Vougidou C, Sandalakis V, Psaroulaki A, Siarkou V, Petridou E, Ekateriniadou L
Institute of Infectious and Parasitic Diseases of Thessaloniki, Ministry of Rural Development and Food, 54627 Thessaloniki, Greece.
Laboratory of Clinical Bacteriology, Parasitology, Zoonoses, and Geographical Medicine, University of Crete, 71110 Crete, Greece; Regional Laboratory of Public Health (Crete), 71110 Crete, Greece.
Microbiol Res. 2015 May;174:1-8. doi: 10.1016/j.micres.2015.02.003. Epub 2015 Feb 27.
Pasteurella multocida is an important pathogen in food-producing animals and numerous virulence genes have been identified in an attempt to elucidate the pathogenesis of pasteurellosis. Currently, some of these genes including the capsule biosynthesis genes, the toxA and the OMPs-encoding genes have been suggested as epidemiological markers. However, the number of studies concerning ruminant isolates is limited, while, no attempt has ever been made to investigate the existence of ompA sequence diversity among P. multocida isolates. The aim of the present study was the comparative analysis of 144 P. multocida pneumonic isolates obtained from sheep, goats, cattle and pigs by determining the distribution of the ompA-types in conjunction with the cap-locus and toxA patterns. The ompA genotypes of the isolates were determined using both a PCR-RFLP method and DNA sequence analysis. The most prevalent capsule biosynthesis gene among the isolates was capA (86.1%); a noticeable, however, rate of capD-positive isolates (38.6%) was found among the ovine isolates that had been associated primarily with the capsule type A in the past. Moreover, an unexpectedly high percentage of toxA-positive pneumonic isolates was noticed among small ruminants (93.2% and 85.7% in sheep and goats, respectively), indicating an important epidemiological role of toxigenic P. multocida for these species. Despite their great heterogeneity, certain ompA-genotypes were associated with specific host species, showing evidence of a host preference. The OmpA-based PCR-RFLP method developed proved to be a valuable tool in typing P. multocida strains.
多杀性巴氏杆菌是家畜中的一种重要病原体，为阐明巴氏杆菌病的发病机制，已鉴定出众多毒力基因。目前，其中一些基因，包括荚膜生物合成基因、toxA基因和编码外膜蛋白（OMPs）的基因已被建议作为流行病学标记。然而，有关反刍动物分离株的研究数量有限，而且从未有人尝试调查多杀性巴氏杆菌分离株中ompA序列多样性的存在情况。本研究的目的是通过确定ompA类型与cap位点及toxA模式的分布，对从绵羊、山羊、牛和猪分离得到的144株多杀性巴氏杆菌肺炎分离株进行比较分析。采用PCR-RFLP方法和DNA序列分析确定分离株的ompA基因型。分离株中最常见的荚膜生物合成基因是capA（86.1%）；不过，在过去主要与A型荚膜相关的绵羊分离株中发现了相当比例的capD阳性分离株（38.6%）。此外，在小反刍动物中发现意外高比例的toxA阳性肺炎分离株（绵羊和山羊中分别为93.2%和85.7%），表明产毒素多杀性巴氏杆菌对这些物种具有重要的流行病学作用。尽管存在很大的异质性，但某些ompA基因型与特定宿主物种相关，显示出宿主偏好的证据。所开发的基于OmpA的PCR-RFLP方法被证明是对多杀性巴氏杆菌菌株进行分型的一种有价值的工具。
