Intro Flashcards
General characteristics of Enterobacteriaceae Normal microbiota of where? Oxygen requirements? Nutritional requirements? Glucose fermentation? Oxidase postive / negative?
Normal microbiota of GI and vagina Facultative anaerobes Simple nutritional requirements Ferment glucose Oxidase negative
K antigen
Capsule. Some bacteria.
H antigen
Flagellum. Some bacteria
O antigen
Lipopolysaccharide (LPS). All Gram Neg.
Which enterobacteriaceae cause sepsis? (4)
E coli, Klebsiella, Enterobacter, and Proteus
Which enterobacteriaceae cause pneumonia? (2 main ones, 2 minor ones)
Klebsiella and Serratia (mainly).
Also Enterobacter and E coli.
Hallmark of Klebsiella
What type of pneumonia?
“Currant jelly” sputum. Mucoid
Lobar pneumonia. Abscess / necrosis is common.
Which enterobacteriaceae causes meningitis (1)?
E coli
Which enterobacteriaceae cause UTI’s? (3)
E coli, Proteus, and Providencia
Which enterobacteriaceae cause gastroenteritis? (4)
Salmonella, Shigella, E coli, and Yersinia
Which enterobacteriaceae causes intraabdominal infections? (1)
E coli
E coli general characteristics
Gram stain / morphology
Oxygen requirement
Normal location
GNR
Facultative anaerobe
Lives in GI tract and aqueous environments
EHEC
Specific strain
Name Disease
Enterohemorrhagic E coli
O157:H7
4th leading bacterial enteropathogen
EPEC
Name
Disease
Enteropathogenic E coli
Childhood diarrhea abroad
UPEC
Disease
Virulence factors (3)
Uropathogenic E coli Leading cause of UTI P pili adhere to uroepithelial cells. Siderophore is iron acquisition mechanism. Endotoxin
NMEC Other name Virulence factor characteristics Normal microbiota location What is #1 cause of bacterial neonatal meningitis?
Neonatal Meningitis E coli
K1-encapsulated E coli.
Capsule made of sialic acid, which is found in many host tissues so body doesn’t make Abs and makes phagocytosis difficult. Mother doesn’t pass Abs to infant.
Normal microbiota in gut and vagina
Group B Strep is #1 cause of bacterial neonatal meningitis. NMEC is #2.
K12 E coli use
Lab tool used as a vehicle for propagating cloned DNA in plasmids.
Main diseases caused by these Gram Neg Non-Enterobacteriaceae: •Bordetella pertussis •Campylobacter •Haemophilus •Helicobacter •Moraxella •Neisseria • N. gonorrhoeae: • N. meningitidis: •Pseudomonas •Vibrio
- Bordetella pertussis - tracheobronchitis, whooping cough
- Campylobacter - gastroenteritis
- Haemophilus - upper respiratory infection (URI), otitis media (OM), meningitis, sepsis
- Helicobacter - gastritis, ulcers, gastric cancer
- Moraxella - upper respiratory infection (URI), otitis media (OM)
- Neisseria
- N. gonorrhoeae: genital tract infection, sexually transmitted infection (STI)
- N. meningitidis: nasopharyngeal colonization, meningitis, sepsis
- Pseudomonas - opportunistic lung, skin, eye, burn/wound, blood infections
- Vibrio - gastroenteritis, skin lesions
What are adhesins usually made of? Where are they found?
Carbohydrates. Found at end of pili / fimbriae.
How does cranberry juice work for UTI prophylaxis?
Sugars block adhesin receptors.
Type I pili
What do they attach to?
Which bacteria have them?
Attach to mannose molecules
Found in all E coli
P / PAP pili Stands for? Function Which bacteria? Which diseases?
Pyelonephritis-associated Pilus
Allow E coli to attach to host galactosyl-galactopyranoside (Gal-Gal) molecules. Occur more often in pyelonephritis (kidney) than cystitis (bladder).
Where are P blood group antigens found?
Renal pelvis cells
Where are P1 blood group antigens found?
Upper urinary tract infections
Which bacteria that cause meningitis have capsules? (4)
K1 E coli, H flu type b, N meningitides, Strep pneumoniae
Siderophores
Iron-chelating compounds secreted by E coli and others that compete for host iron.
Which type of toxin is a secretory toxin? (Causes secretions)
Cholera toxin –> diarrhea
What do cytotoxins do? What are the specific toxins released by these bacteria? •Shigella •EHEC •ETEC •H pylori •Pseudomonas
- Cytotoxins – Damage / destroy host cells
- Shigella – Shiga toxin
- EHEC – Shiga-like toxin or verotoxin
- ETEC – Heat liable enterotoxin
- H pylori – vacuolating toxin
- Pseudomonas – exotoxin A
Which bacteria make IgA protease?
H flu and Neisseriae
Acid resistance / required innoculum for Shigella and EHEC
Highly acid resistant. Small inoculum needed.
Acid resistance / required innoculum for Vibrio cholerae
Acid sensitive. Large inoculum needed.
Which bacterium has intermediate acid-sensitivity?
Salmonella
Which organisms cause hematology / descending UTI’s?
Staph aureus and Candida
What is most common site for infection in long-term care residents and bacteremia in elderly?
UTI’s
Urethritis
Which bugs?
Colonization of the urethra. Often caused by different bugs than those that cause UTI’s
Bacteriuria
Inoculation of the bladder. NOT the same things as a UTI
UTI
Attachment to uroepithelium of bladder (cystitis)
What is #1 cause of UTI’s?
What is #2 cause of UTI’s?
#1 = E coli (both community acquired and nosocomial) #2 = Staph saprophyticus
Proteus spp causing UTI's Location of normal microbiota Proteus mirabilis disease Other proteus spp disease Special enzyme and function
Normal intestinal microbiota
Proteus mirabilis UTI is community acquired
Other Proteus spp UTI’s occur in hospitals, nursing homes, and immunocompromised.
Urease breaks down urea → ammonia → increase in urine pH → stone formation → further susceptibility to infection. Increased pH also helps Proteus survive.
Providentia causes what types of UTI’s?
Nosocomial and catheter UTI’s
Normal vaginal colonizers
Staph saprophyticus (Coag-Neg), enterococcus, and Candida albicans
What usually causes coag-neg staph?
Implanted medical devices
4 oral AB’s that cover for MRSA
Clindamycin, linezolid, doxycyclin, TMP-sulfa
5 clues that suggest life-threatening SSTI’s
- Pain out of proportion to visible presentation
- Systemic toxicity – anion gap, creatinine, CK, shock, organ failure
- Rapid progression
- Necrosis, gangrene, bullae, cutaneous hemorrhage, crepitus (gas-forming)
- Anesthesia – due to nerve destruction
AB’s for CAP
Ceftriaxone / doxycyclin + macrolide or FQ
