Molecular Prevalence and Epidemiological Characteristics of Diarrheagenic <i>E. coli</i>in Children under 5 Years Old in the City of Koula-Moutou, East-Central Gabon

Background and Purpose: Diarrhoeagenic E. coli (DEC) is one of the germs responsible for childhood diarrhea in developing countries. This study aims at determining the prevalence of the five main pathotypes of DEC isolated from faeces of children under five years old with diarrhea or not, living in the city of Koula-Moutou. Methodology: Isolates of E. coli were phenotypically screened on chromIDTM agar and molecularly by multiplex PCR to detect the presence of enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enterohemorragic E. coli (EHEC) and enteroinvasive E. coli (EIEC). The evaluation of their sensitivity to 12 β-lactam antibiotic molecules was carried out by Kirby Bauer method. This method has also made it possible to characterize phenotypically the different β-lactamases produced. Results and Conclusion: Overall, at least one DEC pathovar was detected in the 63 E. coli strains with phenotypic and molecular frequencies of 63.5% and 68.5% respectively. Thus, ETEC (28.3%) and EHEC (28.3%) were the most frequent DEC in diarrheal isolates. ETEC/EHEC hybrid was recorded in both groups with rates of 7.5% in diarrheal cases and 10.0% for controls. The results showed produced carbapenemase type β-lactamases (31.7%), followed by ESBL (24.4%) and few produced high level penicillinases (4.9%). The DEC, in particular ETEC and EHEC are most likely the epidemiological agents responsible for childhood diarrhea in this study.

Frequency of E.coli pathotypes in acute diarrhea of children and its related factorsat Beassat hospital,Sanandaj

Objective:Diarrhea is a leading cause of morbidity and mortality among children in developing countries.The bacterial pathogen most commonly associated with childhood diarrhea is Escherichia coli.A one-year prospective study was carried out in Sanandaj to determine the prevalence and roles of the different E.coli pathotypes in children less than five years of age with acute diarrhea.Methods:Rectal swab were collected prospectively from children with acute diarrhea and transported to the Department of Microbiology,School of Medicine, KUMS,Sanandaj during 2008.The study was approved by the institutional ethics committee.Results:During this study period,rectal swabs were investigated from a total of 466 children 1 to 144 months of age(mean, 29.97 months±S.D) with diarrhea.Among the children,191(41%,191/466) were girls,and 275 (59%,275/466) were boys.The age-specific incidence rates of acute diarrhea among children 13-24 and 1 - 12 months of age were 37.37%(37/99) and 26.26%(26/99),respectively,during the study period.A total of 99 strains of E.coli were detected.EPEC 59(59.59%) and EIEC 22(22.22%),were the most commonly found Escherichia coli strains detected in stools from children.Disk diffusion testing showed E.coli strains resistance to tetracycline(89.89%),chloramphenicol(88.88%),Ampicillin(79.79%),Amoxicillin (75.75%) and Ceficime(75.75%).Among risk factors like age,sex,haemoglubin,fathers and mothers education,food and weight of children only mother's education was significant(P =0.018).Conclusion: In most of the clinical laboratories in Iran,E.coli does not considered as an etiologic agent responsible for diarrhea. Results in this study revealed that E.coli should be considered as an etiologic agent causing acute diarrhea among children.We therefore,recommend the routine isolation and identification of E.coli strains in all the clinical laboratories in Sanandaj.Guidelines for appropriate use of antibiotics in Sanandaj need updating.

上海市嘉定区儿童感染性腹泻病原菌检测结果分析

目的了解上海市嘉定区儿童感染性腹泻中病原菌分布情况。方法依托上海市儿童腹泻病监测工作,从2015年5月—2018年4月采集某哨点医院感染性腹泻的儿童粪便标本333例,开展肠道病原菌检测。结果 74例(22.2%)检出病原菌,包括肠致泻性大肠杆菌52例(15.6%),其中非典型EPEC32株、EAEC17株、STEC2株、ETEC2株,1例EAEC和ETEC混合感染,1例STEC O157:H7;沙门菌18例(5.4%);空肠弯曲菌6例(1.8%);副溶血性弧菌和小肠结肠炎耶尔森菌各1例(0.3%);未检出志贺菌;肠致泻性大肠杆菌检出率夏秋季与冬春季相比差异有统计学意义(χ2=28.774,P <0.05);肠致泻性大肠杆菌和沙门菌在各年龄段间和男女间相比均差异无统计学意义(χ2=5.313、4.925,P> 0.05;χ2=2.941、0.050,P> 0.05)。结论引起儿童感染性腹泻的病原菌主要为肠致泻性大肠杆菌、沙门菌和空肠弯曲菌;肠致泻性大肠杆菌在夏秋季易感,以EPEC和EAEC为主;沙门菌以鼠伤寒、肠炎血清型为主。

太原地区携带OI-28毒力基因组岛致泻大肠埃希菌性小儿腹泻

目的探讨携带OI-28毒力基因组岛致泻大肠埃希菌在小儿腹泻中的病原学作用。方法在山西省儿童医院采集257例腹泻病患儿粪便，做肠道病原菌常规培养和致泻大肠埃希菌血清学分型鉴定，用PCR和DNA斑点杂交检测致泻大肠埃希菌EHECOI-28毒力基因组岛中与RTX相关的5个毒力基因。结果257例腹泻病患儿检出病原菌206株（80．16％）。其中大肠埃希菌149株（57．98％），其他肠道致病菌57株（22．18％）。血清分型检出致泻大肠埃希菌EPEC3株（2．01％）、ETEC2株（1．34％）、EHEC2株（1．34％），其余142株为“疑似致泻大肠埃希菌”（55．25％）。149株大肠埃希菌中OI-28 5个基因全阳性者21株（14．09％），1个基因阳性者8株（5．37％），2个基因阳性者2株（1．34％）。21例携带OI-28毒力基因组岛大肠埃希菌感染的腹泻患儿，以3岁以下小儿为主（80．95％）。结论携带OI-28毒力基因组岛大肠埃希菌是夏季小儿腹泻的重要病原菌之一。

儿童感染致泻性大肠埃希菌的病例对照研究

目的 了解本地区儿童致泻性大肠埃希菌的流行特点及耐药情况,并探讨致泻性大肠埃希菌感染与本地区儿童腹泻的相关性.方法 前瞻性入选680例门诊腹泻儿童和680例非腹泻儿童.采集两组患儿粪便标本,对致泻性大肠埃希菌以及其他肠道病原进行检测,并检测致泻性大肠埃希菌对抗菌药物的敏感性.结果 致泻性大肠埃希菌在病例组和对照组中检出率分别为15.6％ 和13.1％（χ^2=151.8,P〉0.05）,为最常见的肠道细菌.以年龄作为控制因素的多因素logistic回归分析表明,肠致病性大肠埃希菌（aOR=1.2,95％CI：0.8～1.8）、肠黏附性大肠埃希菌（aOR=1.1,95％CI：0.7～1.6）及肠产毒性大肠埃希菌（aOR=1.8,95％CI：0.5～6.2）感染与本地区儿童腹泻的发生无明显相关性（均P〉0.05）.药物敏感性检测结果显示,致泻性大肠埃希菌对氨苄西林、四环素、甲氧苄胺嘧啶-磺胺甲噁唑、阿奇霉素、头孢曲松的耐药率依次为63.8％ 、55.8％ 、48.2％ 、34.2％ 、26.6％,而对环丙沙星、阿莫西林/克拉维酸和头孢西丁的耐药率分别为4.5％ 、1.5％ 和0.5％.结论 致泻性大肠埃希菌是本研究中腹泻儿童及无腹泻症状儿童的粪便标本中最常检出的肠道细菌,肠致病性大肠埃希菌、肠黏附性大肠埃希菌及肠产毒性大肠埃希菌感染与本地区儿童腹泻无明显的临床相关性,肠出血性大肠埃希菌及肠侵袭性大肠埃希菌因检出率低,其在腹泻儿童的致病意义尚需进一步研究.