Ombarak Rabee A, Hinenoya Atsushi, Elbagory Abdel-Rahman M, Yamasaki Shinji
1 Faculty of Veterinary Medicine, University of Sadat City, Sadat City 32897, Egypt.
2 Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 598-8531, Japan.
J Food Prot. 2018 Feb;81(2):226-232. doi: 10.4315/0362-028X.JFP-17-277.
The goal of this study was to examine antimicrobial resistance and characterize the implicated genes in 222 isolates of Escherichia coli from 187 samples of raw milk and the two most popular cheeses in Egypt. E. coli isolates were tested for susceptibility to 12 antimicrobials by a disk diffusion method. Among the 222 E. coli isolates, 66 (29.7%) were resistant to one or more antimicrobials, and half of these resistant isolates showed a multidrug resistance phenotype (resistance to at least three different drug classes). The resistance traits were observed to tetracycline (27.5%), ampicillin (18.9%), streptomycin (18.5%), sulfamethoxazole-trimethoprim (11.3%), cefotaxime (4.5%), kanamycin (4.1%), ceftazidime (3.6%), chloramphenicol (2.3%), nalidixic acid (1.8%), and ciprofloxacin (1.4%). No resistance to fosfomycin and imipenem was observed. Tetracycline resistance genes tetA, tetB, and tetD were detected in 53 isolates, 9 isolates, and 1 isolate, respectively, but tetC was not detected. Aminoglycoside resistance genes strA, strB, aadA, and aphA1 were detected in 41, 41, 11, and 9 isolates, respectively. Sulfonamide resistance genes sul1, sul2, and sul3 were detected in 7, 25, and 3 isolates, respectively. Of 42 ampicillin-resistant isolates, bla, bla, and bla were detected in 40, 9, and 3 isolates, respectively, and 10 (23.8%) ampicillin-resistant isolates were found to produce extended-spectrum β-lactamase. Each bla gene of extended-spectrum β-lactamase-producing E. coli was further subtyped to be bla, bla, bla, and bla. The class 1 integron was also detected in 28 resistant isolates, and three different patterns were obtained by PCR-restriction fragment length polymorphism. Sequencing analysis of the variable region revealed that four isolates had dfrA12/orfF/aadA2, two had aadA22, and one had dfrA1/aadA1. These data suggest that antimicrobial-resistant E. coli are widely distributed in the milk production and processing environment in Egypt and may play a role in dissemination of antimicrobial resistance to other pathogenic and commensal bacteria.
本研究的目的是检测222株来自埃及187份生乳样本及两种最受欢迎奶酪的大肠杆菌的抗菌药物耐药性，并对相关基因进行特征分析。采用纸片扩散法检测大肠杆菌分离株对12种抗菌药物的敏感性。在222株大肠杆菌分离株中，66株（29.7%）对一种或多种抗菌药物耐药，其中一半的耐药分离株表现出多重耐药表型（对至少三种不同类别的药物耐药）。观察到的耐药特性包括对四环素（27.5%）、氨苄西林（18.9%）、链霉素（18.5%）、磺胺甲恶唑-甲氧苄啶（11.3%）、头孢噻肟（4.5%）、卡那霉素（4.1%）、头孢他啶（3.6%）、氯霉素（2.3%）、萘啶酸（1.8%）和环丙沙星（1.4%）耐药。未观察到对磷霉素和亚胺培南的耐药情况。分别在53株、9株和1株分离株中检测到四环素耐药基因tetA、tetB和tetD，但未检测到tetC。分别在41株、41株、11株和9株分离株中检测到氨基糖苷类耐药基因strA、strB、aadA和aphA1。分别在7株、25株和3株分离株中检测到磺胺类耐药基因sul1、sul2和sul3。在42株氨苄西林耐药分离株中，分别在40株、9株和3株分离株中检测到bla、bla和bla，并且发现10株（23.8%）氨苄西林耐药分离株产生超广谱β-内酰胺酶。产生超广谱β-内酰胺酶的大肠杆菌的每个bla基因进一步亚型化为bla、bla、bla和bla。在28株耐药分离株中也检测到1类整合子，通过PCR-限制性片段长度多态性获得三种不同模式。可变区的测序分析显示，4株分离株具有dfrA12/orfF/aadA2，2株具有aadA22，1株具有dfrA1/aadA1。这些数据表明，耐抗菌药物的大肠杆菌在埃及的牛奶生产和加工环境中广泛分布，可能在抗菌药物耐药性向其他致病和共生细菌的传播中起作用。
