Türkel İbrahim, Yıldırım Tuba, Yazgan Burak, Bilgin Melek, Başbulut Eşe
a Department of Biology, Faculty of Arts and Sciences , Amasya University , Amasya , Turkey.
b Central Research Laboratory , Amasya University , Amasya , Turkey.
J Chemother. 2018 Oct-Dec;30(6-8):354-363. doi: 10.1080/1120009X.2018.1521773.
Klebsiella pneumoniae is an important pathogen both in community and hospital environment. In this study, we aimed to determine the antibiotic susceptibilities, expression levels of AcrA, ketM, kdeA, kpnEF, and kexD genes related to efflux pump and biofilm formation in 100 extended-spectrum β-lactamase producing Klebsiella pneumoniae. The relative expression levels of AcrA, ketM, kdeA, kpnEF, and kexD were determined by quantitative real-time PCR and biofilm formation was screened by microtiter plate assay. Based on CLSI breakpoints, zone diameters showed that 72% of isolates were resistant to ceftazidime, 79% to aztreonam, 54% to ciprofloxacin, 32% to ertapenem, 74% to tobramycin, 65% to tetracycline and all isolates were resistant to ampicillin, ceftriaxone, and cefotaxime. The relative expression of AcrA was upregulated in ciprofloxacin susceptible isolates and also upregulation of newly described efflux pump, kexD, was correlated with tobramycin and aztreonam resistance. A significant correlation was observed between resistance-nodulation-division and single-type efflux pumps. On the other hand, ciprofloxacin susceptible isolates formed stronger biofilms than resistant isolates. The up or down regulation of efflux pumps didn't enhance biofilm formation capacity.
肺炎克雷伯菌是社区和医院环境中的重要病原菌。在本研究中，我们旨在测定100株产超广谱β-内酰胺酶的肺炎克雷伯菌中与外排泵及生物膜形成相关的AcrA、ketM、kdeA、kpnEF和kexD基因的抗生素敏感性及表达水平。通过定量实时PCR测定AcrA、ketM、kdeA、kpnEF和kexD的相对表达水平，并采用微量滴定板法筛选生物膜形成情况。根据CLSI断点，抑菌圈直径显示72%的分离株对头孢他啶耐药，79%对氨曲南耐药，54%对环丙沙星耐药，32%对厄他培南耐药，74%对妥布霉素耐药，65%对四环素耐药，所有分离株均对氨苄西林、头孢曲松和头孢噻肟耐药。AcrA的相对表达在环丙沙星敏感分离株中上调，新描述的外排泵kexD的上调也与妥布霉素和氨曲南耐药相关。在耐药-结瘤-分裂和单型外排泵之间观察到显著相关性。另一方面，环丙沙星敏感分离株形成的生物膜比耐药分离株更强。外排泵的上调或下调并未增强生物膜形成能力。
