摘要

超广谱β-内酰胺酶（ESβL）在尿路感染（UTI）的治疗中造成严重问题。产ESβL的生物体是一个不断扩大的全球健康问题。因此，筛选ESβL，检测其耐药模式和分子鉴定应该是一个连续的过程。本研究旨在确定抗生素耐药性特征以及来自医院和社区获得性UTI的ESβL分离株的遗传特征。从Kasr Al-Aini医院的门诊诊所服务人员和住院患者的尿液样本中获得了250个肠杆菌科分离株。通过表型筛选试验，在研究组中检测到100个ESβL分离株。此外，通过PCR研究β-内酰胺酶（bla）头孢噻肟（CTX）-M，SHV和TEMESβL基因的检测。通过基因测序技术进一步鉴定了25个CTX-M阳性分离物的子集。在100个ESβL分离株中，66％是大肠杆菌，34％是克雷伯氏菌属。在社区获得性和医院获得性UTI中，ESβL肠杆菌科的流行率没有统计学差异。所有ESβL分离株对碳青霉烯类的易感性是最普遍的发现。此外，所有ESβL大肠杆菌分离株对磷霉素敏感，而所有社区获得的ESβL分离株对呋喃妥因敏感。总共98％的ESβL分离株含有bla-CTX-M基因，CTX-M-15是最常见的。可以得出结论，在患有医院和社区获得性UTI的埃及患者中，ESβL的产生率很高。 bla-CTX-M的高流行率可能表明它是ESβL分子筛查的候选者。

Extended-spectrum β-lactamases (ESβLs) pose a serious problem in the treatment of urinary tract infections (UTIs). The ESβL-producing organism is an expanding global health problem. Therefore, screening for ESβL, detection of their drug-resistance pattern, and molecular characterization should be a continuous process. The present study was performed to determine the antibiotic resistance profile and the genetic characterization of ESβL isolates from hospital- and community-acquired UTIs. Two hundred fifty Enterobacteriaceae isolates were obtained from urine samples of outpatient clinic attendants and hospitalized patients at Kasr Al-Aini Hospital. By phenotypic screening tests, 100 ESβL isolates were detected among the studied groups. Furthermore, detection of beta-lactamase (bla) cefotaxime (CTX)-M, SHV, and TEM ESβL genes was investigated by PCR. A subset of 25 CTX-M-positive isolates was further identified by gene sequencing technology. Among the 100 ESβL isolates, 66% were Escherichia coli and 34% were Klebsiella spp. There was no statistical difference in the prevalence of ESβL Enterobacteriaceae in community-acquired versus hospital-acquired UTIs. The susceptibility of all ESβL isolates to carbapenems was the most prevalent finding. In addition, all ESβL E. coli isolates were susceptible to fosfomycin, whereas all community-acquired ESβL isolates were susceptible to nitrofurantoin. A total of 98% of the ESβL isolates harbored bla-CTX-M genes, with CTX-M-15 being the most prevalent. It could be concluded that ESβL production is present at a high rate among Egyptian patients with hospital- and community-acquired UTI. The high prevalence of bla-CTX-M may suggest it as a candidate for molecular screening of ESβL.

https://www.ncbi.nlm.nih.gov/pubmed/30594263