Term
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Definition
| gram positive cocci, grape-like clustering, facultative anaerobes, catalase and coagulase positive, form abcesses w/ acute inflammation |
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Term
| virulence factors of S. aureus |
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Definition
| coagulase converts fibrinogen to fibrin; catalase counteracts n-phil killing; hyaluronidase hydrolyses c.t. matrix; B-lactamases resist b-lactam antibiotics; leukocidin makes pores in n-phil membranes and kills them; exfoliatins cause scalded skin syndrome; superantigens that stimulate TNF and IL-1 release systemically; |
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Term
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Definition
| superficial skin and tissue infections, abcesses, bacteremia/endocarditis, pneumonia, septic arthritis, osteomyelitis, food poisoning, acute enterocolitis, and scalded skin syndrome |
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Term
| risk factors for furuncles |
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Definition
| n-phil defects, obesity, steroids, DM, and occlusive dressings |
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Term
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Definition
| incision and drainage plus antibiotics |
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Term
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Definition
| caused by exfoliative toxins (serine proteases), splits apart granular cell layer in skin, bacteria and immune cells not in affected epidermis, staph and strep can cause it |
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Term
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Definition
| highly resistant form; requires special susceptibility testing (pH, time, temp, etc.); both nocosomial and community-acquired; Mec-A gene confers resistance to b-lactam antibiotics; tx is vancomycin and linazolid |
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Term
| S. aureus vs. other staph strains |
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Definition
| coagulase positive while rest are coagulase negative |
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Term
| distinguishing staph from strep and enterococcus |
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Definition
| one is positive while the others are negative |
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Term
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Definition
| facultative anaerobe; Gram positive cocci in pairs or chains; beta hemolytic; causes tonsillitis, _____ throat, erypiselas, impetigo, cellulitis, wound infections, scarlet fever, necrotizing fasciitis, septicemia, and pneumonia; has several virulence factors |
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Term
| virulence factors for group A strep |
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Definition
| M protein resist phagocytosis; erythrogenic toxin causes rash of scarlet fever; streptokinase breaks down fibrin and causes spread of infection; hyaluronidase; exotoxins causing fever/shock/tissue damage |
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Term
|
Definition
| causes pneumonia and meningitis |
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Term
|
Definition
| neonatal sepsis and meningitis |
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Term
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Definition
| several different strains in group; common cause of subacute bacterial endocarditis; requires prophylactic antibiotic use before dental procedures |
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Term
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Definition
| causes mixed wound infections; septicemia; endocarditis; resistant to vancomycin (more common in faecium)!!! |
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Term
| acute community-acquired bacterial meningitis |
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Definition
| common culprits are GBS, E. coli, and N. meningitidis (children more than adults); caused by S. pneumoniae in adults |
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Term
|
Definition
| start empiric antibiotics (vancomycin w/ ceftriaxone or cefotaxime); CT scan if needed; LP; do gram stain and susceptibility testing of CSF |
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Term
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Definition
| 13 serogroups of this organism; most important are A/B/C/W135/X/Y; pathogenesis is oropharynx to bacteremia to fulminant meningococcemia; causes meningitis, septicemia, DIC, and Waterhouse-Frederichsen; most common in young adults; Dx by gram stain and culture from blood, CSF, and skin (rash) |
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Term
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Definition
| remember coffee bean shape and gram negative staining!!! Grows on Chocolate agar |
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Term
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Definition
| tiny gram negative coccobacilli in CSF or upper respiratory specimens; cultured on chocolate agar; requires X and V factors for growth; can be rapidly IDed w/ latex agglutination or DNA probe; pleomorphic in CSF; most common cause of meningitis in unvaccinated children and elderly!!! |
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Term
| spore-producing Gram positive rods |
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Definition
| Bacillus and Clostridium (anaerobe) |
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Term
| pleomorphic gram positives |
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Definition
| Corynebacterium, Listeria, Propionibacterium; Erysipelothrix |
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Term
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Definition
| long, thin, gram positive rods |
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Term
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Definition
| obligate anaerobe; sulfur granules in wounds |
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Term
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Definition
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Term
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Definition
| highly contagious, airborne droplet spread, gram positive rods at mucosal entry site; causes hyperplastic lymph nodes in neck; forms pseudomembrane at local infection of pharynx, larynx, or trachea; causes fatty myocardial degeneration, polyneuritis w/ myelin degeneration, degeneration of kidney/liver/muscle, death by resp. obstruction and myocardial insufficiency; dx by suspicion and culture/toxin tests (require 1 week) |
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Term
| typical infections by anaerobes |
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Definition
| lung abcesses, bacteremia, liver/subhepatic abcess, and necrotizing fasciitis |
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Term
| culprits for anaerobic wound abcesses |
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Definition
| Bacteroides, pigmented Prevotella/Porphyromonas group, Fusobacterium, Peptostreptococcus, Strep intermedius, Actinomyces, Propionibacterium acnes, Eubacterium, and Clostridium |
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Term
| anaerobic infection sites |
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Definition
| skin, genitourinary tract, GI tract, and oral cavity |
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Term
| characteristics of anaerobes |
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Definition
| cause endogenous infections; require compromised tissue in compromised host; often involved in mixed infections; growth is enhanced by decreased oxygen tension |
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Term
| predisposing factors for anaerobic infection |
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Definition
| trauma, surgery, malignancy, vascular insufficiency, steroids/immunosuppressant/cytotoxic drugs, diabetes, and prior antimicrobial agent use |
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Term
| Bacteroides appearance in abcess |
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Definition
| smudgy WBCs in brain abcess, red color, quickly lethal infection |
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Term
| Actinomyces appearance on gram stain |
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Definition
| shows sulfur granules mixed w/ purple (serum proteins); very thin filamentous appearance; not acid-fast |
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Term
| Nocardia appearance on pulmonary specimens |
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Definition
| gram positive, branching filaments, Kinyoun acid-fast positive, aerobic!!! |
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Term
| head/neck anaerobic culprits |
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Definition
| Prevotella/Porphyromonas (darkly pigmented); Fusobacterium mixed w/ S. aureus or Strep spp. (oral) |
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Term
|
Definition
| Fusobacterium necrophorum (Lemierre syndrome- lateral pharyngeal space w/ jugular venous thrombosis) |
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Term
| lung abcess anaerobic culprits |
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Definition
| Fusobacterium, Prevotella/Porphyromonas, and Peptostreptococcus |
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Term
| abdominal anaerobic culprits |
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Definition
| Bacteroides fragilis, Peptostreptococcus, Clostridia (often mixed w/ E. coli) |
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Term
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Definition
| gas gangrene; muscle necrosis in wounds; food poisoning or bowel necrosis in neutropenic pts; phospholipase C in perfringens degrades lecithin; histological appearance: gas bubbles, myonecrosis, systemic hemolysis, thrombosis, infarct w/o inflammatory cells; tetanosporin causes spastic paralysis (GABA inhibited); botulinum causes flaccid paralysis |
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Term
| Clostridium perfringens characteristics |
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Definition
| forms double zone of hemolysis; grows in 6-8 hrs on sheep blood agar; has partial hemolysis in egg yolk agar from lecithinase; spores are rarely seen in culture; nonmotile organisms; rods |
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Term
| Fusobacterium nucleatum characteristics |
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Definition
| look like "~"; common in H/N abcessing infections |
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Term
| fastest food poisoning culprits |
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Definition
| staph (2-4 hrs) and B. cereus (1-6 hr vomiting toxin, 6-24hr diarrheal toxin) |
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Term
| slowest food poisoning culprits |
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Definition
| botulism (avg. 12-24hrs up to 8 days) and perfringens |
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Term
| Vibrio cholerae and E. coli |
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Definition
| multiply inside mucous layer overlying gut epithelium and release exotoxins |
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Term
| Shigella, Salmonella, and Campylobacter |
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Definition
| invade intestinal mucosa and lamina propria at terminal ileum and proximal colon; cause inflammation, ulceration, and bloody stools |
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Term
|
Definition
| damages mucosa, then spreads to Peyer's patches, then to the mesenteric lymph nodes before going septic |
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Term
|
Definition
| typically prefers squamous epithelium; oral thrush or esophagitis common but disseminates to stomach, lower GI tract, and systemic organs |
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Term
|
Definition
| trophs attach to brush border of gut |
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Term
|
Definition
| spores and gametes form inside enterocytes; life cycle occurs there |
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Term
|
Definition
| invades and ulcerates colonic mucosa |
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Term
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Definition
| obstruct gut in large numbers or invade bile ducts |
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Term
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Definition
| very common diarrheal illness in small children, causes non-specific pathology, major cause of dehydration requiring hospitalization |
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Term
|
Definition
| "cruise ship" diarrhea; responsible for 50% of all foodborne cases of gastroenteritis |
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Term
|
Definition
| invasion of the colon by lactase negative gram negative rods; 80% of cases by sonnei sp.; small # of infectious units needed; initially watery diarrhea then bloody; low volume stool |
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Term
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Definition
| motile, comma-shaped gram negative rod; microaerophile; found in the GI tracts of many animals; bloody diarrhea occurs after 2-10 d incubation; inflames entire gut from jejunum to anus; rarely causes septicemia |
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Term
| nontyphoidal Salmonella infections |
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Definition
| cause food poisoning w/ erosion of colonic mucosa; enteric fevers seen; can cause bacteremia with or without intestinal lesions; may also cause local infections (osteomyelitis associated w/ sickle cell disease) |
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Term
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Definition
| causes peritonitis; lives in m-phages; loose granulomas w/o giant cells are key; difficult to cure due to carriage in gallbladder |
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Term
|
Definition
| caused by V. cholerae; toxin activates adenylyl cyclase in small bowel mucosa and causes secretory diarrhea; stools resemble rice water; no invasion/alteration of mucosal cells; severe dehydration kills |
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Term
|
Definition
| cysts are ingested and excyst in intestine; trophs invade colon; attachment to colonic cells occurs and bowel wall is invaded; treated w/ metronidazole |
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Term
| defects predisposing to infections |
|
Definition
| granulocytopenia, dysfunction of cell-mediated immunity, dysfunction of humoral immunity, splenectomy, obstruction, CNS dysfunction, medical procedures/devices, loss of normal microbiota, diabetes, and medical immune suppression |
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