Lim Kelvin, Pennell Michael, Lewis Stephanie, El-Gazzar Mohamed, Gebreyes Wondwossen A
Veterinary Health Management Branch, National Parks Board, 6 Perahu Road, Singapore 718827.
Division of Biostatistics, College of Public Health, The Ohio State University, 1841 Neil Ave, 246 Cunz Hall, Columbus, OH 43210, USA.
JAC Antimicrob Resist. 2021 Mar 11;3(1):dlab022. doi: 10.1093/jacamr/dlab022. eCollection 2021 Mar.
Early studies suggested that flavophospholipol has plasmid-curing effects and could inhibit conjugation by disrupting pilus formation between bacteria.
This 36-day controlled-challenge study aimed to evaluate the anti-conjugative and plasmid-curing effect of flavophospholipol on plasmid-mediated antimicrobial resistance (AMR) in MDR transconjugant Enteritidis in chickens.
A total of 270-day-old chicks were randomly assigned to four control and four treatment groups with two doses of in-feed flavophospholipol (10 ppm and 64 ppm) and in the presence and absence of ampicillin in drinking water. Chicks were orally challenged with Enteritidis with known plasmid-encoded AMR factors. Cloacal swabs were collected on Day 7, 14 and 23. On Day 35, all chickens were euthanized, and caecal tissue and content were collected. Antimicrobial susceptibility testing was done with a panel of 12 antimicrobials and interpreted according to CLSI breakpoints.
Flavophospholipol given in-feed at 64 ppm had an anti-conjugative effect. There was a significant reduction of acquisition of resistance to ampicillin, streptomycin and tetracycline by the recipient strains of Enteritidis in treatment groups given flavophospholipol in-feed at 64 ppm (0.05). This was not seen with flavophospholipol given in-feed at 10 ppm.
The results demonstrate that flavophospholipol given in-feed at 64 ppm had an anti-conjugative effect. The results also suggest that AMR is reduced through other mechanisms of action, which are yet to be determined. There is insufficient evidence that flavophospholipol at 64 ppm in feed alone or with sub-therapeutic levels of antibiotics had a plasmid-curing effect.
早期研究表明，黄霉素具有质粒消除作用，可通过破坏细菌间菌毛形成来抑制接合作用。
这项为期36天的对照挑战研究旨在评估黄霉素对鸡多重耐药转导接合型肠炎沙门氏菌中质粒介导的抗菌药物耐药性（AMR）的抗接合和质粒消除作用。
将总共270只日龄雏鸡随机分为四个对照组和四个处理组，在饮水中添加或不添加氨苄青霉素的情况下，饲料中添加两剂量的黄霉素（10 ppm和64 ppm）。用已知携带质粒编码AMR因子的肠炎沙门氏菌对雏鸡进行口服攻毒。在第7、14和23天收集泄殖腔拭子。在第35天，对所有鸡实施安乐死，并收集盲肠组织和内容物。使用一组12种抗菌药物进行药敏试验，并根据CLSI标准进行解读。
饲料中添加64 ppm的黄霉素具有抗接合作用。在饲料中添加64 ppm黄霉素的处理组中，肠炎沙门氏菌受体菌株对氨苄青霉素、链霉素和四环素的耐药性获得显著降低（P<0.05）。饲料中添加10 ppm黄霉素时未观察到这种情况。
结果表明，饲料中添加64 ppm的黄霉素具有抗接合作用。结果还表明，AMR通过其他尚未确定的作用机制降低。没有足够的证据表明，单独在饲料中添加64 ppm的黄霉素或与亚治疗水平的抗生素联合使用具有质粒消除作用。
