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62 Cards in this Set
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Hugh Leifson OF Broth |
Oxidation (not sealed), fermentation (sealed with mineral oil) tubes Increased carbohydrates, lower amount protein than TSI, bromothymol blue indicator (Yellow = acid, blue/green= alkaline) -Oxidation produces less acid than fermentation (high protein can mask acidic by product) |
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Pseudomonads Non Pseudomonads |
GNB Nonfermenters Pseudomonas, Burkholderia, Stenotrophomonas, Alcaligenes, Brevundimonas Acinetobacter, Achromobacter, Chriseobacterium (Elizabethkingia) |
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Pseudomonas aeruginosa |
GNB Nonfermenter Habitat: Water, skin, ventilator Disease: Self-limiting folliculitis (rash), nosocomial infections (pneumonia, wound infections, UTI), chronic pneumonia in cystic fibrosis patients Virulence factor: flagellum, pilus, alginate capsule, endotoxin (LPS), type III secretion system, toxin A, hemolysin, phospholipase C, protease, exoenzyme S Characteristsics: orange capsule in gram stain, oxidase +, catalase +, nitrate +, gelatinase +, growth at 42, grape-like odor, pyocyanin & pyoverdin, fluorescent, hemolytic, oxidizes Glu P. fluorescens & putida: fluorescent, pyoverdin, no growth at 42, bacteremia from transfusions P. stutzeri: No pigment, dry wrinkled colonies, bacteremia & meningitis in immunocompromised patients, endophthalmitis |
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Burkholderia |
GNB Nonfermenter Burkholderia cepacia: -soil, water, dairy, nosocomial pathogen -bacteremia (2nd leading cause), UTI, pneumonia in cystic fibrosis patients, pseudobacteremia (contaminated disinfectant fluids) -lysine decarboxylation +, oxidase +, DNAse -, Oxidizes Glu,Lac,Suc,Xyl -Pseudomonas cepacia agar (PCA)- pink colony (pyruvate metabolism) B. mallei: glanders (horses) B. pseudomalleri: bioterrorism agent (tropical) -prevalent in Thailand -Melioidosis, pneumonia, Vietnamese Time Bomb (can be asymptomatic for years) -dry, wrinkled colonies, lysine decarb - |
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Brevundimonas diminuta |
GNB Nonfermenter tightly coiled flagella, weak Glu oxidizer, neg for most biochemicals |
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Alcaligenes faecalis |
GNB Nonfermenter UTI Alkaline tolerant, asaccharolytic, peritrichous flagella, oxidase +, catalase +, green apple odor |
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Stenotrophomonas maltophilia |
GNB Nonfermenter habitat: respiratory equipment disease: nosocomial infections, septicemia biofilm (flagella like structures), antibiotic resistant Oxidase -, Lysine decarb +, DNAse +, Oxidizes Glu, Maltose (strong), |
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Achromobacter xylosoxidans |
GNB Nonfermenter -from cystic fibrosis patients Resistant to antimicrobials Oxidase +, Oxidizes Glu, Xyl (strong), Nitrate +, Peritrichous flagella |
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Elizabethkingia meningoseptica (Chriseobacterium) |
GNB Nonfermenter Meningitis & sepsis in neonates Yellow colonies, oxidase +, non-motile |
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Acinetobacter baumannii |
GNB Nonfermenter
Nosocomial infections, multidrug resistant, "Iraquibacter"
Characteristics: Oxidase -, coccobacilli, nonmotile, Oxidizes Glu, Lac (strong)
A. haemolyticus: Oxidizes Glu, beta hemolytic A. lwoffii: asaccharolytic |
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Pseudomonas aeruginosa antibiotic resistant |
Intrinsic: ampC (carbapenemases, low basal level), repression oprD (porin that allows carbapenems in), overexpression of RND efflux pump (pumps out carbapenems and fluoroquinolones), mutation of fluoroquinolone target site (DNA gyrase & topoisomerase genes)
Acquired: class B carbapenemases (metallo-beta-lactamases- bla imp gene) --> test using modified hodge test using Klebsiella pneumoniae; resistant to carbapenems except aztreonam
AmpC induction by cefoxitin & imipenem: binds PBP, increases 1,6-anhydromuropeptides (from cell wall breakdown), ampD unable to cleave fast enough, anhydro-MurNAc-peptide (inducer) forms instead of UDP-MurNAc-pentapeptide (suppressor), bind to ampR, activates ampC |
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HACEK |
Fastidious GNB Capnophilic, opportunistic, flora of oral cavity, endocarditis, slow growing (2 weeks) Haemophilus aphrophilus (Aggregatibacter) Actinobacillus actinomycetemcomitans (Aggregatibacter) Cardiobacterium hominis Eikenella corrodens Kingella |
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Haemophilus aphrophilus (Aggregatibacter) |
Fastidious GNB Dental plaque, endocarditis Characteristic: Bacilli/Coccobacilli, Growth on MacConkey variable, catalase -, indole, - , nitrate +, glu +, mannitol -, suc + |
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Actinobacillus actinomycetemcomitans (Aggregatibacter) |
Fastidious GNB
Periodontitis, biofilm Mac variable, catalase +, oxidase -, bipolar staining, crossed cigar colonies, nonmotile
A. hominis: pneumonia |
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Cardiobacterium hominis |
Fastidious GNB
Upper respiratory tract, GI, GU infections
Pits agar, rosette arrangement, pleomorphic, catalase -, oxidase +, indole + |
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Eikenella corrodens |
Fastidious GNB Human bites Faces abscesses, osteomelytis Characteristics: requires X factor (hemin), bleach smell, spreading growth, twitching motility (no flagella), pits agar, pleomorphic |
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Kingella kinga |
Fastidious GNB Bone & joint infections in children mucoid, beta hemolysis, pits agar, plump rod in chains, oxidase +, catalase - |
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Capnocytophaga |
Fastidious GNB Cat & dog bites Disease: sepsis with DIC Characteristics: spreading colonies, sliding motility, fusiform, curved |
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Pasteurella multocida |
Fastidious GNB Animal bites & scratches Disease: Respiratory infections, meningitis, bacteremia Characteristics: bipolar staining, small rods, weakly oxidase +, catalase +, indole +, nitrate + |
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Bordetella pertussis |
Fastidious GNB Inhibited by components of regular media (protective components: starch, charcoal, blood) Bordet-Gengou media- potato starch, no peptones Regan-Lowe media- Charcoal & horse blood Disease: Pertussis/Whooping cough Characteristics: Oxidase +, urease -, hemolytic on BG, mercury like on RL, pertussis toxin (AB toxin, inhibits G protein, increases cAMP, inhibit immune cell recruitment) B. bronchiseptica: rapid urease + |
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Francisella tularensis |
Fastidious GNB Potential bioterrorism agent, lab acquired infection, ulceroglandular Reservoir in rabbits and rodents Characteristics: require cysteine, tiny rods, pleomorphic, oxidase -, catalase +, urease - |
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Brucella |
Fastidious GNB Potential bioterrorism agent, lab acquired infection, zoonosis, abscesses, meningitis, endocarditis Isolated in bone marrow, liver, spleen, lymph nodes Characteristics: Nonmotile, oxidase +, catalase +, nitrate +, indole +, facultative intracellular, coccobacilli |
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Streptobacillus monoliformis |
Fastidious GNB Zoonosis, rat bite fever, Haverhill fever Characteristics: chain of bacilli, nonmotile, 2 types of colonies (eubacteria - round, smooth; L-phase- defective cell wall, fried egg appearance), slow fermenter, relatively inert, fatty acid analysis |
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Bartonella |
Fastidious GNB Flagella, pleomorphic, curved, faintly stained, 2 types of colonies (molar tooth, circular), oxidase -, catalase - B. henselae: Cat scratch disease, flea vector, pustule, fever, lymphadenopathy, twitching motility B. quintana: Trench fever, transmitted by ticks/louse, headache, truncal rash, joint pain, muscle aches, twitching motility B. bacilliformis: Carrion's disease, Peruvian Wart, Oroya fever, DIC, sandfly bites, intraerythrocytic |
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Legionella pneumophilia |
Fastidious GNB Serotype 1 & 6 most common in infections Habitat: condenser, air conditioners, water, nosocomial Disease: Legionnaires' disease (severe pneumonia), Pontiac fever (self-limiting) Characteristic: Facultative intracellular (macrophages & amoebas), survive high temp and chlorine, biofilm, stains poorly with Gram (better with Giemsa), no growth on BAP (growth on Buffered Charcoal Yeast Extract agar), require cysteine, does not utilize carbohydrates (uses amino acids), hippurate + (other Legionella -), motile, gelatinase +, oxidase +, fluoresces Confirmatory tests: urinary antigen, direct fluorescent antibodies, serology (indirect fluorescent antibodies, titer level 1:128+), PCR |
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Bacillus |
GPB aerobe/facultative anaerobe Habitat: env & water (common contaminant) Characteristics: Large colonies, endospores (no swelling), beta hemolytic except B. anthracis B. anthracis: anthrax (Wool sorter's disease), humans incidental host, capsule, -AB toxin: Protective antigen (binds & recruit receptors after it is cleaved), lethal factor (binds & inhibits MAP kinases, apoptosis), edema factor (increase cAMP) -Penicillin susceptible, non-hemolytic, nonmotile B. cereus: fried rice syndrome, emetic toxin (vomit inducing, food poisoning) -Penicillin resistant, hemolytic, motile, mannitol -, fac. anaerobe B. subtilis: opportunistic infections -Penicillin susceptible, hemolytic, motile, mannitol +, aerobe Spore staining: malachite green/safranin |
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Corynebacterium diphtheria |
GPB aerobe/facultative anaerobe Characteristics: pleomorphic, arranged in V, catalase +, nonmotile, mannitol + Diphtheria- infection of oropharynx, formation of pseudomembrane can lead to suffocation Diphtheria toxin- AB toxin- cleaved by furin inside endosome, inhibits elongation factor & translation -Serum tellurite medium -Tinsdale medium (cystine + tellurite)- tellurite inhibits normal flora of nasopharingeal tract; black colonies and black halo (other Corynebacterium does not have dark halo) -Loeffler's medium- enhance volutin granule formation (purple, beaded appearance) C. jeikenium: multidrug resistant, mannitol -, endocarditis, septicemia |
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Listeria monocytogenes |
GPB aerobe/facultative anaerobe Disease: Listeriosis (food poisoning), neonatal meningitis Virulence factors: actin bind protein (also used by Shigella), Phospholipase C, Listeriolysin O (lyses vacuole) Characteristics: beta hemolysis, tumbling motility, can grow at 4C, esculin +, CAMP +, catalase +, motile at 25, nonmotile at 35, intracellular, replicates in cytoplasm, double membrane vacuole when traverses cell |
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Erysipelothrix rhusiopathiae |
GPB aerobe/facultative anaerobe Disease: Erysipela in swine, erysipeloid fingers, septicemia, endocarditis 2 types of colonies: Small, smooth & large, rough Characteristics: easily decolorizes, bacilli/filament, H2S, weak Glu +, catalase -, oxidase -, pipe cleaner growth in gelatin (gelatinase -) |
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Lactobacillus |
GPB aerobe/facultative anaerobe Normal flora of vagina, GI tract, mouth Disease: (opportunistic) bacteremia, endocarditis, meningitis Converts lactose to lactic acid, bacteriolicin, H2O2 (prevents urogenital infections) Characteristics: pleomorphic, catalase -, oxidase -, nitrate -, indole -, H2S - |
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Kurthia |
GPB aerobe/facultative anaerobe Endocarditis, pneumonia, bacteremia large bacilli, chains, peritrichous flagella |
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Gardenella vaginalis |
GPB aerobe/facultative anaerobe Bacterial vaginosis Characteristic: gram variable, coccobacilli, "clue cells" (epithelial cells covered with bacteria), oxidase - , catalase -, hippurate + Whiff test: 10% KOH on vaginal fluid -> fishy smell |
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Nocardia |
GPB aerobe/facultative anaerobe fungus like, filamentous, spores and hyphae Disease: mycetoma (chronic inflammation of tissue), CNS disease, TB-like disease Characteristic: "Sulfur" granules, branching, beaded, acid fast, slow growth, dry colonies, L-form can survive in macrophages |
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Streptomyces |
GPB aerobe/facultative anaerobe Synthesize antibiotics and antifungal fungus like, filamentous, branching, spores, mycelium, dry colonies, geosmin (volatile metabolite- earthy odor) |
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Mycobacteria |
Found in soil & water Bacillus, Non-motile, Acid Fast, Does not stain with Gram (Ghost Cells) Slow growing Cell envelope: -Capsule -Cell wall (Mycolic acid, arabinogalactan layer, peptidoglycan) -Cytoplasmic membrane |
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Acid Fast Stain |
Carbolfuchsin stain (phenol allows penetration of mycolic acid), Acid alcohol decolorizer, Methylene blue counter stain
Positive= Red/pink
Ziehl-Neeson method: With heat, higher specificity Kinyoun method: No heat, high conc. of carbolfuchsin Truant method: Fluorescent labeling with Auramine O-Rhodamine instead of carbolfuchsin, potassium permanganate counter stain |
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Mycobacteria media |
Complex: Not chemically defined Synthetic: Chemically defined Egg based: Egg, potato flour, salt,, glycerol, malachite green (inhibit other bacillus) -Lowenstein-Jensen media: Cycloheximide (inhibit fungus), Lincomycin (GN), Nalidixic acid (GP) Agar based: Salt, vitamin, oleic acid (need to be kept dark; breaks down into formaldehyde in light), glycerol, dextrose, malachite green -Middlebrook 7H10, 7H11 Liquid media: Middlebrook 7H9, MGIT (Mycobacteria growth indicator tube- detect O2 depletion by fluorescence), BACTEC 460 (detect radioactive CO2) |
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Mycobacterium tuberculosis complex |
Human pathogen, Human-Human transmission Granulomatous lesions M. tuberculosis M. africanum M. bovis M. canetti M. leprae |
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Non-TB mycobacteria (NTM/MOTT) Runyon Groups |
Opportunisitic, No person to person transmission Runyon Group Classification: -I- Photochromogens- photoactivatable yellow/orange pigment (M. kansasii, M. marinum) -II- Scotochromogens- Pigment deepens in light (M. scrofulaceum, M. gordonae) -III- Nonphotochromogens- No pigment change (M. avium, M. avium intercellulare complex, M. ulcerans, M. haemophilum) -IV- Rapid growers- Colonies in less than 7 days (M. fortuitum, M. chelonae, M. abscessus, M. smegmatis) |
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Mycobacterium avium intracellulare complex (MAC) |
Acid fast bacillus, NTM, Nonphotochromogen Pulmonary disease in AIDS patients, Cervical lymphadenitis in children Infects macrophages, Spreads by lymphatics Urease -, Heat catalase +, Semi quantitative catalase - |
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Mycobacterium kansasii |
Acid fast bacillus, NTM, Photochromogen Pulmonary infection in immunocompromised individuals & elderly men with COPD Tween 80 hydrolysis +, Pyrazinamidase - |
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Mycobacterium scrofulaceum |
Acid fast bacillus, NTM, Scotochromogen Cervical lymphadenitis in children (swelling lymph nodes) - Scrofula (King's Evil) |
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Mycobacterium marinum |
Acid fast bacillus, NTM, Photochromogen Fish tank/swimming pool granuloma Waterborne, cutaneous infection (preferred growth at 30C- skin temp) Tween 80 hydrolysis +, Both Catalase tests - |
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Mycobacterium ulcerans |
Acid fast bacillus, NTM, Nonphotochromogen Buruli ulcer (lesions on lower limbs of children) Waterborne, tropical, Preferred growth 30C Does not respond to antibiotics |
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Mycobacterium abscessus |
Acid fast bacillus, NTM, Rapid grower Preferred growth at 28C Cutaneous, disseminated, & pulmonary diseases |
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Mycobacterium fortuitum |
Acid fast bacillus, NTM, Rapid grower Preferred growth at 28C Cutaneous & disseminated diseases Arylsulfatase +, Iron uptake + |
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Mycobacterium gordonae |
Acid fast bacillus, NTM, Scotochromogen Rarely pathogenic, Contaminant Fresh water Tween 80 hydrolysis |
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Mycobacterium leprae |
M. tuberculosis complex Leprosy, Hansen's disease (Skin & peripheral tissue disease) -Stage 1- Enhanced cell mediated immunity -Stage 2- Peripheral nerve damage 95% people naturally immune Grown on footpads of armadillos and mice |
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Mycobacterium tuberculosis |
"Consumption," Pulmonary disease (prolonged cough, hemoptysis-coughing blood, fatigue, fever, chills, chest pain), Extra-pulmonary disease -granuloma, caseation & fibrosis of lungs Extremely infectious (<10 bacteria) Rough, beige/yellow, dry wrinkled colonies on LJ Cording (virulence factor) Niacin accumulation, both catalase tests - Infects macrophages Multidrug resistant 5-10% infection active; 90-95% latent (5-10% of latent infections can reactivate); 10% no lung involvement Bacille Calmette Guerin Vaccine- from attenuated M. bovis (effective against disseminated & meningitis TB, but variable for pulmonary TB) Mantoux Tuberculin Skin test: (PPD- purified protein derivative) measures induration/firm swelling; false position for BCG vaccinated individuals Quantiferon Gold- Blood test for interferon-gamma released by TB infected WBCs |
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Mycobacterium bovis, africanum, microti, canetti |
M. tuberculosis complex M. bovis- Infects cows & humans; transmitted through unpasteurized milk; used to make BCG vaccine M. africanum- Pulmonary disease in Africa M. microti- Small rodents; Pinpoint colonies after 9 weeks M. canetti- Emerging disease in N. Africa; Smooth, white glossy colonies |
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Mycobacterium specimens |
3 sputum samples for smear & culture (gastric aspirate if unable to produce sputum) -Urine- morning -Stool- AIDS patients for MAC -CSF, Blood Processing: -Digestion/Mucolysis- NALC or DTT -Decontamination- 2% NaOH, Oxalic acid (for cystic fibrosis patients to kill P. aeruginosa) -Neutralization- Water or buffer (prevent decontamination agent from killing bacteria) -Concentration- centrifuge |
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Rickettsia R. rickettsii R. prowazekii R. typhi R. akari Orientia tsutsugamushi Ehrlichia chaffeensis Anaplasma phagocytophilium Coxiella burnetti |
Obligate intracellular, Macrophages, GN, Pleomorphic -Transmitted by aerosols & arthropods (except Coxiella) -Actin binding ability R. rickettsii- Rocky mountain spotted fever -Vector- Wood tick (West- Dermacentor andersoni), Dog tick (East- D. variabilis); Infected eggs -Host- Rodents -Maculopapular rash, fever, chills, headache R. prowazekii- Epidemic typhus (Typhus fever) -Vector- Human lice (louse) -Headache, chills, fever, rash caused by hemorrhage -Brill-Zinsser Disease- latent infection with relapses R. typhi- Endemic typhus (Typhus/Rat Flea/Murine Fever) -Vector- Rat fleas -Milder than epidemic typhus R. akari- Rickettsial pox -vector- mouse mite -Papule at site of entry (eschar), fever, headache, rash Orientia tsutsugamushi- Scrub typhus -Vector- Mites in forest underbrush -Reservoir- Rats Ehrlichia chaffeensis -Vector- Tick -Lives in monocytes -Severe-> similiar to Rocky Mt spotted fever; Mild-> similar to mononucleosis Anaplasma phagocytophilium -Vector- Tick -Reservoir- White Tailed Deer -Lives in granulocytes -Similar disease as E. chaffeensis Coxiella burnetti - Q fever -Zoonotic (Cattle, Sheep, Goat) -Found in urine, feces, milk -Potential bioterrorism agent (highly infectious & resistant to heat, drying & disinfectants) -Inhaled -Atypical pneumonia with no rash |
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Chlamydia C. pneumoniae C. trachomatis Chlamydophila psittaci |
Obligate intracellular, GN Most common STD, Leading cause of blindness Cell walls similar to GN but lack muramic acid Biphasic development: -Elementary bodies (infectious, metabolically inert, resistant to stress, inhibit phagosome-lysosome fusion) -Reticular bodies (replicates inside endosome; has persistent form that can reactivate) Tissue culture with McCoy cell line (gold standard); Serology not useful C. pneumoniae: respiratory infection C. trachomatis: -Serotype A-C: Trachoma (blindness, eye infection; transmitted by flies) -Serotype D-K: STD, Nongonococcal urethritis, Conjunctivitis; Freq. found with N. gonorrhoeae -Serotype L1-3: Lymphogranuloma venereum, bubo (inflammed lymph nodes) Chlamydophila psittaci: Parrot fever -Zoonotic (birds) -Subclinical, Pneumonia |
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Mycoplasm M. pneumoniae M. hominis M. genitalum Ureoplasma urealyticum |
Obligate intracellular, Smallest Free living organism -No cell wall nor peptidoglycan; Plasma membrane with high amounts of sterol prevents osmotic lysis -Common contaminant of tissue cultures -Grows on enriched medium with serum & cholesterol (BHI + rabbit serum; Diphasic agar- broth over agar) -Cold agglutinin test- Antibodies agglutinate type O blood at low temps M. pneumoniae- Walking pneumonia (mild pneumonia) -Fried eggs colonies; Stains blue with Dienes stain M. hominis- Colonizes genital tract; Post partum fever M. genitalum- Urethral infections Ureoplasma urealyticum- Normal flora for genital tract; Nongonococcal urethritis |
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Leprospira L. interrogans L. biflexa |
Spirochete, GN, Thin, Helical, Parallel Endoflagella (Btw peptidoglycan & outer membrane), Does not grow on regular media -2 axial filaments, rapid movement, Catalase +, Oxidase + L. interrogans- Leptospirosis -Resembles question mark -Silver stain (Fontana stain) -Zoonosis (Rodents, dogs, swine, cattle) -Transmitted by ingestion or through water -Flu-like symptoms; systemic if untreated -Leptospiremia & leprospiuric (Blood, urine, csf) -Culture on EMJH (oleic acid albumin medium) L. biflexa- Saphrophytic strain from env.; Grows at 13C with azaguanine |
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Treponema T. pallidum (pertenue, endemicum, pallidum) T. carateum |
Spirochete, GN, Thin, Helical, Parallel Endoflagella (Btw peptidoglycan & outer membrane), Does not grow on regular media -Corkscrew motility, Propagated by infecting rabbit testicles, Silver stain T. pallidum subsp. pertenue- Yaws (skin & bone lesions) -Tropical, Affects mostly children -Spread through skin contact -Ulcerated sores on face, feet, hands, legs, genitals T. pallidum endemicum- Bejels (Skin, oropharynx, bone lesions) -Arid regions -Sores in mouth, Lumps along face & long bones (deformations) T. carateum - Pinta (Skin lesions; Mexico) T. pallidum pallidum - Venereal Syphillus -Primary- Lesions, Chancre (painless orogenital ulcers) -Secondary- Flu-like symptoms, Maculopapular rash on palms & soles, Condylomata lata (genital warts) -Tertiary- Gummatas (gummy tumor-like lesions), CV complications, Neurosyphilis -Congenital- 40% Stillborn, 50% asymptomatic; Late stage syphilis symptoms if untreated -Autoimmune disease during secondary & tertiary syphilis (antigen similar to those of the heart- cardiolipin) |
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Treponema Diagnosis Non-treponemal & treponemal tests |
Non-Treponemal Tests (Screening) - Uses cardiolipin antigen -VDRL (Venereal disease research lab)- Uses ox heart extract; Position if aggregation/flocculation -RPR (Rapid Plasma Reagin)- Positive if antigen-antibody lattice trap carbon particles -Can distinguish btw active & past infections (antobodies wane after infection) -Prozone effect- false negative if antibody conc. high Rapid Treponemal Tests- Confirmatory- Uses Treponema pallidum specific antigens -No prozone effect, but cannot distinguish between past and current infections (antibodies high for years) -FTA-ABS (Fluorescent Treponemal Antibody Absorption)- T. pallidum fixed to slide; Patient serum removed of nonspecific T. pallidum antibodies; FITC anti-treponeme antibody (green) & TRITC anti-human antibody (red); Fluoresces yellow if positive -TP-MHA (T. pallidum microhemagglutination assay)- RBC sensitized with T. pallidum antigen added to dilution well, Patient serum added; Positive if cloudy aggregation, negative if red spot |
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Borrelia B. hermesii B. recurrentis B. burgdorferi |
Spirochete, GN, Endoflagella -Corkscrew & oscillating motility; Several periplasmic flagella -Relapsing fever (disease reappears when new antigens expressed) B. hermesii- Tick-borne relapsing fever (endemic/sporadic fever) -Vector: Tick -Host: Rodent B. recurrentis- Louse-borne relapsing fever (epidemic relapsing fever) -Vector: Lice (louse) -Host: Humans B. burgdorferi - Lyme disease -Vector: Deer tick (Ixodes scapularis), Western black legged tick (I. pacificus); nymph main transmission (larvae, nymph, adult; one blood meal per stage) -Host: White footed mice -In guts of ticks; ticks have to attach for 24-48hrs for bacteria to migrate to saliva -Not seen in blood smears -Fastidious; Very slow growers -Stage 1: Red rash (erythema migrans) with bullseye appearance -Stage 2: Spreads to other body tissues -Stage 3: Arthritis, CNS |
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Spirillum minus |
GN Spiral rod, External flagella Rat Bite Fever (Sodoku in Asia) Cannot grow in vitro No molecular diagnostic method |
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DNA Viruses |
Replicate in nucleus Herpesviridae- Can be latent -Herpes Simplex Virus: HSV1 (Cold sores), HSV2 (genital herpes); Tzanck cells (multinucleated giant cells), CPE on lung cells (rounding, enlargement, lysis) -Varicella Zoster Virus: Chickenpox (varicella) & Shingles (zoster), Tzanck smear, CPE large rounding cells -Epstein-Barr Virus: Mononucleosis (Flu-like symptoms) -Cytomegalovirus: Sexually & congenitally transmitted; Breast milk; Owl eye inclusions in lung fibroblast cells -Human herpes virus 6 & 7: Roseola infantum -Human herpes virus 8: Kaposi's sarcoma (lesions & nodules on skin) Poxiviridae- Smallpox -eradicated -vaccine using cowpox Papillomaviridae- Human papilloma virus (Pap smear) -STD, Skin/genital warts -Serotype 6 & 11: Genital warts (condyloma acuminata) -Serotype 16 & 18: Cervical cancer Adenoviruses- Self-limiting respiratory, ocular, gastrointestinal disease -aerosol & fecal-oral route Hepadnaviridae- Hep. B virus -Liver disease, jaundice, STD -Hardy envelope, Dane particle & virion infectious -HBsAg (surface antigen) appears first -IgM against HBcAg (core antigen) appears after 2 weeks (core window) -Anti-HBs confers immunity (appears after 6 months) -Vaccine |
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RNA Viruses |
Replicates in ER Hepatotrophic viruses -"A & E affects the bowel" -Hep A: Acute, Vaccine -Hep C: Mostly chronic; STD -Hep D: Requires HBV to replicate (missing essential genes) Enteroviruses- Fecal-oral route; Respiratory illnesses Polio virus (Picornaviridae) -multiplies in GI tract, Paralysis -95% asymptomatic -Vaccine (eradicated in developed countries) Rhinoviruses- Common cold Coronaviridae- Pharyngitis, Cold, Enveloped (SARS, MERS) Orthomyxoviridae- Influenza virus -Enveloped: H (haemagglutinin- cell attachment), N (Neuraminidase- release from infected cell) -RNA genome in 8 segments allows genetic reassortment -Antigenic shift- H or N exchanged ->pandemic -Antigenic drift- Point mutations -Influenza A- Zoonosis & humans (H5N1- Avian flu) -Influenza B- Young children (Reyes syndrome- inflammation of brain because of aspirin use to reduce fever) -Influenza C- Early childhood -Vaccine- killed & attenuated (nasal spray) Paramyxoviridae: -Parainfluenza virus- Croup (acute upper resp. infection with hoarse cough); cultured on kidney cells -Respiratory syncytial virus (RSV)- syncytia CPE (merged multinucleated cells) -Measles virus (Rubeola)- Skin rash & Koplik's spot (red spots with white centers on oral mucosa- diagnostic), fever, cough -Mumps virus- mumps, epidemic parotiditis (swelling of parotid gland), transmitted by saliva Rubella virus (Togaviridae)- German measles; Epidemic roseola, 3 day measles -fever, rash, papules on soft palate, lymphadenopathy -transmitted by aerosols & breast milk -mild in children, severe in adults -congenital- developmental defects -culture on African green monkey kidney cells (no CPE) Arboviruses- Arthropod-Borne Viruses -Zoonotic -Encephalitis -West Nile, Yellow fever (liver disease-jaundice), Dengue fever (internal bleeding) Gastroenteritis viruses - stomach flu -Noroviruses- cruise ships, Winter vomiting bug -Rotavirus- wheel shaped, dsRNA, affects infants -Adenoviruses Rhabdoviridae- Rabies virus -Saliva of animals, travels slowly to CNS -Flu like symptoms, pain at bite site -Negri bodies- eosinophilic inclusion in neurons Emerging viruses- hemorrhagic fever -Hanta virus- feces of rodents; severe pulmonary disease (drown in pulmonary fluids) -Rift Valley fever virus- transmitted by mosquitoes or contact with cattle -Filoviruses- Marburg & Ebola viruses -Arenaviruses- lymphocytic choriomeningitis, fatal Lassa fever; rodents in Africa & S. America Retroviruses- HTLV 1 &2 (Oncogenes- human t cell leukemia/lymphoma), HIV (AIDS)- attack T helper cells |
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Direct Diagnosis Methods for Viruses |
-Electron microscopy -Culture in eggs or tissue -Cytopathic Effects (CPE) -Plaque assay (for lytic viruses)- Inoculated tissue culture plate with layer of agar on top; 1 plaque = 1CFU -Transformation assay (for oncogenic viruses)- Focus assays- Count foci (infected cells that grow & pile up) -Quantal Assay- Dilution at which 50% cells/animals infected or killed |
