RESUMO
OXA-370 is a recently described OXA-48 variant that has only been described in a few Enterobacter spp. and Klebsiella pneumoniae isolates. The purpose of this study is to assess the prevalence of OXA-370-producing isolates in carbapenem-nonsusceptible Enterobacteriaceae recovered from 28 hospitals from Brazil. Real-time PCR was used to determine the presence of bla NDM-1, bla KPC-2, bla VIM-type, bla GES-type, bla OXA-48-like, and bla IMP-type genes. A total of 4,451 Enterobacteriaceae were screened. The gene bla OXA-48-like was detected in 74 (2.5%) isolates, mostly of Enterobacter spp. (44.6% E. cloacae and 2.7% E. aerogenes) and Klebsiella spp. (31.1% K. pneumoniae and 6.7% K. oxytoca), followed by Escherichia coli, (6.7%), Morganella morganii, (2.7%), Citrobacter freundii (1.3%), Proteus mirabilis (1.3%), Providencia stuartii (1.3%), and Serratia spp. (1.3%). These isolates were from five hospitals, 67 (90.5%) from the hospital where the bla OXA-370 was first described. Sequencing of bla OXA-48-like was performed in 52 isolates, including E. cloacae, E. aerogenes, K. pneumoniae, K. oxytoca, E. coli, and C. freundii; all presenting 100% identity with bla OXA-370. PFGE revealed the presence of distinct clones among K. pneumoniae, E. cloacae, K. oxytoca, and E. coli. Susceptibility rates to meropenem, imipenem, and ertapenem among OXA-370-producing isolates were 92.3%, 78.8%, 7.7% respectively; the MIC50 /MIC90 were 0.38/2 mg/L and 1/3 mg/L for meropenem and imipenem respectively. Overall, antimicrobial susceptibility analysis suggests that OXA-370 lacks carbapenemase activity. Our study demonstrated that the bla OXA-370 gene is disseminated among several Enterobacteriaceae species and clones, indicating a high potential for dissemination.
Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos/enzimologia , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , beta-Lactamases/genética , Brasil , Enterobacteriáceas Resistentes a Carbapenêmicos/classificação , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Genótipo , Hospitais , Humanos , Testes de Sensibilidade Microbiana , Tipagem Molecular , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNARESUMO
Tuberculosis (TB) remains as an important public health problem worldwide. Therefore, the rapid detection of M. tuberculosis is of primary importance to effectively reduce transmission in patients. The aims of this study were to evaluate two in-house molecular tests: nested PCR (nPCR) and real-time PCR (rtPCR) to detect M. tuberculosis complex directly from clinical samples. The results were compared to the culture results and to the culture results plus clinical data of patients. The rtPCR and nPCR presented high sensitivity (Se) and specificity (Sp) (rtPCR 97·6% and 91·5%, nPCR 85·7% and 92·7%, respectively) compared to culture. When the results of the molecular tests were compared to the culture plus clinical data the Se and Sp were 90·2% and 97·3% for rtPCR and 80·4% and 98·6% for the nPCR, respectively. The results demonstrated that molecular assays of M. tuberculosis can provide a sensitive and rapid diagnostic of TB, and when used in addition to the clinical data of TB patients will help to improve the Sp of the diagnosis of pulmonary TB.