Antimicrobial Resistance of Clinically Important Bacteria Isolated from 12 Hospitals in Korea in 2005 and 2006 / 대한임상미생물학회지

BACKGROUND: Emergence and spread of antimicrobial resistant bacteria make it difficult to treat infections. A rapid increase in antimicrobial-resistant bacteria has become a serious problem in many countries including Korea, and it is important to perform a nationwide study of antimicrobial resistance to obtain some basic data that will help solve these problems. The aim of this study was to determine the nationwide prevalence of resistance among frequently isolated bacterial pathogens in 2005 and 2006 in Korea. METHODS: We collected routine susceptibility data for medically important bacterial pathogens from 12 university and general hospital laboratories in Korea from April to September in 2005 and from January to June in 2006. Collected data was analyzed by patient group. RESULTS: The proportions of methicillin-resistant Staphylococcus aureus (MRSA) were 65% in 2005 and 72% in 2006, respectively. The resistance rates of Enterococcus faecium to vancomycin were 29% in 2005 and 24% in 2006. The non-susceptible rates of Streptococcus pneumoniae to penicillin were 68% in 2005 and 74% in 2006. The resistant rates of Escherichia coli and Klebsiella pneumoniae to the 3rd generation cephalosporin were 10~12% and 25~39%, respectively, in 2005 and 11~15% and 30~34% in 2006. In Citrobacter freundii, Enterobacter cloacae and Serratia marcescens, the resistance rates to 3rd generation cephalosporin were 23~31%, 32~34%, and 17~27%, respectively, in 2005 and 21~37%, 37~43%, and 13~31% in 2006. The resistance rates to imipenem and meropenem were 21% and 18%, respectively, in Pseudomonas aeruginosa and 18% and 25% in Acinetobacter baumannii in 2005; 29% and 20% in P. aeruginosa and 18% and 23% in A. baumannii in 2006. Cotrimoxazole and levofloxacin resistance rates of Stenotrophomonas maltophilia were 5% and 13%, respectively, in 2005 and 3% and 7% in 2006. There were no isolates resistant to 3rd generation cephalosporin and fluoroquinolone among non-typhoidal Salmonella in 2005. CONCLUSION: Antimicrobial resistance of medically important bacteria is still a serious problem in Korea. To manage the problem, a continuous nationwide surveillance and diversified investigation and effort have become more important.

The Nationwide Surveillance Results of Nosocomial Infections along with Antimicrobial Resistance in Intensive Care Units of Sixteen University Hospitals in Korea, 2004 / 병원감염관리

BACKGROUND: This study was to evaluate a nationwide nosocomial infection rate and antimicrobial resistance in intensive care units(ICUs) in Korea. METHODS: The study was carried out at 16 university-affiliated teaching hospitals from July through October 2004. We performed a prospective multicenter study to investigate nosocomial infection rates, device-associated infection rated, and causative pathogens and their antimicrobial resistance. RESULTS: The urinary tract was the most commonly involved site. Nosocomial infection rate was 12.48 in medical. ICU (MICU), 9.59 in medical surgical ICU (MSICU), 14.76 in surgical ICU (MSICU), and 11.60 in other lCU. Device-associated infection rates were as follow: 1) rates of urinary catheter-associated urinary tract infection were 4.26 in MICU, 3.17 in SICU, 4.88 in MSICU, and 5.87 in other ICU; 2) rates of central line-associated bloodstream infection were 3.24 in MICU, 1.56 in SlCU, 2.36 in MSICU, and 1.78 in other ICU; 3) rates of ventilator-associated pneumonia were 3.61 in MlCU, 13.05 in SICU, 1.68 in MSICU, and 4.84 in other lCU. Staphylococcus aureus was the most frequently identified microorganism in this study; 93% of S. aurues were resistant to methicillin; 17% of Pseudomonas aeruginosa isolated were resistant to imipenem; 11% of Enterococcus faecium and 18% of Enterococcus faecalis showed resistance to vancomycin. Over a half of Acinetobacter spp, Stenotrophomonas maltophilia, Klebsiella pneumoniae, and Escherichia coli showed resistant to fluoroquinolone. Conclusion: This study shows the seriousness of antimicrobial resistance and the importance of infection control in the lCU in Korea. This study should provide a theoretical strategy to enforce the infection control.

Antimicrobial Resistance of Clinically Important Bacteria Isolated from 12 Hospitals in Korea in 2004 / 대한임상미생물학회지

BACKGROUND: A rapid increase in antimicrobial-resistant bacteria has become a serious problem in many countries including Korea, but the rate and pattern of antimicrobial resistance may vary significantly depending on countries and even on hospitals. The aim of this study was to determine the nationwide prevalence of resistance among frequently isolated bacterial pathogens in Korea. METHODS: Routine susceptibility data for medically important bacterial pathogens from 12 university hospital and general hospital laboratories in Korea were analysed by patient group. These pathogens had been isolated during the period from April to November in 2004. RESULTS: The proportion of methicillin-resistant Staphylococcus aureus (MRSA) was 67%. Van-comycin-resistance rate of Enterococcus faecalis was 1% and that of E.faecium was 20%. The resistance rates of Streptococcus pneumoniae to penicillin and Haemophilus influenzae to ampicillin were 70% and 54%, respectively. The resistant rates of Escherichia coli and Klebsiella pneumoniae were 7-10% and 26-31% to the 3rd generation cephalosporin, respectively. The resistance rates to 3rd generation cephalosporin were 22-30% in Citrobacter freundii, 35-44% in Enterobacter cloacae and 15-22 % in Serratia marcescens. Imipenem resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii were 26% and 17%. Cotrimoxazole and levofloxacin resistance rates of Stenotrophomonas maltophilia were 46% and 44%, respectively. CONCLUSION: Antimicrobial resistance rates of clinically important pathogens in Korea were still high and were generally higher among the bacteria isolated from the intensive care unit patients. Strict infection control and continuous nationwide surveillance program will be required to manage the antimicrobial resistance problem.

Antimicrobial Resistance of Clinically Important Bacteria Isolated from 12 Hospitals in Korea / 대한임상미생물학회지

BACKGROUND: A rapid increase in antimicrobial-resistant bacteria has become a serious problem in Korea. Moreover, the antibiotic resistance problem has worsened noticeably during the past several years. The aim of this study was to determine the prevalence of resistance among frequently isolated gram-positive and -negative bacteria in Korea. METHODS: Routine susceptibility data for medically important bacteria isolated during 6 months of 2003 were collected from 12 university and general hospital laboratories in Korea. RESULTS: The proportion of methicillin-resistant Staphylococcus aureus (MRSA) was 66%; however, vancomycin-resistant strains were not detected. The rates of vancomycin-resistant Enterococcus faecium and penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) were 22% and 73%, respectively. The resistance rates to 3rd generation cephalosporins and monobactam were: Escherichia coli 8-12%, Klebsiella pneumoniae 18-22%, Citrobacter freundii 22-32%, Enterobacter cloacae 34-37%, and Serratia marcescens 12-21%, respectively. Imipenem resistance rates of Acinetobacter baumannii and Pseudomonas aeruginosa were 23% and 25%, respectively. CONCLUSIONS: Antimicrobial resistant strains were already prevalent among the clinically important isolates, especially, MRSA, PNSP, and extended-spectrum cephalosporin resistant gram-negative bacilli in Korea. The imipenem-resistant rates of A. baumannii and P. aeruginosa increased, respectively, from 13% and 20% in 2002 to 23% and 25% in 2003. The results of this study will provide a basis for proper treatment of bacterial infections and prevention of spread of resistant bacteria. A continuous nationwide surveillance of antimicrobial resistance is very important and should be performed.

Antimicrobial Resistance of Clinically Important Bacteria Isolated from Hospitals Located in Representative Provinces of Korea / 대한임상미생물학회지

BACKGROUND: A rapid increase of antimicrobial-resistant bacteria has become a serious problem in many countries. The aim of this study was to determine the prevalence of resistance among frequently isolated gram-positive and -negative bacteria in Korea. METHODS: Data of routine antimicrobial susceptibility test for medically important bacteria, isolated during 3 months of 2002, were collected from 12 university and 1 commercial laboratories in Korea. RESULTS: The proportions of methicillin-resistant Staphylococcus aureus (MRSA) were 60-88%, but vancomycin-resistant S. aureus was not detected. Among the Enterococcus faecium isolates, the resistance rate to vancomycin was 29%. The resistance rates of Escherichia coli and Klebsiella pneumoniae: 11% and 24% to cefotaxime, respectively, and 12% and 21% to cefoxitin, respectively. The resistance rates of Citrobacter freundii, Enterobacter cloacae, and Serratia marcescens: 28%, 34% and 21% to cefotaxime, respectively, <1%, 8% and 14% to cefepime, respectively. The resistance rates of Acinetobacter baumannii and Pseudomonas aeruginosa were: 65% and 37% to piperacillin, 64% and 19% to ceftazidime, 13% and 20% to imipenem, respectively. The resistant rates varied according to the hospital size. The resistance rates were generally higher among the isolates in the hospitals with more than 1,000 beds. The rates of penicillin-nonsusceptible Streptococcus pneumoniae were 58-90%. Among the Haemophilus influenzae isolates, 55-68% were resistant to ampicillin. CONCLUSIONS: Antimicrobial resistant strains were prevalent among the medically important clinical isolates, especially, MRSA, vancomycin-resistant enterococci, extended-spectrum -lactamase- or AmpC -lactamase-producing E. coli and K. pneumoniae, third generation cephalosporin-resistant C. freundii, E. cloacae and S. marcescens, imipenem-resistant A. baumannii and P. aeruginosa, penicillin-nonsusceptible S. pneumoniae and ampicillin-resistant H. influenzae. The antimicrobial resistance has become a serious problem in Korea.