Cookson Adrian L, Burgess Sara, Midwinter Anne C, Marshall Jonathan C, Moinet Marie, Rogers Lynn, Fayaz Ahmed, Biggs Patrick J, Brightwell Gale
AgResearch Limited, Hopkirk Research Institute, Palmerston North, New Zealand.
mEpiLab, School of Veterinary Sciences, Massey University, Palmerston North, New Zealand.
Environ Microbiol. 2024 Dec;26(12):e70016. doi: 10.1111/1462-2920.70016.
This study investigated the diversity of thermophilic Campylobacter species isolated from three New Zealand freshwater catchments affected by pastoral and urban activities. Utilising matrix-assisted laser desorption ionisation-time of flight and whole genome sequence analysis, the study identified Campylobacter jejuni (n = 46, 46.0%), C. coli (n = 39, 39%), C. lari (n = 4, 4.0%), and two novel Campylobacter species lineages (n = 11, 11%). Core genome sequence analysis provided evidence of prolonged persistence or continuous faecal shedding of closely related strains. The C. jejuni isolates displayed distinct sequence types (STs) associated with human, ruminant, and environmental sources, whereas the C. coli STs included waterborne ST3302 and ST7774. Recombination events affecting loci implicated in human pathogenesis and environmental persistence were observed, particularly in the cdtABC operon (encoding the cytolethal distending toxin) of non-human C. jejuni STs. A low diversity of antimicrobial resistance genes (aadE-Cc in C. coli), with genotype/phenotype concordance for tetracycline resistance (tetO) in three ST177 isolates, was noted. The data suggest the existence of two types of naturalised waterborne Campylobacter: environmentally persistent strains originating from waterbirds and new environmental species not linked to human campylobacteriosis. Identifying and understanding naturalised Campylobacter species is crucial for accurate waterborne public health risk assessments and the effective allocation of resources for water quality management.
本研究调查了从受畜牧和城市活动影响的三个新西兰淡水集水区分离出的嗜热弯曲杆菌物种的多样性。利用基质辅助激光解吸电离飞行时间和全基因组序列分析，该研究鉴定出空肠弯曲杆菌（n = 46，46.0%）、大肠弯曲杆菌（n = 39，39%）、海鸥弯曲杆菌（n = 4，4.0%）以及两个新的弯曲杆菌物种谱系（n = 11，11%）。核心基因组序列分析提供了密切相关菌株长期持续存在或持续粪便排出的证据。空肠弯曲杆菌分离株显示出与人类、反刍动物和环境来源相关的不同序列类型（STs），而大肠弯曲杆菌的STs包括水源性的ST3302和ST7774。观察到影响与人类发病机制和环境持久性相关位点的重组事件，特别是在非人类空肠弯曲杆菌STs的cdtABC操纵子（编码细胞致死性膨胀毒素）中。注意到抗菌抗性基因的多样性较低（大肠弯曲杆菌中的aadE-Cc），在三个ST177分离株中四环素抗性（tetO）的基因型/表型一致性。数据表明存在两种归化的水源性弯曲杆菌：源自水鸟的环境持久性菌株和与人类弯曲杆菌病无关的新环境物种。识别和了解归化的弯曲杆菌物种对于准确的水源性公共卫生风险评估以及水质管理资源的有效分配至关重要。
