College of Veterinary Medicine & Zoonoses Research Institute, Kyungpook National University, Daegu, Republic of Korea.
Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, Mississippi State, USA.
Microb Drug Resist. 2021 Oct;27(10):1443-1449. doi: 10.1089/mdr.2020.0028. Epub 2021 Jul 23.
Linezolid (LNZ) is one of the most important antimicrobial agents against infections caused by gram-positive bacteria, including enterococci. In a layer operation system, antimicrobial resistance can be transferred to commercial layers via the fecal-oral route. This study investigated the presence and distribution of LNZ-resistant and in a layer operation system. Among 117 and 154 , 10 (8.5%) and 5 (3.2%) isolates showed resistance to LNZ and chloramphenicol, and they exhibited multidrug resistance against 5 or more classes of antimicrobial agents. Among the resistant isolates, 9 (90.0%) and 2 (20.0%) harbored and genes, respectively. The and genes were not detected in five LNZ-resistant . None of the 15 LNZ-resistant isolates harbored the gene, and no mutations were observed in the genes encoding domain V of 23S ribosomal RNA (rRNA) and ribosomal proteins L3 () and L4 (). Transferability was identified in three of the nine -positive LNZ-resistant isolates. The , , and genes were cotransferred with the gene in all -positive transconjugants. The results indicate that is well-distributed in , implying a greater level of transferability. Thus, enhanced surveillance efforts are needed to monitor the emergence and spread of in enterococci in layer operation system.
利奈唑胺（LNZ）是对抗革兰氏阳性菌感染的最重要的抗菌药物之一，包括肠球菌。在层流操作系统中，抗菌药物耐药性可以通过粪-口途径转移到商业鸡群中。本研究调查了层流操作系统中 LNZ 耐药 和 的存在和分布。在 117 株 和 154 株 中，有 10 株（8.5%）和 5 株（3.2%）分离株对 LNZ 和氯霉素表现出耐药性，它们对 5 种或更多类别的抗菌药物表现出多重耐药性。在耐药分离株中，分别有 9 株（90.0%）和 2 株（20.0%）携带 和 基因。在 5 株 LNZ 耐药 中未检测到 和 基因。在 15 株 LNZ 耐药分离株中均未检测到 基因，也未观察到 23S 核糖体 RNA（rRNA）和核糖体蛋白 L3（）和 L4（）编码结构域 V 中的基因突变。在 9 株 阳性 LNZ 耐药分离株中有 3 株可转移。在所有 阳性转导子中， 、 和 基因与 基因一起被共转移。结果表明， 在 中分布广泛，表明其具有更高的转移能力。因此，需要加强监测工作，以监测层流操作系统中肠球菌中 的出现和传播。
