Spectrum of organisms causing peritonitis in peritoneal dialysis patients--experience from Bangladesh.

In the present study, organisms responsible for peritonitis and their sensitivity to antibiotics were evaluated in peritoneal dialysis (PD) patients in Bangladesh. We collected PD effluent from 100 peritonitis cases and sent samples to the laboratory for Gram stain and cytology. Cultures used direct inoculation of PD fluid in plate media and broth media simultaneously. Organisms were isolated by Gram stain in 60% of cases. Cell counts showed a mean of 700 (range: 90-7000) white blood cells per milliliter Plate media yielded 33% growth, and broth media, 67% growth. In continuous ambulatory PD, 77% samples were culture-positive; the organisms isolated were gram-positive bacteria in 41% of cases, gram-negative bacteria in 52%, and fungus in 7%. In intermittent PD, only 43% samples were culture-positive; the isolated organisms were gram-positive bacteria in 18% cases and gram negative bacteria in 82%. Gram-positive organisms (Staphylococcus and Streptococcus species) were sensitive to vancomycin and rifampicin; moderately sensitive to ciprofloxacin, ceftriaxone, and ceftazidime; and resistant to ampicillin, cloxacillin, and cephalexin. Gram-negative organisms (Escherichia coli, Klebsiella species) were sensitive to imipenem and aztreonam, and moderately sensitive to ciprofloxacin, ceftriaxone, ceftazidime, and gentamicin. Pseudomonas species were sensitive to aztreonam and ceftazidime, and moderately sensitive to ciprofloxacin, ceftriaxone, and gentamicin. Gram-negative organisms were predominantly responsible for peritonitis in PD patients, and before culture results are received, combined empiric therapy with vancomycin and imipenem or aztreonam may be started.