Department of Food Safety, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland.
Res Microbiol. 2010 Mar;161(2):127-35. doi: 10.1016/j.resmic.2009.12.010. Epub 2010 Jan 13.
Lactic acid bacteria isolated from Irish pork and beef abattoirs were analysed for their susceptibility to antimicrobials. Thirty-seven isolates (12 enterococci, 10 lactobacilli, 8 streptococci, 3 lactococci, 2 Leuconostoc, and 2 pediococci) were examined for phenotypic resistance using the E-test and their minimum inhibitory concentration to a panel of six antibiotics (ampicillin, chloramphenicol, erythromycin, streptomycin, tetracycline, and vancomycin) was recorded. The corresponding genetic determinants responsible were characterised by PCR. Also, the transferability of these resistance markers was assessed in filter mating assays. Of the 37 isolates, 33 were found to be resistant to one or more antibiotics. All strains were susceptible to ampicillin and chloramphenicol. The erm(B) and msrA/B genes were detected among the 11 erythromycin-resistant strains of enterococci, lactobacilli, and streptococci. Two tetracycline-resistant strains, Lactobacillus plantarum and Leuconostoc mesenteroides spp., contained tet(M) and tet(S) genes respectively. Intrinsic streptomycin resistance was observed in lactobacilli, streptococci, lactococci and Leuconostoc species; none of the common genetic determinants (strA, strB, aadA, aadE) were identified. Four of 10 strains of Enterococcus faecium were resistant to vancomycin; however, no corresponding genetic determinants for this phenotype were identified. Enterococcus faecalis strains were susceptible to vancomycin. L. plantarum, L. mesenteroides and Pediococcus pentosaceus were intrinsically resistant to vancomycin. Transfer of antibiotic resistance determinants was demonstrated in one strain, wherein the tet(M) gene of L. plantarum (23) isolated from a pork abattoir was transferred to Lactococcus lactis BU-2-60 and to E. faecalis JH2-2. This study identified the presence of antibiotic resistance markers in Irish meat isolates and, in one example, resistance was conjugally transferred to other LAB strains.
从爱尔兰猪肉和牛肉屠宰场分离的乳酸菌对 37 株（12 株肠球菌、10 株乳杆菌、8 株链球菌、3 株乳球菌、2 株肠球菌和 2 株明串珠菌）进行了药敏分析。使用 E 试验对其表型耐药性进行了检测，并记录了它们对 6 种抗生素（氨苄西林、氯霉素、红霉素、链霉素、四环素和万古霉素）的最小抑菌浓度。通过 PCR 对相应的遗传决定因素进行了特征分析。此外，还通过滤膜交配试验评估了这些耐药标记的可转移性。在 37 株分离株中，有 33 株对一种或多种抗生素表现出耐药性。所有菌株均对氨苄西林和氯霉素敏感。在肠球菌、乳杆菌和链球菌的 11 株红霉素耐药株中检测到 erm(B)和 msrA/B 基因。两株四环素耐药株，即植物乳杆菌和肠膜明串珠菌，分别含有 tet(M)和 tet(S)基因。乳杆菌、链球菌、乳球菌和肠球菌均表现出固有链霉素耐药性；未鉴定出常见的遗传决定因素（strA、strB、aadA、aadE）。10 株屎肠球菌中有 4 株对万古霉素耐药；然而，没有鉴定出与该表型相对应的遗传决定因素。屎肠球菌对万古霉素敏感。L. plantarum、L. mesenteroides 和 Pediococcus pentosaceus 对万古霉素具有固有耐药性。在一株分离自猪肉屠宰场的植物乳杆菌（23）中，tet(M)基因被转移到乳球菌 Lactococcus lactis BU-2-60 和粪肠球菌 JH2-2 中，证实了抗生素耐药决定因素的转移。本研究在爱尔兰肉类分离株中发现了抗生素耐药标记，并且在一个例子中，耐药性通过共轭转移到其他 LAB 菌株。
