Human population and activities play an important role in dissemination of antimicrobial resistant bacteria. This study investigated the relationship between carriage rates of critically important antimicrobial-resistant (CIA-R) Escherichia coli and Klebsiella pneumoniae by Silver Gulls and their proximity to human populations. Faecal swabs (n=229) were collected from Silver Gulls across 10 southern coastline locations in Western Australia (WA). The sampling locations included main town centres and remote areas. Fluoroquinolone and extended-spectrum cephalosporin-resistant E. coli and K. pneumoniae were isolated and tested for antimicrobial sensitivity. Genome sequencing was performed to validate phenotypic resistance profiles and determine the molecular characteristics of strains. CIA-R E. coli and K. pneumoniae were detected in 69 (30.1%) and 20 (8.73%) of the faecal swabs respectively. Two large urban locations tested positive for CIA-R E. coli (frequency ranging from 34.3%-84.3%), and/or for CIA-R K. pneumoniae (frequency ranging from 12.5%-50.0%). A small number of CIA-R E. coli (3/31, 9.7%) were identified at a small tourist town, but no CIA-R bacteria were recovered from gulls at remote sites. Commonly detected E. coli sequence types (STs) included ST131 (12.5%) and ST1193 (10.0%), and five K. pneumoniae STs were found. Resistance genes including bla_CTX-M-3, bla_CTX-M-15 and bla_CTX-M-27 were identified in both bacterial species. High-level colonisation of CIA-R E. coli and K. pneumoniae in Silver Gulls in and around urban areas compared to remote locations substantiates that anthropogenic activities are strongly associated with acquisition of resistant bacteria by gulls.

中文翻译：

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靠近人类住区与在银鸥中携带极其重要的抗微生物大肠杆菌和肺炎克雷伯菌直接相关

人口和活动在抗微生物药物耐药性细菌的传播中起着重要作用。本研究调查了银鸥携带极其重要的抗微生物 (CIA-R)大肠杆菌和肺炎克雷伯菌的携带率与其与人群的接近程度之间的关系。粪便拭子 (n=229) 从西澳大利亚 (WA) 的 10 个南部海岸线位置的 Silver Gulls 收集。抽样地点包括主要城镇中心和偏远地区。氟喹诺酮类和超广谱头孢菌素耐药性大肠杆菌和肺炎克雷伯菌被隔离并测试其抗菌敏感性。进行基因组测序以验证表型抗性谱并确定菌株的分子特征。CIA-R大肠杆菌和肺炎克雷伯菌分别在 69 个（30.1%）和 20 个（8.73%）的粪便拭子中检测到。两个大城市的 CIA-R大肠杆菌检测呈阳性（频率范围为 34.3%-84.3%）和/或 CIA-R肺炎克雷伯菌（频率范围为 12.5%-50.0%）。在一个旅游小镇发现了少量CIA-R大肠杆菌（3/31，9.7%），但在偏远地区的海鸥中没有发现 CIA-R 细菌。常见的大肠杆菌序列类型（STs）包括ST131（12.5%）和ST1193（10.0%），发现5个肺炎克雷伯菌STs。在两种细菌物种中鉴定了包括bla _CTX-M-3、bla _CTX-M-15和bla _CTX-M-27的抗性基因。与偏远地区相比，CIA-R大肠杆菌和肺炎克雷伯氏菌在城市地区和周边地区的高水平定植证实了人为活动与海鸥获得抗药性细菌密切相关。