文献类型： 外文期刊

作者： Zhang, Shaqiu ¹ ; Guo, Xiangyuan ¹ ; Wang, Yuwei ⁴ ; Zhong, Zhijun ² ; Wang, Mingshu ¹ ; Jia, Renyong ¹ ; Chen, Shun ¹ ; Liu, Mafeng ¹ ; Zhu, Dekang ¹ ; Zhao, Xinxin ¹ ; Wu, Ying ¹ ; Yang, Qiao ¹ ; Huang, Juan ¹ ; Ou, Xumin ¹ ; Mao, Sai ¹ ; Gao, Qun ¹ ; Sun, Di ¹ ; Tian, Bin ¹ ; Cheng, Anchun ¹ ;

作者机构： 1.Sichuan Agr Univ, Coll Vet Med, Avian Dis Res Ctr, Chengdu 611130, Peoples R China

2.Sichuan Agr Univ, Key Lab Anim Dis & Human Hlth Sichuan Prov, Chengdu 611130, Peoples R China

3.Minist Educ, Engn Res Ctr Southwest Anim Dis Prevent & Control, Chengdu 611130, Peoples R China

4.Mianyang Acad Agr Sci, Mianyang 621023, Peoples R China

关键词： Escherichia coli; extended-spectrum beta-lactamase; conjugational transfer; cephalosporin resistance; blaCTX-M-55

期刊名称：POULTRY SCIENCE （ 影响因子：4.4； 五年影响因子：4.4 ）

ISSN： 0032-5791

年卷期： 2023 年 102 卷 10 期

页码：

收录情况： SCI

摘要： We investigated the cephalosporin resis-tance of Escherichia coli from waterfowl among different breeding mode farms. In 2021, we isolated 200 strains of E. coli from waterfowl feces samples collected from Sich-uan, Heilongjiang, and Anhui provinces. The key find-ings are: Out of the 200 strains, 80, 80, and 40 strains were isolated from waterfowl feces samples in intensive, courtyard, and outdoor breeding mode farms, respec-tively. The overall positive rate of the ESBL phenotype, detecting by the double disk diffusion method, was 68.00% (136/200). In particular, the rates for intensive, courtyard, and outdoor breeding modes were 98.75%, 36.25%, and 70.00%, respectively. Results of MIC test showed drug resistance rates in the intensive breeding mode: 100.00% for cephalothin, 38.75% for cefoxitin, 100.00% for cefotaxime, and 100.00% for cefepime. In courtyard breeding mode, the corresponding rates were 100.00%, 40.00%, 63.75%, and 45.00%, respectively. In outdoor breeding mode, the corresponding rates were 100.00%, 52.50%, 82.50%, and 77.50%, respectively. The PCR results for blaCTX-M, blaTEM, blaOXA, and blaSHV showed the detection rate of blaCTX-M was high-est at 75.50%, with blaCTX-M-55 is the main subtype gene, followed by blaTEM at 73.50%. We screened 58 donor strains carrying blaCTX-M-55, including 52 strains from the intensive breeding mode. These donor bacteria can transfer different plasmids to recipient E. coli J53, resulting in recipient bacteria acquiring cephalosporin resistance, and the conjugational transfer frequency ranged from 1.01 & POUND; 10-5 to 6.56 & POUND; 10-2. The transferred plasmids remained stable in recipient bacteria for up to several days without significant adaptation costs observed. During molecular typing of E. coli with conju-gational transfer ability, the blaCTX-M-55 was found to be widely present in different ST strains with several phylo-genetic groups. In summary, cephalosporin resistance of E. coli carried by waterfowl birds in intensive breeding mode farm was significantly higher than in courtyard and outdoor mode farms. The blaCTX-M-55 subtype gene was the prevalent ARGs and can be horizontally trans-ferred through plasmids, which plays a key role in the spread of cephalosporin drug resistance.