Micro Final

• secreted by gram + or -
• foodborne illness
• proteins, so immune sys forms antibodies
• damage can occur before immune response formed

released by every gram + except listeria

Neurotoxins - act on nerves or motor end plates

enterotoxins - act on GI tract = diahrrea

cytotoxins - damage to cell mechanisms -> cell lysis

LPS - lipid polysaccharide

• immune response is due to innate immunitiy
• they're heat stable

• composed of:
• lipid a, core polysaccharide, O specific polysaccharide

lipid a is the toxic part

staohylococcus or streptococcus

• s. aureus
• s. epidermis

• golden pigment
• coagulase +
• exotoxins
• MRSA

• coagulase -
• opportunistic pathogen

s. epidermis and s. aureus differentiation is important. check or coagulase

• chains, require rich media for growth
• classification of strep is done through lancefield groups

ways to categorize streptococcus - hemolysis of blood cells

• partial hemolysis
• -green around colonies

• complete lysis
• -clear around colonies

no lysis of blood cells

• way to classify strep
• use group a or group b only

• - lactic strep
• -fecal strep
• -viridans strep
• -B-hemolytic strep

• non pathogenic
• no hemolysis = B-hemolytic
• found in milk products
• gives sour taste to foods when bad

• normal flora of GI tract
• can be a-, B-, or y- hemolysis
• opportunistic pathogen
• cause UTI's

• a-hemolysis
• normal flora of the mouth
• cause tooth decay or bacterial endocarditis

• Lancefield group a = Strep pyogenes - major pathogen
• group b = strep agalactiae

• haluronic acid capsule
• pyrogenic exotoxin
• complete hemolysis
• sensitive to bacitracin
• causes: cellulitis, s. pharyngitis, scarlet fever
• use blood agar plates to diagnose

• normal flora of femal genital tract
• causes neonatal meningitis, pneumonia - high mortality

• polysaccharide capsule
• a-hemolysis
• part of normal flora
• infection (pneumonia) occurs if moves to lungs
• causes meningitis or otitis media/sinusitis
• use quellong rxn to diagnose

• neisseria
• - gonorrhoeae
• - meningitis

• pili and G- cell wall
• males: acquired unprocted sex, causes urethritis, painful uriniation and discharge, some remain asymptomatic

• females: from unprotected sex, most females are asymptomatic (reserviors) causes painful urination/discharge could lead to pelvic inflamatory disease PID
• may see mother to child transmission
• DX using oxidase test

• endotoxin and capsule
• many healthy carriers
• may cause meningitis
• DX using oxidase test

• Clostridium or bacillus
• - C. perfringens, c. botulinum, c. tetani, c. difficile
• - B. anthracis, b. cereus

corynebacterium or listeria

• - c. diphtheriae
• - L. monocytogenes

• the enterics
• within this family there are 3 coliforms

ferment lactose with gas production, normal flora of the intestine but should not be outside intestine.

• -e.coli
• -k.pneumoniae
• -enterobacter

• gram - rods
• e.coli
• k.peumoniae
• enterobacter
• serratia
• proteus
• salmonella
• shigella

• yersinia
• vibrio
• campylobacter
• helicobacter

• bacteroides fragilis
• fusobacterium

pseudomonas aeruginosa