Molecular characterization of intrinsic and acquired antibiotic resistance in lactic acid bacteria and bifidobacteria
Molecular characterization of intrinsic and acquired antibiotic resistance in lactic acid bacteria and bifidobacteria
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DOI：
10.1159/000106077
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发表时间：
2008-01-01
影响因子：
1.2
通讯作者：
Mayo, Baltasar
中科院分区：
文献类型：
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作者：
Ammor, Mohammed Salim;Florez, Ana Belen;Mayo, Baltasar
采用Etest法测定了6种抗生素(氯霉素、克林霉素、红霉素、链霉素、四环素和万古霉素)对143株乳酸菌和双歧杆菌的最低抑菌浓度(MIC)。不同种、不同菌株的最低抑菌浓度不同。根据这些MIC值的分布，大多数菌株对这些抗生素要么敏感，要么内在耐药。然而，其中一些抗生素的MIC范围呈双峰分布，这表明一些受试菌株具有获得性抗生素耐药性。耐药基因的筛选是通过使用特定引物的聚合酶链式反应或使用包含代表7类抗生素耐药基因的约300个核苷酸探针的DNA微阵列进行的。耐药基因包括四环素[tet(M)、tet(W)、tet(O)和tet(O/W)]、红霉素和克林霉素[erm(B)]和链霉素[aph(E)和sat(3)]。对其中一些决定因素的内部部分进行了测序，发现与其他细菌中描述的基因相同。除乳酸乳球菌质粒上存在tet(M)外，其余耐药决定基因均位于细菌染色体上。通过克隆和检测双歧杆菌短基因在乳酸杆菌中的表达，探讨内源性多药转运蛋白在乳酸杆菌耐药中的作用。
The minimum inhibitory concentrations (MICs) of 6 different antibiotics ( chloramphenicol, clindamycin, erythromycin, streptomycin, tetracycline and vancomycin) were determined for 143 strains of lactic acid bacteria and bifidobacteria using the Etest. Different MICs were found for different species and strains. Based on the distribution of these MIC values, most of the strains were either susceptible or intrinsically resistant to these antibiotics. However, the MIC range of some of these antibiotics showed a bimodal distribution, which suggested that some of the tested strains possess acquired antibiotic resistance. Screening for resistance genes was performed by PCR using specific primers, or using a DNA microarray with around 300 nucleotide probes representing 7 classes of antibiotic resistance genes. The genes identified encoded resistance to tetracycline [tet ( M), tet (W), tet (O) and tet (O/W)], erythromycin and clindamycin [erm (B)] and streptomycin [aph (E) and sat (3)]. Internal portions of some of these determinants were sequenced and found to be identical to genes described in other bacteria. All resistance determinants were located on the bacterial chromosome, except for tet (M), which was identified on plasmids in Lactococcus lactis. The contribution of intrinsic multidrug transporters to the antibiotic resistance was investigated by cloning and measuring the expression of Bifidobacterium breve genes in L. lactis.