传统发酵食品中乳酸菌的抗生素耐药性评估及耐药基因分析

Antimicrobial Resistance Evaluation and Resistant Gene Profiles of Lactic Acid Bacteria Isolated from Traditional Fermented Foods

对传统发酵食品中分离的97株乳酸菌的抗生素耐药性进行评估及耐药基因分析,结果表明:所有分离菌株对万古霉素、庆大霉素、卡那霉素、链霉素、四环素和替考拉宁的耐药性较强,耐药率达50%以上;对氨苄青霉素、红霉素、甲氧苄啶、头孢呋肟较敏感,耐药率为10%左右。携带最多的耐药基因是tetM(91.75%)和ermB(86.60%)基因,其次为aac(6,)-aph(2’’)(53.61%),lnuA(45.36%),tetK(39.18%),ermC(36.08%),strA(34.02%)和blaZ(32.99%)基因,携带率相对较低的基因为strA(27.84%),msrA/B(22.22%)和aph(3’)-III(7.22%)基因。另外,所有乳酸菌中均未检测出氯霉素(cat)和万古霉素(vanX)耐药基因。多重耐药菌株在发酵乳制品中的分离率最高,且多出现在植物乳杆菌(45.83%)、凝结芽孢杆菌(20.83%)和耐久肠球菌(12.28%)中。MTP试验结果显示70%的菌株都具有产生物被膜的能力,其多重耐药性显著高于不产生物被膜的菌株。综上所述,乳酸菌的耐药性可能成为重要的食品安全隐患,急需出台一系列用药规定,减少抗生素的选择压力,加强食用菌株的安全性检测。

Antibiotics resistance of 97 lactic acid bacteria isolated from traditional fermented foods were analyzed.The results showed that most of strains were resistant to vancomycin,gentamicin,kanamycin,streptomycin,tetracycline,and teicoplanin,and the resistance rate could reach more than 50%.However,the resistance to ampicillin,erythromycin,trimethoprim and cefuroxime were relatively lower,just about 10%.Among of the 13 antimicrobial resistance genes,the most detected genes were tet M(91.75%) and erm B(86.60%),followed by aac(6′)-aph(2″) (53.61%),lnu A(45.36%),tet K(39.18%),erm C(36.08%),str A(34.02%) and bla Z(32.99%) genes,and str A(27.84%),msr A/B(22.22%) and aph(3’)-III(7.22%) was lower detected genes.The cat and van X gene were not detected in our study.Additionally,by MTP methods,70% of isolates were determined to have biofilm producing ability.Compared to the biofilm-producing negative strains,the positive ones were proved to be more frequent multiple resistant.In conclusion,the transmission of multiple drug resistance(MDR) bacteria and related genes would been a huge risk to food safety.Bull antibiotic restrictions policy and programs should be promoted to reduce the selection pressure of antibiotics,and the safety evaluation of the edible strains should been strengthened.