Molina Nora Beatriz, Oderiz Sebastián, Vescina Cecilia, Córdoba Alejandra, Basualdo Juan Ángel, Sparo Mónica Delfina
Centro Universitario de Estudios Microbiológicos y Parasitológicos (CUDEMYP)-CIC, Universidad Nacional de La Plata, La Plata, Argentina.
Sala de Microbiología, Hospital Interzonal de Niños Sor María Ludovica, La Plata, Argentina.
Rev Argent Microbiol. 2022 Jan-Mar;54(1):15-21. doi: 10.1016/j.ram.2021.02.006. Epub 2021 Apr 17.
Diarrheagenic Escherichia coli is a heterogeneous group of strains that presents various virulence factors and causes different diarrheal syndromes. The most studied pathotypes are enteropathogenic Escherichia coli (EPEC), enterotoxigenic Escherichia coli (ETEC), enteroaggregative Escherichia coli (EAEC), enteroinvasive Escherichia coli (EIEC) and Shiga toxin-producing Escherichia coli (STEC). The objective was to estimate the frequency of infection of diarrheagenic E. coli pathotypes in children with diarrhea, attended at the Sor María Ludovica Hospital in La Plata, Argentina, during the period May-October 2017. E. coli pathotypes were detected by molecular amplification of eight characteristic virulence genes. The feces of 211 children (76% under 5 years) were studied. Infection with diarrheagenic E. coli was detected in 12.3% of the samples. The pathotypes were EAEC (10.43%), ETEC (1.42%, all of them positive for thermolabile toxin), EPEC (0.95%) and STEC (0.47%, positive for Shiga toxin 2). The EAEC pathotype was prevalent in children of all age groups, while ETEC, EPEC and STEC were only observed in children under 5 years of age. This study constitutes the first report of diarrheagenic Escherichia coli detection in an outpatient pediatric population with diarrhea from La Plata, using molecular amplification techniques. Broader future studies, including the characterization of the isolates with the largest number of genes, asymptomatic controls, different times of the year and population from different geographic areas will be necessary to clarify the relevance of diarrheagenic E. coli infection in children from Argentina.
致泻性大肠杆菌是一组具有多种毒力因子并能引起不同腹泻综合征的菌株。研究最多的致病型是肠致病性大肠杆菌（EPEC）、产肠毒素大肠杆菌（ETEC）、肠聚集性大肠杆菌（EAEC）、肠侵袭性大肠杆菌（EIEC）和产志贺毒素大肠杆菌（STEC）。目的是估计2017年5月至10月期间在阿根廷拉普拉塔市索非亚·路易莎医院就诊的腹泻儿童中致泻性大肠杆菌致病型的感染频率。通过对八个特征性毒力基因进行分子扩增来检测大肠杆菌致病型。对211名儿童（76%年龄在5岁以下）的粪便进行了研究。在12.3%的样本中检测到致泻性大肠杆菌感染。致病型为EAEC（10.43%）、ETEC（1.42%，均对不耐热毒素呈阳性）、EPEC（0.95%）和STEC（0.47%，对志贺毒素2呈阳性）。EAEC致病型在所有年龄组的儿童中均很普遍，而ETEC、EPEC和STEC仅在5岁以下儿童中观察到。本研究是首次使用分子扩增技术在拉普拉塔市门诊腹泻儿童人群中检测到致泻性大肠杆菌的报告。未来有必要进行更广泛的研究，包括对具有更多基因的分离株进行特征分析、无症状对照、一年中的不同时间以及来自不同地理区域的人群，以阐明致泻性大肠杆菌感染对阿根廷儿童的相关性。
