Oucheriah Yasmine, Heleili Nouzha, Colin Adélie, Mottet Catherine, Tardy Florence, Becker Claire A M
Université de Batna, Laboratoire de Recherche ESPA, Batna, Algeria.
Université de Lyon, Anses, VetAgro Sup, UMR Mycoplasmoses Animales, Lyon, France.
Front Vet Sci. 2022 May 20;9:910799. doi: 10.3389/fvets.2022.910799. eCollection 2022.
Bovine respiratory disease (BRD) is common in calves in Algeria, but to date, has never been monitored as a potential etiological agent. Here, to assess the presence (direct detection) and circulation (indirect detection) of , broncho-alveolar lavage fluids (BALF) and serum samples were collected from 60 veal calf farms in Algeria. A commercial ELISA kit (ID Screen ELISA) was used to screen for the presence of specific antibodies against . bovis in 351 blood sera collected from both diseased and healthy calves, and 69% (241 sera) tested positive. BALFs from the 176 diseased calves were used to screen for by real-time-PCR (rt-PCR), and 102 (58%) tested positive. A non-exhaustive set of 53 clones were isolated from 44 calves and further subtyped using gene sequencing. No predominant subtype was found, and two clones exhibited a new subtype. Fourteen clones were further characterized by multilocus sequence typing, and results showed a high degree of genetic diversity, with some clones having new alleles and subtypes. The minimum inhibitory concentrations (MICs) of 5 antimicrobials regularly used to treat BRD was determined on 45 clones. Susceptibility profiles showed very broad diversity, confirming the variety of clones actively circulating. We detected clones with high MICs, including increased MICs of enrofloxacin ( = 5). This is the first study to report the presence of in Algeria in calves with BRD. This research also finds broad genetic and phenotypic diversity in the actively circulating isolates.
牛呼吸道疾病（BRD）在阿尔及利亚的犊牛中很常见，但迄今为止，从未作为潜在病原体进行监测。在此，为了评估[病原体名称未给出]的存在（直接检测）和传播情况（间接检测），从阿尔及利亚的60个小牛肉犊牛场采集了支气管肺泡灌洗液（BALF）和血清样本。使用一种商业ELISA试剂盒（ID Screen ELISA）对从患病和健康犊牛采集的351份血清样本中抗[病原体名称未给出]的特异性抗体进行筛查，69%（241份血清）检测呈阳性。对176头患病犊牛的BALF进行实时PCR（rt-PCR）筛查以检测[病原体名称未给出]，102头（58%）检测呈阳性。从44头犊牛中分离出一组非详尽的53个克隆，并使用[基因名称未给出]基因测序进一步进行亚型分析。未发现主要亚型，两个克隆表现出一种新的亚型。通过多位点序列分型对14个克隆进行了进一步表征，结果显示出高度的遗传多样性，一些克隆具有新的等位基因和亚型。对常用于治疗BRD的5种抗菌药物的最低抑菌浓度（MIC）在45个克隆上进行了测定。药敏谱显示出非常广泛的多样性，证实了活跃传播的克隆的多样性。我们检测到具有高MIC的克隆，包括恩诺沙星MIC升高（=5）。这是第一项报道在阿尔及利亚患有BRD的犊牛中存在[病原体名称未给出]的研究。这项研究还发现活跃传播的分离株具有广泛的遗传和表型多样性。
