Phenotypic zinc resistance does not correlate with antimicrobial multi-resistance in fecal E. coli isolates of piglets
Phenotypic zinc resistance does not correlate with antimicrobial multi-resistance in fecal E. coli isolates of piglets
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DOI：
10.1186/s13099-019-0342-5
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发表时间：
2020-01-21
期刊：
影响因子：
4.2
通讯作者：
Guenther, Sebastian
中科院分区：
文献类型：
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作者：
Ghazisaeedi, Fereshteh;Ciesinski, L.;Guenther, Sebastian
背景在欧盟禁止在畜牧业中使用抗菌剂促进生长后，建议使用非抗菌剂，包括重金属离子（如锌和铜）、益生元或益生菌作为替代品。锌已广泛用于养猪业，特别是在仔猪断奶期间，以改善动物健康和生长速度。然而，最近的研究表明，仔猪断奶期间高锌饲料喂养增加了多重耐药大肠杆菌的比例。大肠杆菌，禁忌锌作为替代品的适当性。锌对耐药细菌影响的潜在机制尚不清楚，但可能涉及共选择过程。在这项研究中，我们确定是否E。大肠杆菌菌株从肠道内容物的仔猪，已补充了高浓度的锌获得了较高的耐受性，对锌，以及是否多药耐药菌株耐受较高的锌浓度。此外，我们还比较了E.大肠杆菌分离株对不同二价离子金属的表型抗性/耐受性之间可能存在相关性。结果对210株耐药、多重耐药和非耐药大肠埃希菌进行锌/铜耐药表型筛选。大肠杆菌），通过测定锌/铜最小抑制浓度（Merlin，Bornheim-Hersel，德国）。在这两个试验中，仔猪组补充高饮食锌（> 2000 ppm）或对照（50-70 ppm，背景）浓度。我们的观察表明，高浓度锌暴露没有影响的锌或铜的表型耐受性的E。从动物身上分离的大肠杆菌。相同菌株的抗菌素耐药性和表型锌/铜耐受性之间没有显着关联。结论断奶仔猪饲粮补锌后抗菌药物耐药性和锌耐受性的协同选择机制不成立。对高锌饮食喂养仔猪中多药耐药分离株增加的解释可能是，对抗菌剂的耐药细菌对锌或铜暴露等应激更持久。
Background Following the ban on antimicrobial usage for growth promotion in animal husbandry in the EU, non-antimicrobial agents including heavy metal ions (e.g. zinc and copper), prebiotics or probiotics have been suggested as alternatives. Zinc has extensively been used in pig farming, particularly during weaning of piglets to improve animal health and growth rates. Recent studies, however, have suggested that high dietary zinc feeding during weaning of piglets increases the proportion of multi-drug resistant E. coli in the gut, contraindicating the appropriateness of zinc as an alternative. The underlying mechanisms of zinc effects on resistant bacteria remains unclear, but co-selection processes could be involved. In this study, we determined whether E. coli isolates from intestinal contents of piglets that had been supplemented with high concentrations of zinc acquired a higher tolerance towards zinc, and whether multi-drug resistant isolates tolerated higher zinc concentrations. In addition, we compared phenotypic zinc and copper resistance of E. coli isolates for possible correlation between phenotypic resistance/tolerance to different bivalent ionic metals. Results We screened phenotypic zinc/copper tolerance of 210 isolates (including antimicrobial resistant, multi-drug resistant, and non-resistant E. coli) selected from two, independent zinc-feeding animal trials by determining a zinc/copper minimal inhibitory concentration (Merlin, Bornheim-Hersel, Germany). In both trials, groups of piglets were supplemented either with high dietary zinc (> 2000 ppm) or control (50-70 ppm, background) concentrations. Our observations showed that high concentration zinc exposure did not have an effect on either zinc or copper phenotypic tolerance of E. coli isolates from the animals. No significant association was found between antimicrobial resistance and phenotypic zinc/copper tolerance of the same isolates. Conclusion Our findings argue against a co-selection mechanism of antimicrobial drug-resistance and zinc tolerance after dietary zinc supplementation in weaning piglets. An explanation for an increase in multi-drug resistant isolates from piglets with high zinc dietary feeding could be that resistant bacteria to antimicrobial agents are more persistent to stresses such as zinc or copper exposure.