Shetty Veena A, Kumar Sanath H, Shetty Avinash K, Karunasagar Iddya, Karunasagar Indrani
Department of Microbiology, K.S. Hegde Medical Academy, Nitte University Deralakatte, Mangalore, India.
J Lab Physicians. 2012 Jan;4(1):24-9. doi: 10.4103/0974-2727.98666.
Diarrheal diseases are a major cause of morbidity and mortality in resource-limited countries. Among the bacterial pathogens, diarrheagenic E. coli (DEC) are most frequently implicated in cases of epidemic and endemic diarrhea worldwide. The objective of this study was to determine the prevalence of DEC in stool specimens from patients with acute diarrhea using polymerase chain reaction (PCR).
Escherichia coli stool samples were collected from 115 hospitalized children and adults with acute diarrhea in Mangalore, a coastal city, in southern India. PCR amplification of eae, bfp, stx, ehx genes were used for detection of enteropathogenic (EPEC) and shigatoxigenic E. coli (STEC), lt and st genes were used for enterotoxigenic E. coli (ETEC) and astA gene for enteroaggregative E. coli (EAEC).
During the 24 month study period, of the 115 stool samples, DEC type was detected in 20 (17.4%) using the PCR method. The most prevalent DEC was atypical EPEC accounting for 12 (10.4%) cases followed by 4 cases of EAEC (3.4%) and 4 of STEC (3.4%). No ETEC strains were isolated from any of the examined stool samples.
This study suggests that the atypical EPEC are the newly emerging group among DEC stains in Southern India. Further studies are needed to evaluate the epidemiology and virulence properties of atypical EPEC strains.
腹泻病是资源有限国家发病和死亡的主要原因。在细菌病原体中，致泻性大肠杆菌（DEC）在全球流行性和地方性腹泻病例中最常被牵涉其中。本研究的目的是使用聚合酶链反应（PCR）确定急性腹泻患者粪便标本中DEC的流行情况。
从印度南部沿海城市芒格洛尔的115名住院急性腹泻儿童和成人中收集大肠杆菌粪便样本。使用eae、bfp、stx、ehx基因的PCR扩增来检测肠致病性大肠杆菌（EPEC）和志贺毒素产生型大肠杆菌（STEC），lt和st基因用于检测产肠毒素大肠杆菌（ETEC），astA基因用于检测肠集聚性大肠杆菌（EAEC）。
在24个月的研究期间，115份粪便样本中，使用PCR方法检测到20份（17.4%）为DEC型。最常见的DEC是非典型EPEC，占12例（10.4%），其次是4例EAEC（3.4%）和4例STEC（3.4%）。在所检查的任何粪便样本中均未分离出ETEC菌株。
本研究表明，非典型EPEC是印度南部DEC菌株中新出现的群体。需要进一步研究来评估非典型EPEC菌株的流行病学和毒力特性。
