Term
| Characteristics of Anaerobic Non-Clostridium Infection |
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Definition
-most infxns are polymicrobic (anaerobic&aerobic)
-virulence of anaerobes not due to presence of any particular toxin, but rather it is the combination of factors i.e. mixed infxn with reduced redox potential.
-most anaerobe infxns are foul smelling.
-infxns usually occur around sites of colonization followed by a breach of local host defense mechanisms. |
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Term
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Definition
Gram(-) Rods, spindle shaped, obligate anaerobe
Virulence: Adhesins-capsule, fimbriae; Resistance to O2 toxicity-superoxide dismutase, catalase; Antiphago activity-capsule, IgM, IgG, IgA proteases; Tissue Destruction-PLC, hemolysins, proteases, heparinases, lipases, collagenases.
Infxn: head & neck, bacteremia |
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Term
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Definition
Gram(-) Rods, obligate anaerobe
Virulence: Adhesins-capsule, fimbriae; Resistance to O2 toxicity-superoxide dismutase, catalase; Antiphago activity-capsule, IgM, IgG, IgA proteases; Tissue Destruction-PLC, hemolysins, proteases, heparinases, lipases, collagenases.
Infxn: usually below diaphragm(intraabdominal, gyn, skin&soft tissue, bacteremia), use clindamycin or metronidazole. |
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Term
| Prevotella melaninogenica |
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Definition
Gram(-) Rods, obligate anaerobe
Virulence: Adhesins-capsule, fimbriae; Resistance to O2 toxicity-superoxide dismutase, catalase; Antiphago activity-capsule, IgM, IgG, IgA proteases; Tissue Destruction-PLC, hemolysins, proteases, heparinases, lipases, collagenases.
Infxn: head&neck, intra-abdominal, gyn |
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Term
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Definition
| Gram+ cocci, obligate anaerobe |
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Term
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Definition
Gram(-) cocci, obligate anaerobe
rarely involved in human disease.
Infxn: head&neck |
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Term
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Definition
| Gram(+) Rods, obligate anaerobe Normal flora of mucous membranes that can cause a variety of subQ infxn, and infxn of prosthetic devices and IUDs. |
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Term
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Definition
| Gram(+) Rods, obligate anaerobe Normal flora of mucous membranes that can cause a variety of subQ infxn, and infxn of prosthetic devices and IUDs. Infxn: cervical facial actinomycosis (Lumpy Jaw), thoracic actinomycosis, abdominal actinomycosis, pelvic actinomycosis. Tx: surgical debridement of infx tissue, penicillin (use erythromycin or clindamycin if Allx). |
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Term
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Definition
Gram(+) Rods, obligate anaerobe
Normal flora of skin that causes acne. |
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Term
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Definition
Gram(+) curved rod, obligate anaerobe
Normal flora of vagina but can cause vaginosis.
Tx: ampicillin, clindamycin, or erythromycin. |
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Term
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Definition
| Gram(+) Rods, obligate anaerobe |
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Term
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Definition
| Gram(+) Rods, obligate anaerobe |
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Term
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Definition
| Gram(+) Rods, obligate anaerobe |
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Term
| Tx of Anaerobic Infections |
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Definition
Most important - surgical drainage and/or debridement.
Administration of appropriate abx.
Abx susceptibility is not usually tested on anaerobic bacteria.
With exception of Bacteriodes fragilis group, most oligate anaerobes are susceptible to penicillin or other beta-lactam abx.
Since B. fragilis group usually causes infections below the diaphragm and is susceptible to clindamycin or metronidazole, either of these drugs is used to tx anerobic infxns below the diaphragm while penicillin is used to tx infxns above diaphragm. |
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Term
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Definition
-can grow only in absence of O2. -O2 kills because anaerobes lack superoxide dismutase; build-up of free radicals kills bugs.
Reservoirs: Environment (primarily soil), skin, mouth&urogenital tract, colon.
Predisposing factors: anything that reduces the perfusion of blood to tissues, i.e. lowers the redox potential. Trauma(GSW, bowel perf, surg, aspiration), metabolic or pathologic diseases (diabetes, tumor). |
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Term
| Common Endogenous Anaerobic Infections |
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Definition
| CNS-brain abscess, sudural empyema (collection of pus); Oropharynx-periodontal infxn, chronic sinusitis, periotonsillar abscess, lumpy jaw, osteo of jaw; Resp-lung abscess, pneumonia, putrid empyema; Abdominal-intraabdominal abscess, peritonitis, appendicitis; Gyn-endometritis, salpingitis, tubo-ovarian abscess; other-human bites, decubitus ulcers, deep skin and muscle infxn, septecemia, endocarditis. |
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Term
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Definition
| obligate anaerobes grow very slowly. gram stain of clinical specimens can be performed in minutes and provide early presumptive dx. Common things occur commonly! |
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Term
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Definition
Gram+ rods, anaerobe, spore forming, histiotoxic (exotoxin destroys tissue.
Reservoir: soil, bowel (100 billion/gram of stool), other mucous membrane.
Virulence: alpha tox-PLC causes intravasc hemoysis(hemoglobinuria-->cherry red urine), beta tox-necrotizing activity, neuramidase-promotes capillary thrombosis, enterotoxin-alters membrane permeability in ileum.
Disease: clostridial myonecrosis(gas gangrene); also caused by C. histolyticum/septicum/novyii/sordelli.
Presentation: predispose-some type of tissue trauma that lowers redox potential; local edema, pain, crepitation, toxemia. path due to extracellular enzyme-->tissue destruction.
Dx: presentation, hx, culture, gram stain(large gram+ rods w/ or w/o spores).
Tx: surgical drainage and debridement is essential along w/ penicillin. |
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Term
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Definition
Gram+ rod, anaerobe, spore forming
Reservoir: normal flora of bowel (not everyone, if healthy <2%), contaminated fomites in hospital(spores).
Virulence: toxin A-enterotoxin that causes fluid loss, toxin B-cytotoxin destroys colonic mucosal cells.
Risks: abdominal surg, intestinal obstruct due to malign., abx or antineoplastics.
Disease: super infection due to abx tx that eliminates all other flora except c. diff. abx-assoc diarrhea or pseudomembranous colitis(more severe form; plaques form).
Resistance: Clindamycin, Cephalosporins, methicillin, penicillin.
Tx: metronidazole or vancomycin. (25% relapse but 2nd round of abx will eliminate). Fidaxomicin recently approved, limited systemic absorption. Experimental thx: stool donor replacement. |
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Term
| Clostridium difficile, mutant strain |
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Definition
| New mutant strain of C. difficile has a 30 bp deletion in repressor gene. It can no longer turn off synthesis of toxin A & B, leading to hypersecretion of toxins. This causes a more serious life-threatening disease. |
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Term
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Definition
Gram+ rod, anaerobe, spore forming, neurotoxin
Reservoir: soil, spores can germinate in anaerobic env.
Virulence: toxins A-G; A,B,E causes most human disease.
Disease: botulism-acute and often fatal disease that results from ingestion of preformed toxins in food (must boil for 10 minutes to eliminate). Toxin absorbed by GI and binds to pre-synaptic terminal blocking Ach release-->diaphragm paralysis. Most lethal biologic toxin! also infant botulism and wound botulism.
Presentation: 12-36 hour incubation. N&V, diarrhea may occur, but most symptoms related to neurotoxin effects (dizziness, difficulty swallowing, double vision).
Tx: antitoxin to specific serotype. if unknown use polyvalent antitoxin. |
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Term
| Infant, Wound, and Inhalation Botulism |
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Definition
Infant: most common form of botulism. organism can survive in infant's bowel. symptoms are non-specific (failure to thrive).
Wound: toxin produced from infected wound site. symptoms same as foodborne botulism.
Inhalation: aerosolization of spores as agent of bioterrorism. |
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Term
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Definition
Gram+ rod, anaerobe, spore forming (tennis racquet)
Reservoir: soil or GI tract
Virulence: tetanospasmin (neurotoxin)
Disease: local infxn often unnoticed. 1-4 weeks after tissue injury-->headache, irritability, muscle stiffness, spasm of masseter muscle (lockjaw), dysphagia, autonomic dysfxn, general rigidity. Toxin acts by suppressing inhibitory neurons required for cooperative agonist-antagonist fxn.
Tx: usually will not detect primary site of infxn, but if possible locate & debride. Administer human tetanus immunoglobulin and penicillin.
Prevention: tetanus toxoid every 10 years. |
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Term
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Definition
aerobic gram + rod that produces spores
Transmission: found in soil, but causes disease in livestock. Direct contact-cutaneous infxn that produces a necrotic ulcer. Inhalation-pulmonary anthrax leads to pneumonia, sepsis, meningitis, death. Ingestion-GI anthrax is rare in humans but most common in herbivores.
Tx-penicillin (drug of choice), erythromycin, tetracycline
Prevention-vaccinate livestock |
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Term
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Definition
aerobic gram (-) rod, bubonic plague
Transmission-rats (urban); squirrels, rabbits, prairie doges (sylvatic) carry bug, and flea transmits.
Clinical-Bubonic plague: nectrotic skin lesions with swollen lymph nodes; not contagious. Septicemic plague: secondary to BP. Pneumonic plague: secondary to BP or inhalation exposure to individual with pneumonic plague. Very contagious.
Tx-tetracycline or streptomycin.
Prevention-short term immunity vaccine available. |
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Term
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Definition
aerobic gram (-) rod
Transmission-disease of wild animals; lagamorph (rabbit) chief source of human infxn. Contact w/ infected animal and penetrates abraded skin.
Clinical-extremly virulent in humans. Sudden headache, fever, malaise, weakness. Presentation depends on route of exposure; all forms except typhoidal develop ulcer or lesion at site of infxn w/ regional swelling & suppuration of lymph nodes (ulceroglandular, glandular, typhoidal, oculoglandular, oropharyngeal).
Tx-tetracycline or streptomycin |
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Term
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Definition
| Def-a systemic infxn characterized by a variable route of entry, tissue localization, and onset of symptoms (aka undulent fever). Transmission-direct contact with infected animal products (unpasteurized milk, cheese, meats). Brucella abortus-cattle-mild; Brucella melitensis-goats-severe; Brucella suis-pigs-severe. Clinical-organism migrates via lymphatics to regional l.n. and disseminates via blood to spleen, liver, BM, ln). Insidious onset-malaise, weakness, myalgias, weight loss, fatigue, Undulent fever (intermittent spiking fever). Tx-prolonged thx w/ tetracycline and aminoglycoside b/c org is intracellular. |
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Term
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Definition
Listeriosis
Reservoir-animal and bird GI, insects water, normal flora in 1-5% of human GI/vag.
Transmission-usually due to ingestion of fecally contam dairy.
Clinical-biomodal; infants (sepsis&meningitis), elderly (sepsis); adults (mild flu-like, diarrhea).
Tx-ampicillin and aminoglycoside combo. |
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Term
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Definition
cutaneous infxn following cat bite. normal flora of cat's mouth.
Tx-ampicillin |
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Term
| Erysipelothrix rhusiopathiae |
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Definition
cutaneous infection (erysipeloid) following cutaneous exposure to contaminated meats or poultry or skin puncture with fish fin.
Tx- cephalosporin or macrolide |
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Term
| Streptobacillus moniliformis |
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Definition
causes rat-bite fever
normal flora of rat nasopharynx.
Disease acquired via rat bite or ingestion of contaminated food, water, or milk.
Clnical-abrupt recurring onset of fever, headache, chills, myalgias, arthralgias w/ possibility of systemic complications (pneumonia).
Tx-penicillin or doxycyline |
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