There is a general consensus among healthcare leaders that animal production industries should improve practices aiming to mitigate antimicrobial resistance, a significant global threat to public health. However, the epidemiology of antimicrobial resistance in animal production systems is very complex as a result of innumerous sources and dissemination routes of resistant bacteria. Furthermore, antimicrobial resistance can be transferred among bacteria by mobile elements, such as plasmids, which play a major role in the dissemination of antimicrobial resistance. In broiler production, litter contaminated by feces during the production cycle can serve as a potential reservoir for bacteria harboring antimicrobial resistance genes that can then be disseminated to susceptible bacteria. This study reports the effect of 1) different materials used as litter and 2) different litter recycling protocols on the conjugation frequencies of IncIII plasmids harboring extended-spectrum beta-lactamase–resistant genes among Escherichia coli isolates. Results found that, compared with cane bagasse litter, the use of wood shavings as litter decreased the conjugation frequency among E. coli isolates (P < 0.001). In regard to the recycling protocols, the presence of chemical residues in both types of litter materials was associated with a decreased conjugation frequency, with lowest frequencies observed for quicklime and superphosphate. Our findings suggest that the type of material used as poultry litter as well as litter recycling procedures, distinguished by means of chemical compounds, may affect plasmid conjugation among E. coli isolates.

卫生保健领导者之间普遍达成共识，即畜牧业应改善旨在减轻抗菌素耐药性的做法，这是对公共健康的重大全球威胁。然而，由于抗药性细菌的来源和传播途径众多，动物生产系统中抗药性的流行病学非常复杂。此外，可以通过诸如质粒之类的活动元件在细菌之间转移抗药性，其在抗药性的传播中起主要作用。在肉鸡生产中，在生产周期中被粪便污染的垃圾可作为细菌的潜在库，该细菌具有抗菌素抗性基因，然后可传播给易感细菌。大肠杆菌分离物。结果发现，与甘蔗渣垃圾相比，刨花作为垃圾减少了大肠杆菌分离株之间的结合频率（P  <0.001）。关于回收协议，两种类型的垫料中存在化学残留物与降低的共轭频率相关，对于生石灰和过磷酸钙而言观察到的最低频率。我们的发现表明，用作家禽垫料的材料类型以及垫料回收程序（通过化学化合物来区分）可能会影响大肠杆菌分离株之间的质粒结合。