Animal Health Department, NEIKER - Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Bizkaia Science and Technology Park 812L, 48160, Derio, Bizkaia, Spain.
Applied Mathematics Department, NEIKER - Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Bizkaia Science and Technology Park 812L, 48160, Derio, Bizkaia, Spain.
Sci Rep. 2023 Aug 2;13(1):12529. doi: 10.1038/s41598-023-39588-3.
Campylobacter jejuni and Campylobacter coli are important foodborne zoonotic pathogens and cause for concern due to the increasing trend in antimicrobial resistance. A long-run surveillance study was conducted in animals from different age groups in five dairy cattle farms to investigate the within-farm diversity and transmission dynamics of resistant Campylobacter throughout time. The resistance phenotype of the circulating isolates (170 C. jejuni and 37 C. coli) was determined by broth microdilution and a selection of 56 isolates were whole genome sequenced using the Oxford-Nanopore long-fragment sequencing technology resulting in completely resolved and circularized genomes (both chromosomes and plasmids). C. jejuni was isolated from all farms while C. coli was isolated from only two farms, but resistance rates were higher in C. coli than in C. jejuni and in calves than in adult animals. Some genotypes (e.g. ST-48, gyrA_T86I/tet(O)/bla in farm F1; ST-12000, aadE-Cc/tet(O)/bla in F4) persisted throughout the study while others were only sporadically detected. Acquisition of extracellular genes from other isolates and intracellular mutational events were identified as the processes that led to the emergence of the resistant genotypes that spread within the herds. Monitoring with Oxford Nanopore Technologies sequencing helped to decipher the complex molecular epidemiology underlying the within-farm dissemination of resistant Campylobacter.
空肠弯曲菌和结肠弯曲菌是重要的食源性病原体，由于其抗药性呈上升趋势，因此引起了人们的关注。在五个奶牛场的不同年龄组的动物中进行了一项长期监测研究，以调查整个农场中耐药弯曲菌的场内多样性和传播动态。通过肉汤微量稀释法测定了循环分离株（170 株空肠弯曲菌和 37 株结肠弯曲菌）的耐药表型，选择了 56 株分离株进行牛津纳米孔长片段测序技术的全基因组测序，得到了完全解析和环状的基因组（染色体和质粒）。所有农场都分离出空肠弯曲菌，而只有两个农场分离出结肠弯曲菌，但结肠弯曲菌的耐药率高于空肠弯曲菌，犊牛的耐药率高于成年动物。一些基因型（例如 F1 场的 ST-48、gyrA_T86I/tet(O)/bla 和 F4 场的 ST-12000、aadE-Cc/tet(O)/bla）在整个研究期间持续存在，而其他基因型则只是偶尔检测到。从其他分离株获得细胞外基因和细胞内突变事件被确定为导致在畜群中传播的耐药基因型出现的过程。使用牛津纳米孔技术测序进行监测有助于解析耐药弯曲菌在农场内传播的复杂分子流行病学。
