[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents --special references to bacteria isolated between April 2008 and March 2009].

Bacteria isolated from infections in abdominal surgery during the period from April 2008 to March 2009 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 712 strains including 18 strains of Candida spp. were isolated from 173 (80.5%) of 215 patients with surgical infections. Three hundred and sixty-six strains were isolated from primary infections, and 346 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-negative bacteria were predominant, followed by aerobic Gram-negative bacteria, while from postoperative infections 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 postoperative infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa, in this order, and from postoperative infections, P aeruginosa was most predominantly isolated, followed by E. coli, Enterobacter cloacae, and K. pneumoniae. Among anaerobic Gram-positive bacteria, the isolation rate of Eggerthella lenta was the highest from primary infections, followed by Parvimonas micra, Streptococcus constellatus and Gemella morbillorum, and from postoperative infections, E. lenta was most predominantly isolated. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis was the highest from primary infections, followed by Bacteroides thetaiotaomicron, Bacteroides ovatus and Bilophila wadsworthia, and from postoperative infections, B. fragilis was most predominantly isolated, followed by B. thetaiotaomicron, B. wadsworthia and B. ovatus, in this order. In this series, we noticed no vancomycin-resistant methicillin-resistant S. aureus, and Enterococcus spp., nor multidrug-resistant P aeruginosa. We should carefully follow up B. wadsworthia which was resistant to various antibiotics, and also Bacteroides spp. which was resistant to many beta-lactam antibiotics.

[Bacteria isolated from surgical infections and their susceptibility to antimicrobial agents--special reference to bacteria isolated between April 2007 and March 2008].

Bacteria isolated from infections in abdominal surgery during the period from April 2007 to March 2008 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 707 strains including 24 strains of Candida spp. were isolated from 181 (79.0%) of 229 patients with surgical infections. Three hundred and ninety-five strains were isolated from primary infections, and 288 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-negative bacteria were predominant, followed by aerobic Gram-negative bacteria, while from postoperative infections 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 postoperative infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae, Pseudomonas aeruginosa and Enterobacter cloacae, in this order, and from postoperative infections, P. aeruginosa was most predominantly isolated, followed by E. cloacae, E. coli and K. pneumoniae. Among anaerobic Gram-positive bacteria, the isolation rate of Parvimonas micra was the highest from primary infections, followed by Streptococcus constellatus and Gemella morbillorum, and from postoperative infections, Anaerococcus prevotii was most predominantly isolated. Among anaerobic Gram-negative bacteria, the isolation rate of both Bacteroides fragilis and Bilophila wadsworthia were the highest from primary infections, followed by Bacteroides thetaiotaomicron and Campylobacter gracilis, and from postoperative infections, B. thetaiotaomicron was most predominately isolated, followed by B. fragilis, Bacteroides caccae and B. wadsworthia in this order. In this series, we noticed no vancomycin-resistant Gram-positive cocci, nor multidrug-resistant P aeruginosa. There were nine strains of coagulase-negative Staphylococci which show higher MIC against teicoplanin more than 4 gg/mL, but all of them had good susceptibilities against various anti-MRSA antibiotics. We should carefully follow up B. wadsworthia which was resistant to various antibiotics, and also Bacteroides spp. which was resistant to many beta-lactam antibiotics.

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2006 and March 2007].

Tendency of isolated bacteria from infections in abdominal surgery during the period from April 2006 to March 2007 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 474 strains including 23 strains of Candida spp. were isolated from 170 (75.2%) of 226 patients with surgical infections. Two hundred and twenty-six strains were isolated from primary infections, and 224 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-negative bacteria were predominant, followed by aerobic Gram-negative bacteria, while from postoperative infections aerobic Gram-positive bacteria were predominant, followed by anaerobic Gram-negative bacteria. Among aerobic Gram-positive bacteria, the isolation rate of Staphylococcus spp. was higher from postoperative infections, while Enterococcus spp. was higher from primary infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae, Enterobacter cloacae and Pseudomonas aeruginosa, in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by E. coli and E. cloacae. Among anaerobic Gram-negative bacteria, the isolation rate of Bilophila wadsworthia was the highest from primary infections, followed by Bacteroides fragilis and from postoperative infections, B. fragilis was most predominately isolated, followed by Bacteroides caccae, Bacteroides thetaiotaomicron and B. wadsworthia in this order. In this series, we noticed no methicillin-resistant Staphylococcus aureus, nor multidrug-resistant P. aeruginosa. There were three strains of methicillin-resistant coagulase-negative Staphylococcus aureus, but all of them had good susceptibilities against various anti-MRSA antibiotics. We should carefully follow up B. wadsworthia.

[Fundamental study on the selection of antimicrobial prophylactic agents in abdominal surgery].

Most infections after abdominal operations are endogenous and occur by disseminating bacteria present in the intestinal tract during operation. The risk of developing surgical site infection after abdominal operations is related to the extent of intestinal contamination during operation and to the density and type of bacteria in the intestinal tract. Although antimicrobial prophylactic agents must be active against contaminating bacteria during operation, it should not cover all contaminating bacteria but Staphylococcus aureus except MRSA, Escherichia coli, Klebsiella spp., Enterobacter spp., Citrobacter spp., Proteus spp. and Bacteroides spp. As the isolation rate and type of bacteria from primary abdominal infections such as perforated peritonitis and biliary tract infection are resemble to those of bacteria contaminating during operations, antimicrobial prophylactic agents could be chosen considering activities against bacteria isolated from primary infections. According to the isolation rates of these bacteria and antibiotic susceptibilities, cefotiam (CTM) is considered to have most strong activities as prophylactic agent for abdominal surgery, followed by cefmetazole (CMZ) and cefazolin (CEZ), in this order. In order to establish the fundamental principle of antimicrobial prophylaxis in surgery, these results should be evaluated by clinical prospective randomized studies in the near feature.

[Clostridium spp. isolated from surgical specimens].

In the present study, the isolation rate of Clostridium spp. from surgical specimens and its antimicrobial susceptibilities were examined. Last 24 years, Clostridium spp. was isolated from 65 (1.8%) out of 3,644 specimens from the surgical abdominal infections. Clostridium spp. was most frequently isolated from secondary peritonitis such as perforated peritonitis, followed by hepato-biliary tract infection. There were 59 cases (90.8%) of mixed infection with Clostridium spp. and other bacteria. The rate of mixed infection with Bacteroides spp. (23.6%) was highest, followed by Escherichia coli (19.7%), other aerobic Gram-negative rods and Enterococcus spp. Although Clostridium perfringens was highly sensitive to penicillins, cephems and carbapenems, a small number of Clostridium spp. other than Clostridium perfringens were resistant to cephems, erythromycin clindamycin and fosfomycin, respectively.

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between april 2003 and march 2004].

Tendency of isolated bacteria from infections in abdominal surgery during the period from April 2005 to March 2006 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 384 strains including 18 strains of Candida spp. were isolated from 161 (70.3%) of 229 patients with surgical infections. One hundred and ninty-five strains were isolated from primary infections, and 171 strains were isolated from postoperative infections. From primary infections, aerobic Gram-negative bacteria and aerobic Gram-positive bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. The isolation rate of aerobic Gram-positive bacteria, such as Enterococcus spp. and Staphylococcus aureus were higher from both types of infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Pseudomonas aeruginosa, Klebsiella spp. in this order, and from postoperative infections, E. coli was the most predominantly isolated, followed by Klebsiella pneumoniae and P. aeruginosa. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both primary and postoperative infections. In this series, we noticed no vancomycin-resistant Gram-positive cocci, nor multidrug-resistant P. aeruginosa. But cefazolin-resistant E. coli producing extended spectrum fl-lactamase was seen in 5.0 per cents. We should be carefully followed up the facts that the increasing isolation rates of B. fragilis group and Bilophila wadsworthia which were resistant to both penicillins and cephems.

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2003 and March 2004].

Tendency of isolated bacteria from infections in general surgery during the period from April 2004 to March 2005 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 645 strains including 17 strains of Candida spp. were isolated from 226 (79.0%) of 286 patients with surgical infections. Three hundred and seventeen strains were isolated from primary infections, and 345 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-positive bacteria and anaerobic Gram-negative bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. The isolation rate of aerobic Gram-positive bacteria, such as Enterococcus spp. and Staphylococcus aureus were higher from both types of infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Pseudomonas aeruginosa, Klebsiella pneumoniae and Citrobacter freundii in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by E. coli, E. cloacae, and K. pneumoniae. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both primary infections followed by Bilophila wadsworthia. While the isolation rate of B. fragilis group was also the highest from postoperative infections, the following bacteria were Bacteroides thetaiotaomicron and B. wadsworthia in this order. In this series, we noticed no vancomycin-resistant Gram-positive cocci, but a few strains of moderately arbekacin-resistant MRSA. Carbapenem-resistant P. aeruginosa but not multidrug-resistant was seen in 13.3 per cents. Also cefazolin-resistant E. coli probably producing extended spectrum beta-lactamase was seen in 7.0 per cents. We should be carefully followed up the facts that an increasing isolation rates of B. fragilis group and B. wadsworthia which were resistant to both penicillins and cephems.

[Bilophila wadsworthia isolated from surgical specimens].

Bilophila wadsworthia is a recently recognized nonspore-forming anaerobic Gram-negative rod and is reported to be associated with various surgical infections. In the present study, the isolation rate of B. wadsworthia from surgical specimens and its antimicrobial susceptibilities were examined. Last 5 years, B. wadsworthia was isolated from 46 (5.2%) out of 884 specimens from the surgical abdominal infections. B. wadsworthia was most frequently isolated from secondary peritonitis such as perforated peritonitis, followed by postoperative peritonitis. There is no case of single isolation of B. wadsworthia. The rate of mixed infection with Bacteroides spp. (24.8%) was highest, followed by Escherichia coli (11.6%) and Enterococcus spp. (10.1%). Although B. wadsworthia was highly resistant to many beta-lactam antibiotics, clindamycin showed strongest activities with MIC90 of 1 microg/mL, followed by minocycline and ciprofloxacin with 4micro g/mL, and levofloxacin with 8 microg/mL, respectively.

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2003 and March 2004].

Tendency of isolated bacteria from infections in general surgery during the period from April 2003 to March 2004 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 455 strains including 14 strains of Candida spp. were isolated from 191(75.2%) of 254 patients with surgical infections. Two hundred and thirty-nine strains were isolated from primary infections, and 216 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-positive bacteria and aerobic Gram-negative bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. The isolation rate of aerobic Gram-positive bacteria, such as Enterococcus spp. and Staphylococcus aureus were higher from both types of infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae, Enterobacter cloacae and Pseudomonas aeruginosa in this order, and from postoperative infections, E. coli was the most predominantly isolated, followed by P. aeruginosa, E. cloacae, and K. pneumoniae. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. The isolation rate of anaerobic Gram-positive bacteria from primary infections and that of aerobic Gram-positive bacteria from postoperative infections were high in the last several years. In this series, we noticed no vancomycin-resistant Gram-positive cocci, but a few strains of moderately arbekacin-resistant MRSA. Carbapenm-resistant P. aeruginosa was seen in less than 10 per cents. Last year we noticed that there were cefazolin-resistant E. coli producing extended spectrum beta-lactamase, but there was no highly cefazolin-resistant E. coli in this year. In the next series, increase of both anaerobic bacteria and Enterococcus spp. should be carefully followed up.

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2002 and March 2003].

Tendency of isolated bacteria from infections in general surgery during the period from April 2002 to March 2003 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, 334 strains were isolated from 131 (75.3%) of 174 patients with surgical infections. One hundred and seventy-one strains were isolated from primary infections, and 163 strains were isolated from post-operative infections. From primary infections, anaerobic Gram-positive bacteria were predominant, while aerobic Gram-positive bacteria were predominant from postoperative infections. Among aerobic Gram-positive bacteria, although the isolation rate of Staphylococcus aureus was the highest, followed by that of Enterococcus faecalis from primary infections, the isolation rate of E. faecalis was the highest from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, E. coli was the most predominantly isolated, followed by P. aeruginosa, Enterobacter cloacae, and Citobacter freundii. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. The isolation rate of aerobic Gram-negative bacteria from primary infections and that of aerobic Gram-positive bacteria from postoperative infections were high in the last several years. We noticed no vancomycin-resistant Gram-positive cocci nor P. aeruginosa producing metallo-beta-lactamase. But we noticed cefazolin-resistant E. coli probably producing extended spectrum beta-lactamase.

[Bacteria isolated from surgical infections and its susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2001 and March 2002].

Isolated bacteria from infections in general surgery during the period from April 2001 to March 2002 were investigated in a multicenter study in Japan, and the following results were obtained. In this series, four hundred and twenty strains were isolated from 175 (79.2%) of 221 patients with surgical infections. One hundred and eighty-six strains were isolated from primary infections, and 234 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-positive bacteria were predominant, while from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, although the isolation rate of Staphylococcus aureus was the highest, followed by that of Enterococcus faecalis from primary infections, the isolation rate of E. faecalis was the highest from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by Enterobacter spp., E. coli and Klebsiella spp. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. The isolation rate of aerobic Gram-negative bacteria from primary infections and that of aerobic Gram-positive bacteria from postoperative infections were high in the last several years. We noticed no vancomycin-resistant Gram-positive cocci.

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between April 1999 and March 2000].

The annual multicenter studies on isolated bacteria from infections in general surgery and their antimicrobial susceptibility have been conducted in Japan since July 1982. In this paper, the results obtained in the academic year 1999 (from April 1999 to March 2000) have been summarized. Two hundred seven cases were investigated, and 411 strains were isolated from 169 cases (81.6%). Of those strains, 184 and 227 strains were from primary infections and postoperative infections, respectively. In primary infections, the isolation rates of anaerobes, Streptococcus spp., and Escherichia coli were higher than in postoperative infections, while in postoperative infections, those of Gram-positive aerobes were higher than in primary infections. Staphylococcus aureus were most frequently isolated among Gram-positive aerobes, Peptostreptococcus prevotii among Gram-positive anaerobes, E. coli among Gram-negative aerobes, and Bacteroides fragilis among Gram-negative anaerobes. In primary infections, the percentage of Gram-negative aerobes, which gradually increased by the year 1998, decreased in the year 1999. The percentage of Gram-negative anaerobes increased, while that of Gram-negative bacteria was equivalent to that in the last year. In postoperative infections, the percentage of Gram-negative anaerobes, which continuously increased after the year 1990, decreased, while that of Gram-positive aerobes, which decreased in the last year, increased. Methicillin-resistant S. aureus accounted for 70.7% of S. aureus (41 strains). Either the number of strain or the percentage of MRSA decreased. The susceptibilities of E. coli and Klebsiella pneumoniae decreased against third and forth generation cephems, oxacephems, and monobactams. The susceptibilities of P. aeruginosa to carbapenems tend to decrease after the year 1997. S. aureus showed good susceptibilities to the tested drugs including arbekacin, vancomycin, and teicoplanin.

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2000 and March 2001].

Tendency of isolated bacteria from infections in general surgery and their antimicrobial susceptibilities during the period from April 2000 to March 2001 were investigated in a multicenter study in Japan, and the following results were obtained. The number of cases investigated as objectives was 234 for one year. A total of 388 strains (136 strains from primary infections and 252 strains from postoperative infections) were isolated from 165 cases (70.5% of total cases). In primary infections, anaerobic Gram-positive bacteria were predominant, while from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by that of Staphylococcus aureus from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by Enterobacter spp. and Klebsiella spp. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. There was no vancomycin-resistant S. aureus nor Enterococcus spp. Among anaerobic bacteria, there were many resistant strains against penicillins and cephems with MICs higher than 100 micrograms/ml, and the same trend was observed among other Bacteroides spp. and Prevotella spp.