House fly vector for porcine circovirus 2b on commercial pig farms
House fly vector for porcine circovirus 2b on commercial pig farms
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DOI：
10.1016/j.vetmic.2010.11.019
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发表时间：
2011-05-05
影响因子：
3.3
通讯作者：
Mellits, K.
中科院分区：
文献类型：
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作者：
Blunt, R.;McOrist, S.;Mellits, K.
我们研究了常见农场无脊椎动物在农场传播猪圆环病毒基因型 2 (PCV2) 和其他无包膜病毒的潜力。 2007 年（PCV2 疫苗接种前）和 2008 年（PCV2 疫苗接种后），在英格兰 5 个农场研究地点对无脊椎动物群落进行诱捕收集（每年 8 个诱捕日期）、计数并分类为属和种组。总 DNA 是从每年每个农场猪的代表性横截面粪便中提取的，也从完整的双翅目苍蝇样本（每个陷阱约 20 只苍蝇）和任何蟑螂的解剖内脏（每个陷阱约 5 只）中提取。通过针对 ORF1 和 ORF2 的单独 PCR 测试每个 DNA 样本是否存在 PCV2 DNA。通过 PCR 产物的 DNA 测序对阳性样本进行亚型分类。这两年，所有 5 个农场中与猪相关的双翅目蝇群落均以家蝇为主：仅在 1 个农场中发现了大量东方蜚蠊蟑螂。 2007 年，在断奶仔猪/保育猪粪便中常规检测到特定的 PCV2b DNA 元件（占样品的 25-60%），但在其他年龄组中未检测到。 2007 年在 5 个农场中的 4 个农场采集的家蝇 PCV2b DNA 元件也呈阳性。 ORF2序列的比较表明，指示PCV2b基因型的ORF2序列在猪和果蝇中是相同的。不同样本的 ORF1 序列发生了微小变化。在断奶器/育苗区收集的苍蝇最有可能呈阳性（捕蝇器样本的 22-50%）。从所有蟑螂（2007年和2008年）以及2008年所有苍蝇和猪粪便中提取的DNA也始终呈阴性。我们认为，家蝇最有可能在农场携带和传播 PCV2b，因为它们的生命周期包含与猪及其栖息地密切相关的阶段。疫苗接种似乎可以减少 PCV2b 的环境负荷。 (C) 2010 Elsevier B.V. 保留所有权利。
We investigated the on-farm potential of common farm invertebrates to transmit porcine circovirus genotype 2 (PCV2) and other non-enveloped viruses. In 2007 (pre-PCV2 vaccination) and 2008 (post-PCV2 vaccination), invertebrate communities were trap-collected (8 trap-dates per year), counted and sorted into genus and species groups on 5 farm study sites within England. Total DNA was extracted from feces of representational cross-sections of pigs on each farm in each year and also from intact samples of Diptera flies (ca. 20 flies per trap) and dissected viscera of any cockroaches (ca. 5 per trap). Each DNA sample was tested for the presence of PCV2 DNA by separate PCRs for ORF1 and ORF2. Positive samples were sub-typed via DNA sequencing of PCR products. The pig-associated Diptera fly community was dominated by Musca domestica (house fly) in both years on all 5 farms: numerous Blatta orientalis cockroaches were only noted on 1 farm throughout. Specific PCV2b DNA elements were routinely detected (25-60% of samples) in weaner/nursery pig feces in 2007, but not in other age groups. Musca collected on 4 of the 5 farms in 2007 was also positive for PCV2b DNA elements. Comparison of ORF2 sequences indicated that ORF2 sequences indicating PCV2b genotype were identical in pigs and flies. Minor changes were noted in ORF1 sequences from different samples. Flies collected in the weaner/nursery area were most likely to be positive (22-50% of fly-trap samples). DNA extracted from all cockroaches (2007 and 2008) and all flies and pig feces in 2008 were also negative throughout. We suggest that Musca flies have the most likely on-farm potential to carry and transmit PCV2b due to their life cycle incorporating stages in close association with pigs and their habitat. Vaccination appeared to reduce environmental load of PCV2b. (C) 2010 Elsevier B.V. All rights reserved.