Species specific PCR based detection of Escherichia coli from Indian foods
Species specific PCR based detection of Escherichia coli from Indian foods
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基于物种特异性 PCR 检测印度食品中的大肠杆菌
DOI：
10.1007/s13205-017-0784-8
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发表时间：
2017-06-01
期刊：
影响因子：
2.8
通讯作者：
Shashidhar, Ravindranath
中科院分区：
文献类型：
--
作者：
Godambe, Lipika Pansare;Bandekar, Jayant;Shashidhar, Ravindranath
大肠杆菌是粪便指示物，某些病毒型被称为病原体。因此，对大肠杆菌的检测和防治具有重要意义。食物中的大肠杆菌非常重要。现有的快速检测方法主要集中在致病性大肠杆菌的检测上。coli而不是总E.大肠杆菌群。本研究评价了两个特异于大肠杆菌的分子标记（uidA和uspA侧翼区）的应用。大肠杆菌结合微生物法进行确证。大多数分离株（77%）对两种检测基因均呈阳性。然而，22%的E.大肠杆菌菌株对uidA（9%）和uspA侧翼区（13%）的任何一个都呈阳性。高水平的E。在牛肉中发现大肠杆菌的发病率（92%的样本），而在芽菜中发现的发病率较低（19%的样本）。E.大肠埃希菌分离株的毒力基因（lt、ipaH、aggR、eaeA、stx 1和stx 2）检测结果均为阳性。2株分离株stx基因阳性。但包括stx阳性在内的所有分离株均为E. coli0157：H7。最大数量的E。大肠杆菌（44%）菌株的特征下，系统发育组B2。该系统发育群包括肠外和毒性E。大肠杆菌菌株。
Escherichia coli is a faecal indicator and certain virotypes are known as pathogens. Therefore, detection and prevention of E. coli in food is very important. The existing rapid methods concentrate on detecting the pathogenic E. coli instead of total E. coli population. Present study evaluates the use of two molecular markers (uidA and flanking region of uspA) specific for the E. coli in combination with microbiological method for confirmation. Majority of the isolates (77%) were positive for both the genes tested. However, 22% of the E. coli isolates were positive for any one of the two primer sets [uidA (9%) and flanking region of uspA (13%)]. High levels of E. coli incidences (92% samples) were observed in beef while low occurrence (19% samples) was found in sprouts. Low percentage (7.3%) of E. coli isolates was positive for virulence genes tested (lt, ipaH, aggR, eaeA, stx1 and stx2). Two isolates were positive for stx genes. However, none of the isolates including stx positive isolates were E. coli 0157:H7. Maximum number of the E. coli (44%) isolates was characterized under phylogenetic group B2. This phylogenetic group comprises of extra intestinal and virulent E. coli strains.