[Antibiotic susceptibility of bacteria isolated from surgical infection (second report)]

Isolated bacteria from infections in general surgery in 1984 and 1985 have been investigated to find bacterial composition and their susceptibilities to antibiotics in a joint research in which 6 university hospitals in Japan participated. A summary of findings from the investigation is as follows. 1. One hundred and seventy-two (1984) and 211 (1985) cases were included in the study. Cases in which bacteria were detected were 147 and 174 in the respective years. The detection rate was higher than 80% in either year. 2. Total numbers of strains isolated in 1984 and 1985 were 267 and 293, respectively; major sources of these strains were intraperitoneal infection exudates in either year. 3. The most frequent isolate from primary infection cases in both years was Escherichia coli (15-21%), followed by Bacteroides spp. and Staphylococcus spp., in that order. The most frequently isolated from postoperative infection cases were Enterococcus spp. (16-22%), followed by Pseudomonas spp. The diversity of isolated species, as well as the similarity of incidences of different species were noted in cases of postoperative infections. It is suspected that a certain species, even if its pathogenicity is essentially low, may become to be a causative organism once its number increases due to its survival through a perioperative prophylactic use of antibiotics, and also due to the decreased host resistance to infections caused by underlying diseases or surgical stress. 4. Staphylococcus spp. was the most frequent isolate from postoperative infections occurring after clean operations, while Enterococcus spp. and Pseudomonas aeruginosa were major isolates from infections after clean-contaminated operations. Isolates from infections occurring after contaminated operations included Enterococcus spp. greater than E. coli greater than Klebsiella pneumoniae, P. aeruginosa, Bacteroides spp. (1985). 5. In cases without the presence of clinical factors cause by depressed host defense, E. coli and Bacteroides spp. were major isolates, while in cases with the factors, a wide variety of bacterial population tended to be found. 6. Before an administration of antibiotics in primary infections, E. coli, Staphylococcus spp. Bacteroides spp. and Klebsiella spp. were most commonly isolated, while after a chemotherapy, Enterococcus spp. were the most frequent isolates, followed by P. aeruginosa during 1985. These findings reflected the antibacterial spectrum of cephems usually used in surgical field.(ABSTRACT TRUNCATED AT 400 WORDS)