Kahali Soumen, Sarkar Bhaswati, Rajendran K, Khanam Jasmina, Yamasaki Shinji, Nandy Ranjan K, Bhattacharya S K, Ramamurthy T
National Institute of Cholera and Enteric Diseases, P-33, CIT Rd., Scheme XM, Beliaghata, Kolkata-700010, India.
J Clin Microbiol. 2004 Sep;42(9):4111-20. doi: 10.1128/JCM.42.9.4111-4120.2004.
Enteroaggregative Escherichia coli (EAEC) is an important diarrheal enteropathogen defined by aggregative adherence to cultured epithelial cells. We have detected EAEC from 121 (6.6%) of 1,826 hospitalized patients admitted with diarrhea to the Infectious Diseases Hospital in Kolkata, India. Watery diarrhea was recorded significantly (P = 0.0142) more often in children. The majority of the EAEC isolates were not serotypeable (62%) and showed resistance to five or more antibiotics (76%). We studied different virulence genes and the molecular epidemiology of 121 EAEC isolates recovered from diarrheal patients. A PCR assay for detection of virulence genes, an assay for determination of clump formation in liquid culture, and a HeLa cell adherence assay were carried out to characterize the EAEC isolates. Investigations were also conducted to correlate the virulence gene profiles with diarrheal symptoms and molecular epidemiology by pulsed-field gel electrophoresis (PFGE). Two or more virulence genes were detected in 109 (90.1%) EAEC isolates. In the cluster analysis, some isolates with specific gene profiles and phenotypes formed a group or subcluster. This study highlights the comparative distributions of three fimbrial adhesins and other virulence genes among EAEC isolates. The diverse virulence gene and PFGE profiles, along with the existence of diverse serotypes and antibiograms, suggests that the EAEC isolates are genetically heterogeneous in Kolkata.
肠集聚性大肠杆菌（EAEC）是一种重要的致泻性肠道病原体，其定义为对培养的上皮细胞呈集聚性粘附。我们从印度加尔各答传染病医院收治的1826例腹泻住院患者中的121例（6.6%）检测到了EAEC。儿童中水样腹泻的记录显著更多（P = 0.0142）。大多数EAEC分离株无法分型（62%），并且对五种或更多种抗生素耐药（76%）。我们研究了从腹泻患者中分离出的121株EAEC的不同毒力基因和分子流行病学。进行了用于检测毒力基因的PCR检测、用于测定液体培养中菌团形成的检测以及HeLa细胞粘附检测，以对EAEC分离株进行特征分析。还通过脉冲场凝胶电泳（PFGE）进行了研究，以将毒力基因谱与腹泻症状和分子流行病学相关联。在109株（90.1%）EAEC分离株中检测到了两种或更多种毒力基因。在聚类分析中，一些具有特定基因谱和表型的分离株形成了一个组或亚组。本研究突出了三种菌毛粘附素和其他毒力基因在EAEC分离株中的比较分布。多样的毒力基因和PFGE谱，以及多样的血清型和抗菌谱的存在，表明加尔各答的EAEC分离株在基因上是异质的。
