EFFECTIVENESS OF TOBRAMYCIN AND CIPROFLOXACIN AGAINST BACTERIAL ISOLATES IN CANINE OTITIS EXTERNA IN UBERABA, MINAS GERAIS

Abstract Canine otitis externa is a common and recurrent disease in domestic dogs. Although not being life threatening, it can result in the overuse of antibiotics, increased bacterial resistance and reduction of options for treatment. This study aimed to determine: the principal characteristics (age, race, and gender) of dogs affected by otitis externa; the most frequently bacteria identified as being associated with it and their antimicrobial resistance profiles. A total of 221 bacterial isolates were identified by morphological staining and biochemical processes and tested against eleven antibiotics. Among the 148 dogs diagnosed with otitis externa, 51.4% (76/148) were males and 48.6% (72/148) females. The cases were detected mainly in dogs with age above 7 years (54.7%; 81/148. Among the races examined, poodles were the most numerous (14.84%; 22/148). The most common bacteria found were: coagulase-negative Staphylococcus (StCN), 33.9% (75/221); coagulase-positive Staphylococcus (StCP), 19% (42/221); Proteus spp., 17.2% (38/221) and Pseudomonas aeruginosa, 9.5% (21/221). Simultaneous resistance to more than three classes of antimicrobials were most frequently detected in P. aeruginosa (61.9%; 13/21) and Proteus spp (39.47%; 15/38). According to data obtained from this study, two veterinary medications found to be most effective for topical treatment were tobramycin and ciprofloxacin.

摘要 犬外耳炎是家养犬常见且易复发的疾病。尽管该疾病不危及生命，但可引发抗生素过度使用、细菌耐药性上升以及治疗方案选择受限的问题。本研究旨在明确：患外耳炎犬只的主要特征（年龄、品种与性别）、与之关联的最常见分离菌及其抗菌药物耐药谱。研究通过形态学染色与生化鉴定方法，共获得221株细菌分离株，并针对11种抗生素开展药敏试验。在148只确诊外耳炎的犬只中，雄性占比51.4%（76/148），雌性占比48.6%（72/148）；病例主要集中于7岁以上的犬只（54.7%；81/148）；在所检测的犬品种中，贵宾犬（poodles）占比最高（14.84%；22/148）。本次检出的常见致病菌依次为：凝固酶阴性葡萄球菌（Coagulase-negative Staphylococcus, StCN）占比33.9%（75/221）、凝固酶阳性葡萄球菌（Coagulase-positive Staphylococcus, StCP）占比19%（42/221）、变形杆菌属（Proteus spp.）占比17.2%（38/221）以及铜绿假单胞菌（Pseudomonas aeruginosa）占比9.5%（21/221）。同时对三类及以上抗菌药物产生耐药性的情况，在铜绿假单胞菌中最为普遍（61.9%；13/21），其次为变形杆菌属（39.47%；15/38）。根据本研究所得数据，妥布霉素（tobramycin）与环丙沙星（ciprofloxacin）是两种用于犬外耳炎局部治疗效果最佳的兽医用药。