Becker Claire A M, Ambroset Chloé, Huleux Anthéa, Vialatte Angélique, Colin Adélie, Tricot Agnès, Arcangioli Marie-Anne, Tardy Florence
UMR Mycoplasmoses des Ruminants, VetAgro Sup, Université de Lyon, 69280 Marcy-l'Etoile, France.
UMR Mycoplasmoses des Ruminants, ANSES Laboratoire de Lyon, Université de Lyon, 69364 Lyon CEDEX 07, France.
Pathogens. 2020 Jul 21;9(7):593. doi: 10.3390/pathogens9070593.
Bovine respiratory diseases (BRD) are widespread in veal calf feedlots. Several pathogens are implicated, both viruses and bacteria, one of which, , is under-researched. This worldwide-distributed bacterium has been shown to be highly resistant in vitro to the main antimicrobials used to treat BRD. Our objective was to monitor the relative prevalence of during BRD episodes, its diversity, and its resistance phenotype in relation to antimicrobial use. For this purpose, a two-year longitudinal follow-up of 25 feedlots was organized and 537 nasal swabs were collected on 358 veal calves at their arrival in the lot, at the BRD peak and 4 weeks after collective antimicrobial treatments. The presence of was assessed by real-time PCR and culture. The clones isolated were then subtyped ( subtyping and PFGE analysis), and their susceptibility to five antimicrobials was determined. The course of the disease and the antimicrobials used had no influence on the genetic diversity of the strains: The subtype distribution was the same throughout the BRD episode and similar to that already described in France, with a major narrowly-variable subtype circulating, st2. The same conclusion holds for antimicrobial resistance (AMR) phenotypes: All the clones were already multiresistant to the main antimicrobials used (except for fluoroquinolones) prior to any treatments. By contrast, changes of AMR phenotypes could be suspected for Pasteurellaceae in two cases in relation to the treatments registered.
牛呼吸道疾病（BRD）在犊牛饲养场中广泛存在。多种病原体与之相关，包括病毒和细菌，其中一种细菌尚未得到充分研究。这种在全球范围内分布的细菌已被证明在体外对用于治疗BRD的主要抗菌药物具有高度耐药性。我们的目标是监测在BRD发病期间该细菌的相对流行率、其多样性以及与抗菌药物使用相关的耐药表型。为此，我们组织了对25个饲养场为期两年的纵向随访，并在358头犊牛进入饲养场时、BRD高峰期以及集体抗菌治疗后4周收集了537份鼻拭子。通过实时PCR和培养评估该细菌的存在情况。然后对分离出的克隆进行亚型分析（亚型分型和PFGE分析），并确定它们对五种抗菌药物的敏感性。疾病进程和使用的抗菌药物对该细菌菌株的遗传多样性没有影响：在整个BRD发病期间，亚型分布相同，且与法国已描述的情况相似，主要有一个狭窄可变的亚型st2在传播。对于抗菌耐药（AMR）表型也得出了相同的结论：在任何治疗之前，所有克隆对所用的主要抗菌药物（氟喹诺酮类除外）已经具有多重耐药性。相比之下，在两例中，根据记录的治疗情况，怀疑巴斯德氏菌科的AMR表型发生了变化。
