Lai Yun Mei, Zaw Myo Thura, Shamsudin Shamsul Bahari, Lin Zaw
Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia.
J Infect Dev Ctries. 2016 Oct 31;10(10):1053-1058. doi: 10.3855/jidc.6944.
Uropathogenic virulence factors have been identified by comparing the prevalence of these among urinary tract isolates and environmental strains. The uropathogenic-specific protein (USP) gene is present on the pathogenicity island (PAI) of uropathogenic Escherichia coli (UPEC) and, depending on its two diverse gene types and the sequential patterns of three open reading frame units (orfUs) following it, there is a method to characterize UPEC epidemiologically called PAIusp subtyping.
A total of 162 UPEC isolates from Sabah, Malaysia, were tested for the presence of the usp gene and the sequential patterns of three orfUs following it using polymerase chain reaction (PCR). In addition, by means of triplex PCR, the prevalence of the usp gene was compared with other two VFs of UPEC, namely alpha hemolysin (α-hly) and cytotoxic necrotizing factor (cnf-1) genes encoding two toxins.
The results showed that the usp gene was found in 78.40% of UPEC isolates, indicating that its prevalence was comparable to that found in a previous study in Japan. The two or three orfUs were also associated with the usp gene in this study. All the PAIusp subtypes observed in Japan were present in this study, while subtype IIa was the most common in both studies. The usp gene was observed in a higher percentage of isolates when compared with α-hly and cnf-1 genes.
The findings in Japan and Sabah, East Malaysia, were similar, indicating that PAIusp subtyping is applicable to the characterization of UPEC strains epidemiologically elsewhere in the world.
通过比较尿路分离株和环境菌株中这些毒力因子的流行情况，已鉴定出尿路致病性毒力因子。尿路致病性特异性蛋白（USP）基因存在于尿路致病性大肠杆菌（UPEC）的致病岛（PAI）上，根据其两种不同的基因类型以及其后三个开放阅读框单元（orfUs）的序列模式，有一种在流行病学上对UPEC进行特征描述的方法，称为PAIusp分型。
对来自马来西亚沙巴的162株UPEC分离株进行检测，使用聚合酶链反应（PCR）检测usp基因的存在及其后的三个orfUs的序列模式。此外，通过三重PCR，将usp基因的流行情况与UPEC的其他两种毒力因子，即编码两种毒素的α溶血素（α-hly）和细胞毒性坏死因子（cnf-1）基因进行比较。
结果显示，78.40%的UPEC分离株中发现了usp基因，表明其流行率与日本先前的一项研究结果相当。在本研究中，两个或三个orfUs也与usp基因相关。在日本观察到的所有PAIusp亚型在本研究中均有出现，而IIa亚型在两项研究中都是最常见的。与α-hly和cnf-1基因相比，在更高比例的分离株中观察到了usp基因。
日本和马来西亚东部沙巴的研究结果相似，表明PAIusp分型适用于在世界其他地区对UPEC菌株进行流行病学特征描述。
