Bacteriology 2 Flashcards
Neisseria - Both Species
Gram - Diplococci
Metabolize glucose
Produce IgA proteases
Contain LOS (lipoologosaccharides with strong endotoxin activity)
meningococcal also ferments maltose
Gonococci vs Meningococci
Polysaccharide Capsule? Carbohydrate fermentation transmission? ppx? tx?
sx p/w?
GC - no polyssacharide capsule MC - polysaccharide
GC - glucose only MC - glucose & maltose
GC - STI, perinatally MC - resp/oral secretions
GC - condoms, erythromycin eye ointment of newborns (prevents blindness)
MC - close contacts: Rifampin, ciprofloxacine, or ceftriaxone
GC - ceftriaxone (+azithro/doxy for CT)
MC - ceftriaxone or PCN G
GC p/w gonnorhea (purulent vaginal/penile d/c), PID, Fitz-Hugh-Curtis syndrome septic arthritis, neonatal conjunctivitis (2-5 day of life)
MC p/w meningitis, petechia, gangrene of toes, Waterhouse-Friderichsen syndome (adrenal hemorrhage => fever, AI, DIC, shock)
Haemophilus influenzae
morphology?
transmission?
virulence factor?
growth on what medium?
p/w?
non-typeable/nonencapsulated type p/w?
tx
ppx
Gram - coccobacilli
aerosol transmission
produces IgA protease
Culture on chocolate agar (factors V - NAD+ & X - hematin) or with s.aureus (produces NAD+ via hemolysis)
p/w epiglottitis (thumb sign), meningitis, otitis media, PNA
non-typeable most common cause of otitis media, conjunctivitis, bronchitis)
tx - mucosal infxn - amoxacilin or augmentin
meningitis - cetriaxone
ppx - close contacts with rifampin
Bordetella pertussis morphology virulence factor p/w three clincal stages ppx
anaerobic G- coccobacillus 3 virulence factors: - pertussis toxin - diables Gi - adenylate cyclase toxin - increases cAMP - tracheal cytotoxin
3 clinical stages
- catarrhal - low grade fever, coryza (stuffed nose)
- paroxysmal - paroxysms of intense cough, inspiratory whoop, & posstussive vomitting can occur
- convalescent - gradual recovery from chronic cough
ppx: Tdap & DTaP vaccines
Legionella pneumophila
morphology transmission growth medium? dx tx
Legionnaires’ Disease?
Pontiac Fever?
G- rod, silver stain
aerosol from environmental water source (A/C, H20 tank)
charcoal yeast extract w/ Fe and Cysteine
urine antigen, may see hypoNa
Legionnaires’ Dx
- severe PNA, often u/l & lobar
- GI sx
- fever & CNS sx
Pontiac Fever - mild flu-like syndrome
Pseudomonas aeruginosa morphology, oxidase? virulence factors - PEEP + ? p/w PSEUDOMONAS tx - CAMPFIRE
aerobic, motile G- rod
oxidase +
virulence factors - PEEP + ROS
P - phospholipase C (degrade cell membrane)
E - endotoxin ( fever, shock)
E - exotoxin A (inhibit EF2)
P - pigments - Blue-green (pyoverdine, pyocyanin)
p/w
P - pneumonia
S - sepsis
E - ecthyma gangrenosum (necrotic cutaneous lesion, rapidly progressive, a/w immunocompromised)
U - UTI
D - DM
O - osteomyelitis
M - mucoid polysaccharide capsule => chronic PNA in CF pts 2/2 biofilm formation
O - otitis externa (“swimmer’s ear”)
N - nosocomial infxn (ie indwelling catheters)
A - addicts - drugs
S - skin infxn - esp burn victims, hot tub folliculitis
tx - CAMPFIRE C - carbapenems A - aminoglycosides M - monobactamcs P - polymyxins (colistin, polymyxin b) F - floroquinolones IR- 3rd & 4th gen cephalosporins (ceftazidime, cefepime) E - extended spectrum PCN - piperacillin, ticacillin
Salmonella typhi
morphology, oxidase?
growth medium
invasion of GI tract how?
transmission & reservoir H2S production Flagella Virulence factor Infxn Dose Effector of Abx on fecal excretion Immune response GI manifestation Vaccine
Unique Properties (2)
Gram - rod, oxidase -
non-lactose fermenting - not pink on Mcconkey
M cells of peyer’s patches
human only, hematogenous dissemination
yes, H2S
yes, flagella
endotoxin, Vi capsule
High (requires high numbers to cause infxn, inactivated by
gastric acid)
abx prolong infxn
monocytes
constipation ---> diarrhea
PO vaccine - live attenuated; IM vaccine - Vi capsule
1) Causes Yellow Fever:
- fever, abd pain, constipation, rose spots on abd
- tx CTX or floroquinolone
2) Carrier state with GB colonization
Salmonella spp except typhi
morphology, oxidase?
growth medium
invasion of GI tract how?
transmission & reservoir H2S production Flagella Virulence factor Infxn Dose Effector of Abx on fecal excretion Immune response GI manifestation Vaccine
Unique Properties (1)
G - rod, oxidase -
non-lactose fermentin ( no pink McConkey agar)
invades M cells in peyer’s patches
humans & animals (pets, turtles, poultry, eggs); hematogenous spread
yes H2S yes, flagella Endotoxin High Abx prolong infxn, not indicated mostly polymorphic neutrophils diarrhea, sometimes bloody no vaccine
1) common cause of gastroenteritis
Shigella
morphology, oxidase?
growth medium
invasion of GI tract how?
transmission & reservoir H2S production Flagella Virulence factor Infxn Dose Effector of Abx on fecal excretion Immune response GI manifestation Vaccine
Unique Properties
4f’s
most severe:
G - rod, oxidase -
non-lactose fermenting - no pink on macconkey agar
invades M cells in peyer’s patches - key for pathogenicity (little bugs can cause big dx with lottsa toxin)
humans only; hematogenous spread no H2S no flagella endotoxin, shiga toxin/enterotoxin low abx shorten duration PMN bloody diarrhea (bacillary dysentary) no vaccine
fingers, flies, food, feces
S dysenteriae > S flexneri > S boydii > S sonnei
Yersina enterocolitica
morphology
transmission
p/w
G- rod
pet feces, contaminated milk, pork
diarrhea, pseudoappendicitis (RLQ pain 2/2 ileitis or mesenteric adenitis)
Lactose Fermenting Enteric Bacteria
MacConkey - MacConKEE’S
MacConKEE'S: C - citrobacter K - klebsiella E - enterobacter E - E.coli (beta-galactosidase) S - serratia
E coli
Morphology
Virulence Factor & their consequence (2)
G - rod, lactose fermenting
fimbriae/P-pili - cytitis, pyelonephritis
K capsule - PNA, neonatal meningitis
LPS endotoxin - septic shock
EIEC
Enteroinvasive E. coli
microbe invades intestinal mucosa & causes necrosis and inflammation
p/w dysentery
ETEC
Enterotoxigenic E.coli
produces heat-labile and heat-stable enterotoxins
p/w Traveler’s (watery) diarrhea
EPEC
Enterpathogenic E.coli
adheres to apical surface, flattens villi, & prevents absorption
p/w diarrhea in children
EHEC
Enterohemorrhagic E.coli
O157:H7
Hemorrhagic Dysentery (toxin–>necrosis & inflammation), Hamburgers (uncooked & raw leafy vegetables) - transmission
Hemolytic-Uremic Syndrome
- p/w triad of anemia, thrombocytopenia & acute renal failure 2/2 microthrombi
- microangiopathic hemolytic anemia
Klebsiella
morphology
capsule
p/w
G- rod
polysaccharide capsule –> mucoid colonies
lobar aspiration pneumonia in DM and ETOHics and currant red sputum
abscesses in liver & lungs
nosocomial UTI
Campylobacter jejuni Morphology oxidase preferred temperature transmission p/w can be c/b (2)
G - comma, polar flagella,
oxidase +
grows 42C
F/O, pets, uncooked meat/poultry, unpasteurized milk
bloody diarrhea esp in children
reactive arthritis, GBS
Vibrio cholerae Morphology Oxidase growth media where found? virulence factor inoculation dose acid labile or stabile? transmission p/w tx
G - comma, flagella oxidase + growth alkaline media endemic to developing countries enterotoxin - permanently activates Gs (increased cAMP) high inoculation dose acid labile water, raw shellfish rice water diarrhea oral rehydration
Helicobacter pylori morphology oxidase, catalase, urease ? virulence where does it colonize? p/w RF for what? Tx - triple therapy
G - curve flagellated
oxidase + catalase + urease +
urease produces ammonia, alkalizing gastic environment
antrum of stomach
gastritis, peptic ulcers esp duodenal
RF for MALT lymphoma, gastric adenoCA, and PUD
triple therapy: PPI, clarithromycin, amoxacillin (metronidazole if PCN allergy)
