摘要
      质粒介导的粘菌素和超广谱β-内酰胺酶（ESBL）耐药基因的出现影响了粘菌素类和β-内胺类药物（如第3代、第4代头孢菌素）的疗效。本研究旨在调查巴基斯坦产肉商品肉鸡大肠杆菌分离株中的抗微生物基因（ARGs）。在2018年1月至2019年8月期间采集了200份粪便样本。为了分离大肠杆菌，将MacConkey琼脂上的粉红色菌落转移到EMB琼脂上。使用API-20E试剂盒对金属光泽色菌落进行生化测试。通过聚合酶链式反应（PCR）扩增uid基因和不同的ARGs，即庆大霉素、链霉素、四环素、粘菌素、β-内酰胺类药物、喹诺酮和氨苄青霉素，然后进行序列分析，从而对大肠杆菌（n=153）进行分子鉴定。分离的PCR证实的大肠杆菌（153）对庆大霉素（aac（3）-IV）、链霉素（aadA1）、四环素（tetA）、大肠杆菌（mcr-1）、氨苄青霉素（bla-TEM）和bla-CTX-M的耐药ARGs的基因型和表型分别为86%、88%、86%、88%，83%和77%。33/38（86%）的分离物对喹诺酮类药物的耐药性呈阳性。大肠杆菌（mcr-1）、ESBLs（bla-TEM）和（bla-CTX-M）抗性基因分别为88%、83%和77%。大约33株分离的大肠杆菌同时携带mcr-1和ESBLs基因。所有大肠杆菌分离株均对头孢曲松（CTX-30）和亚胺培南（IMP-10）敏感。分离的大肠杆菌表现出单支或多支的衰退性。大肠杆菌和ARGs序列显示出单支或多支的衰退性。这是来自巴基斯坦的第一项全面研究，描述了ARGs及其在源自商业家禽的单个分离株中共存的分子证据。商品鸡（肉鸡）可以作为人类抗生素抗性基因的熔炉。由于巴基斯坦对抗菌药物的处方进行了更多的监管，抗生素耐药性监测项目的情况令人担忧
Abstract
Emergence of plasmid mediated colistin and extended spectrum β-lactamases (ESBL) resistant genes has been impacted the efficacy of colistin and β-lactams drugs like 3rd, 4th generation cephalosporin. Current study was aimed to investigate antimicrobial resistance genes (ARGs) among Escherichia coli isolates from meat producing commercial broilers in Pakistan. Two hundred (n=200) fecal samples were collected during January-2018 to August-2019. For isolation of E. coli, pink colonies on MacConkey agar were transferred to EMB agar. Metallic sheen color colonies were tested biochemically using API-20E kit. The molecular identification of E. coli (n=153) was targeted by amplification of uid gene through polymerase chain reaction (PCR) and different ARGs i.e. gentamicin, streptomycin, tetracycline, colistin, β-lactams drugs, quinolone and ampicillin followed by sequence analysis. Genotypically, followed by phenotypically of resistant ARGs of isolated PCR-confirmed E. coli (153) shoed resistant against gentamicin (aac(3)-IV), streptomycin (aadA1), tetracycline (tetA), colistine (mcr-1), ampicillin (bla-TEM) and bla-CTX-M were 86%, 88%, 86%, 88%, 83% & 77% respectively. 33/38 (86%) of the isolate was positive for quinolone resistance. Colistine (mcr-1), ESBLs (bla-TEM) and (bla-CTX-M) resistance genes were 88%, 83% and 77% respectively. About 33 isolated E. coli harbored the both mcr-1 and ESBLs genes. All of E. coli isolates were found sensitive to ceftriaxone (CTX-30) and imipenem (IMP-10). The Isolated E. coli showed single or multi clade decadency. The E. coli and ARGs sequences showed single or multi clade decadency. This is first comprehensive study from Pakistan that described the molecular evidences of ARGs and their co-existence in single isolates originated from commercial poultry. Commercial chicken (Broilers) can act as melting pot of antibiotic resistance genes for human being. It is alarming situation for surveillance of antibiotic resistance program because of more regulated prescription of antimicrobial agents in Pakistan

https://www.scielo.br/j/bjb/a/xjkR6rrvntvyGBKyGnVC8gN/abstract/?lang=en