Colitis antibiotic-associated

Important members of this toxin family are Clostridium difficile toxins A and B, which are implicated in antibiotics-associated diarrhea and pseudomembranous colitis. The large clostridial cytotoxins are single-chain toxins with molecular masses of 250-308 kDa. The enzyme domain is located at the N terminus. The toxins are taken up from an acidic endosomal compartment. They glucosylate RhoA at Thr37 also, Rac and Cdc42 are substrates. Other members of this toxin family such as Clostridium sordellii lethal toxin possess a different substrate specificity and modify Rac but not Rho. In addition, Ras subfamily proteins (e.g., Ras, Ral, and Rap) are modified. As for C3, they are widely used as tools to study Rho functions [2] [4]. 

As with all drugs, the specific side effects of the quinolones must be considered when they are chosen for treatment of bacterial infections [5]. Reactions of the gastrointestinal tract and the central neivous system are the most often observed adverse effects during therapy with quinolones. It should be underlined, however, that compared with many other antimicrobials, diarrhea is less frequently observed during quinolone treatment. Antibiotic-associated colitis has been observed rarely during quinolone therapy. Similarly, hypersensitivity reactions, as observed during therapy with penicillins and other (3-lactams, is less frequently caused by quinolones. Some other risks of quinolone therapy have been defined and must be considered if a drug from this class is chosen for treatment of bacterial infections. 

Surawicz CM Antibiotic-associated diarrhea and pseudomembranous colitis Are they less common with poorly absorbed antimicrobials Chemotherapy 2005 51(suppl 1 ) 81—89. 

Antibiotic-associated diarrhea Pseudomembranous colitis Clostridium difficile Rifaximin Clostridium difficile-assodated diarrhea... 

The answer is c. (Hardman, pp 996-997r 1145—1146. Ka tzung, p 8455 Metronidazole is often used to treat antibiotic-associated enterocolitis, especially when caused by C difficile. Vancomycin is no longer preferred because it induces selection of resistant staphylococci. Clindamycin is also associated with C difficile colitis, but in another way a higher percentage of patients taking this over other antibiotics develop antibiotic-associated enterocolitis. 

Clindamycin, which is active against Gram-positive aerobic organisms and Gram-negative anaerobes, may cause antibiotic-associated colitis. 

Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of Clostridia. Studies indicate that a toxin produced by Clostridium difficile is a primary cause of antibiotic-associated colitis. ... 

Oral Staphylococcal enterocolitis and antibiotic-associated pseudomembranous colitis produced by C. difficile. The parenteral product may also be given orally for these infections. Oral vancomycin is not effective for other types of infection. 

Vancomycin is not absorbed after oral administration and must be given intravenously. Oral administrations are used for intraluminal gastrointestinal infections such as antibiotic-associated pseudomembranous colitis produced by Clostridium difficile. Vancomycin is widely distributed in the body but does not cross the blood brain barrier and does not penetrate into bone. It is excreted mainly via the urine, resulting in accumulation in patients with renal insufficiency. Its elimination half-life is 4-11 hours but can increase to 6-10 days in renal failure. 

The spectrum of gastrointestinal tract infections (GTI) cover a wide spectrum from asymptomatic Helicobacter pylori gastritis to self-limiting viral gastroenteritis to food poisoning to bacterial enterocolitis to antibiotic-associated Clostridium difficile colitis to typhoid fever with sepsis and multi-organ failure. 

Antibiotic-associated colitis and other superinfections may result from altered bacterial balance. 

Daily bowel activity and stool consistency although mild GI effects may be tolerable, severe symptoms may indicate the onset of antibiotic-associated colitis... 

Antibiotic-associated colitis manifested as severe abdominal pain and tenderness, fever, and watery and severe diarrhea, and other superinfections, may result from altered bacterial balance,... 

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