Infectious Disease and Microbiome Program, Genomic Center for Infectious Diseases, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.
Department of Ophthalmology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA.
Appl Environ Microbiol. 2019 Oct 30;85(22). doi: 10.1128/AEM.01559-19. Print 2019 Nov 15.
Industrial farms are unique, human-created ecosystems that provide the perfect setting for the development and dissemination of antibiotic resistance. Agricultural antibiotic use amplifies naturally occurring resistance mechanisms from soil ecologies, promoting their spread and sharing with other bacteria, including those poised to become endemic within hospital environments. To better understand the role of enterococci in the movement of antibiotic resistance from farm to table to clinic, we characterized over 300 isolates of cultured from raw chicken meat purchased at U.S. supermarkets by the Consumers Union in 2013. and were the predominant species found, and antimicrobial susceptibility testing uncovered striking levels of resistance to medically important antibiotic classes, particularly from classes approved by the FDA for use in animal production. While nearly all isolates were resistant to at least one drug, bacteria from meat labeled as raised without antibiotics had fewer resistances, particularly for Whole-genome sequencing of 92 isolates revealed that both commensal- and clinical-isolate-like enterococcal strains were associated with chicken meat, including isolates bearing important resistance-conferring elements and virulence factors. The ability of enterococci to persist in the food system positions them as vehicles to move resistance genes from the industrial farm ecosystem into more human-proximal ecologies. Bacteria that contaminate food can serve as a conduit for moving drug resistance genes from farm to table to clinic. Our results show that chicken meat-associated isolates of are often multidrug resistant, closely related to pathogenic lineages, and harbor worrisome virulence factors. These drug-resistant agricultural isolates could thus represent important stepping stones in the evolution of enterococci into drug-resistant human pathogens. Although significant efforts have been made over the past few years to reduce the agricultural use of antibiotics, continued assessment of agricultural practices, including the roles of processing plants, shared breeding flocks, and probiotics as sources for resistance spread, is needed in order to slow the evolution of antibiotic resistance. Because antibiotic resistance is a global problem, global policies are needed to address this threat. Additional measures must be taken to mitigate the development and spread of antibiotic resistance elements from farms to clinics throughout the world.
工业化农场是独特的人为生态系统，为抗生素耐药性的发展和传播提供了绝佳的环境。农业抗生素的使用放大了土壤生态中自然存在的耐药机制，促进了它们的传播和与其他细菌的共享，包括那些有可能成为医院环境中地方性的细菌。为了更好地了解肠球菌在抗生素耐药性从农场到餐桌再到临床的传播中的作用，我们对 2013 年由消费者联盟在美国超市购买的生鸡肉中培养的 300 多个分离株进行了表征。屎肠球菌和粪肠球菌是主要发现的物种，抗菌药物敏感性测试发现它们对重要的抗生素类别具有惊人的耐药性，特别是对 FDA 批准用于动物生产的抗生素类别。虽然几乎所有分离株都至少对一种药物具有耐药性，但标签为无抗生素饲养的肉类中的细菌耐药性较少，特别是对于全基因组测序的 92 个分离株，发现既有益生又有临床相似的肠球菌菌株与鸡肉有关，包括携带重要耐药基因和毒力因子的分离株。肠球菌在食品系统中持续存在的能力使它们成为将耐药基因从工业农场生态系统转移到更接近人类的生态系统的载体。污染食物的细菌可以作为将耐药基因从农场转移到餐桌再转移到临床的媒介。我们的研究结果表明，与鸡肉相关的肠球菌分离株通常具有多重耐药性，与致病性谱系密切相关，并携带令人担忧的毒力因子。因此，这些具有耐药性的农业分离株可能是肠球菌进化为耐药性人类病原体的重要垫脚石。尽管过去几年在减少农业抗生素使用方面做出了重大努力，但仍需要继续评估农业实践，包括加工厂、共享繁殖鸡群和益生菌作为耐药传播来源的作用，以减缓抗生素耐药性的进化。由于抗生素耐药性是一个全球性问题，需要制定全球政策来应对这一威胁。必须采取额外措施，以减轻世界各地从农场到诊所的抗生素耐药性元素的发展和传播。
