从巴西东南部儿童和成人中分离出的携带毒素编码基因的致泻性大肠杆菌的高流行率。
High prevalence of diarrheagenic Escherichia coli carrying toxin-encoding genes isolated from children and adults in southeastern Brazil.
作者信息
Spano Liliana Cruz, da Cunha Keyla Fonseca, Monfardini Mariane Vedovatti, de Cássia Bergamaschi Fonseca Rita, Scaletsky Isabel Christina Affonso
机构信息
Departamento de Patologia, Laboratório de Virologia e Gastrenterite Infecciosa, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Av. Marechal Campos 1468, 29043-900, Maruípe, Vitória, Espírito Santo, Brazil.
Núcleo de Doenças Infecciosas, Departamento de Medicina Social, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, Vitória, Espírito Santo, Brazil.
出版信息
BMC Infect Dis. 2017 Dec 18;17(1):773. doi: 10.1186/s12879-017-2872-0.
BACKGROUND
Diarrheagenic Escherichia coli (DEC) are important bacterial causes of childhood diarrhea in Brazil, but its impact in adults is unknown. This study aimed at investigating DEC among children and adults living in endemic areas.
METHODS
A total of 327 stools specimens were collected from children (n = 141) and adults (n = 186) with diarrhea attending health centers. Diarrheagenic E. coli (DEC) were identified by their virulence genes (multiplex polymerase chain reaction) and HEp-2 cell adherence patterns.
RESULTS
DEC were detected in 56 (40%) children and 74 (39%) adults; enteroaggregative E. coli (EAEC) (23%) was the most prevalent pathotype, followed by diffusely adherent E. coli (DAEC) (13%), and occurred at similar frequencies in both diarrheal groups. Atypical enteropathogenic E. coli (aEPEC) strains were recovered more frequently from children (6%) than from adults (1%). Twenty-six percent of the EAEC were classified as typical EAEC possessing aggR gene, and carried the aap gene. EAEC strains carrying aggR-aap-aatA genes were significantly more frequent among children than adults (p < 0.05). DAEC strains possessing Afa/Dr. genes were detected from children (10%) and adults (6%). EAEC and DAEC strains harboring genes for the EAST1 (astA), Pet, Pic, and Sat toxins were common in both diarrheal groups. The astA and the porcine AE/associated adhesin (paa) genes were found in most of aEPEC strains. High levels of resistance to antimicrobial drugs were found among DAEC and aEPEC isolates.
CONCLUSION
The results show a high proportion of EAEC and DAEC carrying toxin-encoding genes among adults with diarrhea.
背景
致泻性大肠杆菌（DEC）是巴西儿童腹泻的重要细菌病因，但其对成年人的影响尚不清楚。本研究旨在调查生活在流行地区的儿童和成年人中的DEC。
方法
从前往健康中心就诊的腹泻儿童（n = 141）和成年人（n = 186）中总共收集了327份粪便标本。通过其毒力基因（多重聚合酶链反应）和HEp-2细胞黏附模式鉴定致泻性大肠杆菌（DEC）。
结果
在56名（40%）儿童和74名（39%）成年人中检测到DEC；肠聚集性大肠杆菌（EAEC）（23%）是最常见的致病型，其次是弥漫性黏附大肠杆菌（DAEC）（13%），在两个腹泻组中的发生率相似。非典型肠致病性大肠杆菌（aEPEC）菌株在儿童中（6%）的检出频率高于成年人（1%）。26%的EAEC被分类为具有aggR基因的典型EAEC，并携带aap基因。携带aggR-aap-aatA基因的EAEC菌株在儿童中比成年人更常见（p < 0.05）。从儿童（10%）和成年人（6%）中检测到具有Afa/Dr.基因的DAEC菌株。携带EAST1（astA）、Pet、Pic和Sat毒素基因的EAEC和DAEC菌株在两个腹泻组中都很常见。大多数aEPEC菌株中发现了astA和猪源聚集性黏附大肠杆菌/相关黏附素（paa）基因。在DAEC和aEPEC分离株中发现了高水平的抗菌药物耐药性。
结论
结果显示腹泻成年人中携带毒素编码基因的EAEC和DAEC比例很高。
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