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82 Cards in this Set
- Front
- Back
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S. saprophyticus
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Catalase +
Coagulase - Gram + cocci Resistant to Novobiocin Dz: Honeymoon Cystitis (UTI's in newly sexually active females) |
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S. epidermidis
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Catalase +, Coagulase -
Gram + cocci Novobiocin sensitive Biofilm producer Infections of catheters/shunts Subacute endocarditis in IV drug abusers |
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Staph aureus
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Catalase +, Coagulase +
Gram + cocci in clusters Gastroenteritis: 2-6h onset -salty foods, custards -picnic foods Acute infective endocarditis Toxic Shock Syndrome -desquamating rash (palms and soles), fever, hypotension Bullous impetigo Pneumonia: nosocomial, typical, acute (salmon colored sputum) Osteomyelitis: #1 cause unless sickle cell dz |
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Streptococcus pyogenes
(Group A streptococcus) |
Catalase -, B hemolytic
Bacitracin sensitive Gram + cocci M12 strains of M-protein (antiphagocytic) Pharyngitis: abrupt onset, tonsillar abscesses Scarlet fever: blanching, sandpaper rash, strawberry tongue Impetigo: honey crusted lesions (children) |
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Strep pyogenes
(group A) |
Rheumatic fever
-after streptococcal pharyngitis - increase ASO titer |
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Strep pyogenes (group A)
M12 serotype |
Acute glomerulonephritis
-after streptococcal skin or throat infection -HTN, edema, smoky urine |
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Streptococcus agalectiae
(group B strep) |
Gram +, Catalase -,
B hemolytic, CAMP test + Bacitracin resistant Located in the human vagina in 15-20% of women Neonatal meningitis and septicema: #1 cause, esp in prolonged labors |
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Streptococcus pneumoniae
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Gram + lancet shaped diplocci, Catalase -
Alpha hemolytic Soluble in bile, Optochin sens. major virulence factor: polysaccharide capsule IgA protease Most common cause of typical pneumonia -rusty colored sputum Most common cause of meningitis in adults -many PMNs, decreased glucose, increased protein in CSF Most common cause of otitis media and sinusitis in kids |
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Rust: S. pneumoniae
Current jelly: K. pneumoniae Salmon color: S. aureus Elderly smoker: Legionella pneumophilus |
Pnemonias:
Rust Colored Sputum Current Jelly Sputum Salmon colored Sputum Elderly smoker |
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S. pneumoniae vaccines
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Pediatrics: pneumococcal capsular vaccine (hapten)
-conjugated to diphteria toxin (carrier) Adult: pneumococcal polysaccharide vaccine |
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Viridans Streptococci
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Gram +, Catalase -
alpha hemolytic, optochin resistant bile insoluble Normal flora in human oropharynx Dextran (biofilm) mediated adherence Plaque and dental carries Subacute bacterial endocarditis -preexisting damage to heart valves -follows dental work -splinter hemorrhages |
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Enterococcus faecalis/faecium
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Gram +, Catalase -
hydrolyzes esculin (black colonies) Reservoir: human colon, urethra +/- female genital tract Urinary/biliary tract infections -elderly male Subacute bacterial endocarditis -elderly males following GI/GU surgery, preexisting heart valve damage Elderly male with prostate prob |
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Bacillus anthracis
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Gram +, spore forming
Aerobic rods Capsule is polypeptide (poly-D- glutamate) Contact with animal hides or postal worker Eschar: black necrotic lesion with red ring Life threatening pneumonia -mediastinal widening -vasculature dissolves |
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Bacillus cereus
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Spores
Rapid-onset gastroenteritis -non bloody -fried rice, Chinese restaurant |
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Clostridium tetani
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Large G+, spore forming rods
Anerobic Dirty puncture wound Rigid paralysis -blocks release of inhibitory neurons in spinal synpase |
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Linear, 1 cm deep cut, without devitalized tissue or major contamination
Less than 6hrs old Vaccine if no hx Vaccine if more than 10yrs since last booster |
Wound management:
Not Tetanus Prone |
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Blunt/missile, burn, frostbite, any wound >6hrs old
Not completed primary or no hx of vaccine: Vaccine + TIG Vaccine if more than 5yrs since last booster |
Wound management:
Tetaus Prone |
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Clostridium botulinum
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G+, spore forming rods
Anaerobic Coded for my a prophage Absorbed by gut, blocks release of ACh --> flaccid paralysis Home canned alkaline veggies Vacum packed fish Infants: honey (child becomes less active) |
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Clostridium perfringens
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Large G+ spore forming rods
Anaerobic: "stormy fermentation" in milk media Double zone of hemolysis Alpha toxin is a lecithinase Identified by Nagler rxn Gas Gangrene -contaminated wound -fever, tachycardia, tense tissue (edema, gas) Food Poisoning -reheated meat dishes -noninflammatory diarrhea |
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Clostridium difficile
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Part of normal flora in human colon/GI tract
Abx associated (clindamycin) diarrhea, colitis or pseudomembranous colitis (yellow plaques on colon) Hospitalized pt on abx that develops colitis or diarrhea Tx: metronidazole |
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Listeria monocytogenes
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G+ rods, tumbling motility
facultative intracellular B hemolytic, cold growth Listeriolysin O: pathogenesis Foodborne-- deli meats, unpasteruzied milk products -cold growth: soft cheese, cabbage, **goat milk/cheese Can cross placenta: granulomatosis infantisepticum Most common cause of meningitis in renal transplant pts and adults with cancer 3rd most common cause of neonatal septicemia and meningitis |
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Corynebacterium diphteriae
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G+, aerobic, club shaped rod
black colonies on tellurite med. Toxin producing strains have B-prophage Non-invasive organism -inhibits protein synthesis by adding ADP-ribose to eEF-2 Dirty gray pseudomembrane in oropharynx --> obstruction -profuse bleeding if dislodged Diphtheria: Bull neck, myocarditis, nerve palsy -must be unvaccinated Elek test to document toxin |
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Actinomyces israelli
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Anaerobic, non-acid fast
G+ branching rods Endogenous transmission -gingival crevices and female genital tract (normal flora) Pt with mycetoma (draining abscess) on jaw line or spread from IUD Solitary brain abscess Sulfur granules in pus |
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Nocardia
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G+ branching rods, aerobic
Partially acid fast Reservoir: soil and dust Cavitary bronchopulmonary dz mycetomas Multiple foci brain abscesses |
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Neisseria meningitidis
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G-, kidney bean shaped diplococci
Large capsule Ferments maltose Virulence factors: -polysaccharide capsule -IgA protease -Endotoxin -Pili Meningitis -abrupt onset, petechial rash -can lead to waterhouse-friderischsen syndrome Dx: latex agglutination Vaccine: Y, W-135, C and A prophylaxi of close contacts: rifampin |
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Neisseria gonorrhoeae
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G-, kidney bean shaped diplococci
Pathogenesis: -pili (most important) -IgA protease -invades mucosal surfaces males: urethritis females: endocervicitis Infants: ophthalmia (leads to blindness if untreated) Dx: G- dipplococcus in neutrophils Thayer-Martin medium |
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Moraxella catarrhalis
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G- diplococcus
normal upper respiratory tract flora Causes otitis media |
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Pseudomonas aeruginosa
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G- rod, oxidase +, aerobic
Blue-green pigment, fruity odor Slime layer Exotoxin A ADP ribosylates eEF-2 inhibitin protein synthesis (like diphtheria) Liver is primary target Burn infection: blue green pus Typical pneumonia: CGD/CF -recurrent pneumonias in CF UTI-catherized pts |
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Legionella pneumophilia
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Fastidious- requires increased iron and cysteine
Elderly smoker, heavy drinkiner or immunosuppresed Exposure to aerosols of water -air conditioning, common shower facilities Atypical pneumonia Dx: DFA |
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Francisella tularensis
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Small G- rod
Hunter with ulceroglandular dz, atypical pneumnoia or GI disease Arkansas/Missouri Exposure to rabbits, deer, ticks (Dermacentor) |
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Bordetella pertussis
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G- small rods, aerobic
mucuosal surface pathogen toxins damage resp. epithel. -adenyalte cyclase toxin -tracheal cytotoxin -Pertussis toxin unvaccinated child (immigrant family or religious objections) cough with inspiratory "whoop" |
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Brucella
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G- aerobic rods
Pt with acute septicemia Exposure to animals or unpasteruzied dariy California/Texas, travel to Mexico |
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Campylobacter jejuni
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G-, curved rods with polar flagella ("gull's wings")
Oxidase + Microaerophilic, grows at 42C Low infectious dose Pt with inflammatory diarrhea -#1 cause of bacterial diarrhea in the US Complications: Guillain-Barre syndrome -serotype O:19 |
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Helicobacter pylori
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G-, spiral bacilli w/ flagella
Microaerophilic, grows at 37C Urease + Pt with gastritis, ulcers, stomach cancer -**Type I carcinogen** Dx: breath test |
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Vibrio cholerae
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G- curved rod with polar flagella
Oxidase + Growth on alkaline media -TCBS Requires high dose Rice water stools -tremendous fluid loss -dehydration **Natural disasters** |
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Cholera enterotoxcin
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ADP ribosylates (Gs alpha) activating adenylate cyclase-> increased cAMP -> efflux of Cl and H20
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Enterobacteriaceae
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G- rods, facultative anerobes
Ferment glucose Cytochrome C oxidase - reduce nitrates --> nitrites Catalase + Lactose fermenters (colored colonies) on MacConkey Antigens -O= cell envelope -H= flagellar -K= capsular polysaccharide antigen -Vi= Salmonella capsular antigen |
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Mycobacterium characteristics
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Acid fast rod with waxy cell wall
Obligate aerobe No outer membrane |
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Mycobacterium tuberculosis
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Auramine rhodamine staining bacilli (fluorescent apple green)
Acid fast Produces niacin and a heat sensitive catalase Pathogenesis: -sulfatides inhibit phagosome-lyosome fusion -Cord factor inhibits leukocyte migration (the more cord factor the more pathogenic the strain) -Tuberculin (surface protein) causes delayed hypersensitivity and cell mediate immunity High risk pt (HIV +) Chronic cough, weight loss Ghon complex Positive PPD test |
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M. avium-intracellulare
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AIDs pt, cancer, chronic lung disease
Nonchromogen (produces no pigment) AIDS pts start prophylaxis when CD4 <50 -macrolide + ethambutol |
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M. scrofulaceum
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Solitary cervical lymph node in kids
Scotochromogen (produces dark pigment) Tx: surgery |
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M. marinum
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"Fish tank granuloma"
tropical fish enthusiasts with cutaneous granulomas Photochromogen (produces pigment after light exposure) |
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Mycobacterium leprae
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Acid fast rods in punch biopsy
Obligate intracellular parasite Optimal growth at less than body temp. Immigrant pt with sensory loss in extremities |
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Strong CMI (TH1)
Lepromin test + Low # of organisms in tissue Damage from the immune response --> granuloma formation --> loss of sensation Few lesions nerve enlargement paresthesia |
Tuberculoid form of Leprosy
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Weak CMI (TH2)
Lepromin test - high # of organisms in tissue nerve damage from overgrowth of bacteria in cells Numerous lesions becoming nodular Paresthesia Leonine facies |
Lepromatous form of Leprosy
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Escheria Genus Characteristics
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Gram - rods
Enterobacteriaceae Ferment lactose |
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E. coli
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Gram - rod
facultative anaerobe Oxidase - Lactose fermenter |
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ETEC
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Traveler's diarrhea
LT: heat labile toxin stimulates adenylate cyclase by ADP ribosylation of Gs ST: stimulates guanylate cyclase Capsule impedes phagocytosis colonizing factor adhesins bind to mucosa |
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EPEC
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2nd most common cuase of infantile diarrhea
Adheres to M cells causing rearrangment of actin and effacement of brush border microvilli |
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EHEC (O157:H7)
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H= hamburger
Verotoxin: Shigella like toxin No fever, no PMNs, blood in stool, nonfermenters of sorbitol (colorless colonies on MacConkeys) Most common in children <5 Abx increase risk of HUS |
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EAEC
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Frimbriae produce "stacked brick like" biolfilm
Enterotoxin EAST |
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EIEC
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I= inflammatory
Invades large bowel Inflammatory diarrhea (with blood and pus) |
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E.coli and UTI's
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Most common cause of UTI
pathogenesis: motility clinical clues: G- bacilli >10/\5 CFU/ml |
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E. coli and Neonatal septicemia/meningitis
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2nd most common cause of neonatal septicemia/meningitis
Pathogenesis: capsule (K1) |
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E. coli and septicemia
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Indwelling IV lines, cytotoxic drugs damage intestinal mucosa and allowe escape
Pathogenesis: endotoxin |
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Klebsiella pneumoniae
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G- rods with large polysaccharide capule
Lactose fermenter Elderly pt with atypical pneumonia: currant jelly sputum UTI- catheter associated |
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Shigella
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G- rods, nonmotile
nonlactose fermenter do NOT produce H2S Pt with acute bloody diarrhea and fever Shigellae invade M cells -causes shallowe ulcers of mucosa Few organisms required (extremely acid resistant) Fever, diarrhea (1st watery then bloody) **proper sanitation |
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Yersinia pestis
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Small G- rod
facultative intracellular parasite Coagulase + US desert southwest: rodents Envelope antigen (F-1) inhibits phagocytosis Bubonic plaque -rapidly increasing fever -regional buboes -conjunctivitis Pneumonic Plague -highly contagious |
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Yersinia enterocolitica
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G- bacilli, nonlactose fermenter
non H2S producer Motile-25C, nonmotile-37C Unpasteurized milk, pork Northern climates Multiplies in the cold Pt with inflammatory diarrhea or pseudoappendicitis |
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Proteus
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G- rod
Swarming motility Non-lactose fermenter Urease + Kidney stones (staghorn) Pt with UTI or septicemia To prevent promptly remove urinary catheters Weil-Felix test |
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Salmonella enterica
Subspecies typhi |
G- rods, highly motile
non-lactose fermenting Produce H2S sensitive to acid Human carriers (gallbladder) Typhoid fever: infections begin in the ileocecal region At 1 wk: 80% have + blood cultures, 25% have rose spots By week 3: 85% of stool cultures are + Resistant to macrophage killing due to defensins Widal test |
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Salmonella enteria
Subspecies other than typhi |
G- bacilli, motile
Non-lactose fermenters produce H2S Invades mucosa in ileocecal region --> increase PG --> increase cAMP --> diarrhea Reservoir: chickens and turtles Dx: Widal Test Enterocolitis- 2nd most common cause of bacterial gastroenteritis -inflammatory follows ingestion of poulty products or handling reptiles Osteomyelitis- sickle cell dz |
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Haemophilus influenzae
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G- rod, encapsulated
requires factors X and V Polysaccharide capsule (type b capsule is polyribotol phosphate) IgA protease Epidemic in UNvaccinated children ages 3mo-2yrs Otitis media Epiglottitis Dx: latex particle agglutination |
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IgA Protease
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Strep pneumo
Neisseria H. influenzae |
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Haemophilus ducreyi
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Soft, painful chancre
Open lesions increase transmission of HIV Culture on chocolate agar |
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Gardnerella
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G- pleomorphic rods
Catalase and Oxidase - Bacterial vaginosis -follows abx or menses Dx: -pH >4.5 -clue cells (epithelial cells covered with bacteria) -Whiff test (fishy smell) |
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Pasteurella multocida
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Small G- rod
Patient with animal (cat) bite Cellulitis/lymphadenitis |
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Bartonella henselae
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G- rods
Cat/dog scratches Cat scratch fever Bacillary angiomatosis (AIDS) |
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Bacteroides fragilis
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G- rod, anaerobic
Modified LPS with reduced activity Reservoir: human colon Transmission: endogenous Pt with abdominal trauma, emergency abdominal surgery Septicemia, peritonitis, abscess Tx: Metronidazole prevention: prophylactic abx |
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Borrelia burgdorferi
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Large spirochete, G-
Microaerophilic Transmitted by Ixodes (deer) tick #1 tickborne dz in US Pt with influenza like sx and erythema migrans Spring/summer seasons NE, MW, West coast later: neuro, cardiac, arthritis |
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Chlamydia trachomatis
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Obligate intracellular
-can't make ATP Infective form: elementary body Active form: replicating reticulate body STDs: Serotypes D-K -most common bacterial STD in US Lymphogranuloma venereum -Africa/Asia -Serotypes L1-3 Trachoma -leading cause of preventable infectious blindess -Serotypes A-C Infants: inclusion conjunctivitis, pneumonia Dx: cytoplasmic inclusions |
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Gonorrheae/Chlamydia
- purluent/mucoid Trichomonas - frothy yellow-green, malodorous Candida -cottage cheese like Gardnerella -thin, greyish fluid, malodorous |
STD Discharge
Gonorrheae/Chlamydia Trichomonas Candida Gardnerella |
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Chlamydia pneumoniae
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Potential association with atherosclerosis
Reservoir: human resp. tract infects smooth muscle Atypical "walking" pneumonia Sputum with intracytoplasmic inclusions |
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Chlamydia psittaci
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Reservoir: birds, parrots
Atypical Pneumonia |
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Rickettsia rickettsii
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Obligate intracellular
produced limited ATP Rocky Mountain Spotted Fever -transmitted by Dermacentor ticks -Reservoir: small wild rodents and dogs -Prevalent on East coast -Spring/summer months Rash: starts on ankles and wrists and then spreads to trunk, palms, soles and face Weil-Felix + |
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Ehrlichia
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G- bacilli
Obligate intracellular morulae-- mulberry like structures inside infected cells Pt with influenza like sx, no rash, leukopenia, thrombocytopenia Same geographic area as lyme disease spring/summer |
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Ureaplasma urealyticum
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Urease +
Non gram staining Adult pt with urethritis, prostatitis, renal calculi Alkaline urine |
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Mycoplasma pneumoniae
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Extracellular, tiny
No cell wall Membrane contains cholesterol Inhibits ciliary action produces hydrogen peroxide, superoxide radicals and cytolytic enzymes that destroy the resp epithelium leading to a bad, hacking cough Most common atypical pneumonia in young adults -walking pneumonia Mulberry shaped colonies on sterol containing media + cold agglutinins |
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Treponema pallidum
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Spirochetes, G-
Visualized by dark field or fluorescent Ab Trasmitted sexually and crosses placenta Dz characterized by endarteritis resulting in lesions |
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Stages of Syphilis
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1- nontender chancre with indurated edges
-dark field or fluorescent microscopy 2- maculopapular (copper colored) rash including plams and soles, condylomata lata -serology nonsepcific and specific both positive 3- Gummas in CNS and CV Congenital- babies of IV drug users -notched teeth (hutchinsons) -signs of secondary syphilis |
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Diagnosis of Syphilis
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Nontreponemal Ab
-Ab binds to cardiolipin -very sensitive in 1 and 2 syphilis -not specific -confirm with FTA-ABS Specific tests for treponemal Ab -earliest Ab bind to spirochetes -FTA-ABS |
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Jarisch Herxheimer rxn
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May occur during tx of any of the spirochete diseases
Starts w/in 24hrs of abx increase in temp, decrease in BP, rigors, leukopenia |
