Prevalence of serogroups and virulence genes in Escherichia coli associated with postweaning diarrhoea and edema disease in pigs and a comparison of diagnostic approaches
Prevalence of serogroups and virulence genes in Escherichia coli associated with postweaning diarrhoea and edema disease in pigs and a comparison of diagnostic approaches
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DOI：
10.1016/s0378-1135(01)00504-1
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发表时间：
2002-03-01
影响因子：
3.3
通讯作者：
Frydendahl, K
中科院分区：
文献类型：
--
作者：
Frydendahl, K
鉴定引起猪断奶后腹泻（PWD）或水肿病（艾德）的大肠杆菌需要了解给定地区内流行的致病型。本研究旨在确定目前血清群的分布。猪致病性E.大肠杆菌分离株在丹麦和比较检测这些特征作为诊断方法。563个E。coli进行血清分型。coli O-抗血清，并研究溶血活性。用5 ′-核酸酶PCR法对219株分离株进行了进一步的鉴定，发现有42个不同的血清群，其中以0 149血清群最多，占49.9%，其次为0 138血清群（14.9%）、O139（6.9%）、O141（4.1%）和O8（3.7%）。溶血活性检测87.7%，所有菌株。检测到的毒力因子基因为F4（44.7%）、F18（39.3%）。F6（0.9%）、STb（77.6%）、EAST 1（65.8%）。LT（61.6%）、STa（26.5%）和Me（16.4%）。6种致病型占调查菌株的65.7%。以毒力因子基因的拥有情况为参照，采用代表常见猪致病血清群的抗血清进行O血清群鉴定和溶血检测，作为致病性的流行病学标记进行了评价。两种标准均与致病性相关（P <0.001）。然而，这两种方法也分别导致11.9%和13.2%的分离株的致病性的错误分类。当诊断PWD和艾德时，粘附因子基因F4、F18和紧密粘附素的检测被建议作为可操作的替代方案，（C）2002 Elsevier Science B.V.保留所有权利。
Identification of Escherichia coli causing porcine postweaning diarrhoea (PWD) or edema disease (ED) requires knowledge regarding the prevalent pathotypes within a given region. This study was undertaken to determine the present distribution of serogroups. hemolytic activity and virulence factor gene profiles among porcine pathogenic E. coli isolates in Denmark and to compare detection of these characteristics as diagnostic approaches. Five hundred and sixty-three E. coli were serogrouped using E. coli O-antisera and investigated for hemolytic activity. Of these, 219 isolates were further characterized using a 5'-nuclease PCR assay detecting genes for adhesion factors, enterotoxins and verocytotoxin 2e (VT2e), Forty-two different serogroups were found. The most prevalent serogroup was 0 149 accounting for 49.9% of all isolates, followed by O138 (14.9%), O139 (6.9%), O141 (4.1%) and O8 (3.7%). Hemolytic activity was detected in 87.7%, of all isolates. Virulence factor genes detected were F4 (44.7%), F18 (39.3%). intimin ( 1.4%), F6 (0.9%), STb (77.6%), EAST1 (65.8%). LT (61.6%), STa (26.5%) and Me (16.4%). Six pathotypes accounted for 65.7% of all isolates investigated. Using possession of virulence factor genes as reference, O-serogrouping employing a selection of antisera representing common pig pathogenic serogroups and detection of hemolysis were evaluated as epidemiological markers for pathogenicity. Both criteria were associated with pathogenicity (P < 0.001. for both), however, both methods also resulted in false classifications regarding pathogenicity for 11.9 and 13.2% of isolates, respectively, Detection of adhesion factor genes F4, F18 and intimin is suggested as an operational alternative when diagnosing PWD and ED, (C) 2002 Elsevier Science B.V. All rights reserved.