ABSTRACT
BACKGROUND: Increasing numbers of resistant and multidrug resistant (MDR) isolates of Pseudomonas aeruginosa have become a worldwide problem. This report provides the trend of antimicrobial resistance, the proportions of MDR and metallo-beta-lactamase-producing isolates among clinical isolates of P. aeruginosa in Korea. MATERIALS AND METHODS: Clinical isolates of P. aeruginosa were collected from two representative reference laboratories during 2002-2004. Clinical information regarding specimens and type of hospital for isolates was investigated. Antimicrobial susceptibility against 11 antibiotics was tested by disk diffusion according to NCCLS criteria. MDR was assessed as resistance to > or =3 of the core drugs (ceftazidime, ciprofloxacin, gentamicin, imipenem and piperacillin). PCR assays and sequencing for detection of blaVIM-2 and blaIMP-1 gene were carried out. RESULTS: Of 1,748 P. aeruginosa isolates, 179 isolates were collected from primary care hospitals and 1,569 isolates were recovered from outpatients and inpatients in secondary care hospitals. From 2002 to 2004, rates of resistance to ceftazidime and imipenem increased from 10% to 12.3% and from 14.8% to 15.9%, respectively. Rates of resistance to amikacin (from 26.2% to 31.0%) and ciprofloxacin (from 35.6% to 46.2%) increased annually. In the period 2002-2004, decreasing of susceptibility to meropenem (from 83.4% to 76.8%) was observed, but meropenem was the most potent agent against P. aeruginosa isolates studied. During the 3-year period, MDR P. aeruginosa accounted for 26.4-33.5% of clinical isolates and the most common MDR phenotype was concurrent resistance to piperacillin, gentamicin and ciprofloxacin. The prevalence of VIM-2-producing isolates obviously increased from 1.7% in 2002 to 6.3% in 2004. CONCLUSIONS: These results suggested that MDR P. aeruginosa was already prevalent in one third of clinical isolates and VIM-2-producing P. aeruginosa isolates disseminated in non-tertiary care hospitals in Korea.
Subject(s)
Humans , Amikacin , Anti-Bacterial Agents , Ceftazidime , Ciprofloxacin , Diffusion , Drug Resistance, Multiple , Gentamicins , Imipenem , Inpatients , Korea , Outpatients , Phenotype , Piperacillin , Polymerase Chain Reaction , Prevalence , Primary Health Care , Pseudomonas aeruginosa , Pseudomonas , Secondary CareABSTRACT
BACKGROUND: Increasing numbers of resistant and multidrug resistant (MDR) isolates of Pseudomonas aeruginosa have become a worldwide problem. This report provides the trend of antimicrobial resistance, the proportions of MDR and metallo-beta-lactamase-producing isolates among clinical isolates of P. aeruginosa in Korea. MATERIALS AND METHODS: Clinical isolates of P. aeruginosa were collected from two representative reference laboratories during 2002-2004. Clinical information regarding specimens and type of hospital for isolates was investigated. Antimicrobial susceptibility against 11 antibiotics was tested by disk diffusion according to NCCLS criteria. MDR was assessed as resistance to > or =3 of the core drugs (ceftazidime, ciprofloxacin, gentamicin, imipenem and piperacillin). PCR assays and sequencing for detection of blaVIM-2 and blaIMP-1 gene were carried out. RESULTS: Of 1,748 P. aeruginosa isolates, 179 isolates were collected from primary care hospitals and 1,569 isolates were recovered from outpatients and inpatients in secondary care hospitals. From 2002 to 2004, rates of resistance to ceftazidime and imipenem increased from 10% to 12.3% and from 14.8% to 15.9%, respectively. Rates of resistance to amikacin (from 26.2% to 31.0%) and ciprofloxacin (from 35.6% to 46.2%) increased annually. In the period 2002-2004, decreasing of susceptibility to meropenem (from 83.4% to 76.8%) was observed, but meropenem was the most potent agent against P. aeruginosa isolates studied. During the 3-year period, MDR P. aeruginosa accounted for 26.4-33.5% of clinical isolates and the most common MDR phenotype was concurrent resistance to piperacillin, gentamicin and ciprofloxacin. The prevalence of VIM-2-producing isolates obviously increased from 1.7% in 2002 to 6.3% in 2004. CONCLUSIONS: These results suggested that MDR P. aeruginosa was already prevalent in one third of clinical isolates and VIM-2-producing P. aeruginosa isolates disseminated in non-tertiary care hospitals in Korea.
Subject(s)
Humans , Amikacin , Anti-Bacterial Agents , Ceftazidime , Ciprofloxacin , Diffusion , Drug Resistance, Multiple , Gentamicins , Imipenem , Inpatients , Korea , Outpatients , Phenotype , Piperacillin , Polymerase Chain Reaction , Prevalence , Primary Health Care , Pseudomonas aeruginosa , Pseudomonas , Secondary CareABSTRACT
BACKGROUND: The aim of this study was to investigate the antimicrobial resistance of clinical isolates of Acinetobacter spp. collected from non-tertiary hospitals and to characterize the phenotype and the genotype of imipenem-non-susceptible isolates. MATERIALS AND METHODS: Clinical isolates of Acinetobacter spp. were identified using recA-restriction fragment length polymorphism (RFLP) analysis with Tsp5091. Susceptibility to antimicrobial agents was determined using disk diffusion test and agar dilution test according to the criteria of the National Committee for Clinical Laboratory Standards. PCR and sequence analyses were used to detect the blaIMP-1 and blaVIM-2 genes, and to determine the content and order of the resistance genes inserted in integron. RESULTS: Of 71 Acinetobacter spp. isolates collected from non-tertiary hospitals during 2002 and 2003, 60 isolates were A. baumannii, and 2, 4, and 5 isolates were Acinetobacter genomic species 3, 13TU, and A. lwoffii, respectively. The resistance rate of Acinetobacter spp. isolates to beta-lactams, aminoglycosides, and fluoroquinolones was high except for imipenem and meropenem. The presence of blaVIM-2 gene was found in one isolate, Acinetobacter genomic species 13TU, for which the MIC of imipenem was 8 mg/L; the blaVIM-2 gene of this strain was located on 3 kb class 1 integron with aacA7 and aadA1 genes. CONCLUSIONS: Among the tested agents, imipenem and meropenem retained greatest activity against Acinetobacter spp. isolates collected from non-tertiary hospitals. This is the first report of VIM-2-producing Acinetobacter genomic species 13TU strains with class 1 integron containing blaVIM-2 gene.
Subject(s)
Acinetobacter , Agar , Aminoglycosides , Anti-Infective Agents , beta-Lactams , Diffusion , Fluoroquinolones , Genotype , Imipenem , Integrons , Phenotype , Polymerase Chain Reaction , Sequence AnalysisABSTRACT
BACKGROUND: The aim of this study was to investigate the antimicrobial resistance of clinical isolates of Acinetobacter spp. collected from non-tertiary hospitals and to characterize the phenotype and the genotype of imipenem-non-susceptible isolates. MATERIALS AND METHODS: Clinical isolates of Acinetobacter spp. were identified using recA-restriction fragment length polymorphism (RFLP) analysis with Tsp5091. Susceptibility to antimicrobial agents was determined using disk diffusion test and agar dilution test according to the criteria of the National Committee for Clinical Laboratory Standards. PCR and sequence analyses were used to detect the blaIMP-1 and blaVIM-2 genes, and to determine the content and order of the resistance genes inserted in integron. RESULTS: Of 71 Acinetobacter spp. isolates collected from non-tertiary hospitals during 2002 and 2003, 60 isolates were A. baumannii, and 2, 4, and 5 isolates were Acinetobacter genomic species 3, 13TU, and A. lwoffii, respectively. The resistance rate of Acinetobacter spp. isolates to beta-lactams, aminoglycosides, and fluoroquinolones was high except for imipenem and meropenem. The presence of blaVIM-2 gene was found in one isolate, Acinetobacter genomic species 13TU, for which the MIC of imipenem was 8 mg/L; the blaVIM-2 gene of this strain was located on 3 kb class 1 integron with aacA7 and aadA1 genes. CONCLUSIONS: Among the tested agents, imipenem and meropenem retained greatest activity against Acinetobacter spp. isolates collected from non-tertiary hospitals. This is the first report of VIM-2-producing Acinetobacter genomic species 13TU strains with class 1 integron containing blaVIM-2 gene.