四川泡菜发酵原料-灯笼辣椒附生乳酸菌的抗生素耐药性评估与耐药基因分析

以四川泡菜蔬菜原料——新鲜灯笼辣椒为对象，分析其表面附生乳酸菌Enterococcus mundtii（5 株）、Enterococcus faecalis（2 株）、Enterococcus hirae（5 株）、Lactococcus lactis（7 株）、Leuconostocmesenteroides（2 株）、Leuconostoc holzapfelii（3 株）和Weissella cibaria（79 株）对青霉素（penicillin，PEN）、红霉素（erythromycin，ERY）、四环素（tetracycline，TET）、链霉素（streptomycin，STR）和氯霉素（chloramphenicol，CHL）的抗生素耐药性和耐药基因分布，为制定合理的食品安全防控措施提供科学依据。研究表明：所有分离菌株均无PEN和ERY耐药性，其他种属部分菌株对TET、STR和CHL表现出单一、二重或三重耐药性。除E. hirae、E. faecalis和L. holzapfelii部分菌株对STR表现出单一耐药性外，所有L. mesenteroide菌株只表现出了STR单一耐药性；STR和TET、STR和CHL二重耐药菌株在E. faecalis、E. hirae、L. lactis和W. cibaria分离菌株中都有发现，但是STR、TET、CHL三重耐药菌株仅在W. cibaria中发现。聚合酶链式反应检测发现：除基因norA、sepA、tet(A)、tet(O)和aac(6’)-aph(2’)未被检出外，其他耐药菌株都有相应1 个或多个耐药基因被检出。多重耐药外排泵基因efrA、tolC、norC、sugE和mdfA较核糖体蛋白质保护和酶修饰基因检出率高，分别达到了49%、41%、48%、41%和47%。虽然辣椒表面附生乳酸菌的抗生素耐药基因在四川泡菜发酵过程中的扩散行为需要进一步研究，但根据食品加工过程安全规范标准，也应关注其表面附生的乳酸菌抗生素耐药性存在的潜在食品安全问题。

Antibiotic Resistance Evaluation and Resistance Gene Profile of Epibiotic Lactic Acid Bacteria on Red Bell Peppers Used for Sichuan Pickle Fermentation

For formulating reasonable measures for the prevention and control of bacterial antibiotic resistance to ensurefood safety, penicillin (PEN), erythromycin (ERY), tetracycline (TET), streptomycin (STR) and chloramphenicol (CHL)resistance of lactic acid bacteria (LABs) and the corresponding resistance genes were evaluated, including Enterococcusmundtii (n = 5), Enterococcus faecalis (n = 2), Enterococcus hirae (n = 2), Lactococcus lactis (n = 7), Leuconostocmesenteroides (n = 2), Leuconostoc holzapfelii (n = 3) and Weissella cibaria (n = 79) from fresh red bell peppers usedfor Sichuan pickle fermentation. All of the isolated strains were susceptible to PEN or ERY, but they had solo, doubleor triplicate resistance to TET, STR and CHL. All the isolates of L. mesenteroides as well as some strains of E. hirae,E. faecalis and L. holzapfelii showed solo STR resistance. Some strains of E. faecalis, E. hirae, L. lactis and W. cibaria haddouble resistance to STR and TET, as well as STR and CHL. However, isolates with triplicate resistances to STR, TETand CHL were only found in W. cibaria. It was found that except norA, sepA, tet(A), tet(O) and aac(6’)-aph(2’) genes,all antibiotic resistance genes were harbored by the resistant isolates partly or completely. The multiple-drug resistanceefflux pump genes efrA, tolC, norC, sugE and mdfA showed higher positive rates (which were 49%, 41%, 48%, 41% and47%, respectively) than the ribosomal protection protein genes and the enzymatic modification genes in the correspondingpolymerase chain reaction (PCR). Even though the dissemination of these antibiotic resistances needs to be further studied,such results demonstrated that food safety concerns will be partly focused on antibiotic resistance of LABs on fresh red bellpeppers according to Qualified Presumption of Safety criteria.