Pootong A, Mungkornkeaw N, Norrapong B, Cowawintaweewat S
Department of Medical Technology, Faculty of Allied Health Sciences, Thammasat University, Pathum Thani, Thailand.
Bacteriology Unit, Medical Technology Laboratory, Thammasat University Hospital, Thammasat University, Pathum Thani, Thailand.
Trop Biomed. 2018 Mar 1;35(1):195-204.
Uropathogenic Escherichia coli (UPEC) is an important pathogen of the urinary tract infection (UTI) and is most commonly associated with human disease among the extraintestinal pathogenic E. coli (ExPEC). The aim of this study is to determine drug susceptibility pattern, virulence factors and the distribution of phylogenetic groups of UPEC in clinical isolates of a tertiary university hospital in central Thailand. A total of 119 UPEC isolates were tested for antimicrobial drug susceptibility. The prevalence of hemolysin, biofilm and the presence of papC and fimH genes were analyzed. The phylogenetic groups were determined by detection of yjaA and chuA genes and TspE4.C2 fragment. Antimicrobial susceptibility tests showed that the resistance of UPEC isolates to ampicillin, trimethoprim/ sulfamethoxazole, ciprofloxacin, and norfloxacin were 89.1, 60.5, 59.7 and 57.1%, respectively. Moreover, 38.7 and 62.2% of UPEC were ESBL producing and multidrug-resistant strains (MDR), respectively. The prevalence of hemolysin production, biofilm formation, and the presence of papC and fimH virulence genes were 5.9, 44.5, 29.4 and 82.4%, respectively. Phylogenetic classification revealed that 54.6% of UPEC belonged to group B2, followed by groups D (19.3%), A (15.1%) and B1 (10.9%). When compared to other groups, UPEC belongs to group B2 that harbored a battery of virulence factors and had a high rate of multidrug resistance (p<0.05). Stratified according to ciprofloxacin susceptibility, the prevalence of virulence of group B2 resistant strains was lower than the susceptible strains. MDR strains among groups B2 and D showed lower prevalence of virulence than non-MDR isolates. This study showed that multidrug resistance of UPEC and treatment of UTI with antimicrobial agents in this area should be highlighted. Since the relationship between virulence factor and drug susceptibility of UPEC is complex, further studies are required.
尿路致病性大肠杆菌（UPEC）是尿路感染（UTI）的重要病原体，在肠外致病性大肠杆菌（ExPEC）中，它与人类疾病的关联最为常见。本研究的目的是确定泰国中部一家三级大学医院临床分离株中UPEC的药敏模式、毒力因子及系统发育群的分布。共对119株UPEC分离株进行了抗菌药物敏感性测试。分析了溶血素、生物膜的流行情况以及papC和fimH基因的存在情况。通过检测yjaA和chuA基因以及TspE4.C2片段来确定系统发育群。抗菌药物敏感性测试表明，UPEC分离株对氨苄西林、甲氧苄啶/磺胺甲恶唑、环丙沙星和诺氟沙星的耐药率分别为89.1%、60.5%、59.7%和57.1%。此外，分别有38.7%和62.2%的UPEC是产超广谱β-内酰胺酶（ESBL）菌株和多重耐药菌株（MDR）。溶血素产生、生物膜形成以及papC和fimH毒力基因存在的流行率分别为5.9%、44.5%、29.4%和82.4%。系统发育分类显示，54.6%的UPEC属于B2群，其次是D群（19.3%）、A群（15.1%）和B1群（10.9%）。与其他群相比，属于B2群的UPEC携带一系列毒力因子且多重耐药率较高（p<0.05）。根据环丙沙星敏感性分层，B2群耐药菌株的毒力流行率低于敏感菌株。B2群和D群中的MDR菌株的毒力流行率低于非MDR分离株。本研究表明，该地区UPEC的多重耐药性以及使用抗菌药物治疗UTI应受到重视。由于UPEC毒力因子与药敏性之间的关系复杂，需要进一步研究。
