This study analyzed fresh feces from three common bird species that live in urban environments and interact with human communities. Antibiotic resistance genes (ARGs) encoding resistance to three major classes of antibiotics (i.e., tetracyclines, β-lactams, and sulfonamides) and the mobile genetic element integrase gene (intI1) were abundant (up to 10⁹, 10⁸, 10⁹, and 10¹⁰ copies/g dry feces for tetW, bla_TEM, sul1, and intI1, respectively), with relative concentrations surprisingly comparable to that in poultry and livestock that are occasionally fed antibiotics. Biomarkers for opportunistic pathogens were also abundant (up to 10⁷ copies/g dry feces) and the dominant isolates (i.e., Enterococcus spp. and Pseudomonas aeruginosa) harbored both ARGs and virulence genes. ARGs in bird feces followed first-order attenuation with half-lives ranging from 1.3 to 11.1 days in impacted soil. Although residual antibiotics were detected in the feces, no significant correlation was observed between fecal antibiotic concentrations and ARG relative abundance. Thus, other unaccounted factors likely contributed selective pressure for ARG maintenance. These findings highlight the contribution of wild urban bird feces to the maintenance and dissemination of ARGs, and the associated health risks.

这项研究分析了生活在城市环境中并与人类社区互动的三种常见鸟类的新鲜粪便。抗生素抗性基因（参数）编码的抗生素三大类（即，四环素类，β内酰胺，和磺胺）和整合酶基因（移动遗传元件电阻intI1）较丰富（最多10 ⁹，10 ⁸，10 ⁹，和10 ¹⁰拷贝/克干粪便，用于tetW，bla _TEM，sul1和intI1，其相对浓度令人惊讶地与偶尔喂食抗生素的家禽和家畜相当。机会病原体的生物标志物也很丰富（最多10 ⁷拷贝/克干粪便）和主要分离物（即肠球菌和铜绿假单胞菌））包含ARGs和毒力基因。鸟类粪便中的ARGs受到一阶衰减，在受影响的土壤中半衰期为1.3到11.1天。尽管在粪便中检测到残留抗生素，但粪便抗生素浓度与ARG相对丰度之间未发现显着相关性。因此，其他无法解释的因素可能会为ARG维护贡献选择性压力。这些发现强调了城市野生禽粪对ARGs的维持和传播的贡献以及相关的健康风险。