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109 Cards in this Set
- Front
- Back
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Teichoic acid
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part of cell wall of gram +
induces TNF and IL-1 |
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Lipopolysaccharide
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Part of outer membrane of gram -
= ENDOTOXIN *major surface antigen LIpid A is part of it; induces TNF and IL-1 |
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Periplasm
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only in gram-
space between cytoplasmic membrane and peptidoglycan wall *location of many beta-lactamases |
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Petidoglycan
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gives rigid support, protects against osmotic pressure
-sugar backbone with cross-linked peptide side chains |
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Capsule
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protects against phagocytosis
polysaccharide; except Bacillus anthracis, which contains D-glutamate Strep pneumo Neisseria meningitidis H. flu type B Klebsiella Salmonella GBS |
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Spore-forming
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Resistance to dehydration, heat, chemical
-keratin-like coat; dipicolinic acid -kill with 121C for 15min Gram + rods Bacillus Clostridium Coxiella burnetii (Q fever) |
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Plasmid
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contains a variety of genes for antibiotic resistance, enzymes, toxins
made of DNA |
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Glycocalyx
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mediates adherence to surfaces, esp foreign surfaces (catheters)
*polysaccharide |
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Gram + rods/branching
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ABCD LNM
Actinomyces (branching filamentous) Bacillus Clostridium Diphtheria Listeria Mycobacterium (acid fast) Nocardia (weakly acid fast; branching filamentous) |
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Don't gram stain well
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These Rascals May Microscopically Lack Color:
Treponema (too thin) --> darkfield, fluorescent a.b.staining Rickettsia (intracell) Mycobacteria (high lipid content) Mycoplasma (no cell wall) Legionella (intracell) --> silver stain Chlamydia (intracell; lacks muramic acid in cell wall) |
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Giemsa
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Borrelia
Chlamydia Plasmodium Trypanosomes |
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PAS
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Glycogen
Mucopolysaccharides Whipple's disease (Tropheryma whippelii) --> glycoproteins |
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Ziehl-Neelsen
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acid fast organisms
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India ink
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Crypt. neoformans (mucicarmine also can be used to stain polysach capsule red)
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Silver stain
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Legionella
Fungi: PCP |
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H. flu culture
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chocolate agar with
Factors V (NAD+) and X (hematin) |
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N. gonorrhoeae culture
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Thayer-Martin or
VPN: Vanc, Polymyxin, Nystatin |
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B. pertussis culture
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Bordet-Gengou (potato) agar
Bordetella!! |
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C. diphtheriae
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Tellurite plate
Loeffler's media |
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TB
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Lowenstein-Jensen agar
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Mycoplasma
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Eaton's agar
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MacConkey's agar
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lactose-fermenting enterics:
bile salts, crystal violet, lactose, neutral red *fermentation produces acid --> turns pink macConKEES: Citrobacter Klebsiella E.coli Enterobacter Serratia |
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E. coli culture
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MacConkey's
Eosin-methylene blue agar (blue-black colonies with metallic sheetn) |
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Legionella culture
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Charcoal yeast extract agar buffered with Cysteine & Fe
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Fungal culture
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Sabouraud's agar
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Obligate aerobes
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Nagging Pests Must Breathe
Nocardia Pseudomonas Mycobacterium tuberculosis Bacillus Use O2-dependent system to generate ATP |
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Obligate anaerobes
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Can't Breathe Air
Clostridium Bacteroides Actinomyces lack catalase and/or superoxide dismutase; susceptible to oxidative damage *foul smelling (short-chain FA), difficult to culture, produce gas in tissue (CO2, H2) Tx: clinda or metronidazole aminoglycosides ineffective (req O2) |
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Obligate intracellular
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Really Cold
Rickettsia Chlamydia *can't make own ATP |
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Facultative intracellular
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Some Nasty Bugs May Live FacultativeLY
Salmonella Neisseria Brucella Mycobacterium Listeria Francisella Legionella Yersinia |
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Quellung reaction
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if encapsulated bug is present, capsule swells when specific anticapsular antisera are added
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Vaccines
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if contains polysaccharide capsule antigens, a protein is conjugated to promote T cell activation and class switching:
Pneumovax Hflu type B Meningococcus |
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Urease +
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PHUK Urease
Proteus H. pylori Ureaplasma Klebsiella |
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PIgment-producing
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Actinomyces israelii: yellow "sulfar" granules (composed of filaments and formed in pus)
S. aureus: yellow Pseudomonas: blue-green Serratia marcescens: red |
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Protein A
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S. aureus
binds Fc region of Ig; prevents opsonization and phagocytosis (prevents complement fixation) |
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IgA protease
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enzyme that cleaves IgA:
S. pneumo H flu type B Neisseria *colonize/penetrate mucosa |
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M protein
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G.A.S
prevents phagocytosis |
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Intracellular survival
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inhibit phagosome-lysosome fusion or resistance to lysosomal enzymes:
Mycobacterium: TB, Leprae Legionella Ehrlichia |
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Growth curve
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Lag: metabolic acitvity without division
Log: rapid cell division Stationary: nutrient depletion slows growth; SPORE formation Death: prolonged nutrient depletion & build up of waste --> death |
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Transformation
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take up DNA from environment (aka "competence")
esp used in SHiN bugs |
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Conjugation
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F+ x F-
F+ plasmid contains genes required for conjugation; Plasmid is replicated and transferred through pilus from F+ cell to F-(without plasmid) *no transfer of chr genes HFr x F-: F+ plasmid can become incorporated into bacterial chr DNA (Hfr cell) *transfer of plasmid AND chr genes |
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Transposition
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Segment of DNA that can "jump" (excision and reincorporation) from one location to another
-can transfer genes from plasmid to chr and vice versa |
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Transduction: generalized
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A "packing" event: LYTIC phage infects bacterium and destroys it immediately after replicatoin
-cleavage of bacterial DNA and synthesis of viral proteins -parts of bacterial chr DNA may become packaged in viral capsid -phage infects another bacterium, transferring these genes |
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Transduction: specialized
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"excision" events
LYSOGENIC phage infects bacterium --> viral DNA incorporated into bacterial chr -when phage DNA is excised, flanking bacterial genes may be excised with it -DNA is packaged into phage viral capsid and can infect another bacterium *can replicate in host without killing it until later |
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Toxins encoded in lysogenic phage
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ABCDE
shigA-like toxin Botulinum Cholera Diphtheria Erythrogenic toxin of G.A.S. |
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Beta-Hemolytic
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1. GAS
2. GBS 3. Staph aureus 4. Listeria |
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Staph aureus
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Catalase +
Coagulase + (converts fibrinogen to fibrin; can hide out in clots) Hemolysin Protein A: binds Fc-IgG inhibition complement/phagocytosis *causes skin/soft tissue TSST-1 Exfoliative toxin: scalded skin syndrome Enterotoxin: food poisoning MRSA Endocarditis, osteo |
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Staph Epi
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blood culture contaminant
Prosthetic devices and catheters **produces bilfilms endocarditis in IVDU (tx. with vanc) |
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Strep pneumo
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MOPS:
meningitis otitis pna sinusitis lancet shaped encapsulated IgA protease *rusty sputum, sepsis in SCA & splenectomy Vaccine: for >65, asplenic, HIV, chronic lung dz |
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Viridans
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dental caries: mutans, sanguis
subacute endocarditis: sanguis *can produce extracell polysacc (dextrins) using sucrose, which facilitates adherence to fibrin (deposited at sites of endothelial trauma -->damaged valves) |
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Strep pyogenes
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Pyogenic: pharyngitis, cellulitis, impetigo
Toxigenic: scarlet fever, toxic shock-like syndrome Immune: rheumatic fever, acute GN (after impetigo OR strep throat) M protein = major virulence factor; inhibits phagocytosis and complement activation; mediates adherence a.b. to M protein enhance host defenses against s. pyogenes but can give rise to rheumatic fever Streptolysin O: O2-labile protein; lyses RBCs and pmns ASO titer: detects recent S. pyogenes infxn *DNase: degrades DNA in pus to facilitate spread |
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Strep agalactiae
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colonizes vagina
BABIES; pna, meningitis, sepsis produces CAMP factor, which enlarges the area of hemolysis formed by S. aureus *screen pregnant at 35-37weeks; give intrapartum penicillin or amp |
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Enterococci
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normal colonic flora; PCN G resistant
cause UTI and subacute endocarditis VRE **can grow in 6.5% NaCl and bile (vs. nonenterococcal group D strep) |
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Lancefield grouping
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based on differences in C carbohydrate on cell wall
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Strep bovis
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Group D strep
colonizes gut; can cause bacteremia and subacute endocarditis; in colon cancer patients |
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Diphtheria
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exotoxin encoded by beta-prophage (lysogenic)
ADP ribosylation of EF-2 pseudomembranous pharyngitis LAD Lab: metachromatic blue & red granules on gram stain (+) grows on tellurite agar, Loeffler's media Toxoid vaccine Tx: antitoxin, PCN, vaccine |
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Clostridium tetani
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tetanospasmin
blocks glycine and GABA release from RENSHAW CELLS in spinal cord |
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C. botulinum
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heat-labile toxin that inhibits ACh release at neuromuscular junction
*canned food, honey |
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C. perfringens
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alpha toxin: licithinase, a phospholipase
can cause myonecrosis (gas gangrene) and hemolysis |
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C. difficile
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AB toxin is DIFFerent (A binds, B destroys)
Toxin A: enterotoxin binds to brush border of gut; pmn chemoattractant, inflammation Toxin B: cytotoxin, destroys cytoskeletal structure of enterocytes (actin depolymerization), causing pseudomembranous colitis Tx: flagyl or vanc |
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Anthrax
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Virulence factors:
1. exotoxin (EF, LF, protective antigen) 2. Anti-phag capsule: only bacterium with a polypeptide capsule: D-glutamate Cutaneous: due to contact; black eschar (painless ulcer) surrounded by edematous ring --> bacteremia, death *caused by lethal factor and edema factor (adenylyl cyclase); suppresses pmns and accumulates fluid Pulm: inhalation of spores --> fluelike --> fever, hemorrhage, mediastinitis, shock Woolsorters' disease: inhalation of spores from contaminated wool |
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Listeria
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Only gram + to produce LPS endotoxin
ingestion of unpasteurized milk/cheese/deli meats; vaginal transmission during birth *form actin rockets to move from cell to cell; tumbling @22C; can culture at 4C (narrow zone of beta-hemolysis on sheep blood) granulomatosis infantiseptica neonatal meningitis amnionitis, spontaneous abortion *dz in compromised CMI |
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Actinomyces
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gram + branching filamentous rod
anaerobe oral/facial abscesses that may drain through sinus tracts in skin yellow sulfur granules normal oral flora SNAP: Sulfa for Nocardia Actinomyces use PCN |
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Nocardia asteroides
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gram + branching filamentous rod
aerobic, weakly acid-fast pulm infection in immunocompromised SNAP: Sulfa for Nocardia Actinomyces use PCN |
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Catalase +
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ppl with CGD are susceptible
SNAPS: Staph aureus Nocardia Aspergillus Pseudomonas cepacia Serratia Also catalase + (but CGD not at increased risk: Mycobacteria Diphtheria Crypt. neoformans |
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Ghon complex
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TB granulomas: Ghon focus + lobar and perihilar node involvement
*reflects primary infection |
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Mycobacteria
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kansasii: pulm TB-like sxs; water contaminant
MAC: disseminated dz in AIDS; px with azithro Marinum: aquatic Scrofulacem **all are acid fast dx: early morning sputum acid fast stain x3d Culture in Lowenstein-Jensen agar (2-4wks) |
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Leprosy
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Hansen's disease
Acid-fast bacillus that likes cool temperatures; cannot be grown in vitro **armadillos Tx: long-term dapsone (tox: methemoglobinemia and hemolysis) Alternative: rifampin, clofazimine, dapsone Lepromatous: diffusely over skin and is communicable (patients with low CMI and a Th2 response) Tuberculoid: few hypoesthetic skin nodules; patients with high CMI and TH1 response |
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Oxidase +
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Campylobacter (42C)
Vibrio cholera (alkaline media) Pseudomonas (loves air!) Neisseria Moraxella |
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H2S production
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Salmonella
Proteus |
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Non-lactose fermenting GNRs
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Oxidase -:
Shigella Salmonella Proteus Oxidase +: Pseudomonas |
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Coccoid rods
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H flu
Pasteurella Brucella Bordetella |
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Lactose fermenters
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Fast: (KEE)
Klebsiella E coli Enterobacter Slow: Citrobacter Serratia |
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PCN & GNRs
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Resistant to PCN G and vanc bc outer membrane inhibits entry
*but may be susceptible to derivatives like amp |
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Neisseria
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Diplococci
Gonococci: ferment Glucose (not maltose) no polysaccharide capsule no vaccine (bc rapid antigenic variation of pilus proteins) Meningococci: ferments Maltose + Glucose Polysaccharide capsule Vaccine (except type B) Transmitted through resp and oral secretions Rifampin px of contacts **LPS = endotoxin, assoc with disease manifestations and severeity |
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Route for meningitis
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meningoCoccus:
nasopharynx --> blood --> CHOroid plexus HaemoPHilus: pharynx --> lymPHatics --> meninges |
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Haemophilus
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MOPE:
meningitis otitis pna epiglottitis coccobacillus aerosol transmission *produces IgA protease Culture on chocolate agar (with factors V(NAD) and X(hematin) **can be grown with S. aureus, which provides fasctor V tx: meningitis with ceftriaxone Rifampin px capsule is immunogenic: anti-polyribitol ribose phosphate a.b. vaccine: contains type B capsule conjugated to diphtheria toxoid 2-18months |
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Legionella
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Legionnaires: severe pna and high fever; diarrhea, HA, confusion, hypoNa
Pontiac fever: mild flulike Use silver stain grow on charcoal yeast extract with iron and cysteine dx: antigen in urine *aerosol transmission from water source Tx: erythromycin |
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Pseudomonas
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Pna (esp in CF)
Sepsis (black lesions on skin) External otitis (swimmer's) UTI Drug use & DM Osteo Hot tub folliculitis aerobic, non-lactose, oxidase+ -produces pyocyanin (blue-green) pigment; grapelike odor -water source endotoxin and exotoxin (inactivates EF-2) tx: AG + extended spectrum PCN (piper, ticar) |
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E. coli
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virulence factors:
fimbriae: cystitis, pyelo K capsule: pna, neonatal meningitis LPS: sepsis EIEC: invades mucosa; necrosis and inflammation; bloody diarrhea ETEC: labile/stable toxins; watery diarrhea EPEC: no toxin; adheres to apical surface, flattens villi, prevents absorption -Pediatrics EAEC: "stacked-brick" intestinal adhesion (infants in developing countries) EHEC: O157:H7; shiga-like toxin and HUS (anemia, tcp, ARF) -endothelium swells and narrows lumen --> mechanical hemolysis and reduced renal blood flow; damaged endothelium consumes PLTs ***does not ferment sorbitol (vs other E coli) |
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Klebsiella
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Asp pna
Abscess in lungs Alcoholics diAbetics *red currant jelly sputum -nosocomial UTIs |
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Salmonella & Shigella
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-both non-lactose fermenting GNRs
-both invade mucosa and cause bloody diarrhea Salmonella: flagella can disseminate hematogenously produce H2S monocyte response Typhoid fever: fever, diarrhea, HA, rose spots; can remain in gallbladder Shigella: more virulent fecal-oral no flagella but propel themselves within cells by actin polymerization only in humans, no animal reservoir |
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Campylobacter
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*major cause of bloody diarrhea, esp in children
fecal-oral; poultry, milk; can be transmitted from domestic animals Comma or S-shaped (corkscrew mobility) oxidase+, grows at 42C (likes the CAMPfire) Can cause Guillain-Barre |
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Vibrio cholerae
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rice-water diarrhea
**grows in alkaline media comma shaped, oxidase + activates Gs --> increase cAMP |
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Yersinia enterocolitica
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pet feces (puppies)
contaminated milk, pork day care center outbreaks of diarrhea **causes mesenteric adenitis that can mimic Crohn's or appendicitis |
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H. pylori
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causes gastritis and up to 90% duodenal ulcers
Urease + creates alklaline environment Tx: PPI, Clarithromycin, amoxicillin, Metronidazole |
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Spirochetes
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spiral-shaped bacteria with axial filaments
BLT Borrelia (big) Leptospira Treponema |
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Leptospira
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? -shaped
water contaminated with animal urine flulike, fever, HA, abd pain, jaundice, photophobia with conjunctivitis *surfers and in the tropics Weil''s disease: icterohemorrhagic leptospirosis -severe form with jaundice and azotemia from liver and kidney dysfunction; fever hemorrhage, anemia |
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Lyme disease
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Borrelia burgdorferi
Ixodes tick (mice and deer are reservoirs) BAKE and key LYME pie: Bell's palsy (bilateral) Arthritis Kardiac block Erythema chronicum migrans Stage 1: erythema migrans, flulike Stage 2: Bell's, cardiac (AV block), myopericarditis Stage 3: chronic arthritis Tx: early - doxy; late - ceftriaxone |
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Syphilis
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1. painless chancre (many treponemes present)
2. SYSTEMIC; maculopapular rash on palms & soles, alopecia arriata, condylomata lata (many treponemes present) 3. Gummas (chronic granulomas), aortitis (vasa vasorum destruction, tree-barking), neurosyphilis (tabes dorsalis), Argyll Robertson pupil Congenital: saber shins (bowing of tibia), saddle nose, CN8 deafness, Hutchinson's teeth, mulberry molars, frontal bossing, snuffles- blood-tinged nasal secretions signs: + romberg, charcot joint, stroke w/o HTN Screen: VDRL confirm: FTA-ABS |
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VDRL false postives
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Viruses (mono, hep)
Drugs Rheumatic fever Lupus & Leprosy |
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Yaws
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Treponema pertenue
-infection of skin, bone, joints; healing with keloids -limb deformities not STD; +VDRL |
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Carteonella
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cat scratch
can cause bacillary angiomatosis in immunocompromised (often confused with Kaposi's) |
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Borrelia recurrentis
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Recurrent fever (variable surface antigens)
Louse |
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Brucella
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UNdulant fever (from UNpasteurized)
dairy, contact with animals |
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Francisella tularensis
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Tick bite; rabbits, deer
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Yersinia pestis
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Plague
flea bit, rodents, prairie dogs |
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Pasteurella multocida
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cellultits, osteomyelitis
animal bite: cats, dogs |
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Gardnerella vaginalis
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pleomorphic
gram-variable rod **polymicrobial: involved Mobiluncus, anaerobe gray vaginal discharge, fishy smell; painless tx: Flagyl **CLUE CELLS: vaginal epithelial cells covered with bacteria |
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Rickettsiae
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obligate intracell
need CoA and NAD+!!!! (vit B3 and B5) triad: HA, fever, rash (vasculitis) *all have arthropod vectors except Coxiella (aerosol- pna) tx; doxy |
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Bacteroides fragilis
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MC organism in colon
peritoneal abscess when gut lining compromised |
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Rocky Mountain spotted fever
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rickettsia rickettsii
tick *rash starts on hands and feet; migrates to wrists, ankles, then trunk -HA, fever **EAST coast |
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Typhus
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Endemic: R. typhi; fleas
Epidemic: R. prowazekii; human body louse Typhus rash starts centrally and spreads outwards (no palms and soles) Typhus on the Trunk Ricketssia on the Rists |
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Ehrlichiosis
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tick
no rash granulocytes with berry cluster organisms |
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Q fever
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Coxiella burnetii
tick feces and cattle placenta release spores --> inhaled --> PNA no rash, no vector, neg Weil-Felix |
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Weil-Felix
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Test for Rickettsial infxn
Serum mixed with Proteus antigens: antirickettsial a.b. cross-react to Proteus O antigens and agglutinate **negative in Coxiella |
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Rash on palms and soles
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CARS
Coxsackie A (hand, foot, mouth) RMSF Syphilis |
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Chlamydiae
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cannot make their own ATP
obligate intracellular; mucosal infxns **cell wall LACKS MURAMIC ACID lab: cytoplasmic inclusions on Giemsa or fluorescent a.b-stained smear 1. Elementary body: small, dense; is Enfectious and Enters cell via Endocytosis 2. Reticulate body: Replicates in cell by fission; form seen on tissue culture Trachomatis: reactive arthritis, conjunctivitis, urethritis, PID Psittaci: atypical pna; avian reservoir Pneumoniae: atypical pna tx: azithro or doxy |
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Chlamydia trachomatis
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A,B,C: chronic infxn, blindness in AFrica
D-K: urethritis, PID, ectopic preg, neo pna, neo conjunctivitis L1-L3: lymphogranuloma venereum -primary ulcers, inguinal lymphadenitis, rectal dz (can look like IBD) |
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Mycoplasma
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walking pneumonia
CXR worse than patient **high titers of cold agglutinins (IgM), which can agglutinate or lyse RBCs -grown on Eaton's agar -no cell wall -only bacterial membrane containing cholesterol *outbreaks in military recruits, prisons tx: tetra, erythro (can't use abx that target cell wall!) |
