Stefani Sara, Giovanelli Ilaria, Anacarso Immacolata, Condò Carla, Messi Patrizia, de Niederhäusern Simona, Bondi Moreno, Iseppi Ramona, Sabia Carla
Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
New Microbiol. 2014 Oct;37(4):551-5. Epub 2014 Oct 1.
The aim of this study was to assess the production of extended spectrum beta-lactamases (ESBL) in 56 strains of Enterobacteriaceae, obtained from 100 rectal swabs of farm animals, and to evaluate the horizontal transfer ca- pacity of the genetic determinants of resistance. The ESBL-positive strains were confirmed by phenotypic testing, confirmed by PCR and DNA sequence analysis. The localization of beta-lactamase genes was established by conju- gation experiments. Of the 56 analyzed strains, 20 (36%) resulted positive for ESBL production by the double-disk synergy test, and belonged to Escherichia coli 15 (75%) and Klebsiella ozaenae 5 (25%) species. Molecular analysis showed that all ESBL-producing isolates possessed genes encoding for TEM-type enzymes and/or CTX-M. The conjugation assays yielded positive results, thus denoting a plasmidic localization of the genes. This study high- lights the high percentage of ESBL-positive Enterobacteriaceae and the mobility of the responsible genes. Gene mo- bility implies highly negative consequences in terms of drug therapy because of the spread of antibiotic resistance.
本研究的目的是评估从100份农场动物直肠拭子中分离出的56株肠杆菌科细菌中广谱β-内酰胺酶（ESBL）的产生情况，并评估耐药基因决定簇的水平转移能力。通过表型检测、PCR和DNA序列分析确认ESBL阳性菌株。通过接合实验确定β-内酰胺酶基因的定位。在56株被分析的菌株中，20株（36%）通过双纸片协同试验检测出ESBL阳性，其中15株（75%）属于大肠杆菌，5株（25%）属于奥泽博克克雷伯菌。分子分析表明，所有产ESBL的分离株都拥有编码TEM型酶和/或CTX-M的基因。接合试验结果呈阳性，表明这些基因定位于质粒。本研究突出了ESBL阳性肠杆菌科细菌的高比例以及相关基因的可移动性。由于抗生素耐药性的传播，基因移动性在药物治疗方面意味着极其负面的后果。
