BACTERIOLOGICAL EXAMINATION OF THE ABDOMINAL EFFUSION IN BACTERIAL PERITONITIS

This study provides a contemporary epidemiology of aspirates taken during surgery from the abdominal cavity among patients with bacterial peritonitis to identify the isolates and study their sensitivity to antibiotics. Our bacteriology investigations included isolation of poor cultures, and detection of microbes was conducted using a rapid identification system (API20E, API Staph, API Strep, API Ana, BioMerieux). Rapid tests for detection of oxidase and catalase activity were also used. Susceptibility of microorganisms to antibiotics was defined by the disc-diffusion method using standard discs (EUCAST guidelines 2015) according to Clinical Laboratory Standard Institute (CLSI) protocols (ATB strips: ATB G, ATB Staph, ATBANA, ATBPse, ATBStrep. BioMerieux). The recovery rate from the clinical samples was good, likely because our protocol immediately inoculated study material into the thioglycollate broth which is an appropriate medium both for aerobic and anaerobic bacteria. Among the 36 patients with monomicrobial growth by bacteriological investigation, Gram-negative bacteria prevailed; Escherichia coli was recovered in 14 patients and Enterobacter cloacae in 9 patients. Among the Gram-positive bacteria, D-group Streptococci were prevalent, Enterococcus faecalis was found in six patients, Staphylococcus aureus in three patients, Candida albicans in two patients. In one patient, we observed dual colonization of two Gram-negative anaerobes Bacteroides fragilis and Fusobacterium spp. Polymicrobial growth was evident in three cases in the following combinations: Candida albicans and Escherichia coli, Enterobacter cloacae and Candida albicans, Escherichia coli and Bacteroides fragilis. Antibiotic susceptibility testing indicated that 12% of Gram-negative bacteria were resistant to quinolones and 19% to third-generation cephalosporins. No evidence of methicillin-resistant Staphylococcus aureus was found in Gram-positive specimens. The timely identification of microbes and administration of appropriate therapy based on antibiotic sensitivity profiles is important to optimizing clinical outcomes in bacterial peritonitis.