Schnee Christiane, Heller Martin, Schubert Evelyn, Sachse Konrad
Institute of Molecular Pathogenesis, Friedrich-Loeffler-lnstitut (Federal Research Institute for Animal Health), Naumburger Str. 96a, 07743 Jena, Germany.
Institute of Molecular Pathogenesis, Friedrich-Loeffler-lnstitut (Federal Research Institute for Animal Health), Naumburger Str. 96a, 07743 Jena, Germany.
Vet J. 2015 Jan;203(1):92-6. doi: 10.1016/j.tvjl.2014.11.009. Epub 2014 Nov 20.
Infectious bovine keratoconjunctivitis (IBK) has significant economic consequences and a detrimental impact on animal welfare. Although Moraxella (Mor.) bovis is the primary causative agent, the role of other bacteria, such as Mor. ovis, Mor. bovoculi and Mycoplasma (Myc.) bovoculi, is not well understood. To assess the prevalence of infection with these organisms, and to correlate this with outbreaks of IBK, conjunctival samples from four herds of cattle in Germany of differing IBK status were examined. Herds were selected to represent a hypothetical course of IBK ranging from the pre-outbreak stage (herd 1), to the acute disease stage (herd 2), to a stage where treatment had ceased (herd 3). Unaffected animals were also included (herd 4). To facilitate effective, sensitive sample analysis, a new real-time PCR for Myc. bovoculi was developed and used in concert with established real-time PCR protocols for Myc. bovis and Moraxella spp. Herds 1 and 2 showed similarly high rates of detection for Myc. bovoculi (92.5% and 84.0%, respectively), whereas herds 3 and 4 had a lower prevalence (35.5% and 26.2%, respectively). Mor. bovis and Mor. ovis were more prevalent in herd 1 (32.5% and 87.5%, respectively) and herd 2 (38% and 58%, respectively) than herd 3 (10.4% and 1.3%, respectively) and herd 4 (9.8% and 31.1%, respectively). Mor. bovoculi was the only pathogen that correlated with clinical signs of IBK; at 20% prevalence, it was almost exclusively detected in herd 2. The results indicate that herds with high Myc. bovoculi prevalence are more predisposed to outbreaks of IBK, possibly due to a synergistic interaction with Moraxella spp.
传染性牛角膜结膜炎(IBK)会造成重大经济后果,并对动物福利产生不利影响。虽然牛莫拉菌(Moraxella (Mor.) bovis)是主要病原体,但其他细菌,如绵羊莫拉菌(Mor. ovis)、牛眼莫拉菌(Mor. bovoculi)和牛支原体(Mycoplasma (Myc.) bovoculi)的作用尚不清楚。为了评估这些微生物的感染率,并将其与IBK的暴发相关联,对德国四群不同IBK状态的牛的结膜样本进行了检测。选择这些牛群以代表IBK从暴发前阶段(牛群1)到急性疾病阶段(牛群2)再到停止治疗阶段(牛群3)的假设病程。还纳入了未受影响的动物(牛群4)。为便于进行有效、灵敏的样本分析,开发了一种用于检测牛支原体的新型实时PCR方法,并与用于检测牛莫拉菌和莫拉菌属的既定实时PCR方案一起使用。牛群1和牛群2中牛支原体的检出率同样很高(分别为92.5%和84.0%),而牛群3和牛群4的患病率较低(分别为35.5%和26.2%)。牛莫拉菌和绵羊莫拉菌在牛群1(分别为32.5%和87.5%)和牛群2(分别为38%和58%)中比牛群3(分别为10.4%和1.3%)和牛群4(分别为9.8%和31.1%)更普遍。牛眼莫拉菌是唯一与IBK临床症状相关的病原体;在患病率为20%时,几乎只在牛群2中检测到。结果表明,牛支原体患病率高的牛群更容易暴发IBK,这可能是由于与莫拉菌属的协同相互作用。