Sudden onset of nausea vomiting rice water diarrhea 5

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- sudden onset of nausea, vomiting, “rice water” diarrhea - 5-10 L H 2 O loss / day can circulatory collapse - death from dehydration after only 24 hrs w/o Tx pay attention to the types of diarrhea, various bacteria cause (watery, bloody, etc.) Diagnosis Treatment(s) - oral rehydration therapy - tetracycline Prevotella melaninogenica N = formerly Bacteroides melaninogenicus Lab ID - G- bacilli - grown black on special agar Metabolism obligate aerobe Other Unique Features Virulence - capsule - collagenase - leukocyte inhibitory factor Transmission constitutes normal flora of oral pharynx, GI & vagina Associated Diseases * Lung infections – necrotizing anaerobic pneumonias from sputum aspiration (drunken or seizure state) * Dental infections Diagnosis Treatment(s) * 10-25% are penicillin -resistant
Helicobacter pylori Lab ID - G- slender curved rod - sheathed polar flagella > accounts for characteristic “darting” - oxidase (+) - urease (+) Metabolism - microaerophilic (acidophilic) - fastidious & slow-growing Other Unique Features - highly variable genome = very adaptable - NATURAL TRANSFORMER, change surface Ag Ab resistance Reside in ( ± ectopic) gastric mucosa and close to gastric epith cells Virulence - no invasive potential on its own - urease enzyme on surface ammonia > protects against acid > expression at low pH - adhesins bind epith cells (1) IL-8 T H 1 response (2) IL-1 cell act gastric atrophy hypochlorydia, gastric cancer - CagA + path island proteins secrete virulence factors into host, type IV secretion system , loosens TJ’s - Vac + cytotoxin disrupts organelles Most Asian isolates are Cag + Most Cag + are also Vac + Transmission - probably fecal-oral or oral-oral - reservoir = humans (only) - 50% of world population infected > usu. acquired in childhood Associated Diseases * Infection always assoc. w/ INFLAMMATION ( “gastritis” ) - may be aSx * Duodenal ulcer (precursor is Antral gastritis) - preventive for gastric cancer (Note: not true of gastric ulcers) * Gastric ulcer * Gastric cancer (2 nd leading worldwide cancer) * MALT lymphoma * chronic/acute antral/corpal gastritis > corpal gastritis can metaplasia * there is a negative assoc. b/w H. pylori infxn & GERD Diagnosis - Endoscopy + test of antral biopsy for urease activity ( CLO test ) - common: serology - accurate: stool antigen testing, urea breath test test pts w/ gastric ulcer disease (peptic ulcers or MALT lymphoma) Treatment(s) high variability = high resistance * “cure” w/ antacids 50% recurrence rate * Antimicrobials eradication - triple combo = omeprazole + amoxicillin, bismuth, tetracyclines, macrolides, clarithromycin , metronidazol Urea breath test (urea CO 2 + NH 4 + ), inhale tagged C13, C14 Fusobacterium nucleatum N Lab ID Pale, staining slender G- rods w/thin pointed ends contrast to F. necrophorum Metabolism obligate anaerobe - butyric acid = principle metabolic end product Other Unique Features - no capsule Virulence - very potent LPS Transmission - constitutes normal flora of mouth, GI & vagina Associated Diseases * Pulmonary Infections * periodontal disease Diagnosis Treatment(s) Metronidazole Gram stain of Fusobacterium nucleatum

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