Austrian Agency for Health and Food Safety (AGES GmbH), Data, Statistics, Integrative Risk Assessment, Spargelfeldstrasse 191, A-1220 Wien, Austria.
Austrian Agency for Health and Food Safety (AGES GmbH), Data, Statistics, Integrative Risk Assessment, Spargelfeldstrasse 191, A-1220 Wien, Austria.
Prev Vet Med. 2019 Nov 1;171:104755. doi: 10.1016/j.prevetmed.2019.104755. Epub 2019 Aug 27.
The prevalence of antimicrobial resistance in commensal Escherichia coli isolated from organically raised broiler flocks was compared to the prevalence in isolates from conventional flocks. From 2010 to 2014, and in 2016, resistance trends and multidrug resistance in isolates from the caecal contents of flocks from both broiler production forms were analyzed. Samples were taken in four abattoirs accounting for at least 90% of the national slaughtered broiler population. In total, 962 commensal E. coli were obtained from organically raised broiler flocks (n = 142) and from conventionally raised broiler flocks (n = 820). The mean prevalence of commensal E. coli isolates, which were fully susceptible to the antimicrobials tested, was 43.3% in organically raised broiler flocks and thus significantly higher (P < 0.001) compared to 16.7% in conventionally operated flocks. During the study period, the proportion of fully susceptible isolates increased significantly in both broiler populations. Antimicrobial resistance rates were significantly lower in commensal E. coli isolated from organic compared to conventional production regarding ciprofloxacin (33.3% versus 69.1%), nalidixic acid (33.7% versus 67.4%), sulfamethoxazole (26.7% versus 39.9%), ampicillin (19.0% versus 33.8%) and trimethoprim (12.8% versus 24.9%). Regarding tetracycline, tigecycline and ceftazidime resistance rates were slightly but not significantly higher in isolates from organic flocks (27.6% versus 25.9%; 4.0% versus 1.4%; 2.0% versus 1.9%). This fact is surprising for tetracycline, as none of the investigated organic flocks had been treated with this antimicrobial during their lifetime. No resistances were found in isolates from both production forms against colistin and meropenem, and from organic flocks against azithromycin. The annual prevalence of resistance against ciprofloxacin and nalidixic acid decreased significantly in isolates from both broiler production forms. In isolates from organic flocks, it also decreased regarding ampicillin and sulfamethoxazole. Significant increasing trends were observed in the resistance prevalence against trimethoprim and borderline significantly for ampicillin in commensal E. coli from conventional flocks. Multidrug resistance was detected at a significantly higher prevalence in isolates from conventionally raised flocks (35.1%) compared to organic flocks (22.7%). Findings from this study clearly indicate the influences of organic compared to conventional broiler production practices on the prevalence of antimicrobial resistance in commensal E. coli from broiler flocks.
本研究比较了有机饲养肉鸡群与传统饲养肉鸡群中分离的共生大肠杆菌的抗药性流行情况。2010 年至 2014 年以及 2016 年，分析了来自这两种肉鸡生产形式鸡群盲肠内容物中分离物的耐药趋势和多药耐药性。样本取自至少占全国肉鸡屠宰量 90%的 4 个屠宰场。共从有机饲养的肉鸡群（n=142）和传统饲养的肉鸡群（n=820）中获得了 962 株共生大肠杆菌。完全耐受所检测抗生素的共生大肠杆菌分离株的总体流行率在有机饲养的肉鸡群中为 43.3%，显著高于（P<0.001）传统饲养肉鸡群中的 16.7%。在研究期间，两种肉鸡群体中完全敏感的分离株比例均显著增加。与传统生产相比，有机生产中分离的共生大肠杆菌对抗生素的耐药率显著降低，如环丙沙星（33.3%对 69.1%）、萘啶酸（33.7%对 67.4%）、磺胺甲恶唑（26.7%对 39.9%）、氨苄西林（19.0%对 33.8%）和甲氧苄啶（12.8%对 24.9%）。然而，关于四环素、替加环素和头孢他啶的耐药率，有机鸡群分离株略高，但无统计学意义（27.6%对 25.9%；4.0%对 1.4%；2.0%对 1.9%）。这一事实令人惊讶，因为在整个生命周期中，没有任何一个调查的有机鸡群使用过这种抗生素。两种生产形式的分离株均未发现对黏菌素和美罗培南的耐药性，且有机鸡群分离株也未发现对阿奇霉素的耐药性。两种生产形式的分离株对环丙沙星和萘啶酸的耐药率均显著下降。在有机鸡群中，氨苄西林和磺胺甲恶唑的耐药率也有所下降。在传统饲养的肉鸡群中，分离株对甲氧苄啶的耐药率呈显著上升趋势，对氨苄西林的耐药率呈边缘显著上升趋势。与有机鸡群相比，传统饲养鸡群中分离的共生大肠杆菌的多重耐药性明显更高（35.1%）。本研究结果清楚地表明，与传统肉鸡生产相比，有机肉鸡生产实践对肉鸡群共生大肠杆菌中抗生素耐药性的流行有影响。
