广东地区猪链球菌的耐药性特点及四环素耐药基因携带情况

猪链球菌(Streptococcus suis,SS)是危害世界养猪业的重要细菌性病原菌之一,本研究旨在了解猪链球菌临床分离株的耐药性特点和四环素耐药基因的携带情况,为临床上该病的防控提供科学依据。本试验采用K-B法和CLSI推荐的肉汤微量稀释法检测猪链球菌广东分离株对18种抗菌药物的耐药性。结果显示,被检菌株对四环素类、磺胺类和氨基糖苷类抗菌药物表现较强的耐药性,尤其对四环素类药物的耐药率高达98.2%;对头孢菌素类药物比较敏感;菌株都耐受6种或6种以上的抗菌药物,其中以6和14重耐药菌株的数量最多,分别占20%和17%。本试验设计了4对引物检测四环素耐药基因携带情况,结果发现56株菌中以携带tetM基因为最多(85.71%)。结果表明tetM很可能是介导广东SS分离株对四环素产生极高耐药率的主要原因之一。

Resistance Characteristics and Distribution of Tetracycline Resistance Genes in Streptococcus suis from Pigs in Guangdong

Streptococcus suis was one of the most frequent pathogenic bacteria which had caused a serious of problems in pig industry all over the world. Therefore, it was important to evaluate the resistance to antibiotics and the distribution of tetracycline resistance determinants in Streptococcus suis from pigs in order to prevent and control this diseases. All Streptococcus suis were isolated from clinically diseased pigs and antimicrobial susceptibility to 18 antibiotics was performed by Kirby-Bauer and broth microdilution method. The results showed that most of the SS isolates showed resistance to tetracycline,sulfamethoxazole and gentamicin.Especially, a high level of resistance was found for tetracycline(98.2%);the isolates were susceptible to cephalosporins,all isolates showed multiple-drug resistance, resistance to 6 and 14 antibiotics was the main trend, the percentage were 20% and 17%, respectively.Four pairs of primers were designed to detect the presence of tetracycline resistance gene taken by SS.The results showed that most of the SS had tetracycline drug resistance gene tetM(85.71%),which indicated that tetM might be one of the main molecular mechanisms mediated the resistance of the SS isolates from Guangdong to tetracycline.