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101 Cards in this Set
- Front
- Back
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Sterilization
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Killing of all microorganisms
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Germicide
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the agent used to kill bacteria
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Disinfection
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Use of germicide to destroy the potential infectivity of an inanimate object
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Antisepsis
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application of chem agents to the surface of human body to kill or inhibit path bacteria
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Septic
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Path bacteria in living tissue
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Sanitize
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Lowering of bacterial content of objects.
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Preservative
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Agent used in small concentrations to inhibit growth of organisms in food or vaccines.
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Phenol coefficient
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measure of the killing capacity of agent
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Wet heat
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Most effective - disrupts H-bonds in proteins
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UV light
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Produces cross-linked thymine dimers --> SOS response
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Ethylene oxide
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alkylating agent - toxic to humans
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Triclosan
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Inhibits specific step in lipid biosynthesis
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Gentian violet
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Dye that is used as an antifungal agent
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Enteric family characteristics (4)
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Facultative anaerobes, fermentation of glucose, oxidase negative, reduction of nitrates to nitrites.
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Salmonella genus - main characteristics
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Gram (-), Facultative intracellular anaerobes, non-spore forming, Glu (+), Lac(-), Produce H2S, Motile, O, H & Vi antigen. Use of EMB agar to ID (Lac -). Requires high inoculum for disease (10^5).
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Salmonella typhi
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Enteric fever. Insidious onset (7-14 d). Survive gastric acid. Induce endocytosis into epithelial cells. Type 3 secretion system (injection needle). Multiplies in peyer's patches --> septicemia, LPS symptoms.
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Salmonella typhi patho island
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SPI-1 encodes invasion, SPI-2 = genes for intracellular survival
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Salmonella typhi diagnosis
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Early + stool, blood + 7-14 days, stool again later. O, H, Vi antigens. Rose spots.
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Salmonella typhi treatment
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Fluoroquinolones (cipro)/3rd gen cephalosporins (ceftriaxone). Second line: cholarmphenicol, ampicillin, trimethoprim. Chronic carrier states: 1) ampicillin/cipro 2) cholecystectomy
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Salmonella typhi vaccine
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Oral live attentuated or Vi capsular polysach given 2 weeks prior to exposure. 50-80% effective.
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Salmonella choleraesuis
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Rare form of septicemia, one serotype, swine source, high fever and bacteremia, suppurative lesions
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Salmonella typhimurium
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Gastroenteritis with 8-48 hr incubation, confined to GI tract, 1500 serotypes, diagnosis dependent on finding in feces, mostly self-limiting.
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Salmonella enteritidis
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Most frequent serotype in egg contamination.
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Shigella
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Gram (-), facultative intracell anaerobe, nonmotile, no H2S, 4 serotypes, 1-4 day incubation, invades epithelial cells, rarely bacteremia. Low inoculum (100) - resists stomach acid
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Shiga toxin
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A (blocks 60S) and B (invades) subunits. Blocks fluid absorb by killing epithelial cells.
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Shigella Dx
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Watery diarrhea at first, later blood and mucus, PMN's in stool. Shigella in stool.
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Shigella treatment
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fluid and electrolytes!
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Escherichia Coli general
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Gram - rod, facultative anaerobe, lac+. O157:H7 is sorbitol negative (colorless).
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Enterohemorrhagic E Coli
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O157:H7 - large intestine, extracellular, bloody diarrhea, TIIISS. LEE pathogenicity island - Tir (attachment) and Intimin (binding) - A/E lesions.
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Hemolytic uremic syndrome
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Caused by EHEC shiga-like toxin - destruction of RBC's and lining of blood vessels.
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Shiga-like toxin
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EHEC - also contains hemolysin - pore-forming protein.
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EnteroPathogenic E. Coli
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EPEC - small intestine - Person to Person (P). Leading cause of childhood diarrhea in developing countries.
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EnteroToxigenic E. Coli
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ETEC - Traveler's diarrhea. Fimbrae attachment - small intestine. Heat-labile toxin --> increased cAMP
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EnteroAggregative E. Coli
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EAEC - childhood diarrhea like EPEC. Heat-stabile toxin causes hemolysin.
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EnteroInvasive E. Coli
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EIEC - non fibrial adhesins - invades mucosal cells, diarrhea like Shigella.
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Diffuse Adhering E. Coli
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DAEC - diarrhea in older children in developing countries.
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Uropathogenic E. Coli
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UPEC - 95% UTIs, mannose-sensitive adhesins, >10^5/mL for infection, cystitis, pyelonephritis, persistent infections due to biofilms
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UPEC pili
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P pili - mannose resistant, cause of pyeloneph,/cystisis, P fimbriae - glycolipids on human P blood group, type 1 pili - cystitis
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E. Coli bacteremia
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Leading cause of nosocomial bactermia, K1 capsule - polysialic - serum resistant - like N. meningitides, endotoxic shock
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Neonatal Meningitis - E. Coli
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Most common neonatal pathogen. Cross blood-brain, K1 capsule (escapes phagocytosis), siderophores and hemolysin.
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Klebseilla pneumoniae
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Gram (-), fac anaerobe, lac +, primary pneumonia, red current jelly sputum, capsule is main virulence factor
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Enterobacter cloacae
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Gram (-) fac anaerobe, lac +, burns, wounds, 2nd to antibiotic therapy, motile
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Serratia marcesens
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Gram (-), fac anaerobe, lac -, prodigiosins (antifungal) red color, 2nd to AB, heroin users, resp and UTI, septic arthritis, MS-fimbrae, protease, siderophores, swarming motility
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Proteus
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Gram (-), fac anaerobe, lac -, UTI's, flagella, urease makes stones.
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Pseudomonas aeruginosa
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Gram (-), ob aerobe, lac -, pyocyanin blue, chronic resp diseases, exotoxins, proteases, phospholipases, alginate slime capsule and biofilms avoid clearance
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Acinetobacter
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Gram (-) non fermenter, 2nd only to pseudomonas in contagion, many virulence factors
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Morganella
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Gram (-) similar to proteus
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Providencia
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Gram (-)nosocomial infections of UT, blood, resp, wounds
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Citrobacter
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Gram (-) neonatal meningitis and brain abcess
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Edwardsiella
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Gram (-) gastroenteritis
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Vibrio cholerae
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Gram (-) comma shaped, fermenter with polar flagellum. Potent enterotoxin that binds to gangliosides of cell mem. TCP virulence factor - microcolonies in crypts.
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Cholera toxin
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AB5 toxin assembled in periplasm and secreted by T2SS --> increased cAMP.
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Cholera pilus
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Type 4 - polymerized pilA - binds other pilli to make microcolony (autoagglutination)
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Cholera clinical features
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Rice water diarrhea, tetracycline, no proven vaccine.
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Campylobacter
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comma shaped gram (-), raw chicken, most common cause of diarrhea in world, <500 required for infection, supportive therapy
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Helicobacter
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G (-), spiral shaped, lives in stomach and duodenum (urease +), ulcers, oral transmission
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Helicobacter Dx
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Radiolabeled urea breath test
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Helicobacter virulence island
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Cag Island - VacA, CagA, GabA2
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Haemophilus influenzae
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Small, Gram (-), fac anaerobe coccobacillus, no spores. 2 types: encap and unencap. Requires X (hemin) and V (NAD) to grow --chocolate agar. Satellite colonies.
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Encapsulated H. influenzae
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bac meningitis in children under 4. Capsule for virulence - type B (ribose) most virulent. Quellung rxn to capsule. IgA protease and neuraminadase. Resp aerosol transmission - crosses BBB.
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Encap H influenzae vaccine
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PRP - conjugate capsular vaccine against type B linked to diptheria toxoid.
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Encap H influenzae treatment
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Ampicillin or 3rd gen cephalosporin.
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Unencap H. influenzae
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2nd most common cause of otitis media. resp tract and ear. adhesins and LPS. biofilm factors. amoxicillin.
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Haemophilus ducreyi
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STD - chancroid
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Haemophilus aegypticus
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purulent conjunctivitis in hot climates
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Haemophilus parainfluenza
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pharyngitis and bac endocarditis
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Bordetella pertussis
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Small, G (-), aerobic, coccobacillus, very fresh media for growth, catarrhal and paroxysmal stage.
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Bordetella virulence factors
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Pertussis toxin - higher cAMP, Calmodulin adenylate cylase toxin, dermonectrotic toxin, tracheal cytotoxin - ciliostatis, filamentous hemagglutinin, pertactin, LPS
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Bordetella vaccine/treatment
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DTaP - erythromycin
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Bordetella parapertussis/bronchiseptica
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Similar to whooping cough - no pertussis toxin
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Legionella pneumophila
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G (-), fac anaerobic intracellular pleomorphic rod, lac (+). Lives in ameoba in AC and water - airborn transmission. Pneumonia. Direct fluorescent Ab - slow growth, so rarely isolated from patients. Apoptosis and pore-forming in macrophages and alveolar cells.
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Corynebacterium diphtheriae
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Club-shaped (chinese characters) G(+). Aerobic. Resp droplets. Pseudomembrane in throat. Systemic damage from exotoxin. Toxigenic strains are lysogenic for bacteriophage beta.
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Diphtheria exotoxin
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2 domains: B binds to cell surface receptor. A enters cytoplasm and blocks EIF2.
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Diphtheria Dx
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In vitro test - grown in line perpendicular to antitoxin soaked paper - line of PPT forms X.
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Diphtheria Tx
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Horse or human antitoxin.
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Mycoplasma pneumoniae
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Smallest replicating bac, no cell wall (penicillin/cephalosporin resistant), very slow growth - must provide sterols - fried egg appearance. Atypical pneu (nonresponsive to penicillin/sulfonamides. Variable lipoproteins
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Mycoplasma pneuomoniae epidemiology, pathogen, Dx, treatment
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Teenagers through young adults / aerosol transmission - P1 complex adheres to epithelium, H202 / cold agglutination with serum IgM, macrolides/tetracycline, no vaccine
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Mycoplasma hominis
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genital tract - females. PID. Resistant to erythromycin.
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M. arthritidis
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mycoplasma with superantigen - RA?
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Ureaplasma urealyticum
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mycoplasma - 20% nongonococcal urethritis. urease. male infertility.
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Mycoplasma genitalium
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NGU in males
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M. fermentans, M. incognitus
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Mycoplasma cofactor for HIV infection?
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Chlamydia and Rickettsia
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Obligate intracellular Small (300nm) but not viruses, contain DNA and RNA, multiply by binary fission, have own protein machinery, tetracycline - elements of Gram (-)
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Chlamydia general
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No arthropod host. Obligate intracell - need host ATP. Two stages: Elementary bodies (infectious, cell wall), initial bodies (larger, actively multiplying), Dx - inclusion bodies
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Chlamydia psittaci
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Parasite of birds - constant fecal excretion. Interstitial pneumonia.
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Chlamydia pneumoniae
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10% of adult pneumonia, person to person via resp aerosols.
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Chlamydia trachomatis (D-K)
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Nongonococcal urethritis. 90 million infections/yr. 4.2% of young US. Frequently asymptomatic. Increases HIV transmission. Can lead to permanent scarring and sterility. Single high dose azithromycin. Can also cause neonatal transmission of conjunctivitis/infant pneuomonia
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Chlamydial Dx
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immunoflourescence, PCr-based (identify serotype)
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Chlamydia trachomatis (A, B, C)
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Mechanical transmission - infolding of eyelashes that results in corneal scarring and blindness. Annual universal treatment with azithromycin.
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Chlamydia trachomatis L1, L2, L3
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Lymphogranuloma venereum - more invasive than NGU. Papule progressing to ulcerating vesicle. Painful regional lymph nodes. DTH test.
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Rickettsia basic properties
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Obligate intracellular. Most human infections from arthropods. Enter by phagocytosis. No explanation for intracellular parasitism. Tetracyline
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Rickettsia Prowazekii
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Epidemic typhus. Incubation of 10 days - multiply in cap endothel. Rash 4 to 7 days. High fever and headache. Body lice. Liver function tests often elevated - PCR test. Secondary disorder - Brill-Zinsser. Tetracyline
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Rickettsia typhi
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Endemic murine typhus (zoonosis). Like typhus but milder. Maintained in rats and squirrels.
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Rickettsia rickettsii
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Rocky Mountain Spotted Fever - tick. Incubation one week - fever, headache, arthritic pain, abdominal pain, nausea, vomiting, rash beginning on hands and feet. Treatment and Dx like typhus. Patients die of DIC - gangrene.
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Rickettsia akari
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Rickettsial pox - skin lesion at site of bite - resembles chicken pox - benign disease.
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Coxiella burnetii
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Q fever - intracellular but unrelated to rickettsia. Infection by inhaling spore-like stage. From sheep placenta.
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Ehrlichiosis
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New tick-borne diseases caused by obligate intracellular bacteria. Monocytic and granulocytic. Fever, lymphocytopenia. Tetracycline.
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Neisseria gen characteristics
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Gram (-) diplococci - kidney bean. Thayer-martin (chocolate with vancomycin and colistin). Oxidase positive. IgA protease. LOS.
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Neisseria meningitidis
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Meningococcus - Encapsulated, resp droplets, moves from nasopharynx into blood into meninges, high mortality. sub-saharan meningitis belt.
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Meningococcus Dx, treatment
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Patechiae, examine blood, spinal fluid for diplococci. Sugar ferm/latex agglute. IV penicillin, 3rd gen cephalosporins. rifamin as prophylaxis. Vaccines mod successful except to type B, which resembles sialic acid. Can distinguish from H. influ because Neisseria will grow on blood agar.
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Neisseria gonorrhoeae
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Gonococcus - gram stain in pus - bacteria in phagocytic cells. Pili = virulence. Infection within 1 hour of exposure. Antigenic variation and resistance to penicillin. IM ceftriaxone with 10 day azythromycin - assume also chlamydia.
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