Havt Alexandre, Lima Ila Fn, Medeiros Pedro Hqs, Clementino Marco Af, Santos Ana Ks, Amaral Marília Smg, Veras Herlice N, Prata Mara Mg, Lima Noélia L, Di Moura Alessandra, Leite Álvaro M, Soares Alberto M, Filho José Q, Houpt Eric R, Nataro James P, Guerrant Richard L, Lima Aldo Am
Institute of Biomedicine for Brazilian Semiarid, Federal University of Ceará, 1315 Coronel Nunes de Melo, 60430-270, Fortaleza, Brazil.
Institute of Biomedicine for Brazilian Semiarid, Federal University of Ceará, 1315 Coronel Nunes de Melo, 60430-270, Fortaleza, Brazil.
Diagn Microbiol Infect Dis. 2017 Oct;89(2):98-105. doi: 10.1016/j.diagmicrobio.2017.06.024. Epub 2017 Jul 4.
The impact of enteroaggregative E. coli (EAEC) infection on childhood malnutrition and inflammation has been suggested, regardless of diarrhea. We investigated whether EAEC and its virulence-related genes (VRGs) are associated with malnutrition in a case-control study. Children aged 6-24 months from Brazil were enrolled as malnourished if weight-for-age Z-score (WAZ) ≤ -2 and nourished if WAZ > -1. Stools were cultured and examined for E. coli. DNA was extracted from fecal isolates and tested for EAEC by polymerase chain reaction (PCR). Positive samples were analyzed by 5 multiplex PCRs to identify 20 EAEC VRGs. Biomarkers of intestinal barrier function and inflammation were measured. The prevalence of EAEC was 39.94%. Samples that presented both aaiC and aatA genes were associated with malnutrition (P = 0.045). A high prevalence of VRGs was observed and the aafC gene was significantly associated with malnourished (P = 0.0101). Strains lacking aar and pic genes were associated with malnutrition (P = 0.018), while the concomitant presence of aar, pic, agg4A, and capU genes was associated with nourished (P = 0.031). These data reinforce the EAEC impact on malnutrition, the importance of aar as negative regulator and the great contribution of AAF/II fimbria for the pathobiology of EAEC.
肠聚集性大肠杆菌（EAEC）感染对儿童营养不良和炎症的影响已被提出，无论是否伴有腹泻。在一项病例对照研究中，我们调查了EAEC及其毒力相关基因（VRG）是否与营养不良有关。来自巴西的6至24个月大的儿童，如果年龄别体重Z评分（WAZ）≤ -2则被纳入营养不良组，如果WAZ > -1则被纳入营养良好组。对粪便进行培养并检测大肠杆菌。从粪便分离株中提取DNA，并通过聚合酶链反应（PCR）检测EAEC。对阳性样本进行5重PCR分析以鉴定20个EAEC VRG。测量肠道屏障功能和炎症的生物标志物。EAEC的患病率为39.94%。同时呈现aaiC和aatA基因的样本与营养不良有关（P = 0.045）。观察到VRG的高患病率，并且aafC基因与营养不良显著相关（P = 0.0101）。缺乏aar和pic基因的菌株与营养不良有关（P = 0.018），而aar、pic、agg4A和capU基因同时存在与营养良好有关（P = 0.031）。这些数据强化了EAEC对营养不良的影响、aar作为负调节因子的重要性以及AAF/II菌毛对EAEC病理生物学的巨大贡献。
