de Sá Barreto Maia Leite Denny Parente, de Oliveira Pollyanne Raysa Fernandes, Oliveira Flavia Cristina Matos, Melo-Santos Gabriel, Maricato Guilherme, Beraldo Karolina Rosa Fernandes, Rodrigues Angélica Lúcia Figueiredo, Damasceno Alexsandro Antonio Portilho, Oliveira Rodrigo Hipólito Tardin, Fraga-Silva Thais Fernanda Campos, Juliano Maria Aparecida, Monteiro Frederico Ozanan Barros, Silva-Júnior Abelardo, Mota Rinaldo Aparecido
Department of Veterinary Medicine, University Federal Rural of Pernambuco, Recife, PE, Brazil.
Institute of Biological Sciences, Federal University of Pará, Belém, PA, Brazil.
Vet Res Commun. 2025 Aug 5;49(5):271. doi: 10.1007/s11259-025-10836-3.
Antimicrobial resistance in natural environments poses an increasing threat to public health and biodiversity conservation. This study investigated antimicrobial resistance and biofilm formation in bacteria isolated from Inia araguaiaensis, an Amazonian endemic dolphin species. Skin lesion samples were collected from eight individuals in the Mocajuba region, Pará, Brazil. Bacterial isolation was performed on Brain Heart Infusion agar and Mannitol Salt agar. Species identification was carried out using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and antimicrobial susceptibility testing was conducted by disk diffusion following. Resistance genes were detected by polymerase chain reaction, and biofilm formation was assessed using the crystal violet staining method. A total of 19 bacterial isolates were recovered, including Staphylococcus spp. (n = 14) and Mammaliicoccus sciuri (n = 5). The most frequently identified species were Staphylococcus aureus (4/19; 21.1%), S. warneri (4/19; 21.1%), and S. epidermidis (4/19; 21.1%). A high prevalence of penicillin resistance was observed (18/19; 94.7%), followed by resistance to erythromycin, tetracycline, and sulfamethoxazole-trimethoprim (each 4/19; 21.1%), and gentamicin (3/19; 15.8%). Four isolates (4/19; 21.1%) exhibited a multidrug-resistant (MDR) profile. Genotypic screening revealed the presence of the blaZ gene in 8/19 isolates (44.4%), followed by mecA, msrA, and norC (each 2/19; 10.5%). The tetracycline resistance genes tetL and tetM were detected in 3/19 (15.8%) and 1/19 (5.3%) isolates, respectively. Biofilm formation was detected on 15/19 (78.9%) of the isolates, of which 4/15 (26.7%) were classified as strong producers, 1/15 (6.7%) as moderate, and 10/15 (66.7%) as weak producers. These findings support the recognition of river dolphins as potential sentinels for antimicrobial resistance in aquatic ecosystems and reinforce the importance of integrating microbiological monitoring into broader conservation efforts under the One Health perspective.
自然环境中的抗菌药物耐药性对公众健康和生物多样性保护构成了日益严重的威胁。本研究调查了从亚马逊特有海豚物种伊尼亚瓜亚河豚（Inia araguaiaensis）分离出的细菌中的抗菌药物耐药性和生物膜形成情况。从巴西帕拉州莫卡茹巴地区的8只个体采集了皮肤损伤样本。在脑心浸液琼脂和甘露醇盐琼脂上进行细菌分离。使用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）进行物种鉴定，并通过纸片扩散法进行抗菌药物敏感性测试。通过聚合酶链反应检测耐药基因，并使用结晶紫染色法评估生物膜形成。共分离出19株细菌，包括葡萄球菌属（n = 14）和松鼠葡萄球菌（Mammaliicoccus sciuri，n = 5）。最常鉴定出的物种是金黄色葡萄球菌（4/19；21.1%）、沃氏葡萄球菌（S. warneri，4/19；21.1%）和表皮葡萄球菌（S. epidermidis，4/19；21.1%）。观察到青霉素耐药率很高（18/19；94.7%），其次是对红霉素、四环素和磺胺甲恶唑-甲氧苄啶的耐药率（均为4/19；21.1%）以及对庆大霉素的耐药率（3/19；15.8%）。4株分离株（4/19；21.1%）表现出多重耐药（MDR）特征。基因型筛查显示，19株分离株中有8株（44.4%）存在blaZ基因，但其次是mecA、msrA和norC基因（均为2/19；10.5%）。在19株分离株中，分别有3株（15.8%）和1株（5.3%）检测到四环素耐药基因tetL和tetM。在19株分离株中的15株（78.9%）检测到生物膜形成，其中4/15（26.7%）被归类为强生产者，1/15（6.7%）为中度生产者，10/15（66.7%）为弱生产者。这些发现支持将江豚视为水生生态系统中抗菌药物耐药性的潜在哨兵，并强化了在“同一健康”视角下将微生物监测纳入更广泛保护工作的重要性。
