Nocera Francesca Paola, Chiaromonte Adriana, Schena Rossana, Pizzano Francesca, Arslan Sinem, Pedicini Chiara, De Martino Luisa
Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples 80137, Italy.
Vet Med Int. 2025 May 16;2025:5566151. doi: 10.1155/vmi/5566151. eCollection 2025.
is considered the second major causative agent of otitis externa in dogs, after . This study aimed to evaluate the antimicrobial resistance profiles and to detect the extended-spectrum β-lactamase (ESBL) and metallo-β-lactamase (MBL) genes in (). Precisely, seventeen strains, recovered from auricular specimens of dogs affected by otitis externa, were identified by MALDI-TOF MS. Antimicrobial susceptibility testing was carried out against eleven clinically relevant antimicrobials using the Kirby Bauer disk diffusion method on Mueller Hinton agar plates. The PCR assay was performed to detect ESBL , , , , and MBL , , , , genes. The results showed that isolates had a phenotypic resistance value of 100% to ceftazidime, imipenem, and meropenem, followed by piperacillin-tazobactam, sulfamethoxazole-trimethoprim (94%), and aztreonam (88%). An alarming result was represented by the high prevalence of multidrug-resistant strains with 100% of the total isolates. The most common ESBL-genotype combination was + (29.4%). Thirteen isolates (76.5%) carried together + genes, which resulted to be the most common MBL-genotype combination. All the isolates harboring ESBL and MBL genes were biofilm producers, evaluated by the crystal violet-based assay and PCR. Precisely, 76.5% were strong biofilm producers, and 23.5% resulted in being moderate producers. No relationship was observed between strong or moderate biofilm producers and numerical variability of ESBL and MBL genes. This study revealed worrying antimicrobial resistance profiles of associated canine otitis externa, considering also the zoonotic potential of this pathogen.
被认为是犬外耳炎的第二大主要病原体，仅次于 。本研究旨在评估 （）的抗菌药物耐药性谱，并检测超广谱β-内酰胺酶（ESBL）和金属β-内酰胺酶（MBL）基因。具体而言，通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）鉴定了从患有外耳炎的犬的耳标本中分离出的17株 菌株。使用Kirby Bauer纸片扩散法在Mueller Hinton琼脂平板上对11种临床相关抗菌药物进行了药敏试验。进行PCR检测以检测ESBL 、 、 、 以及MBL 、 、 、 、 基因。结果显示， 分离株对头孢他啶、亚胺培南和美罗培南的表型耐药率为100%，其次是哌拉西林-他唑巴坦、磺胺甲恶唑-甲氧苄啶（94%）和氨曲南（88%）。一个令人担忧的结果是多重耐药菌株的高流行率，占分离株总数的100%。最常见的ESBL基因型组合是 + （29.4%）。13株分离株（76.5%）同时携带 + 基因，这是最常见的MBL基因型组合。通过基于结晶紫的试验和PCR评估，所有携带ESBL和MBL基因的分离株都是生物膜产生菌。具体而言，76.5%是强生物膜产生菌，23.5%是中度产生菌。在强或中度生物膜产生菌与ESBL和MBL基因的数量变异性之间未观察到相关性。考虑到这种病原体的人畜共患病潜力，本研究揭示了与犬外耳炎相关的令人担忧的抗菌药物耐药性谱。
