Mateus-Vargas Rafael Hernán, Arias-Pérez Verónica, Sandoval-Hernández Iván, Hammerl Jens Andre, Barquero-Calvo Elías
Department of Animal Sciences, University of Göttingen, Göttingen, Germany.
Escuela de Ciencias Biológicas, Universidad Nacional, Heredia, Costa Rica.
Front Vet Sci. 2024 Apr 5;11:1374677. doi: 10.3389/fvets.2024.1374677. eCollection 2024.
Apex predators are exposed to antimicrobial compounds and resistant microbes, which accumulate at different trophic levels of the related ecosystems. The study aimed to characterize the presence and the antimicrobial resistance patterns of fecal isolated from cloacal swab samples obtained from wild-living American crocodiles () ( = 53). Sampling was conducted within the distinctive context of a freshwater-intensive aquaculture farm in Costa Rica, where incoming crocodiles are temporarily held in captivity before release. Phenotypic antimicrobial susceptibility profiles were determined in all isolates, while resistant isolates were subjected to whole-genome sequencing and bioinformatics analyses. In total, 24 samples contained tetracycline-resistant (45.3%). Isolates carried either (A), (B), or (C) genes. Furthermore, genes conferring resistance to ß-lactams, aminoglycosides, fosfomycin, sulfonamides, phenicol, quinolones, trimethoprim, and colistin were detected in single isolates, with seven of them carrying these genes on plasmids. Genome sequencing further revealed that sequence types, prevalence of antibiotic resistance carriage, and antibiotic resistance profiles differed between the individuals liberated within the next 24 h after their capture in the ponds and those liberated from enclosures after longer abodes. The overall presence of tetracycline-resistant , coupled with potential interactions with various anthropogenic factors before arriving at the facilities, hinders clear conclusions on the sources of antimicrobial resistance for the studied individuals. These aspects hold significant implications for both the aquaculture farm's biosecurity and the planning of environmental monitoring programs using such specimens. Considering human-crocodile conflicts from the One Health perspective, the occurrence of antimicrobial resistance underscores the importance of systematical surveillance of antibiotic resistance development in American crocodiles.
顶级捕食者会接触到抗菌化合物和耐药微生物，这些物质会在相关生态系统的不同营养级中积累。本研究旨在描述从野生美洲鳄（Crocodylus acutus）（n = 53）泄殖腔拭子样本中分离出的粪便微生物的存在情况及其抗菌耐药模式。采样是在哥斯达黎加一个淡水密集型水产养殖场的特殊背景下进行的，捕获的鳄鱼在放生前会被暂时圈养在养殖场中。对所有分离菌株进行了表型抗菌药敏分析，对耐药菌株进行了全基因组测序和生物信息学分析。总共24个样本含有耐四环素的微生物（45.3%）。分离菌株携带tet(A)、tet(B)或tet(C)基因。此外，在单个分离菌株中检测到了赋予对β-内酰胺类、氨基糖苷类、磷霉素、磺胺类、氯霉素、喹诺酮类、甲氧苄啶和黏菌素耐药的基因，其中7个菌株在质粒上携带这些基因。基因组测序进一步显示，在池塘中捕获后24小时内放生的个体与在围栏中停留较长时间后放生的个体之间，序列类型、抗生素耐药性携带率和抗生素耐药谱存在差异。耐四环素微生物的总体存在，以及在到达养殖场之前与各种人为因素的潜在相互作用，使得难以明确确定所研究个体的抗菌耐药性来源。这些方面对水产养殖场的生物安全以及使用此类样本的环境监测计划的规划都具有重要意义。从“同一健康”的角度考虑人与鳄鱼的冲突，抗菌耐药性的出现凸显了系统监测美洲鳄抗生素耐药性发展的重要性。
