Molecular characterization of extended-spectrum beta-lactamases in Enterobacteriaceae from patients of two hospitals in Saxony, Germany

作者：Schmitt Joachim; Jacobs Enno; Schmidt Herbert^*

来源：Journal of Medical Microbiology, 2007, 56(2): 241-249.

DOI：10.1099/jmm.0.46670-0

Between January and September 2003, 39 isolates of the family Enterobacteriaceae with phenotypically positive Vitek 1 extended-spectrum beta-lactamase (ESBL) test results were collected, originating from patients of two hospitals in Saxony, Germany. Plasmid DNA was isolated and screened by PCR for the presence of genes encoding beta-lactamases of SHV, TEM and CTX-M types. To differentiate ESBL and non-ESBL among SHV and TEM genes, detailed analysis of PCR products was performed. Twenty-four strains carried SHV-2, SHV-5 or SHV-12 genes. In a further 11 strains a CTX-M gene was detected. The CTX-M genes could be affiliated to the CTX-M-1 and CTX-M-9 cluster by RFLP analysis. In the case of four Klebsiella oxytoca isolates, hyperproduction of the chromosomal beta-lactamase K1 was inferred, because genes of the above-mentioned types were not detected. The strains contained plasmid DNA between 45 and 160 klo in size, Common plasmid restriction patterns among SHV-5 producers provided evidence of horizontal spread. Twenty strains had a MIC for cefotaxime of <= 4 mg l(-1), 18 strains had the same MIC for ceftazidime, and nine strains had this MIC of > 4 mg l(-1) for both antibiotics. The ESBL phenotypes often coincided with ciprofloxacin or gentamicin resistance.

• 出版日期2007-2
• 单位河北医科大学