Escherichia coli from clinical mastitis: serotypes and virulence factors
Escherichia coli from clinical mastitis: serotypes and virulence factors
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DOI：
10.1177/1040638711425581
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发表时间：
2011-11-01
影响因子：
1.5
通讯作者：
Moreira, Maria Aparecida S.
中科院分区：
文献类型：
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作者：
Fernandes, Jose Benedito C.;Zanardo, Larissa G.;Moreira, Maria Aparecida S.
在本研究中，研究了牛乳腺炎大肠杆菌分离株的毒力因子，并利用表型和基因型分析评估了这些因素与感染之间的联系。对27株大肠杆菌分离株进行了分析，其中2株显示产生韦罗毒素。所有分离株都具有产生生物膜的能力，尽管水平不同。1株菌株对牛血清的杀菌活性敏感，11株为中等，15株为耐药菌株。部分分离株对甲氧苄氨嘧啶(9)和氨苄青霉素(4)耐药，对新霉素(1)和甲氧苄氨嘧啶(5)耐药，对氨苄青霉素和甲氧苄氨嘧啶同时耐药(4)。fimH基因在所有分离株中均存在，并与其他毒力标记相关：pap(1)、stb(8)、cs31a(3)、stb和vt2(2)、cs31a和stb(3)、east1和kps(1)、stb和east1(1)、cs31a和east1(1)、cs31a、stb、pap和iucD(1)。测定了O93:H4、O83:H19和O15:H11 3株分离株的血清群。系统发育分析表明，A群23株，B1群4株。结果表明，这些大肠杆菌分离株是具有不同毒力因子的机会致病菌。结果表明，大肠杆菌在牛乳腺炎中的致病性途径不是一个特定毒力因子的结果。
In the current study, the virulence factors in Escherichia coli isolates from bovine mastitis were investigated, and the connection between these factors and infection was evaluated using phenotypic and genotypic analyses. Twenty-seven E. coli isolates were analyzed, and 2 were shown to produce verotoxin. All isolates had the ability to produce biofilms, although at different levels. One isolate was found to be sensitive to the bactericidal activity of bovine serum, 11 were intermediate, and 15 were resistant. Some isolates showed resistance to trimethoprim sulfa (9) and ampicillin (4), intermediate resistance to neomycin (1) and trimethoprim sulfa (5), and simultaneous resistance to ampicillin and trimethoprim sulfa (4). The fimH gene was found in all isolates and was associated with other virulence markers:pap (1), stb (8), cs31a (3), stb and vt2 (2), cs31a and stb (3), east1 and kps (1), stb and east1 (1), cs31a and east1 (1), and cs31a, stb, pap, and iucD (1). Serogroups were determined for 3 isolates: O93:H4, O83:H19, and O15:H11. Phylogenetic analysis showed that 23 isolates belonged to group A and 4 belonged to B1. The findings revealed that these E. coli isolates are opportunistic pathogens with different virulence factors. The results indicate that the pathogenicity route of E. coli in bovine mastitis is not a consequence of 1 specific virulence factor.