Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents -Special references to bacteria isolated between April 2011 and March 2012-

Bacteria isolated from surgical infections during the period from April 2011 to March 2012 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 785 strains including 3 1 strains of Candida spp. were isolated from 204 (78.8%) of 259 patients with surgical infections. Five hundred and twenty three strains were isolated from primary infections, and 231 strains were isolated from surgical site infection. From primary infections, anaerobic Gram-negative bacteria were predominant, followed by aerobic Gram-negative bacteria, while from surgical site infection aerobic Gram-positive bacteria were predominant, followed by anaerobic Gram-negative bacteria. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus spp. was highest, followed by Streptococcus spp. and Staphylococcus spp., in this order, from primary infections, while Enterococcus spp. was highest, followed by Staphylococcus spp. from surgical site infection. Among aerobic Gram-negative bacteria, Escherichia coil was the most predominantly isolated from primary infections, followed by Kiebsielia pneumoniae, Pseudomonas aeruginosa and Enterobacter cioacae, in this order, and from surgical site infection, E. coil was most predominantly isolated, followed by F aeruginosa, K. pneumoniae, and E. cioacae. Among anaerobic Gram-positive bacteria, the isolation rate of Eggertheiia lenta was the highest from primary infections, followed by Parvimonas micra, Coilinseila aerofaciens, Lactobaciiius acidophilus and Finegoidia magna, and from surgical site infection, E. ienta was most predominantly isolated, followed by F micra and L. acidophiius, in this order. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroidesfragiiis was the highest from primary infections, followed by Bilophila wadsworthia, Bactero ides thetaiotaomicron, Bacteroides unformis and Bactero ides vuigatus, and from surgical site infection, B. fragiiis was most predominantly isolated, followed by Bactero ides caccae, B. thetaiotaomicron, Bactero ides ovatus and B. wadsworthia, in this order. In this series, vancomycin-resistant MRSA (methicillin-resistant Staphylococcus aureus), vancomycinresistant Enterococcus spp. and multidrug-resistant F aeruginosa were not observed. We should carefully follow up B. wadsworthia which was resistant to various antimicrobial agents, and also Bacteroides spp. which was resistant to many ,lJ-lactams.