The increase and spread of antimicrobial resistance, particularly multidrug resistance (MDR), in Salmonella isolated from food animal pose a serious public health concern worldwide. Therefore, the objective of this study was to characterize antimicrobial resistance and analyze the transferability of integrons and antimicrobial resistance genes in MDR Salmonella isolates from retail chicken meat in Korea. Among the 57 Salmonella isolates, 43 (75.4%) showed resistance to at least 1 antimicrobial agent and 29 (50.9%) exhibited MDR. The highest resistance was to nalidixic acid (73.7%), ampicillin (50.9%), tetracycline (42.1%), chloramphenicol (33.3%), and trimethoprim/sulfamethoxazole (33.3%). β-lactamase–encoding genes were detected in 9 (31.0%) of 29 β-lactam–resistant isolates. These genes were as follows: bla_CMY-2 (1 S. Albany), bla_CTX-M-79 (1 S. Virchow), and bla_CTX-M-15 (6 S. Virchow and 1 S. Enteritidis). Seventeen (70.8%) of the 24 tetracycline-resistant isolates harbored only tetA. Among the 19 trimethoprim/sulfamethoxazole-resistant isolates, sul1 was only identified in 3 (68.4%) isolates. cmlA was detected in 4 (21.1%) of the 19 chloramphenicol-resistant isolates. Both aminoglycoside-resistant isolates were positive for ant(2″)-I. Class 1 integrons were observed in 28 (49.1%) isolates belonging to S. Albany (21 isolates), S. Virchow (6 isolate), and S. Enteritidis (1 isolate). All 29 MDR isolates carried one or more integrons and antimicrobial resistance genes. All isolates harboring the ESBL and pAmpC genes exhibited resistance to at least 4 different classes of antimicrobials, including cephalosporins and noncephalosporins. Furthermore, most (79.3%) of the MDR isolates carried 1 or 2 of conjugable plasmids, and the transfer of integrons and resistance genes via plasmids was confirmed in transconjugants, which showed resistance patterns similar to those of the donor strains.

从食用动物分离出的沙门氏菌中，抗菌素耐药性，特别是多药耐药性（MDR）的增加和传播引起了全世界严重的公共卫生关注。因此，本研究的目的是表征抗药性，并分析韩国零售鸡肉中MDR沙门氏菌分离株中整合素和抗药性基因的可转移性。在57株沙门氏菌中分离株中，有43株（75.4％）表现出对至少一种抗菌剂的耐药性，29株（50.9％）表现出耐多药耐药性。耐性最高的是萘啶酸（73.7％），氨苄青霉素（50.9％），四环素（42.1％），氯霉素（33.3％）和甲氧苄啶/磺胺甲恶唑（33.3％）。在29株抗β-内酰胺酶的菌株中，有9株（31.0％）检测到了β-内酰胺酶编码基因。这些基因如下：bla _CMY-2（1  S.奥尔巴尼），bla _CTX-M-79（1  S. Virchow）和bla _CTX-M-15（6  S. Virchow和1  S. Enteritidis）。24种四环素抗性菌株中有17种（70.8％）仅含有tetA。在19株耐甲氧苄氨嘧啶/磺胺甲基异恶唑的菌株中，仅在3株（68.4％）菌株中发现了sul1。在19株耐氯霉素分离株中，有4株（21.1％）检测到了cmlA。两种对氨基糖苷具有抗性的分离株均对ant（2''）- I呈阳性。在28（49.1％）中观察到1类整合株属于S.奥尔巴尼（21株），S.菲尔绍（6分离物），和S.肠炎（1个分离物）。所有29种MDR分离物均带有一个或多个整合素和抗菌素耐药基因。所有带有ESBL和pAmpC的分离株这些基因对至少4种不同类型的抗菌素（包括头孢菌素和非头孢菌素）表现出抗药性。此外，大多数（79.3％）的MDR分离物带有1或2个可接合的质粒，并且在转接合子中证实了整合素和抗性基因通过质粒的转移，显示出与供体菌株相似的抗性模式。