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What are the general tests and results of Vibrio species?
- Most Indole POS
- All are Oxidase POS - except V. metschnikovii
- Halophilic (salt loving) - except V. cholerae and V. mimicus
- Most labs use biochemical testing to presumptively ID then confirm with serology based on somatic O antigens
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What agar is used for its' selective properties and for differential for Vibrio species?
TCBS (Thiosulfate citrate salt sucrose agar)
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What bacteria:
Sucrose POS
Yellow colonies with TCBS (Thiosulfate citrate bile salt) sucrose agar?
V. cholerae
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What bacteria is Sucrose NEG with TCBS (Thiosulfate citrate bile salt) sucrose agar?
V. parahaemolyticus
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What bacteria is associated with:
Cholera (Severe watery diarrhea with flecks of mucus sometimes referred to as "rice-water" stool)
Bacteremia
Wound infections
Otitis media
Vibrio cholerae O1 serological group
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What clinical conditions are associated with Vibrio cholera Serogroups Non-O1?
Mild choleralike illness
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What clinical conditions are associated with Vibrio cholera Serogroup O139?
Severe disease similar to V. cholerae O1
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What are the 3 serotypes and 2 biotypes of Vibrio cholerae O1?
- Serotypes: Inaba, Ogawa, Hikojima
- Biotypes: Classical El Tor
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How are cholera infections acquired?
Ingestion of undercooked seafood or contaminated drinking water
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Where is Cholera usually seen?
- Southeast Asia
- Africa
- South America
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What are the important virulence mechanisms of Vibrio cholera?
- Cholera toxin (choleragen, an enterotoxin)
- Motility
- Pili (hairlike appendage on bacteria)
- Mucinase
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What clinical conditions are associated with Vibrio parahaemolyticus?
- Mild to moderate choleralike diarrhea disease
- Food poisoning (mostly in Asia because of eating raw shellfish)
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What clinical conditions are associated with Vibrio vulnificus?
- Septicemia
- (after ingestion of undercooked seafood, notably raw oysters)
- Rapidly progressive wound infections
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What clinical conditions are associated with Vibrio alginolyticus
- Otitis media
- Wound infections
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What clinical conditions are associated with Aeromonas?
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What are the clinically important species of Aeromonas?
- A. hydrophilia
- A. caviae
- A. veronii biovar sobria
- A. veronia biovar veronii
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What bacteria:
Beta hemolytic
Oxidase POS
Citrate POS
Indole POS
VP POS
ONPG POS
Aeromonas hydrophilia
-
What bacteria:
Eating undercooked seafood
Oxidase POS
Associated with Self-limiting gastroenteritis (treatment only in immunosuppressed or severe cases)
Plesiomonas shigelloides
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What species of Campylobacter causes most of the infections?
Campylobacter jejuni
-
What bacteria:
Associated with Food poisoning, Gastroenteritis, Diarrhea, Septic arthritis
Gram stain: curved bacilli that appear S-shaped or spiral
Microaerophilic
Need selective media for isolation (charcoal cefoperzone deoxycholate agar and Campy-colistin vancomycin amphotericin B)
Grows at 42 degrees celcius (will grow at 37 degrees but slowly)Catalase POS
Oxidase POS
Darting motility
Campylobacter
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What bacteria:
Associated with Peptic ulcers, Duodenal ulcers, Stomach cancer
Oxidase POS
Rapid Urease POS
Catalase POS
Other labs: fecal antigen detection, urea breath test, demonstration of urease activity in stomach biopsy material
Use the media: BAP, Brucella, Skirrow's agar Incubated microaerophilically
Helicobacter pylori
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What specimen is helicobacter mostly isolated from?
Gastric biopsy
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What are the general characteristics of Nonfermentative Bacilli (NFB)?
- Most are obligate aerobes
- Do NOT form spores
- Do NOT metabolize carbohydrates under anaerobic conditions (fermentation)
- Most are Oxidase POS
- TSI K/no (alkaline over nothing)
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What is the most important Nonfermentative Bacilli (NFB)?
Pseudomonas aeruginosa
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Name the members of Psudomonas fluorescent group
- P. aeruginosa
- P. fluoresceins
- P. putida
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What do all of the members of Pseudomonas fluorescent group produce?
Fluorescein (pyoverdin) - a yellow pigment that fluoresces
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What agar enhances fluorescein production?
Cetrimide agar
-
What bacteria:
Associated with Eye infections (for those who wear contact lenses), Ear infections, Swimmer's ear (external otitis), Lower respiratory tract infections (for those with cystic fibrosis (CF)Burn wound infections, Important in immunocompromised individuals, Nosocomial infections
Oxidase POS
Motile
Lactose NEG
Beta hemolytic with grapelike odor and metallic sheen on SBA
Produces a blue (blue-green) pigment because of the production of pyocyanin
Very resistant to antimicrobial agents
Pseudomonas aeruginosa
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What bacteria:
Associated with Pneumonia, UTIs, Wound infections
Oxidase NEG
Maltose POS
Nonfermenter
Lysine decarboxylase POS
Resistant to most antimicrobials
Stenotrophomonas maltophilia
-
What bacteria:
Nosocomial infections, Repiratory tract pathogen (in patient's with CF), Potential bioterrorism agent
Oxidase POS
Lactose POS
Lysine decarboxylase POS
Nonmotile
Enhanced growth on PC (P. cepacia) agar that inhibits P. aeruginosa
Burkholderia cepacia
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What are the two clinically encountered Nonfermentative Bacilli (NFB) that are lysine decarboxylase POS?
- Stenotrophomonas maltophilia
- Burkholderia cepacia
-
What bacteria:
Associated with Glanders (highly contagious disease of livestock, like horses, mules, and donkeys), Potential bioterrorism agent
Oxidase VARIABLE
Nonmotile
Reduces nitrate to nitrite without gas
Oxidizes glucose
Burkholderia mallei
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What bacteria:
Associated with Meliodosis - disease of humans and animals to endemic to Southeast Asia and northern Australia
Oxidase POS
Motile
Reduces nitrate to nitrite with gas
Oxidizes several sugars (including glucose and lactose)
Burkholderia pseudomallei
-
What bacteria:
Associated with Nosocomial infections (usually A. baumanii), UTIs
Multidrug resistant
Some produce acid from glucose (saccharolytic group)
Others are asacchrolytic (can't breakdown carbs)
Nonmotile
Oxidase NEG
Nitrate NEG
Catalase POS
Multidrug resistant
Acinetobacter
-
What bacteria:
Associated with Variety of infections in neonates, pregnant women, and immunosuppressed patients, Meningitis is the common outcome of infection
End-over-end (tumbling) motility on wet mount
Hippurate hydrolysis - POS
CAMP test - POS
Esculin - POS
Catalase - POS
Listeria monocytogenes
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What bacteria causes diphtheria?
Corynebacterium diphtheriae
-
Describe diphtheria
Pseudomembrane formed by dead cells and exudate at the back of the throat
-
What bacteria:
Associated with Bacterial toxins damage major organs, resulting in a high death rate, Toxigenic strains are infected with a bacteriophage that contains the gene for the diphtheria toxin
Gram stain - can be pleomorphic, "picket fence", or "Chinese letters"
Staining with methylene blue will reveal metachromatic granules, which are red to purple intracellular granules
Urease - NEG
Pyrazidamidase - NEG
Nitrate - POS
Catalase - POS
Nonmotile
Elek test (uses anti-toxin to detect the toxin)
Corynebacterium diphtheriae
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What media is used for the detection of Corynebacterium and what will it look like on the media?
- Tinsdale agar - form brown to black colonies with halos from hydrolysis of tellurite
- Cystine-tellurite - form black colonies from hydrolysis of tellurite
- Loeffler agar - nonselective medium that supports growth and enhances pleomorphism and the formation of metachromatic granules; form small white to gray colonies
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What bacteria:
Associated with Nosocomial infections, Infections after prosthetic device implants, Infections in immunocompromised patients
Pyrazidamidase - POS
Resistant to most antimicrobial agents
Corynebacterium jeikeium
-
What bacteria:
Associated with UTIs
Rapid Urease - POS
Grows very slowly
Corynebacterium urealyticum
-
What bacteria:
Associated with Abcess formations, Wound, Soft tissue infections
Small beta-hemolytic colonies on SBA
Catalase - NEG
Nonmotile
Arcanobacterium pyogenes
-
What bacteria:
Associated with Pharyngitis, Wound infections, Tissue infections
CAMP inhibition test: Produces phopholipase D, which inhibits the activity of the Staphylococcus aureus beta-lysine
Small beta-hemolytic colonies on SBA
Catalase - NEG
Nonmotile
Arcanobacterium haemolyticum
-
What bacteria:
Associated with Cellulitis (erysipelois lesions that can resemble erysipelas cause by Streptococcus pyogenes), Bacteremia, Endocarditis
Nonmotile
Pleomorphic gram positive bacilli
Catalase - NEG
Hydrogen sulfide - POS
Erysipelothrix rhusiopathiea
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Name the other clinical relevant species of Nocardia
- Nocardia asteroides (most significant)
- N. brasiliensis
- N. otitidiscaviarum
-
What bacteria:
Pleomorphic, branching gram-positve bacilli in chains that produce a beading arrangement, appear fungal-like
Partially acid fast
Catalase - POS
Nonmotile
Requires 6 weeks for growth
Exudate contains masses of filamentous organisms with pus that resemble sulfur granules
Nocardia asteroides
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