da Silva Maria Eduarda Rocha Jacques, Breyer Gabriela Merker, Weyh Tainara Soares, de Oliveira Silvia Dias, Siqueira Franciele Maboni
Department of Veterinary Clinical Pathology, Faculty of Veterinary Medicine, Federal University of Rio Grande Do Sul, Porto Alegre, 91540-000, Brazil.
Postgraduate Program in Veterinary Science, Federal University of Rio Grande Do Sul, Porto Alegre, 91540-000, Brazil.
Vet Res Commun. 2025 Jun 20;49(4):230. doi: 10.1007/s11259-025-10796-8.
Antibiotic resistance in pathogenic bacteria has emerged as an important issue in public health. Additionally, climate change increases the risk of bacterial infections and pathogens dissemination, posing a serious challenge to public health. Among these threats, the emergence and spread of carbapenem-resistant Gram-negative bacteria are of particular concern, given the limited therapeutic options and high mortality rates associated with these bacterial infections. This study investigated the presence of carbapenem-resistant Gram-negative bacteria in the urine samples of 192 dogs rescued from the 2024 floods in Rio Grande do Sul, Brazil. Among this, 18 dogs (9%, 18/192) harbored 31 Gram-negative bacteria with potential resistance to carbapenems, which were further identified based on MALDI-TOF/MS and partial 16S-rDNA gene sequencing. Most strains belonged to the genera Pseudomonas (39%, 12/31) followed by Stenotrophomonas (19%, 6/31), with the remaining 42% (13/31) being distributed across other genera. Confirmation of carbapenem resistance was performed using the broth microdilution method to determine the minimum inhibitory concentration of meropenem. This test identified six strains (19%, 6/31) resistant to meropenem, with concentrations ranging from 8 μg/mL to > 128 μg/mL, including three Pseudomonas spp. (8 μg/mL) and three Stenotrophomonas spp. (128 μg/mL). As Stenotrophomonas spp. are potentially intrinsically resistant to meropenem, a phylogenetic analysis based on partial 16S-rDNA gene was conducted only for the three meropenem-resistant Pseudomonas strains. The phylogenetic tree revealed two distinct clades, with two strains clustering with high similarity to P. aeruginosa and one strain with P. huaxiensis. Our findings highlight the importance of monitoring antimicrobial resistance, particularly during climate-related disasters, which may facilitate the dissemination of resistant strains.
病原菌中的抗生素耐药性已成为公共卫生领域的一个重要问题。此外，气候变化增加了细菌感染和病原体传播的风险，对公共卫生构成了严峻挑战。在这些威胁中，耐碳青霉烯类革兰氏阴性菌的出现和传播尤其令人担忧，因为针对这些细菌感染的治疗选择有限且死亡率很高。本研究调查了从巴西南里奥格兰德州2024年洪水中救出的192只犬尿液样本中耐碳青霉烯类革兰氏阴性菌的存在情况。其中，18只犬（9%，18/192）携带了31株对碳青霉烯类可能耐药的革兰氏阴性菌，通过基质辅助激光解吸电离飞行时间质谱（MALDI-TOF/MS）和部分16S核糖体DNA（rDNA）基因测序对其进行了进一步鉴定。大多数菌株属于假单胞菌属（39%，12/31），其次是嗜麦芽窄食单胞菌属（19%，6/31），其余42%（13/31）分布在其他属。使用肉汤微量稀释法测定美罗培南的最低抑菌浓度，以确认碳青霉烯类耐药性。该试验鉴定出6株（19%，6/31）对美罗培南耐药，浓度范围为8μg/mL至>128μg/mL，包括3株假单胞菌属（8μg/mL）和3株嗜麦芽窄食单胞菌属（128μg/mL）。由于嗜麦芽窄食单胞菌属可能对美罗培南具有固有耐药性，仅对3株耐美罗培南的假单胞菌菌株进行了基于部分16S-rDNA基因的系统发育分析。系统发育树显示出两个不同的进化枝，其中两株与铜绿假单胞菌高度相似地聚类，一株与华西假单胞菌聚类。我们的研究结果强调了监测抗菌药物耐药性的重要性，特别是在与气候相关的灾害期间，这可能会促进耐药菌株的传播。
