Prevalence and Mechanism of Third-Generation Cephalosporins-Resistant Escherichia coli and Klebsiella pneumoniae Strains Isolated from Clinical Specimen / 대한임상미생물학회지
Korean Journal of Clinical Microbiology
; : 6-14, 2002.
Article
em Ko
| WPRIM
| ID: wpr-73287
Biblioteca responsável:
WPRO
ABSTRACT
BACKGROUND: Among Gram-negative pathogens in Korea, the incidence of resistance to thirdgeneration cephalosporins is becoming an ever-increasing problem. This study was designed to determine the prevalence of third-generation cephalosporins-resistant Escherichia coli and Klebsiella pneumoniae isolates from patients in a tertiary care hospital in Busan, Korea, and to characterize the mechanism of resistance. METHODS: A total of 710 E. coli and 237 K. pneumoniae non-duplicate isolates were collected from patients in Kosin Medical Center in 1999. Antimicrobial susceptibilities were tested by the disk diffusion method. Extended-spectrum beta-lactamase (ESBL) production was determined by the double disk synergy test. MICs were determined by the agar dilution method. Searches for blaTEM, blaSHV, and blaCMY genes in cefotaxime-resistant or intermediate isolates were performed by PCR amplification. PCR products were used to determine the sequence of resistance genes by the dideoxy-chain termination method. RESULTS: Seven percent of E. coli and 25% of K. pneumoniae isolates were resistant to cefotaxime. Among the isolates with decreased susceptibility to cefotaxime, 69% (18/26) of E. coli and 80% (20/25) of K. pneumoniae isolates showed positive results in double disk synergy test. Banding patterns of PCR amplification showed that the blaTEM, blaSHV, and blaCMY genes were harboured by 71% (20/28), 86% (24/28) and 14% (4/28) of isolates with decreased susceptibility to cefotaxime,respectively. Seventy-one percent (20/28) of the isolates contained more than two types of beta- lactamase genes. Nucleotide sequence analysis of PCR products revealed that blaSHV-12 and blaTEM-1b were the dominant types of beta-lactamase gene. In addition, we also identified blaTEM-52, blaSHV-5, and a new ESBL gene named blaTEM-17b. CONCLUSIONS: Third-generation cephalosporins-resistant E. coli and K. pneumoniae are wide spread in Kosin Medical Center, Busan, Korea. Most of the isolates with decreased susceptibility to cefotaxime had blaTEM and/or blaSHV, and some isolates harboured blaCMY genes that may confer resistance against cephamycins. The spread of these beta-lactamase genes could compromise the future usefulness of third-generation cephalosporins for the treatment of infections caused by E. coli and K. pneumoniae.
Palavras-chave
Texto completo:
1
Base de dados:
WPRIM
Assunto principal:
Pneumonia
/
Beta-Lactamases
/
Atenção Terciária à Saúde
/
Sequência de Bases
/
Cefotaxima
/
Cefalosporinas
/
Cefamicinas
/
Reação em Cadeia da Polimerase
/
Incidência
/
Prevalência
Tipo de estudo:
Incidence_studies
/
Prevalence_studies
/
Prognostic_studies
Limite:
Humans
País/Região como assunto:
Asia
Idioma:
Ko
Revista:
Korean Journal of Clinical Microbiology
Ano de publicação:
2002
Tipo de documento:
Article