Department of Microbiology, George Emil Palade University of Medicine, Pharmacy, Sciences and Technology Târgu Mureș, Romania.
Department of Pneumology, George Emil Palade University of Medicine, Pharmacy, Sciences and Technology Târgu Mureș, Romania.
J Infect Dev Ctries. 2022 May 30;16(5):827-834. doi: 10.3855/jidc.15703.
Diverse serogroups of Escherichia coli cause sporadic cases and outbreaks of diarrhea among children. Our study aimed to evaluate the serogroups of diarrheagenic strains of E. coli that cause diarrheal disease in children under two years old, and clarify if the cases were sporadic or outbreaks.
The retrospective study included 130 strains of pathogenic E. coli, isolated from children who were less than two years of age, and had diarrheal disease, between May 2016 and July 2019. The study was conducted in the Bacteriology Laboratory (County Clinical Hospital, Mureș, Romania). The 130 strains were sero-grouped using polyvalent and monovalent O antisera. Enterobacterial Repetitive Intergenic Consensus-PCR (ERIC-PCR) was performed to evaluate the similarity between different E. coli strains, and a simplex polymerase chain reaction (PCR) was performed to detect the presence of the hlyA gene that is specific to the enterohemorrhagic strains.
After agglutination with polyvalent O antisera, slightly more than half of the strains (50.77%) were sero-grouped as Shiga toxin-producing E. coli (STEC), and the rest of the strains belonged to the Enteropathogenic Escherichia coli (EPEC) serogroups. Serogroup O157 was the most frequently identified (16.51% of the total number of typeable strains), and one strain was positive for hlyA. ERIC-PCR revealed a high diversity of strains, with an overall 50% similarity.
STEC serogroups were the most common strains causing diarrheal disease, and O-157 was the dominant serogroup identified. The strains included in our study presented high genetic diversity, suggesting that most of the cases were sporadic.
不同血清群的大肠杆菌可导致儿童散发性和暴发腹泻。我们的研究旨在评估导致 2 岁以下儿童腹泻病的致泻性大肠杆菌菌株的血清群，并明确这些病例是散发性的还是暴发的。
本回顾性研究纳入了 2016 年 5 月至 2019 年 7 月期间，来自 2 岁以下腹泻患儿的 130 株致病性大肠杆菌。该研究在罗马尼亚穆列什县临床医院的细菌学实验室进行。使用多价和单价 O 抗血清对 130 株菌株进行血清群分型。采用肠杆菌重复基因间一致性聚合酶链反应（ERIC-PCR）评估不同大肠杆菌菌株之间的相似性，并进行单重聚合酶链反应（PCR）检测志贺毒素产生大肠杆菌（STEC）特有 hlyA 基因的存在。
与多价 O 抗血清凝集后，超过一半的菌株（50.77%）被归为产志贺毒素大肠杆菌（STEC），其余菌株属于肠致病性大肠杆菌（EPEC）血清群。O157 血清群是最常见的（占可分型菌株总数的 16.51%），有 1 株菌株 hlyA 阳性。ERIC-PCR 显示菌株具有高度多样性，总体相似度为 50%。
STEC 血清群是引起腹泻病的最常见菌株，O-157 是鉴定出的主要血清群。我们研究中纳入的菌株具有较高的遗传多样性，表明大多数病例为散发性。
