Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071 Jaén, Spain.
Área de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071 Jaén, Spain.
Int J Food Microbiol. 2014 Feb 17;172:49-56. doi: 10.1016/j.ijfoodmicro.2013.11.032. Epub 2013 Dec 7.
Bacterial biocide resistance is becoming a matter of concern. In the present study, a collection of biocide-resistant, Gram-positive bacteria from organic foods (including 11 isolates from genus Bacillus, 25 from Enterococcus and 10 from Staphylococcus) were analyzed for genes associated to biocide resistance efflux pumps and antibiotic resistance. The only qac-genes detected were qacA/B (one Bacillus cereus isolate) and smr (one B. cereus and two Staphylococcus saprophyticus isolates). Efflux pump genes efrA and efrB genes were detected in Staphylococcus (60% of isolates), Bacillus (54.54%) and Enterococcus (24%); sugE was detected in Enterococcus (20%) and in one Bacillus licheniformis; mepA was detected in Staphylococcus (60%) and in one Enterococcus isolate (which also carried mdeA), and norE gene was detected only in one Enterococcus faecium and one S. saprophyticus isolate. An amplicon for acrB efflux pump was detected in all but one isolate. When minimal inhibitory concentrations (MICs) were determined, it was found that the addition of reserpine reduced the MICs by eight fold for most of the biocides and isolates, corroborating the role of efflux pumps in biocide resistance. Erythromycin resistance gene ermB was detected in 90% of Bacillus isolates, and in one Staphylococcus, while ereA was detected only in one Bacillus and one Staphyloccus, and ereB only in one Staphylococcus. The ATP-dependent msrA gene (which confers resistance to macrolides, lincosamides and type B streptogramins) was detected in 60% of Bacillus isolates and in all staphylococci, which in addition carried msrB. The lincosamide and streptogramin A resistance gene lsa was detected in Staphylococcus (40%), Bacillus (27.27%) and Enterococcus (8%) isolates. The aminoglycoside resistance determinant aph (3_)-IIIa was detected in Staphylococcus (40%) and Bacillus (one isolate), aph(2_)-1d in Bacillus (27.27%) and Enterococcus (8%), aph(2_)-Ib in Bacillus (one isolate), and the bifunctional aac(6_)1e-aph(2_)-Ia in Staphylococcus (20%), Enterococcus (8%) and Bacillus (one isolate). Chloramphenicol resistance cat gene was detected in Enterococcus (8%) and Staphylococcus (20%), and blaZ only in Staphylococcus (20%). All other antibiotic or biocide resistance genes investigated were not detected in any isolate. Isolates carrying multiple biocide and antibiotic determinants were frequent among Bacillus (36.36%) and Staphylococcus (50%), but not Enterococcus. These results suggest that biocide and antibiotic determinants may be co-selected.
细菌杀菌剂耐药性正成为一个值得关注的问题。在本研究中，对来自有机食品的一组抗杀菌剂的革兰氏阳性细菌（包括 11 株芽孢杆菌属、25 株肠球菌属和 10 株葡萄球菌属）进行了分析，以研究与杀菌剂耐药性外排泵和抗生素耐药性相关的基因。仅检测到 qacA/B（1 株蜡样芽孢杆菌）和 smr（1 株蜡样芽孢杆菌和 2 株表皮葡萄球菌）基因。在葡萄球菌属（60%的分离株）、芽孢杆菌属（54.54%）和肠球菌属（24%）中检测到 efflux pump 基因 efrA 和 efrB；在肠球菌属（20%）和 1 株地衣芽孢杆菌中检测到 sugE；在葡萄球菌属（60%）和 1 株肠球菌属分离株中检测到 mepA，norE 基因仅在 1 株粪肠球菌和 1 株表皮葡萄球菌分离株中检测到。除 1 株分离株外，所有分离株均检测到 acrB 外排泵的扩增子。当确定最小抑菌浓度（MIC）时，发现利血平的加入使大多数杀菌剂和分离株的 MIC 降低了 8 倍，这证实了外排泵在杀菌剂耐药性中的作用。90%的芽孢杆菌分离株和 1 株葡萄球菌中检测到红霉素耐药基因 ermB，而 ereA 仅在 1 株芽孢杆菌和 1 株葡萄球菌中检测到，ereB 仅在 1 株葡萄球菌中检测到。ATP 依赖性 msrA 基因（赋予大环内酯类、林可酰胺类和 B 型链阳性菌素的耐药性）在 60%的芽孢杆菌分离株和所有葡萄球菌中均有检测到，这些葡萄球菌还携带 msrB。在 40%的葡萄球菌、27.27%的芽孢杆菌和 8%的肠球菌分离株中检测到林可酰胺和链阳性菌素 A 耐药基因 lsa。在葡萄球菌（40%）和芽孢杆菌（1 株）中检测到氨基糖苷类耐药决定因子 aph（3_）-IIIa，在芽孢杆菌（27.27%）和肠球菌（8%）中检测到 aph（2_）-1d，在芽孢杆菌（1 株）中检测到 aph（2_）-Ib，在葡萄球菌（20%）、肠球菌（8%）和芽孢杆菌（1 株）中检测到双功能 aac(6_)1e-aph(2_)-Ia。在肠球菌（8%）和葡萄球菌（20%）中检测到氯霉素耐药 cat 基因，在葡萄球菌（20%）中检测到 blaZ。在任何分离株中均未检测到其他抗生素或杀菌剂耐药基因。携带多种杀菌剂和抗生素决定因子的分离株在芽孢杆菌属（36.36%）和葡萄球菌属（50%）中很常见，但在肠球菌属中却不常见。这些结果表明，杀菌剂和抗生素决定因子可能会共同选择。
Zotero 插件