Pantoja Lucina Galina, Pettit Kalie, Dos Santos Lucas F, Tubbs Rick, Pieters Maria
Zoetis, Florham Park, NJ (Galina Pantoja)University of Minnesota, St. Paul, MN (Pettit, Dos Santos, Pieters)Tubbs Contract Research Organization, Jasper, AL (Tubbs)
Zoetis, Florham Park, NJ (Galina Pantoja)University of Minnesota, St. Paul, MN (Pettit, Dos Santos, Pieters)Tubbs Contract Research Organization, Jasper, AL (Tubbs).
J Vet Diagn Invest. 2016 Mar;28(2):175-9. doi: 10.1177/1040638716630767.
The objective of our study was to characterize the Mycoplasma hyopneumoniae genetic diversity within a swine operation comingling weaned pigs. Bronchial swabs and tracheal aspirates were collected from 3 nursery-to-finish farms. During the finishing production stages, samples were obtained from mortalities and from live coughing pigs in rooms where mortality was not observed. A total of 105 samples were examined by a M. hyopneumoniae real-time polymerase chain reaction and subjected to genetic typing using a multilocus variable number tandem repeat analysis (MLVA) assay. The MLVA was used to identify genetic variants based on the number of repeats in 2 variable number tandem repeats loci, namely P97 and P146, thought to mediate adherence of M. hyopneumoniae to swine cilia. Four distinguishable M. hyopneumoniae variants were identified: MVLA variants 9-15, 11-21, 9-21, and 7-15. Variant 9-15 was the most prevalent, observed in 79% of rooms, and detected on all 3 farms. Variant 11-21 was present in 37% of the rooms on 2 of the 3 farms. Only one 9-21 variant was identified in 1 farm, and all samples of variant 7-15 were recovered from another farm. Based on the low prevalence and limited geographic distribution of the last 2 variants, it is hypothesized that they might be the result of in-situ recombination. All variants detected in this investigation appeared to belong to 3 clusters. Overall, a limited number of variants and clusters were identified in a system that comingles pigs from different sources, suggesting limited M. hyopneumoniae genetic variation within commercial swine production environments.
我们研究的目的是描述在一个混合饲养断奶仔猪的猪场中猪肺炎支原体的遗传多样性。从3个保育到育肥猪场采集支气管拭子和气管吸出物。在育肥生产阶段，从死亡猪以及未观察到死亡的猪舍中咳嗽的活猪采集样本。总共105个样本通过猪肺炎支原体实时聚合酶链反应进行检测，并使用多位点可变数目串联重复分析（MLVA）测定法进行基因分型。MLVA用于根据2个可变数目串联重复位点（即P97和P146）中的重复次数来鉴定基因变体，这2个位点被认为介导猪肺炎支原体与猪纤毛的黏附。鉴定出4种可区分的猪肺炎支原体变体：MVLA变体9 - 15、11 - 21、9 - 21和7 - 15。变体9 - 15最为普遍，在79%的猪舍中观察到，并且在所有3个猪场中都检测到。变体11 - 21存在于3个猪场中2个猪场的37%的猪舍中。在1个猪场中仅鉴定出1个9 - 21变体，并且7 - 15变体的所有样本均从另一个猪场中采集到。基于后2个变体的低流行率和有限的地理分布，推测它们可能是原位重组的结果。在本次调查中检测到的所有变体似乎都属于3个簇。总体而言，在一个混合来自不同来源猪的系统中鉴定出的变体和簇数量有限，这表明在商业养猪生产环境中猪肺炎支原体的遗传变异有限。
