精胺与β-内酰胺类抗生素对耐甲氧西林金黄色葡萄球菌的协同抗菌功能探讨

Synergistic antibacterial effect of spermine and β-lactam antibiotics on methicillin-resistant Staphylococcus aureus

目的研究外源性精胺与β-内酰胺类抗生素联用时对耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylo-coccusaureus,MRSA)的抗菌效果。方法收集5株临床MRSA菌株,通过分析全基因组测序结果,进行多位点序列分型和耐药基因预测,并通过纸片扩散法和微量肉汤稀释法,评估精胺和β-内酰胺类抗生素单用/联用时的抗菌效果。结果精胺对MRSA具有一定的抗菌作用,5株菌株有效最小抑菌浓度值均为2mmol/L。精胺与苯唑西林、头孢西丁联合应用时,5株菌株MIC值均出现大幅度下降,显著提高2种药物抗菌效果。结论精胺可显著削弱MRSA对传统β-内酰胺类抗生素抵抗能力,其合理使用有望提高传统β-内酰胺类抗生素使用效果。

Objective To explore the antibacterial effect of exogenous spermine combined with traditional β-lactam antibiotics on methicillin-resistant Staphylococcus aureus(MRSA). Methods A total of 5 clinical MRSA strains were collected and multilocus sequence typing and antibiotic resistance genes prediction were performed by whole genome sequencing analysis.The antibacterial effects of spermine and/or β-lactam antibiotics were evaluated by disc diffusion and standard micro broth dilution methods. Results Spermine had certain cytotoxic effect on MRSA,the effective minimum inhibitory concentration(MIC) of the 5 strains were 2 mmol/L.When spermine was combined with oxacillin and cefoxitin, the MIC values of the 5 strains decreased dramatically, which significantly improved the antibacterial effect of the 2 antibiotics. Conclution Spermine significantly weakens the resistance of MRSA to traditional β-lactam antibiotics, which can improve the efficiency of traditional β-lactam antibiotics by rational prescription.