中文摘要：

为研究鸡蛋生产链中沙门氏菌的污染情况及抗生素、消毒剂耐药情况,本文鉴定了鸡蛋生产链中分离得到的111株沙门氏菌（Salmonella）血清型,并测定了抗生素和消毒剂对沙门氏菌的最小抑菌浓度（Minimum inhibitory concentrations,MICs）,检测了其对抗生素和消毒剂的耐药基因的表达情况。研究结果表明,沙门氏菌对甲氧苄啶（Trimethoprim,TMP）耐药率最高（N=100,P=90.09%）,对阿莫西林/克拉维酸（Amoxicillin and clavulanate,AMC）、头孢噻呋钠（Sodium ceftiofur,CFS）、庆大霉素（Gentamicin,CN）敏感。沙门氏菌共产生6种不同的耐药谱型,TMP是最主要的耐药谱型（N=36,P=32.43%）,52.25%的菌株（N=58）具有多重耐药性。苯扎氯铵（Benzalkonium chloride,BC）与氯化十六烷基吡啶（Cetylpyridinium chloride,CPC）对沙门氏菌的MIC的范围分别为：8～128μg/m L、8～256μg/m L。相对于质控菌株Escherichia coli ATCC10536,101株沙门氏菌对BC和CPC同时具有较高的耐药性（P=90.99%）,109株沙门氏菌对抗生素和消毒剂具有共同耐药性（P=98.20%）。抗生素耐药基因检出率最高为bla TEM（N=49,P=44.14%）,未检测出qnr A、qnr B、qep A基因,仅检测出qac EΔ1消毒剂耐药基因（N=63,P=56.76%）。抗生素耐药基因sul1和消毒剂耐药基因qac EΔ1具有显著相关性（P〈0.01）。S.Derby对TMP、土霉素（Oxytetracycline,OTC）、阿莫西林（Amoxicillin,AML）、环丙沙星（Ciprofloxacin,CIP）同时表现较高的耐药性,S.Derby检出了11种抗生素耐药基因,消毒剂耐药基因qac EΔ1的检出率为81.25%（N=52）。鸡场中养殖内环境沙门氏菌对抗生素和消毒剂的耐药率以及耐药基因检出率均高于养殖外环境,鸡蛋包装、储存及销售等环节中沙门氏菌耐药率及耐药基因检出率均较高。由此可见,鸡蛋生产链中沙门氏菌对抗生素、消毒剂耐药性较严重,且存在共同耐药的现象。因此,需要进一步规范防?

英文摘要：

To investigate the contamination of Salmonella and its drug resistance in egg production chains, 111 Salmonella strains of different serotypes isolated from egg production chains were used in the study. The minimum inhibitory concentrations（MICs） of antibiotics and disinfectants against Salmonella isolates were determined, meanwhile, antibiotic and disinfectant resistance genes were amplified. The results showed that the resistance frequency of trimethoprim（TMP, N=100, P=90.09%） was highest among Salmonella isolates and all isolates were sensitive to amoxicillin and clavulanate（AMC）, ceftiofur sodium（CFS） and gentamicin（CN）, respectively. There were six different antibiotic resistance profiles, and TMP profile was the most prevalent type（N=36, P=32.43%）. 52.25% of Salmonella isolates appeared multi-drug resistance. The MICs of benzalkonium chloride（BC） and cetylpyridinium chloride（CPC） against Salmonella strains ranged from 8 to 128 μg/m L and 8 to 256 μg/m L, respectively. Compared to quality control strain Escherichia coli ATCC10536, 101 Salmonella isolates（P=90.99%） had dual resistances to BC and CPC. 109 Salmonella（P=98.20%） were co-resistant to antibiotic and disinfectant. Detection of drug resistance genes showed that bla TEM gene was dominant（N=49, P=44.14%）. The qnr A, qnr B and qep A genes were not detected. Only qac EΔ1 gene（N=63, P=56.76%） was detected among the disinfectant resistance genes. There was a significant correlation between sul1 gene and qac EΔ1 gene（P〈 0.01）. S. Derby showed multi-resistances to TMP, oxytetracycline（OTC）, amoxicillin（AML） and ciprofloxacin（CIP）. Eleven antibiotic resistance genes were found in S. Derby, in which the prevalence of qac EΔ1 gene was 81.25%（N=52）. Besides, the drug resistance frequency and the prevalence of drug resistance genes in internal farm environment were higher than those in external environment. High frequency of drug resistances and high prevalence of drug resistance genes wer