Aerobic Gram negative Rods Flashcards
1
Q
Escherichia coli
A
pathology:
- nonpathogenic E coli (normal gut flora) + virulence factors = disease
- exotoxin production (heat-labile and stable toxin, Shiga-like toxin)
- endotoxin (Lipid A portion of LPS)
Diseases:
- Diarrhea
- death usually due to dehydration
- Traveller’s D
- enterotoxin-producing strains (do not invade intestine and cause nonbloody D)
- enteroinvasice strains (invade epithelium and cause bloody D)
- enterohemorrhagic strains (produce exotoxin and cause blood D and hemolytic-uremic syndrom [HUS])
- HUS w/ anemia, thrombocytopenia (dec in platelets), and renal failure (thus uremia aka urea in blood)
- UTIs (fullness of bladder, dysuria, frequency)
- Neonatal meningitis (K1 capsular antigen); in first month of life
- Gram-neg sepsis
- Pneumonia (hospital-acquired)
epidemiology:
- Diarrhea
- adults and infants (not yet developed immunity)
- adults and kids from developed countries, travelling to undeveloped countries (Traveller’s D)
- UTIs
- most common cause of UTIs
- usually in women and hospitalized pts w/ catheters in urethra
- Gram-neg sepsis
- most common cause of this
- debilitated hospitalized pts
- intestinal disease in developing countries
- extra-intestinal involvement more common in developed areas
2
Q
Klebsiella
A
disease:
- Rhinoscleroma
- Sepsis (in hospitalized pts)
- UTIs (pts in hospital w/ catheters)
- Pneumonia (hospitalized pts and alcoholics)
P/TX:
- abx resistance
- extended spectrum beta-lactamases (ESBLs)
- carbapenemase
3
Q
Proteus
A
disease:
- staghorn calculi (more common in women than men)
- increases urine pH
epidemiology:
ABX resistance and TX:
- P. mirabilis: usually ampicillin sensitive
- P. vulgaris: more antibiotic resistant
4
Q
Serratia
A
disease
epidemiology:
* mostly environmental rather than part of normal flora
abx resistance
- Can survive some disinfectants and non-bacterial soaps, and has been the source of related outbreaks
TX
5
Q
Enterobacter
A
disease:
* mainly nosocomial pathogen
epidemiology:
- infections most common in pts on abx and those in ICUs
ABX resistance
- resistance to beta-lactamase (produces beta-lactamase)
6
Q
Yersinia
A
disease
- enterocolitis
- mesenteric adenitis (mimics appendicitis)
- septicemia
- outbreaks associated w/ contamination at cold temps (related to diseases of refrigerated products)
epidemiology
abx resistance
TX
7
Q
Acinetobacter
A
disease:
epidemiology:
ABX resistance:
TX:
8
Q
Halophilic vibrios
A
disease:
- Diarrheal pathogen ass w/ raw, undercooked shellfish
- mild to severe watery D, N/V, abdominal cramps, fever
- self -limiting, lasting about 3 days (need to take good hx)
epidemiology:
- common in Japan, uncommon in US
- outbreaks on cruise ships
ABX resistance:
TX:
9
Q
Aeromonas
A
disease:
epidemiology:
ABX resistance:
TX:
10
Q
Pasteurella multocida
A
disease:
- focal soft tissue infections
- acute onest (hrs)
- erythema, pain, swelling
epidemiology:
* in mouths of cats and dogs => infections usually from bites, scratches or licking
ABX resistance:
TX:
11
Q
Brucella
A
disease:
- get through abrasions in skin from infected carcasses, ingestion of unpasteurized dairy products, inhalation from aborting animals
- Brucellosis:
- acute presents w/ high fever, sweats, malaise, HA, anorexia, abd pain, D, back pain
- resolved after a few weeks
- lymphadenopathy, hepatosplenomegaly
- followed by “undulant/Malta” fever (subacute brucellosis)
- acute presents w/ high fever, sweats, malaise, HA, anorexia, abd pain, D, back pain
epidemiology:
- disease in animals so see in abattoir workers (slaughterhouse), vets are at risk
- recently ass w/ hunting wild/feral pigs
- ingestion of unpasteurized dairy products
- zoonosis = can be transmitted from other vertebrate animals to humans
ABX resistance:
TX:
- requires prolonged abx therapy
12
Q
Bartonella
A
disease:
epidemiology:
ABX resistance:
TX:
