Toombs-Ruane L J, Riley C B, Rosanowski S M, Kendall A T, Benschop J
Institute of Veterinary and Biomedical Sciences, Massey University, Palmerston North, 4442, New Zealand.
Royal Veterinary College, University of London, London, NW1 0TU, UK.
Equine Vet J. 2015 Sep;47 Suppl 48:20. doi: 10.1111/evj.12486_45.
Decreased efficacy of veterinary antimicrobials and increased prevalence of multi-drug resistance (MDR) is of concern, but little is known of antimicrobial resistance encompassing the New Zealand (NZ) equine population. Recent concerns have arisen over the emergence of multi-resistant bacteria [1], especially on NZ stud farms where antibiotics are frequently used for respiratory disease without veterinary input [2].
To describe bacterial culture and antimicrobial sensitivity results from respiratory samples submitted of young horses (4 weeks to 3 years old).
Retrospective study of clinical pathology records.
A database search for isolates and sensitivity of respiratory samples from young horses (April 2004-July 2014) was conducted. The results of in vitro sensitivity testing by Kirby-Bauer disk diffusion were tabulated for major bacterial species isolated. Multiple correspondence analysis was used to describe clustering of multi-drug resistance (MDR) and selected demographic variables.
237/289 eligible respiratory samples had at least one aerobic bacterial isolate. Most of the 774 bacterial isolates were Gram-positive (68%). Streptococcus species were the most common genus isolated (40% of isolates). Sensitivity of Streptococcus spp. to penicillin, gentamicin and ceftiofur was >85%, but only 53% to trimethoprim-sulfamethoxone. Gram-negative sensitivity to ceftiofur, tetracycline, and trimethoprim-sulfamethoxone was <75%. MDR was found for 16% of isolates and in 39% of horses.
Penicillin is an appropriate first-line antimicrobial for use in most NZ young horses with suspected bacterial respiratory infection. However, based on findings of MDR, submission of samples for culture and monitoring of sensitivity should be used to inform antimicrobial selection. Ethical animal research: Not applicable. Sources of funding: Massey University McGeorge Fund; New Zealand Equine Research Foundation. Competing interests: None declared.
兽医抗菌药物疗效降低以及多重耐药性（MDR）患病率增加令人担忧，但对于新西兰马群的抗菌药物耐药情况知之甚少。近期，人们对多重耐药细菌的出现感到担忧[1]，尤其是在新西兰种马场，抗生素常被用于治疗呼吸道疾病，且未经兽医指导[2]。
描述4周龄至3岁幼马呼吸道样本的细菌培养及抗菌药物敏感性结果。
对临床病理记录进行回顾性研究。
对2004年4月至2014年7月幼马呼吸道样本的分离菌及敏感性进行数据库检索。通过Kirby-Bauer纸片扩散法进行的体外敏感性测试结果，针对分离出的主要细菌种类制成表格。采用多重对应分析来描述多重耐药性（MDR）聚类情况及选定的人口统计学变量。
237/289份符合条件的呼吸道样本至少有1种需氧细菌分离株。774株细菌分离株中大多数为革兰氏阳性菌（68%）。链球菌属是最常见的分离菌属（占分离株的40%）。链球菌对青霉素、庆大霉素和头孢噻呋的敏感性>85%，但对甲氧苄啶-磺胺甲恶唑的敏感性仅为53%。革兰氏阴性菌对头孢噻呋、四环素和甲氧苄啶-磺胺甲恶唑的敏感性<75%。16%的分离株及39%的马匹存在多重耐药性。
青霉素是大多数疑似细菌性呼吸道感染的新西兰幼马的合适一线抗菌药物。然而，基于多重耐药性的研究结果，应通过送检样本进行培养及监测敏感性来指导抗菌药物的选择。动物伦理研究：不适用。资金来源：梅西大学麦克乔治基金；新西兰马研究基金会。利益冲突：未声明。
