Gram + cocci

Staphylococcus

• facultative anaerobes, halophiles, test catalase +
• S. aureus, S. epidermidis

Staphylococcus epidermidis

• tests coagulase - (no agglutination)
• less virulent

• hyaluronidase (enzyme breaks down cell "glue")
• Protein A prevents opsonization and compliment factors
• slimy capsule makes hard to phagocytize
• cytolytic/enterotoxins
• infects hair follicles (boils/carbuncles)
• impetigo
• causes TSS, bacteremia, endocarditis, osteomyelitis
• treatment w/ penicillin, MRSA w/ vancomycin

Gram +, cocci

Enterococcus

• group D streptococcus
• E. faecalis

• secretes bacteriocins which inhibit other bacterial growth
• nosocomial or opportunistic infection

Gram +

nonendospore forming bacillus

• Listeria monocytogenes
• Mycoplasma pneumoniae
• Mycobacterium tuberculosis
• Mycobacterium leprae
• Corynebacterium diphtheria

• no cell wall
• paralyzes cilia in respiratory tract
• lighter case of pneumonia
• grows too slow to culture test, use immunofluorescent or hemagglutination

• has mycolic acid
• like cooler temperatures
• tuberculoid is less aggressive
• lepromatoces can cause digit loss
• treat w/ rifampin

• Resists cold temperatures
• O protein punctures phagosome then reproduces in phagocyte
• problem in immunocomprimised
• causes listeriosis which can lead to neurological damage

• normal flora of the throat
• pseudomembrane can suffocate patient
• can cause myocarditis
• very contagious
• antitoxin- immunoglobulin
• prevention- Tdap vaccine

• has mycolic acid
• cord factor which stops chemotaxis of WBCs
• primary- cough
• secondary- cough up blood (vampire myth)
• disseminated TB- macrophages carry TB to other organs
• treat with rifampin+isoniazid (cause orange tears)

Gram +

endospore forming bacillus

• Bacillus anthracis
• Bacillus cereus
• Clostridium perfringes
• Clostridium difficile
• Clostridium botulinum
• Clostridium tetani

• gas gangrene- dead tissue and gaseous bacterial waste
• causes food poisoning
• can lead to hypovolemic shock
• gas gangrene needs debridement
• anaerobic

• anaerobic
• botulin is a neurotoxin
• botulin causes paralysis which lead to death
• most cases from poorly canned food
• need antitoxin

• lock jaw
• tetanospasmin blocks GABA and glycin in antagonist muscles so that the cannot relax
• respiratory failure is cause of death
• need antitoxin then penicillin

• normal flora of the gut
• can cause ulcers which escalates to perforations which cause perintonitis = death
• pseudomembranous colitis- wall sloughs off
• treat with metronidazole and vancomycin
• anaerobic

• have capsule
• anaerobic
• toxins form pores in host cells
• GI anthrax- intestinal hemorrhaging
• cutaneous anthrax- black, crusty ulcers

• food poisoning
• emetic form has shorter incubation period than diarrheal form

Gram + cocci

Streptococcus

• Group a - Streptococci pyogenes
• Group b - Streptococci agalactiae
• viridans - Streptococci pneumoniae
  

• has M protein which stops compliment factors and opsonization, cause cell lysis
• hyluronic acid capsule
• streptokinase breaks down clots to help it move quickly
• causes strep throat, scarlet fever, rheumatic fever, and necrotizing faciitis
• glomerulonephritis cause damage to the nephrons in the kidneys because of clumps of antibodies

• beta hymolytic
• produce protease, hemolysins, and hyaluronidase
• causes puerperal fever in women which is deadly to newborns

• alpha hemolytic
• has capsule and phosphorylcholine which allos it to cross the blood brain barrier
• 85% of cases of pneumonia
• diplococci
• causes sinusitis, otitis media, endocarditis, pneumococcal meningitis
• treat with penicillin, erythromycin, cephalosporin