ANTIMICROBIAL ACTIVITY OF 11 NEWER AND INVESTIGATIONAL DRUGS TESTED AGAINST AEROBIC ISOLATES FROM SPONTANEOUS BACTERIAL PERITONITIS

The in vitro susceptibility of 124 aerobic bacterial pathogens isolate d from patients with spontaneous bacterial peritonitis (SEP) were test ed against 11 antimicrobial agents, including parenteral or oral cepha losporins and fluoroquinolones. Most SEP isolates were Gram-negative o rganisms, and Escherichia coli and Klebsiella pneumoniae were responsi ble for 63% of the episodes evaluated, The fluoroquinolones (ciproflox acin and ofloxacin) and the ''fourth-generation'' cephalosporin cefpir ome were the most active agents against the Gram-negative bacteria. Co mmonly used cefotaxime and cefotaxime-desacetylcefotaxime (DES-CTX) co mbinations were also very active against Gram-negative bacteria with o nly few Enterobacter cloacae isolates being resistant (minimum inhibit ory concentrations > 32 mu g/ml). All streprococci were susceptible to cefotaxime, cefpirome, and cefdaloxime and to the cefotaxime-DES-CTX combinations, whereas only ofloxacin demonstrated acceptable activity against the enterococci. The widest spectrum of activity versus SEP is olates was found for ofloxacin (98% susceptibility) among the fluoroqu inolanes. For the beta-lactams, the widest spectrum of activity was de monstrated by cefpirome and the 2:1 cefotaxime-DES-CTX combination (93 % susceptibility). These results indicate that the role of of ofloxaci n and newer parenteral or orally administered cephalosporins in the tr eatment of prophylaxis of SEP should be further evaluated.