Kalantari Mohsen, Sharifiyazdi Hassan, Asasi Keramat, Abdi-Hachesoo Bahman
Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran .
Vet Res Forum. 2021 Winter;12(1):101-107. doi: 10.30466/vrf.2019.96366.2309. Epub 2021 Mar 15.
The objective was to investigate the multidrug resistance and presence of class 1 and 2 integrons in 300 isolates obtained from 20 broiler farms during three rearing periods (one-day-old chicks, thirty-day-old chickens, and one day before slaughter) in Fars, South Iran. Results showed that 81.00%, 82.00%, and 85.00% of isolates were multidrug-resistant on the first day, thirty-day-old chickens, and one day before slaughter, respectively. Multidrug-resistant isolates were further examined for the presence of class 1 and 2 integrons using PCR assay. The existence of class 1 integron-integrase gene () was confirmed in 68.40%, 72.70%, and 60.90% of multidrug-resistant isolates from stage 1, stage 2, and stage 3 of the rearing period, respectively. The frequency of class 2 integron-integrase gene () during the first to the third stage of sampling was 2.60%, 25.50%, and 30.40%. Also, sequence analysis of the cassette arrays within class 1 integron revealed the presence of the genes associated with resistance for trimethoprim (A), streptomycin (A), erythromycin (A), and F genes. The results revealed that percentages of antimicrobial resistance in isolates were significantly higher in the middle and end stages of the rearing period. In conclusion, widespread dissemination of class 1 integrons in all three stages and rising trends of class 2 integrons existence in isolates during the rearing period of broiler chickens could exacerbate the spread of resistance factors among bacteria in the poultry industry. Future research is needed to clarify its implication for human health.
目的是调查从伊朗南部法尔斯省20个肉鸡养殖场在三个饲养阶段（一日龄雏鸡、三十日龄鸡和屠宰前一天）获得的300株分离株中的多重耐药性以及1类和2类整合子的存在情况。结果显示，分离株在一日龄、三十日龄鸡和屠宰前一天的多重耐药率分别为81.00%、82.00%和85.00%。使用聚合酶链反应（PCR）检测法对多重耐药分离株进一步检测1类和2类整合子的存在情况。在饲养期第1阶段、第2阶段和第3阶段的多重耐药分离株中，分别有68.40%、72.70%和60.90%证实存在1类整合子整合酶基因（）。在采样的第一阶段至第三阶段，2类整合子整合酶基因（）的检出率分别为2.60%、25.50%和30.40%。此外，对1类整合子内盒式阵列的序列分析显示存在与甲氧苄啶（A）、链霉素（A）、红霉素（A）和F基因耐药相关的基因。结果显示，分离株中的抗菌药物耐药率在饲养期的中期和末期显著更高。总之，1类整合子在所有三个阶段广泛传播，以及肉鸡饲养期分离株中2类整合子存在率呈上升趋势，可能会加剧家禽业细菌中耐药因子的传播。需要进一步研究以阐明其对人类健康的影响。
