不同的大肠杆菌血清群导致儿童腹泻的零星病例和暴发。我们的研究旨在评估导致两岁以下儿童腹泻病的大肠杆菌腹泻菌株的血清组,并澄清这些病例是零星还是爆发。
回顾性研究包括130株致病性大肠杆菌,与不到两岁的儿童隔离,患有腹泻病,2016年5月至2019年7月。这项研究是在细菌学实验室(县临床医院,穆雷,罗马尼亚)。使用多价和单价O抗血清对130个菌株进行血清分组。进行肠杆菌重复基因间共有PCR(ERIC-PCR)以评估不同大肠杆菌菌株之间的相似性,进行单纯形聚合酶链反应(PCR)以检测肠出血性菌株特异性hlyA基因的存在。
用多价O抗血清凝集后,略多于一半的菌株(50.77%)被血清分组为产志贺毒素的大肠杆菌(STEC),其余菌株属于肠致病性大肠杆菌(EPEC)血清群。血清群O157是最常见的鉴定(占可分型菌株总数的16.51%),其中一株hlyA阳性.ERIC-PCR揭示了菌株的高度多样性,总体上有50%的相似性。
STEC血清群是引起腹泻病的最常见菌株,O-157是确定的主要血清群。我们研究中包含的菌株具有很高的遗传多样性,表明大多数病例是零星的。
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.