Slomka Marek J, Pavlidis Theo, Coward Vivien J, Voermans John, Koch Guus, Hanna Amanda, Banks Jill, Brown Ian H
Avian Virology Workgroup, Virology Department, Veterinary Laboratories Agency (VLA Weybridge), Addlestone, Surrey, UK.
Influenza Other Respir Viruses. 2009 Jul;3(4):151-64. doi: 10.1111/j.1750-2659.2009.00083.x.
Avian influenza (AI) caused by H7 AI viruses (AIVs) of both low pathogenicity (LP) and high pathogenicity (HP) are notifiable poultry diseases.
Design and validate two RealTime reverse transcriptase polymerase chain reactions (RRT PCRs) for Eurasian H7 AIV detection and pathotyping.
The H7 RRT PCRs amplified within the (i) HA2 and (ii) cleavage site CS regions of the haemagglutinin gene. Both were validated against 65 H7 AIVs, 57 non-H7 AIVs and 259 poultry swabs in comparison to M gene (AI generic) RRT PCR and virus isolation (VI). An additional 38 swabs and 20 tissue specimens extended validation against M gene RRT PCR.
Both H7 RRT PCRs amplified all 61 Eurasian lineage H7 AIVs and none of 57 non-H7 AIVs. A total of 297 poultry swabs were used to determine diagnostic sensitivity and specificity relative to M gene RRT PCR, sensitivity was 95.4% and 64.6% for the HA2 and CS RRT PCRs respectively, and specificity 97.9% and 99.6% respectively. The H7 HA2 RRT PCR was more sensitive than VI. This was emphasized by analysis of 37 swabs from turkeys infected experimentally with HPAI H7N1 virus sampled at 24 hours post-inoculation and LPAI H7N1 chicken infections sampled at 40-64 hours. Although less sensitive, usefulness of the H7 CS RRT PCR was confirmed by the correct molecular pathotyping for all 61 Eurasian lineage H7 AIVs tested.
The high sensitivity of H7 HA2 RRT PCR confirms its suitability for use in poultry surveillance and disease diagnosis. H7 CS RRT PCR provides an opportunity for rapid pathotyping of H7 AIVs.
由低致病性（LP）和高致病性（HP）H7禽流感病毒（AIV）引起的禽流感（AI）是须通报的禽类疾病。
设计并验证两种用于检测欧亚H7禽流感病毒并进行致病型鉴定的实时逆转录聚合酶链反应（RRT PCR）。
H7 RRT PCR在血凝素基因的（i）HA2和（ii）裂解位点CS区域内进行扩增。与M基因（AI通用型）RRT PCR和病毒分离（VI）相比，二者均针对65株H7 AIV、57株非H7 AIV和259份家禽拭子样本进行了验证。另外38份拭子和20份组织样本进一步针对M基因RRT PCR进行了验证。
两种H7 RRT PCR均扩增出了所有61株欧亚谱系H7 AIV，而57株非H7 AIV均未扩增出。共使用297份家禽拭子样本，相对于M基因RRT PCR来确定诊断敏感性和特异性，HA2和CS RRT PCR的敏感性分别为95.4%和64.6%，特异性分别为97.9%和99.6%。H7 HA2 RRT PCR比病毒分离更敏感。对37份接种HPAI H7N1病毒24小时后采集的火鸡拭子样本以及接种LPAI H7N1病毒40 - 64小时后采集的鸡拭子样本进行分析，突出了这一点。尽管敏感性较低，但对所有61株检测的欧亚谱系H7 AIV进行正确的分子致病型鉴定，证实了H7 CS RRT PCR的实用性。
H7 HA2 RRT PCR的高敏感性证实了其适用于家禽监测和疾病诊断。H7 CS RRT PCR为H7 AIV的快速致病型鉴定提供了机会。
