Gram Negative Bacteria Flashcards
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
Rickettsia rickettsii
Vector: wood tick or dog tick
Rocky Mountain Spotted Fever
Fever, conjunctival redness, severe headache, rash
Rickettsia prowazekii
CM: Brill-Zinser’s Dse/epidemic typhus (vector = louse)
Rickettsia typhi
Murine typhus (Rat flea)
Orientia tsutsugamushi
CM: Scrub Typhus (vector = mite)
Rickettsia akari
CM: Rickettsial Pox (vector = mite)
Rickettsia australis
CM: Queensland Tick Fever (vector = tick)
Spirochetes
Corkscrew movement
Spiral, motile
Have axial filaments (ENDOFLAGELLA)
Treponema, Borrelia, Leptospira
Treponema pallidum
STD hard chancre
Microaerophilic
Darkfield microscopy, immunofluorescence, silver stains
Causes syphilis
CM: Syphilis
Types of treponema pallidum
- Congenital (newborn, during 4th month)
s/s: keratoconjunctivitis, perforated palate, saddle nose, patchy mucus membrane, Hutchinson’s teeth
ID test: Flruoresent Treponema test - Acquired/STD
1st Stage: hard chancre
2nd Stage: condylema – macupapular rash with cigar butt like burn
Latent: Several years
3rd Stage: gummas characterized by CNS problems
ID test: venereal dse research lab test (VDRL), Rapid plasma regain
Rx: Pen G (DOC) – administer at gluteus maximuss
Borrelia recurrentis
Highly flexible
Can be cultured in fluid media (blood serum and tissue)
Causes Relapsing fever
White footed mouse and white tailed deer
Borrelia burgdorferi
CM: Lyme’s disease
Vector: Ixodes tick
S/s: erythema chronicum migrans, bull’s eye rash
Leptospira interrogans
Tightly coiled, thin, flexible
Causes Leptospirosis/Weil’s Dse
Culture: Fletcher’s media
Commonly from rodents but may be from dogs, bats, squirrels
Acquired by humans from contaminated water
S/s: nephritis, meningitis, conjunctivitis, splenomegaly, jaundice
Rx: Doxycycline
Mycoplasma pneumoniae
Plastic, pleomorphic shape
Ribosomes Lacks peptidoglycan cell wall
Enclosed by lipid bilayer membrane
Can’t synthesize sterol
Smallest known free-living self-replicating prokaryotic cell
Produces “walking pneumonia”
Resistant to Penicillin, Cephalosporin, Vancomycin
NOSOCOMIAL
Highly resistant to CW Inhibitors
