Frey Caroline F, Müller Norbert, Stäuber Norbert, Marreros Nelson, Hofmann Larissa, Hentrich Brigitte, Hirsbrunner Gaby
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, 3012 Bern, Switzerland.
Institute of Parasitology, Vetsuisse Faculty, University of Bern, Länggassstrasse 122, 3012 Bern, Switzerland.
Vet Parasitol. 2017 Apr 15;237:30-36. doi: 10.1016/j.vetpar.2017.02.024. Epub 2017 Feb 24.
Cows on an alpine pasture were presented with severe signs of vaginitis. To rule out infection with Tritrichomonas foetus, vaginal swabs were taken and real-time PCR based on detection via fluorescence resonance energy transfer (FRET) probes and targeting the first internal transcribed spacer (ITS-1) of nuclear ribosomal DNA (rDNA) was performed. PCR was positive in 25 of totally 34 assessed cows. However, the melting profiles of the probes targeting the diagnostic PCR products differed from the T. foetus positive control. Subsequent sequencing of the amplicons revealed 91% identity to Simplicimonas sp. sequences deposited in GenBank™. Furthermore, there was no clear association between positive PCR result and presence of vaginitis. To investigate the distribution of this Simplicimonas-like organism in cows, more herds grazing on the same alpine pastures as well as unrelated cows were tested. In total, 133 cows and 16 heifers were sampled, 53 cows and 6 heifers even twice. Vaginitis was evident in 43 cows and 4 heifers. All-over-positivity of PCR was 44%, including nine tests performed on heifers. Melting peak analysis indicated Simplicimonas-like organisms in all positive samples. Culture attempts in bovine InPouch ™ TF failed. No association between a positive PCR result and the presence of vaginitis was found. This is, to the best of our knowledge, the first report on Simplicimonas-like DNA in vaginal swabs of female cattle. Our data suggest that when testing vaginal swabs of cattle by means of T. foetus PCR, false positive reactions due to Simplicimonas-like organisms may occur.
高山牧场上的奶牛出现了严重的阴道炎症状。为排除胎儿三毛滴虫感染，采集了阴道拭子，并基于荧光共振能量转移（FRET）探针检测和靶向核糖体DNA（rDNA）的第一个内部转录间隔区（ITS-1）进行了实时PCR。在总共34头评估奶牛中，25头PCR呈阳性。然而，靶向诊断性PCR产物的探针熔解曲线与胎儿三毛滴虫阳性对照不同。随后对扩增子进行测序，结果显示与GenBank™中保存的简单单胞菌属序列有91%的同一性。此外，PCR阳性结果与阴道炎的存在之间没有明显关联。为了研究这种类简单单胞菌在奶牛中的分布情况，对更多在同一高山牧场放牧的牛群以及无关奶牛进行了检测。总共采集了133头奶牛和16头小母牛的样本，其中53头奶牛和6头小母牛甚至采集了两次样本。43头奶牛和4头小母牛出现了明显的阴道炎症状。PCR总体阳性率为44%，其中包括对小母牛进行的9次检测。熔解峰分析表明所有阳性样本中均存在类简单单胞菌。在牛用InPouch™ TF中进行培养尝试失败。未发现PCR阳性结果与阴道炎存在之间的关联。据我们所知，这是关于雌性牛阴道拭子中类简单单胞菌DNA的首次报告。我们的数据表明，在用胎儿三毛滴虫PCR检测牛的阴道拭子时，可能会因类简单单胞菌而出现假阳性反应。
