DD Bugs Brainscape Flashcards
Staphylococcus aureus- Gram Stain and Characteristics
Gram + cocci, B-hemolytic, and mannitol fermenters
Staphylococcus aureus- Disease Association
cutaneous infections, TSS, food poisoning, pneumonia, foreign body infections, endocarditis
Staphylococcus aureus -Virulence Trait and Factors Eliciting an Immune Response
Coagulase (fibrin walls off abscess, no phagocytosis) and Protein A (B-barrel toxin that binds to Fc-IgG -> no complement or phagocytosis), superantigen toxin -> TSS and food poisoning.
Staphylococcus aureus -Common Antibiotic Resistance Mechanism
B-lactamase (MRSA) and change in PBP.
Staphlycoccus epidermis- Gram Stain and Characteristics
Gram + cocci, catalase and urease +
Staphlycoccus epidermis-Disease Association
Infection with foreign bodies, i.e. catheters, prothesis and heart valves
Staphlycoccus epidermis-Virulence Trait
Extracellular glycocalyx (slime) to help adhere
Streptococcus pyogenes (GAS)- Gram Stain and Characteristics
Gram + Cocci
Streptococcus pyogenes (GAS)- Disease Association
Pharyngitis, skin and wound infections, post-strep (glomerunephritis and rheumatic fever)
Streptococcus pyogenes (GAS)- Virulence Trait
M protein; resist phagocytosis and hydrolytic enzymes
Streptococcus pneumonia- Gram Stain and Characteristics
gram + diplococci, alpha hemolytic and bile soluble
Streptococcus pneumonia- Disease Association
BS MOPS- Bacteremia, Septicemia, Meningitis, Otitis media, Pneumonia!, Sinusitis
Streptococcus pneumonia- Virulence Trait
Antiphagocytic polysacchardie capsule (also elicits response), IgA catalase
Viridans streptococci- Gram Stain and Characteristics
Gram + cocci, alpha/non hemolytic, abundant in mouth
Viridans streptococci- Disease Association
Endocarditis (esp. after dental work)
Viridans streptococci- Virulence Trait
Dextran which allows for it to adhere to mouth and heart
Enterococcus faecalis and faecium- Gram Stain and Characteristics
Gram + cocci, normal flora of intestine (selected by therapy with cephalosporin)
Enterococcus faecalis and faecium- Disease Association
Do U <3 trees? UTI, endocarditis, biliary tree, and surgical wounds
Enterococcus faecalis and faecium- Common Antibiotic Resistance Mechanism
Vancyomycin resistant, nosocomial (pt to pt contact)
Clostridium difficile- Gram Stain and Characteristics
Gram + rods
Clostridium difficile- Disease Association
nosocomial diarrhea, pseudomembranous colitis (resist from superinfection)
Clostridium difficile- Virulence Trait
exotoxin A: brush border (traveler’s diarrhea), exotoxin B: depolymerize actin (pseudo. colitis)
Clostridium difficile- Common Antibiotic Resistance Mechanism
Resistant to most antibiotics (except Vancomycin and Metronidazole)
Clostridium tetani- Gram Stain and Characteristics
gram + rod, soil, GI tract, and rusty nails
Clostridium tetani- Disease Association
tetanus (spastic paralysis, lock jaw, and arching back)
Clostridium tetani- Virulence Trait
Tetanus toxin; retrograde axonal transport of toxin to CNS, blocks inhibitory interneurons leading to spastic paralysis)
Clostridium botulinum- Gram Stain and Characteristics
gram + rods, spore forming
Clostridium botulinum- Disease Association
botulism (jaundice and flaccid paralysis)
Clostridium botulinum- Virulence Trait
botulinum toxin (blocks ACh transmission, resulting in flaccid paralysis)
Clostridium perfringens- Gram Stain and Characteristics
gram + rod
Clostridium perfringens-Disease Association
“crushing wound infections, watery diarrhea
Clostridium perfringens-Virulence Trait
alpha toxin (phospholipase enzyme that kills phagocytic cells and muscle tissue) and enterotoxin (in food; disturbs tight junctions in ileum)
Escherichia coli- Gram Stain and Characteristics
Gram - rod, catalase +, ferments lactose, normal flora in large intestine
Escherichia coli- Disease Association
GI (travelers diarrhea and enterohemorrhagic), UTI, abdominal infections (escape into peritoneal cavity)
Escherichia coli- Virulence Trait
Pili (for adhesion to intestinal wall and bladder epithelium), enterotoxin and shiga-like toxin
Escherichia coli- Common Antibiotic Resistance Mechanism
Can aquire resistance through acquisition of plasmids
Pseudomonas aeruginosa- Gram Stain and Characteristics
Gram -rod, oxidase and catalase +
Pseudomonas aeruginosa- Disease Association
Cystic Fibrosis (intrinsic resistance), nosocomial infections (UTIs, #1 for pneumonia, and intravascular catheter-related infections (consider if hospitalized pt has new infection)
Pseudomonas aeruginosa- Virulence Trait
exopolysaccharides
Pseudomonas aeruginosa- Common Antibiotic Resistance Mechanism
Intrinsic resistance to staphlococcal drugs
Neisseria gonorhoeae- Gram Stain and Characteristics
gram - diplococci
Neisseria gonorhoeae- Disease Association
gonorrhea, conjunctivitis leading to blindness in infants born to infected mothers
Neisseria gonorhoeae- Virulence Trait
pilus for adherance and resistance to phagocytosis, also phase variation on H pili antigen
Neisseria gonorhoeae- Common Antibiotic Resistance Mechanism
PCN, FQ, and emerging cephalosporin resistance
Bacteroides fragilis- Gram Stain and Characteristics
gram - rod, anaerobic (other then clostridia, but aerotolerant)
Bacteroides fragilis- Disease Association
endogeneous (brain and abdominal) anaerobic abscesses
Bacteroides fragilis- Virulence Trait
antiphagocytic capsule and production of superoxide dismutase
Chlamydia trachomatis- Gram Stain and Characteristics
gram - cocci or rod, obligate intracellular bacteria
Chlamydia trachomatis- Disease Association
Trachoma (chronic conjunctiva leading to blindness, in countries w/poor hygiene) and Genital infections (co-infect w/gonorrhea can can cause conjuntiva too in fetus of infected mothers)
Mycoplasma pneumonia- Gram Stain and Characteristics
No gram stain b/c no cell wall, but contain sterols in PM
Mycoplasma pneumonia- Disease Association
Walking pneumonia in young ages by direct contact with infected respiratory secretions
Mycoplasma pneumonia- Virulence Trait
adherence to respiratory epithelial cells, produces H2O2 and superoxide radicals, which damages host tissue.
