Infectious Diseases Flashcards
throat culture
- used for bacterial pharyngitis identification
- can identify all bacteria (not just S. pyrogenes)
- not ALWAYS indicated (Centor score 2-3)
nasopharyngeal swab uses
- viral cultures and identification
- pertussis
- S. aureus carriers
wound cultures
- may need to open surgical wounds to culture
- superficial swabs (high amount of skin flora and contaminants)
- deep swab or aspirates (better for identification)
- pustules and vesicles (express before swab)
positive urine culture
- everyone = colony count less greater than or equal to 10^5
- women with pyuria can be positive with greater than or equal to 10^2
- indicates presence of bacteria in bladder
men genitourinary swabs
- urethral
- 2-4 cm into urethral
- rotated 2-3 times
- rectal
- 1cm into anus
- rotate for 5-10 seconds
women genitourinary swabs
-
cervical
- 1-2 cm into cervical canal
- rotate for 30 seconds
-
vaginal
- 1cm into vagina
- rotate for 15 sec
-
rectal
- 1cm into anus
- rotate 5-10 sec
staphylococcus
- gram positive coci in clusters
- catalase (+)
- part of normal skin flora
what are the two staphylococcus species
S aureus
S epidermidis
S aureus
- coagulase (+)
- B-hemolysis
- MRSA has no hemolysis
S epidermidis
- coagulase (-)
- no hemolysis
streptococcus
- gram positive cocci in chains
- catalase (-)
2 main genus of streptococcus
streptococcus
enterococcus
streptococcus
- S. pyogenes
- S. pneumoniae
- S. agalactiae
enterococcus
E. faecalis
S. pyogenes
- group A
- oxidase (-)
- PYR (+)
- B-hemolysis
- pharyngitis, impetigo, erysipelas, necrotizing fasciitis
S. agalactiae
- group B
- oxidase (-)
- hippurate (+)
- less pronounced, B-hemolysis
- part of female urogenital tract
- neonatal infections
S. pneumoniae
- group B
- oxidase (-)
- alpha-hemolysis
- HEENT, pulmonary, neurologic, blood infections
group D streptococcus
no hemolysis
endocarditis, bacteremia
group D streptococcus species
- S. bovis
- S. viridans
E. faecalis
- oval, diplococci
- facultative anaerobes
- no or weak alpha-hemolysis
- normal GI tract flora
- UTI, bacteremia, endocarditis, surgical site infection (SSI)
peptostreptococcus species
- gram positive cocci
- non-spore forming
- anaerobic
- can be found in GI/GU tract, mouth, skin
- infections refractory to antibiotics
c. diptheriae
- catalase (+)
- facultative anaerobe
- pleomorphic rods - form brown/black colones
- normal skin flora
- diptheria
l. monocytogenes
- weak beta-hemolysis
- coccobacillus
- hippurate (+)
- facultative anerobe
- motile
- found in soil, streams, foods
- neonatal infections
bacillus species
- large gram positive rods
- may form spores
- aerobic
- B hemolysis
what are the bacillus species
b anthracis
b cereus
b anthracis
anthrax
b cereus
undercooked fried rice
clostridium
- large gram positive rods
- spore forming
- anaerobes
- B hemolysis
what are the main clostridium species
- C. perfringens
- C. difficile
- C. botulinum
- C. tetani
C. perfringens
part of clostridium species
- gas gangrene
- necrotizing fasciitis
C. difficile
part of clostridium species
- antibiotic associated diarrhea
C. botulinum
part of clostridium species
- Botulism
C. tetani
part of clostridium species
- tetanus
gardnerella vaginalis
- gram positive rods
- hippurate (+)
- bacterial vaginitis
lactobacillus species
- gram positive rod
- non spore forming
- facultative anaerobic
- normal vaginal flora
mycobacterium species
- acid-fast bacillus
- classified as gram positive due to lack of outer membrane
- waxy, outer coating mycolic acid
- classified as gram positive due to lack of outer membrane
- aerobic
- extremely slow growing - takes 6 weeks to culture
what are the mycobacterium species
- M. tuberculosis
- M. avium
- M. leprae
mycoplasmatacea family
- very small cell size
- no cell wall present - classified as gram +
- highly fastidious
- difficult to culture
what are the mycoplasmatacea species
- M. pneumoniae
- U. urealyticum
M. pneumoniae
- atypical pneumonia
- (+) agglutinins
U. urealyticum
- UTI, STI
- (+) urease
neisseria
- Gram-negative diplococci
- Facultative anaerobes
- Oxidase (+)
- Catalase (+)
- Carbohydrate utilization differentiates
what are the neisseria species
- N. gonorrhea
- N. meningitidis
moraxella catarrhalis
- gram negative coccobacillus
- oxidase (+)
- tributyrin (+)
- infections of upper respiratory system