basic classification, major distinguishing features, genus, pathogenicity, clinical significance Flashcards
C. difficile
clostridium
anaerobic gram + bacilli
straight rods, spores
pathogenicity = toxin A and toxin B
clinical: diarrhea (antibiotic or nosocomial)
Neisseria menigitidis
neisseria
fastidious gram -
diplococci, oxidase +
pathogenicity = polysaccharide capsule, outer membrane protein
clinical: meningitis
C. botulinum
clostridium
anaerobic gram + bacilli
straight or curved rods, spores
pathogenicity = neurotoxin
clinical: botulism (flaccid paralysis)
neisseria gonorrhea
neisseria
fastidious gram -
diplococci, oxidase +
pathogenicity: pili, capsule, proteases, adherence proteins
clinical: gonorrhea, conjunctivitis, pharyngitis
E. coli
enterobacteriaceae
aerobic gram - fermenters
rods, oxidase -
pathogenicity = endotoxins, exotoxins, capsule, pili
clinical= meningitis in newborns, UTIs, GI infection
Listeria monocytogenes
listeria
aerobic gram + bacilli
single or short chain rods, NONbranching, motile
catalase +
pathogenicity = hemolysin
clinical: gastroenteritis, meningitis/encephalitis
in pregnancy can cause abortions, stillbirth, preterm
C. perfringens
clostridium
anaerobic gram + bacilli
box car shaped rods (blunt ends), spores
pathogenicity = alpha toxin, enterotoxins
clinical: gas gangrene, diarrhea (bloody = acute necrotizing GI infection)
peptostreptococcus spp
peptostreptococcus
anaerobic gram + bacilli
elongated cocci, NONspore forming
pathogenicity is unknown
clinical = mixed anaerobic and aerobic bacterial infections including cutaneous, respiratory, oral, female pelvic
C. diptheriae
corynebacterium
aerobic gram + bacilli
rods, NONbranching
catalase +
pathogenicity = diptheria toxin
clinical: diptheria (pharyngeal)
Group A strep (S. pyogenes)
streptococcus
aerobic gram + cocci
cocci in PAIRS and CHAINS
catalase -
B hemolytic
pathogenicity = streptolysin O & S
clinical: pharyngitis, necrotizing fasciitis, rheumatic fever, streptococcal toxic shock syndrome (STSS)
Salmonella spp
enterobacteriaceae
aerobic gram - fermenter
rods, oxidase -
pathogenicity = adhesion proteins, survival in phagocytes, dissemination to other tissues
clinical: GI infection, bacteremia
Proteus spp
enterobacteriaceae
aerobic gram - fermenter
rods, oxidase -
pathogenicity = endotoxins, exotoxins, capsules, adhesion proteins
clinical: UTIs, nosocomial infections, blood infections
Vibrio cholerae
vibrio
aerobic gram - fermenter
rods, oxidase +
pathogenicity: somatic O antigens, exotoxins
clinical: cholera (GI)
moraxella catarrhalis
moraxella
aerobic gram - non-fermenter
diplococci, oxidase +
pathogenicity: uncertain; cell envelope adhesion factors
clinical: CAP
enterococci
streptococci
aerobic gram + cocci
cocci in PAIRS, CHAINS
catalase -
NON-hemolytic
pathogenicity = surface adhesins
clinical: UTIs, endocarditis, nosocomial vanco-resistant enterococcus
A. israelii
actinomyces
anaerobic gram + bacilli
beaded, irregular staining on gram stain
branching, filamentous bacilli
pathogenicity = unknown
clinical = oral/cervicofacial infections, pelvic infections (IUD)
C. jeikeium
corynebacterium
aerobic gram + bacilli
rods, NONbranching
catalase +
pathogenicity = unknown
clinical = foreign body infections
C. tetani
clostridium
anaerobic gram + bacilli
straight rods, spores
pathogenicity = tetanus toxin
clinical: tetanus
Pseudomonas aerigunosa
Pseudomonas
aerobic gram - NONfermenter
slender bacilli, oxidase +, metallic sheen, grape-like color
pathogenicity = exotoxin A, endotoxins
clinical: otitis externa, pneumonia in CF, ventilator acquired pneumonia, UTIs
S. epidermis
coagulase - staphylococci
aerobic gram + cocci
cocci in CLUSTERS
catalase +
pathogenicity = biofilm production
clinical= nosocomial blood stream infections associated with IV catheters, prosthetic material infections
S. pneumoniae
streptococcus
aerobic gram + cocci
cocci in PAIRS/CHAINS
catalase -
alpha hemolytic
pathogenicity = polysccharide capsule
clinical = CAP, otitis media, conjunctivitis, meningitis
Haemophilus influenzae
haemophilus
fastidious gram -
coccobacilli or short rods, satellite, oxidase +
pathogenicity = polysaccharide capsule, outer membrane protein
clinical = meningitis, epiglottitis, conjunctivitis, otitis media, pneumonia
S. aureus
Staphylococcus
aerobic gram + cocci
cocci in CLUSTERS
catalase +
pathogenicity = toxic shock syndrome toxin (TSST1), enterotoxins
clinical: skin and soft tissue infections, necrotizing fasciitis, osteomyelitis, endocarditis, toxic shock syndrome, CF pneumonia, diarrhea
S. mitis
streptococcus
aerobic gram + cocci
cocci in pairs/chains
catalase -
alpha hemolytic
pathogenicity = polysaccharide capsule
clinical = native valve endocarditis, bacteremia
Strep. agalactiae (group B strep)
streptococcus
aerobic gram + cocci
cocci in pairs/chains
catalase -
Beta hemolytic
pathogenicity = polysaccharide capsule
clinical = early onset neonatal disease (pneumonia, sepsis), late onset neonatal disease (meningitis, sepsis)
Bacteroides fragilis
bacteroides
anaerobic gram -
straight bacilli, pale staining
pathogenicity = capsules, endotoxins, enzymes
clinical = abscesses throughout body, bacteremia, aspirational pneumonia
Enterobacter spp
enterobacteriaceae
aerobic gram - fermenter
rods, oxidase -
pathogenicity = endotoxins, exotoxins, capsule
clinical = UTIs, nosocomial, blood infections
M. pneumonia
mycoplasma
non gram staining bacteria
no cell wall, need special growth media
pathogenicity = polyclonal T cell and B cell activators, trigger formation of cold agglutinins (CLUMP RBCs)
clinical = atypical pneumonia, dermatologic involvement, cardiac and neuro complications
Chlamydia trachomatis
obligate intracellular bacteria
non-cultivable, requires living cells
pathogenicity = complicated intracellular lifecycle, inhibits phagosome/lysosome fusion
clinical = urethritis, epididymitis, proctitis, cervicitis, PID, conjunctivitis, lymphogranuloma venereum
genital mycoplasma (M. hominis, M. genitalium)
non gram staining bacteria
no cell wall, need special growth medium
pathogenicity = resistant to B lactam antibiotics
clinical: non gonococcal urethritis in males
chlamydia psittaci
obligate intracellular bacteria
non-cultivable as requires livings cells
pathogenicity = vertebrate vector (birds)
clinical = atypical pneumonia
Helicobacter pylori
spirochetes
gram -
pathogenicity = acid resistance, establishes residence in stomach
clinical significance = duodenal and gastric ulcers
mycobacterium avium complex (MAC)
acid fast bacilli
non-spore forming, non-motile
Ziehl-Neelsen stain needed
slow growing, fastidious growth requirements
pathogenicity = inhibition of lysosome-phagosome fusion
clinical = pulmonary disease, disseminated infection in AIDS patients, opportunistic in immune compromised patients
Treponema pallidum
spirochete
CANNOT gram stain
tightly wound slender coils with pointed ends
pathogenicity = lack of proteins on outer membrane of cell wall, antigenic variation
clinical = primary syphilis (painless chancre) ; secondary syphilis (myalgia, headache, fever, rash); tertiary syphilis (neurosyphilis i.e general paralysis), Cv syphilis and congenital syphilis (facial and tooth abnormalities)
Rickettsia rickettsii
obligate intracellular bacteria
small and gram -
growth requires living cells
zoonotic infections caused by ticks, flease, mites
pathogenicity = tick vector and cell to cell spread (hundreds of contagious epithelial cells are infected)
clinical = rocky mountain spotted fever (fever and rash)
mycobacterium tuberculosis
acid fast bacilli
non spore forming, non motile
Ziehl-Neelsen stain required due to waxy outer membrane
slow growing
fastidious growth requirements
pathogenicity = survive and multiply in alveolar macrophages, carried to lymphatics and can start other foci of infection
clinical = primary pulmonary disease, reactivation disease, disseminated disease
