Gram Negative Bacteria Flashcards
(37 cards)
Escherichia coli
Normally found in GI
Become pathogenic only when they reach tissues outside of their normal intestinal sites
EPEC: infant and children’s diarrhea ENTEROPATHOGENIC
ETEC: traveler’s diarrhea (Montezuma’s revenge) ENTEROTOXIGENIC
EIEC: similar to shigellosis ENTEROINVASIVE
EHEC: verotoxin; bloody diarrhea ENTEROHEMORRHAGIC
UTI
Sepsis
Meningitis
Klebsiella pneumoniae
2nd most common cause of G(-) sepsis
Pneumonia
Contains a capsule
Proteus mirabilis
Very motile, alkaline urine that hydrolyze urea to ammonia
Common cause of UTI and nosocomial infections
Shigella dysenteriae
Fluorescent
Non-motile; non-lactose fermenter
Highly adapted to humans
Acid resistant
Shiga toxin: inactivates 60s ribosomes
DYSENTERY: Diarrhea + colon inflammation
Salmonella sp definition
Mostly motile; non-lactose fermenter
Most produce H2S
Form acid in glucose and mannose
Lives in GI of animals
Salmonella sp example
- Typhoid fever – S. typhi
DOC: Chloramphenicol, Ciprofloxacin, Ceftriaxone - Sepsis – S. choleraesius
- Diarrhea/Gastroenteritis – S. enetritidis
Formations of flagella
Monotrichous- 1 flagella
Lophotrichous- 2/more flagella
Amphitrichous- 2 side 1 flagella on each side
Peritrichous- surrounded
Vibrio cholerae
Curved bacilli
Exotoxin: cholera toxin
Watery diarrhea: “rice watery” stools
Not an invasive infection
Helicobacter pylori
Spiral shaped, highly motile, microaerophilic
Produce large amounts of urease (ulceration destroy protective layer)
Adherence factors, motility, mucinase
Gastritis, gastric/duodenal ulcers
Haemophilus influenzae
Small uniform coccobacillus
Aerobic or facultative anaerobe
Encapsulated
6 distinct antigenic types
Growth factors (X,Y)
Causes meningitis, epiglottitis, septic arthritis, sepsis
Lab diagnosis: Chocolate agar
S/s: Flu-like
Haemophilus aegyptius
Aka Koch-Week’s bacillus, H.infuenzae biotype III
CM: Conjunctivitis (pus formation and red sclera)
Haemophilus ducreyi
CM: soft chancre known as chancroid (hard chancre –CM of syphilis)
S/S: ulcerative lesions in genitalia, Lymphadenitis in the groin area
Brucella
B. abortus (cow)
B. suis (swine)
B. cannis (dog)
B. miletensis (goat)
CM: Brucellosis aka Malta fever, undulant fever, Bang’s dse
TERATOGENIC
Yersinia pestis
CM: Bubonic plague aka black death, black plague
S/S: buboes (wound)
Rodents – rat flea (vector) – humans
Francisella tularensis
CM: Tularemia aka rabbit fever, deer fly fever
S/s: swollen lymph glands
Bordetella pertussis
“Whooping cough”
Fastidious coccobacilli
(+) capsule in virulent strains
Strict aerobe
Legionella pneumophila
Facultative intracellular
Aerobic, fastidious
Natural habitat is water
Causes Legionnaire’s disease and Pontiac fever
Transmitted via Aircon
S/s: pneumonia-like
Neisseria meningitides
Diplococci
Meningococcus
Glucose and maltose fermenter
Piliated
Meningitis, meningococcemia
Neisseria gonnorheae
Gonorrhea, STD (uncontrollable drip)
PID
Gonococcal ophthalmia neonatorum- normal delivery DOC: Erythromycin
Pseudomonas aeruginosa
Motile, obligate aerobic rods
Occurs as single bacterium, in pairs in short chains
Not ferment CHO
UTI, pneumonia
Pigments produced by P. Aeruginosa:
Pyocyanin
Pyoverdin
Pyorubin
Pyomelanin
Chlamydia and Rickettsiae
Small, obligate, intracellular (only grow inside cell)
Energy parasites
Contain DNA and RNA
Can synthesize own CHONS
Chlamydia
Elementary Bodies (EB): infective form
Reticulate Bodies (RB): non-infective form
Causes conjunctivitis, cervicitis, pneumonia
1. C. trachomatis- inclusion conjunctivitis
2. C. pneumoniae- atypical
3. C. psittaci- colorful bird infection through inhalation aka ornithosis
Rickettsia
Pleomorphic coccobacilli
Peptidoglycan-ctg muraminic acid and diaminopimelic acid
Growth enhanced by sulfonamides
Vector: transmitted via ticks, mites, louse, fleas
ID test: Weil-Felix Test
s/s: diffused rashes from arthropod bite
Rx: TCN, Chloramphenicol, increased resistance to sulfonamides
