Final Exam (new info) Flashcards
Non-branching, catalase positive
Bacillus, Listeria, Corynebacterium
Non-branching, catalase negative
Erysipelothrix, Lactobacillus
Branching or Partially Acid Fast
Nocardia
Confirmatory “test” for Bacillus species
Endospore staining
Virulence factors of Bacillus anthracis
Polypeptide capsule, potent endotoxins, edema toxin, lethal toxin
Most common form of anthrax
Cutaneous anthrax
How can anthrax be acquired?
contamination of wound (cutaneous anthrax), inhalation of spores (pulmonary anthrax/wool sorter’s disease), ingestion (gastrointestinal anthrax)
Clinical presentation of Bacillus cereus
food poisoning, diarrheal syndrome, is associated with rice, meat, poultry, and soups
Differentiation between Listeria monocytogenes and Group B Strep
Catalase positive (Group B Strep is catalase negative)
Listeria monocytogenes biochemical results
Catalase positive
Bile esculin positive
Umbrella motility
Block-type hemolysis on CAMP test
Beta hemolytic
Clinical presentation of diphtheria
respiratory: acquired by droplet spray, can cause demyelinating peripheral neuritis, cardiac failure, paralysis
cutaneous: infections occur at the site of minor abrasions; nonhealing ulcers with a dirty gray membrane
Corynebacterium diphtheriae biochemical results
Catalase positive
Bile esculin negative
Erysipelothrix rhusiopathiae biochemical results
Catalase negative
production of H2S on TSI
Erysipelothrix rhusiopathiae clinical presentation
infection through occupational exposure: farmers, butches, fishermen
Erysipeloid: produces painful swelling usually on the hands or fingers
Endocarditis may occur in patients with valve replacements
Gardnerella vaginalis clinical presentation
Bacterial vaginosis (BV): malodorous (fishy) discharge, vaginal pH greater than 4.5
How can Nocardia species be identified?
Using paraffin bait test: only Nocardia can break it down as a substrate
Nonselective anaerobic culture media
Cooked meat broth, Anaerobic blood agar, Egg-yolk agar (EYA), Peptone-yeast extract glucose broth (PYG), Thioglycolate broth
Selective anaerobic culture media
Bacteroides bile esculin agar (BBE), Laked Kanamycin-vancomycin blood agar (LKV), Anaerobic phenylethyl alcohol agar (PEA), Cycloserine cefoxitin fructose agar (CCFA)
Clostridium perfringens clinical presentation
Type A and C most common for disease
Acute gastrointestinal infections: diarrhea to necrotizing enterocolitis
Most common cause of Gas Gangrene (myonecrosis)
Clostridium difficile clinical presentation
Most common cause of nosocomial infections associated with antibiotic use
Causes watery diarrhea, pseudomembranous colitis with destruction of intestinal lining, toxic colon
Propionibacterium acnes clinical presentation
Infections of human skin (pimples), intestines, corneal ulcers, heart valves, prosthetic devices (artificial joints), ventricular shunts
Can present as osteomyelitis, bacteremia, endocarditis, meningitis
Difference between Nocardia and Anaerobic Actinomyces species
Nocardia grows aerobically and stain acid fast
Actinomyces does not!
Actinomyces biochemical results
CAMP -
Catalase -
No hemolysis
Indole -
Nitrate reduction +
Actinomyces species clinical presentation
“lumpy jaw”, sulfur granules in fluid, abdominal GI lesions, colonization of female genital tract, indistinguishable from pelvic inflammatory disease, associated with long term use of IUDs
Bacteroides spp. virulence factors
pili, fimbriae, adhesins, peroxidase, superoxide dismutase, lipopolysaccharide endotoxin, capsular polysaccharide toxin
Bacteroides fragilis group biochemical results
Esculin hydrolysis +
Indole -
Urease -
Catalase +
Oxidase +/-
Ferments glucose, sucrose, lactose, maltose
Bacteroides fragilis group clinical presentation
GI mucosal barrier breach, diarrhea from enterotoxigenic B fragilis (ETBF), produces beta-lactamase
Porphyromonas species biochemical results
Esculin hydrolysis +
Catalase -
Indole -
Porphyromonas species clinical presentation
Periodontal disease, inflammatory bowel disease
Fusobacterium species biochemical results
Catalase +/-
Lipase -
Indole +/-
Esculin hydrolysis -
Fusobacterium species clinical presentation
Lemierre’s syndrome: thrombophlebitis of the internal jugular vein
Abscesses, bacteremia, puerperal infections, septic shock
Veillonella species biochemical results
Non-motile
Ferments lactate
Reduces nitrate to nitrite
Peptostreptococcus species biochemical results
Urease +/-
Catalase -
Indole -
Nonhemolytic
Common isolates of Peptostreptococcus species
P. magnus
P. anaerobius
P. asaccharolyticus
