species". Enterococci usually reacts as Lancefield group D.)

Buxton (2005) Blood Agar Plates and Hemolysis Protocols. American Society for Microbiology, 1-9.https://asm.org/getattachment/7ec0de2b-bb16-4f6e-ba07-2aea25a43e76/protocol-2885.pdf

-

Optochin

Al-mohanna, Moshtaq. (2006). Identification and Characterization of Streptococcus pneumoniae.

Resistant

Viridans Streptococci

(STMI)

Sensitive

Streptococcus pneumoniae

R (rough) - Phase

S (smooth) / M (mucous) - Phase

https://www.microbiologyinpictures.com/bacteria%20photos/streptococcus%20pneumoniae%20photos/streptococcus%20pneumoniae%20020.jpg

+

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcS25YM8yI6WgFj-vyBkUajUJdWtNgMDfULutg&s

PYR

pyrolidonyl arylamidase (also called pyrolidonyl aminopeptidase) activity

(Left circle shows PYR -ve, Right circle shows PYR +ve)

http://www.medical-labs.net/wp-content/uploads/2014/04/PYR-test-results-Left-circle-shows-PYR-ve-Right-circle-shows-PYR-+ve.jpg

-

GDS: STBO (S. bovis)

(Vancomycin S)

+

Enterococcus sp. (Bacitracin R)

arabinose

E. faecium colonies (left) showing arabinose fermentation and E. faecalis colonies (right) showing no fermentation on Cephalexin-Aztreonam-Arabinose Agar

Ford, Michael & Perry, John & Gould, Frances. (1995). Use of Cephalexin-Aztreonam-Arabinose Agar for selective isolation of Enterococcus faecium. Journal of clinical microbiology. 32. 2999-3001. 10.1128/JCM.32.12.2999-3001.1994.

-

Enterococcus faecalis - ampicillin S

+

Enterococcus faecium - ampicillin R

+

Neisseria meningitidis

https://www.britannica.com/science/meningococcus

-

Neisseria gonorrhoeae

https://microbeonline.com/neisseria-gonorrhoeae-properties-disease-pathogenesis-and-laboratory-diagnosis/

+

Haemophilus influenzae

(beta / gamma HL)

Hib

https://www.creative-diagnostics.com/upload/image/Haemophilus-influenzae.png

-

Bordetella pertusis

https://cdn.britannica.com/18/123218-050-34CE57E0/Bordetella-pertussis-whooping-cough-agent-stain-Gram.jpg?w=400&h=300&c=crop

maltose

Cystine tryptic agar 

https://microbenotes.com/cystine-tryptic-agar/

X+V Disc

X (hemin) and V (nicotinamide adenine dinucleotide – NAD) growth factors

https://www.medical-labs.net/wp-content/uploads/2014/12/Haemophilus-species-growth-dependent-on-X-and-V-Factor.jpg

https://www.medical-labs.net/wp-content/uploads/2014/12/Haemophilus-influenzae-X-V-Factor.jpg

urease test

https://image.slideserve.com/1472923/slide38-l.jpg

+

Acinetobacter sp.

https://www.bioworld.com/ext/resources/BWS/BWS-source/Multidrug-resistant-A-baumannii.jpg?1704384396

+

Neisseria

(alpha / gamma HL)

urease test

https://image.slideserve.com/1472923/slide38-l.

-

Francisella sp.

https://phil.cdc.gov//PHIL_Images/14506/14506_lores.jpg

Nitrate Reduction

https://microbenotes.com/nitrate-reduction-test-objectives-principle-procedure-and-results/

-

Growth on ChocA only

++

Moraxella catarrhalis

https://www.microbiologyinpictures.com/bacteria-photos/moraxella-catarrhalis-photos/moraxella-catarrhalis-gram-stain.jpg

+

Growth on BA

+

cytochrome oxidase test

https://i0.wp.com/microbeonline.com/wp-content/uploads/2012/12/Mechanism-of-the-Cytochrome-Oxidase-Reaction.png?ssl=1

-

urease test

https://image.slideserve.com/1472923/slide38-l.

+

Brucella sp.

https://phil.cdc.gov//PHIL_Images/19255/19255_lores.jpg

GNC

No Growth on Endo (MAC)

Gram staining

1. Place a loopful of tap water onto a slide. Touch a colony with a loop and mix the bacteria with the water until there is a uniform, thin film of microorganisms on the slide. Air dry sample
2. Heat fix the slide. Allow the slide to cool.
3. Stain with Crystal Violet for 1 minute by flooding the slide with stain. Rinse with water.
4. Apply Iodine solution for 1 minute by flooding the slide with iodine. Rinse with water.
5. Decolorize by flooding the slide with acetone decolorizer. Rinse with water.
6. Counterstain with Safranin for 30 seconds by flooding the slide with stain. Rinse with water.
7. Dry the slide. View organisms using the oil immersion objective of your microscope.

-

Pasteurella sp.

https://en.wikipedia.org/wiki/Pasteurella

GNCB

curved rods

microaerophilic

+

cytochrome oxidase test

https://i0.wp.com/microbeonline.com/wp-content/uploads/2012/12/Mechanism-of-the-Cytochrome-Oxidase-Reaction.png?ssl=1

+

Campylobacter sp.

https://phil.cdc.gov//PHIL_Images/23238/23238_lores.jpg

Gram Negative

catalase positive

GNR

Growth on Endo (MAC)

-

Helicobacter sp.

https://phil.cdc.gov//phil_images/20040506/1/089_lores.jpg

-

Vibrio sp. (oxidase +)

https://phil.cdc.gov//PHIL_Images/23062/23062_lores.jpg

GPR

OF (oxidative/fermentative) glucose test

https://i0.wp.com/microbeonline.com/wp-content/uploads/2016/02/of-test.jpg?fit=1876%2C817&ssl=1

bacilli

branching filaments

https://cdn.lecturio.com/assets/Stain-nocardia-species.jpg

+/- (oxidative only)

(a) P. aeruginosa incubated for 24 hours. Note pH change in the top of the open tube only. (b) P. aeruginosa incubated for 48 hours. Note the diffusion of the acid down the tube. (c) P. aeruginosa incubated for 5 days. Note the diffusion of the acid throughout the tube.

https://asm.org/ASM/media/Protocol-Images/Oxidative-Fermentative-Test-Protocol.pdf?ext=.pdf

cytochrome oxidase test

https://i0.wp.com/microbeonline.com/wp-content/uploads/2012/12/Mechanism-of-the-Cytochrome-Oxidase-Reaction.png?ssl=1

+

Pseudomonas sp.

Mubbunu, Lumamba & Simukoko, Humphrey & Hang'ombe, Mudenda & Mwaanga, Edwell. (2023). Effects of Angiotensin-converting Enzyme Inhibitors and Angiotensin II Receptor Blockers on the Immune System of Pseudomonas aeruginosa Challenged Hamsters. Asian Pacific Journal of Health Sciences. 10. 31–36. 10.21276/apjhs.2023.10.2.08.

https://cdn-prod.medicalnewstoday.com/content/images/articles/322/322386/pseudomonas-bacteria-3d-render.jpg

anaerobic metabolism

https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/images/150/214/8a9de816-3f47-4e9c-83e6-b4d5cca2c9b2/640/8a9de816-3f47-4e9c-83e6-b4d5cca2c9b2.jpg

aerobic metabolism

Actinomyces sp.

Actinomyces israelii 

https://phil.cdc.gov//PHIL_Images/22293/22293_lores.jpg

Nocardia sp.

aerobic

Nocardia sp.

https://phil.cdc.gov//PHIL_Images/21742/21742_lores.jpg

+/+ (oxidative and fermentative)

Oxidative-fermentative test inoculated with Escherichia coli. Acid production in both the open and oil-covered tubes indicates a fermentative result. Hazy growth throughout is positive for motility.

https://asm.org/ASM/media/Protocol-Images/Oxidative-Fermentative-Test-Protocol.pdf?ext=.pdf

Clostridium sp.

https://phil.cdc.gov//PHIL_Images/21911/21911_lores.jpg

beta-hemolysis on BA

https://upload.wikimedia.org/wikipedia/commons/thumb/9/99/Arcanobacterium_haemolyticum_after_48_hours.jpg/330px-Arcanobacterium_haemolyticum_after_48_hours.jpg

-

+

-

Corynebacterium sp.

https://phil.cdc.gov//PHIL_Images/22877/22877_lores.jpg

colistin

S

Stenotrophomonas maltophilia

https://upload.wikimedia.org/wikipedia/commons/thumb/8/84/Stenotrophomonas_maltophilia.jpg/220px-Stenotrophomonas_maltophilia.jpg

MacConkey or Endo agar

https://www.microbiologyinpictures.com/bacteria-photos/klebsiella-pneumoniae-photos/klebsiella-pneumoniae-on-agar-media.jpg

TSIA/nitrate/MAC

1. The red slant and yellow butt (Red/Yellow or Alkaline (K)/Acidic (A)) indicate only glucose is fermented. 
2. Yellow slant and yellow butt (Yellow/Yellow or Acidic (A)/Acidic (A)) indicate lactose and/or sucrose fermentation or fermentation of all three sugars.
3. Red slant and red butt (Red/Red or Alkaline (K)/Alkaline (K)) indicate none of the three sugars are fermented. 
4. Blackening of the media or formation of the black-colored spots indicates H₂S production.
5. Cracking of the media, gas bubbles of the media, or forming a gap in the media indicates gas production.

TSIA Test Results of Some Common Enteric Pathogens

https://microbenotes.com/triple-sugar-iron-agar-tsia-test/

Nitrate Reduction

https://microbenotes.com/nitrate-reduction-test-objectives-principle-procedure-and-results/

endospore formation

Left. Bacillus thuringiensis phase micrograph. Endospores can be readily recognized microscopically by their intracellular site of formation and their extreme refractility. Right. Bacillus anthracis Crystal violet stain…

https://textbookofbacteriology.net/Bacsporecombo.jpeg

+

Bacillus sp.

Bacillus cereus

https://phil.cdc.gov//PHIL_Images/12378/12378_lores.jpg

-

R

Burkholderia sp.

Antibiotic susceptibility of Burkholderia pseudomallei demonstrating resistance to Polymyxin B 300U (PB) and colistin 10µg (CL) disks.

https://phil.cdc.gov//PHIL_Images/19017/19017_lores.jpg

CAMP test

+

Listeria sp.

https://www.semicrobiologia.org/wp-content/uploads/elementor/thumbs/CAMP-scaled-p6h1o87uqf0af04fapjqocg56z9iher7poiinaw6ns.jpg

inverse

Arcanobacterium sp.

Parija, S.C., Kaliaperumal, V., Kumar, S.V. et al. Arcanobacterium haemolyticum associated with pyothorax: case report. BMC Infect Dis 5, 68 (2005). https://doi.org/10.1186/1471-2334-5-68

Enterobacteriaceae

Lactose fermentation

https://www.jfmed.uniba.sk/fileadmin/jlf/Pracoviska/ustav-mikrobiologie-a-imunologie/ENTEROBACTERIACEAE__CAMPYLOBACTER__HELICOBACTER.pdf

+

ESCO

Klebsiella

Enterobacter

Citrobacter

Serratia

-

Salmonella

Shigella

Proteus

Morganella

Providencia

Yersinia

extended spectrum beta-lactamase

H₂S production

Some bacteria utilize thiosulfate anion as a terminal electron acceptor, reducing it to sulfide. If this occurs, the newly formed hydrogen sulfide (H₂S) reacts with ferrous sulfate in the medium to form ferrous sulfide, which is visible as a black precipitate.

Examples of sulfide-producing bacteria include Salmonella, Proteus, Citrobacter and Edwardsiella species.

H₂S production

Some bacteria utilize thiosulfate anion as a terminal electron acceptor, reducing it to sulfide. If this occurs, the newly formed hydrogen sulfide (H₂S) reacts with ferrous sulfate in the medium to form ferrous sulfide, which is visible as a black precipitate.

Examples of sulfide-producing bacteria include Salmonella, Proteus, Citrobacter and Edwardsiella species.

-

+

Citrobacter sp.

https://microbenotes.com/biochemical-test-of-citrobacter-freundii/

-

+

Salmonella and Shigella species do not ferment lactose but Salmonella may produce H2S, forming colorless colonies with or without black centers. 

https://microbeonline.com/deoxycholate-citrate-agar-dca-preparation-uses-colony/

indole test

Cefsulodin-Irgasan-Novobiocin Agar (CIN Agar or Yersinia Selective Agar)

https://microbenotes.com/cin-agar/

+

E. coli

https://microbenotes.com/escherichia-coli-e-coli/

urease test

https://image.slideserve.com/1472923/slide38-l.jpg

-

-

Shigella sp.

Britannica, The Editors of Encyclopaedia. "shigella". Encyclopedia Britannica, 6 Apr. 2024, https://www.britannica.com/science/Shigella.

+

Yersinia sp.

Yersinia enterocolitica

Rogers, Kara. "Yersinia". Encyclopedia Britannica, 28 Apr. 2016, https://www.britannica.com/science/Yersinia.

urease test

https://image.slideserve.com/1472923/slide38-l.jpg

-

Salmonella sp.

Salmonella enterica (arrows) on desoxycholate citrate agar. Cultivation 24 hours, 37°C.

https://www.microbiologyinpictures.com/bacteria-photos/salmonella-photos/deoxycholate-citrate-dx-agar.html

+

Proteus sp.

https://microbeonline.com/proteus-species-properties-diseases-identification/

+

Klebsiella pneumoniae

https://en.wikipedia.org/wiki/Klebsiella_pneumoniae

-

Enterobacter sp.

Enterobacter cloacae colonies on blood agar. Cultivation 24 hours, 37°C.Morphology: large, smooth, flat colonies with entire margin without beta hemolysis.

https://www.microbiologyinpictures.com/bacteria-photos/enterobacter-cloacae-photos/enterobacter-cloacae-colony-morphology.html

serotyping-agglutination