RESUMO
A group of Acinetobacter baumannii confers multidrug resistance, but the molecular epidemiology and multidrug resistance mechanisms are poorly understood. Nineteen isolates were identified, and the antimicrobial susceptibility profile was determined using the disc diffusion method. Then, PCR of 78 kinds of resistance-associated genes were performed. A novel variant of blaADC gene: blaADC-67 gene (Genbank accession No. JX169789) was prevalent in all 19 isolates. Moreover, ISAba1 could also provide strong promoter to upregulate the expression of blaADC67 to confer resistance to beta-lactam. This is the first report of emergence of blaADC-67 in A. baumannii worldwide, which might confer resistance to beta-lactam.
Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Infecções por Acinetobacter/microbiologia , Proteínas de Bactérias/genética , China , Farmacorresistência Bacteriana Múltipla , Genes Bacterianos , Testes de Sensibilidade Microbiana/métodos , Regiões Promotoras Genéticas , Regulação para Cima , beta-Lactamases/farmacologiaRESUMO
<p><b>OBJECTIVE</b>To investigate the relationship between the drug resistance of Pseudomonas aeruginosa (PA) isolated from burn patients wounds and its mobile genetic elements, including plasmid, transposon, and integron.</p><p><b>METHODS</b>Thirty-two strains of PA were isolated from wounds exudate of hospitalized burn patients in Ningbo No. 2 Hospital. PA drug sensitivity was determined using GNS-448 drug sensitivity card and K-B tests. The genetic markers of plasmid, transposon and integron including traA, traF, tnpA, tnpU, merA, int I 1 were amplified by PCR and verified by gene sequencing.</p><p><b>RESULTS</b>Drug resistant rate of 32 PA strains to gentamicin, amikacin, cefoperazone/sulbactam, ciprofloxacin was 43.7%, 32.0%, 46.8%, 49.9%, respectively. PA drug resistant rates to piperacillin, cefotaxime, ceftazidime, cefepime, aztreonam, piperacillin/tazobactam, levofloxacin, imipenem and meropenem were all above 56.0%. Seventeen out of 32 PA strains were found to carry transposon and (or) integron genetic markers. One strain was positive for both tnpA and merA, 8 strains were positive for both merA and int I 1, 1 strain was only positive for tnpA, 2 strains were only positive for merA, and 5 strains were positive for int I 1 only.</p><p><b>CONCLUSIONS</b>PA isolated from burn wounds of hospitalized patients in Ningbo No. 2 Hospital is seriously drug resistant, which may relate with its high positive rate of mobile genetic elements of transposon and (or) integron.</p>
