胸膜肺炎放线杆菌和猪繁殖与呼吸综合征病毒在保育猪中的空气传播

Airborne transmission of Actinobacillus pleuropneumoniae and porcine reproductive and respiratory syndrome virus in nursery pigs.

作者信息

Torremorell M, Pijoan C, Janni K, Walker R, Joo H S

机构信息

Department of Clinical and Population Sciences, College of Veterinary Medicine, University of Minnesota, St Paul 55108, USA.

出版信息

Am J Vet Res. 1997 Aug;58(8):828-32.

PMID:9256964

Abstract

OBJECTIVE

To document airborne transmission of Actinobacillus pleuropneumoniae and porcine reproductive and respiratory syndrome virus (PRRSV) infection in nursery pigs.

ANIMALS

32 two-week-old pigs obtained from 3 farms, but with similar Landrace X Yorkshire genetics for trial 1 of each experiment; 16 pigs for trial 2 of the A pleuropneumoniae experiment; and 14 pigs for trial 2 of the PRRSV experiment.

PROCEDURE

In experiment 1, pigs were inoculated with A pleuropneumoniae serotype 1 (6/8) or were left as contacts (2/8). At the beginning of trial 1, pigs were seronegative to A pleuropneumoniae serotypes 1 and 5 on the basis of results of an ELISA, but had positive results on the A pleuropneumoniae hemolysin I (Apx1)-neutralization test. Pigs in trial 2 had negative results on both tests. Pigs of trial 1 of experiment 2 were inoculated with a PRRSV virulent field isolate (MN-1b); pigs of trial 2 were inoculated with the virus reference strain VR-2332. Aerosol-exposed pigs were placed on the other side of the air duct and kept there for 2 to 7 weeks depending on evidence of airborne transmission.

RESULTS

In trial 1 of experiment 1, evidence of airborne transmission was not found. In trial 2, most airborne-exposed pigs died as a result of A pleuropneumoniae infection 12 days after initiation of the experiment. In trial 1 of experiment 2, all inoculated pigs (8/8) seroconverted, but only 2 of 8 contact-exposed pigs seroconverted. Aerosol-exposed pigs did not seroconvert nor was virus isolated. In trial 2, all inoculated and contact-exposed pigs seroconverted. All aerosol-exposed pigs seroconverted after 21 days, and virus was isolated at 16 days.

CONCLUSIONS

A pleuropneumoniae was transmitted by air at a distance of 1 m when pigs were fully susceptible to the organism. Transmission of PRRSV appeared to be strain dependent; when reference strain VR-2332 was used, airborne transmission of PRRSV was documented.

摘要

目的

记录胸膜肺炎放线杆菌和气源性传播的猪繁殖与呼吸综合征病毒（PRRSV）在保育猪中的传播情况。

动物

从3个猪场获取32头2周龄仔猪，每个实验的试验1中，这些仔猪具有相似的长白猪×约克夏猪遗传背景；胸膜肺炎放线杆菌实验的试验2用16头猪；PRRSV实验的试验2用14头猪。

方法

在实验1中，给仔猪接种1型胸膜肺炎放线杆菌（6/8）或作为接触组（2/8）。在试验1开始时，根据ELISA结果，仔猪对1型和5型胸膜肺炎放线杆菌血清学检测呈阴性，但对胸膜肺炎放线杆菌溶血素I（Apx1）中和试验呈阳性。试验2中的仔猪两项检测结果均为阴性。实验2的试验1中的仔猪接种PRRSV强毒田间分离株（MN-1b）；试验2中的仔猪接种病毒参考株VR-2332。暴露于气溶胶的仔猪被放置在风道的另一侧，并根据气源性传播的证据在那里饲养2至7周。

结果

在实验1的试验1中，未发现气源性传播的证据。在试验2中，大多数暴露于气溶胶的仔猪在实验开始12天后因胸膜肺炎放线杆菌感染死亡。在实验2的试验1中，所有接种的仔猪（8/8）血清转化，但8头接触暴露的仔猪中只有2头血清转化。暴露于气溶胶的仔猪未血清转化，也未分离到病毒。在试验2中，所有接种和接触暴露的仔猪均血清转化。所有暴露于气溶胶的仔猪在21天后血清转化，并在16天时分离到病毒。