[Dissemination of insertion sequence common regions 1 and int1 gene and drug resistance of 483 Escherichia coli and Klebsiella pneumonia broiler isolates].

Objective: To investigate and analyze distribution characteristics of two multidrug resistance related genes in broiler isolates in Shandong province. Methods: The pre slaughter broilers were chosen from Shandong province in this study in June, 2014. A total of 400 fecal samples from five different zones (east, south, west, north and middle) of the hen house were collected. 373(77.2%) Escherichia coli and 110 (22.8%) Klebsiella pneumonia strains were isolated, and ISCR1 and int1 gene were detected by PCR assay and sequencing. The resistance to 10 drugs belonging to 8 classes antimicrobial drugs were obtained by using minimal broth dilution method and data analysis. The difference between isolates and drug resistance profiles was analyzed. Results: Among 483 isolates, 440 isolates (91.1%), 126 isolates (26.1%) and 126 isolates (26.1%) were detected as int1, ISCR1 and both two gene carriers, respectively. The rate of 37 E. coli isolates not carried ISCR1 or int1 gene resistant to 0 to 2, 3 to 5, 6 to 8 classes antimicrobial agents was 13.5% (n=5), 78.4% (n=29), and 8.1% (n=3), respectively; the rate of 288 only int1 gene E. coli carriers resistant to 0 to 2, 3 to 5, 6 to 8 groups antimicrobial agents was 2.4% (n=7), 74.7% (n=215), and 22.9% (n=6), respectively. The data above showed significant difference (P<0.001). The rate of 26 only int1 gene K. pneumonia carriers resistant to 0 to 2, 3 to 5, 6 to 8 classes antimicrobial agents was 11.5% (n=3), 76.9% (n=20), and 11.5% (n=3), respectively; the rate of 78 both two gene K. pneumonia carriers resistant to0 to 2, 3 to 5, 6 to 8 groups antimicrobial agents was 0, 35.9% (n=28), and 64.1% (n=50), respectively. The data above showed significant difference (P<0.001). Conclusion: Gene int1 and ISCR1 showed high prevalence in E. coli and K. pneumonia isolates. High level multi-drug resistance profile could be mediated by int1 and ISCR1 gene co-existence.目的： 研究山东肉鸡源细菌中ISCR1和int1基因的流行及耐药情况。 方法： 于2014年6月，在山东某大型肉鸡养殖场中选择日龄在37 d的待宰肉鸡作为采样对象。将鸡舍分为东部、南部、西部、北部、中部5区，选取不同区域肉鸡，采用单纯随机方法，按照1∶50比例进行泄殖腔拭子采样，共得到肉鸡粪便样本400份，经分离共得到483株非重复性样本菌株，其中大肠埃希菌373株（77.2%），肺炎克雷伯菌110株（22.8%）；采用微量肉汤稀释法，测定菌株对8类10种抗菌药物的最低抑菌浓度；并对int1和ISCR1基因进行PCR扩增和测序；比较携带两种基因的大肠埃希菌、肺炎克雷伯菌的耐药程度差异。 结果： 483株菌株中，共检测到携带int1基因的菌株为440株（91.1%），携带ISCR1基因的菌株为126株（26.1%），同时携带int1和ISCR1基因的菌株共有126株（26.1%）。37株同时不携带ISCR1和int1基因的大肠埃希菌耐受0~2、3~5、6~8类药物的比例分别为13.5%（5株）、78.4%（29株）和8.1%（3株），288株仅携带int1基因的大肠埃希菌耐受0~2、3~5、6~8类药物的比例分别为2.4%（7株）、74.7%（215株）和22.9%（6株），两者差异有统计学意义（P<0.001）；26株仅携带int1基因的肺炎克雷伯菌耐受0~2、3~5、6~8类药物的比例分别为11.5%（3株）、76.9%（20株）和11.5%（3株），78株同时携带ISCR1和int1基因的肺炎克雷伯菌耐受0~2、3~5、6~8类药物的比例分别为0、35.9%（28株）和64.1%（50株），两者差异有统计学意义（P<0.001）。 结论：int1和ISCR1基因在大肠埃希菌和肺炎克雷伯菌中的检出率较高，两类基因同时存在可介导更高程度的耐多药表型。.