Abstract：
The aim of this study was to evaluate the phenotypic and genotypic responses of Salmonella Typhimurium ATCC 19585 (ST) and Staphylococcus aureus KACC 13236 (SA) preadapted to sublethal concentrations of lactic acid (LA) and sodium chloride (NaCl) for 48 hr at 37°C, followed by re-exposure to lethal concentrations of LA and NaCl for 24 hr at 37°C. ST and SA treated in a sequential and ordered manner with LA and NaCl were assigned as LA-LA, LA-NaCl, NaCl-LA, and NaCl-NaCl. The treatments, LA-LA, LA-NaCl, NaCl-LA, and NaCl-NaCl, were evaluated by antimicrobial susceptibility, bacterial fluctuation, relative fitness, zeta potential, and gene expression. The MICt/MICc ratios of LA, NaCl, CIP, GEN, and TET against ST treated with LA-LA were 1.0 to 0.8, 0.8, 0.3, 0.4, and 0.5, respectively. The MICt/MICc ratios of NaCl, CIP, GEN, and TET were between 0.5-0.8 for SA treated with LA-LA. ST treated with LA-LA and SA treated with LA-NaCl exhibited the highest coefficient of variance. The lowest relative fitness was observed at ST treated with LA-LA (0.5). ST and SA treated with LA-LA showed the lowest zeta potential. The transporter-, toxin-antitoxin system-, chaperone protein-, and SOS response-related genes were suppressed at ST and SA treated with LA-LA. The transporter-, toxin-antitoxin system-, and chaperone protein-related genes were overexpressed in SA treated with LA-NaCl, NaCl-LA, and NaCl-NaCl. The results suggest that ST and SA treated with LA-LA, LA-NaCl, NaCl-LA, and NaCl-NaCl could induce collateral sensitivity and cross-resistance.
摘要：
这项研究的目的是评估鼠伤寒沙门氏菌ATCC19585（ST）和金黄色葡萄球菌KACC13236（SA）的表型和基因型反应，适应亚致死浓度的乳酸（LA）和氯化钠（NaCl）在37°C下48小时，然后在37°C下再次暴露于致死浓度的LA和NaCl24小时。用LA和NaCl按顺序和顺序处理的ST和SA被指定为LA-LA，LA-NaCl,NaCl-LA,和NaCl-NaCl。治疗,LA-LA,LA-NaCl,NaCl-LA,和NaCl-NaCl，通过抗菌药物敏感性评估，细菌波动，相对适应度，zeta电位,和基因表达。LA的MICt/MICc比率，NaCl,CIP,GEN,用LA-LA治疗的ST和TET分别为1.0至0.8、0.8、0.3、0.4和0.5。NaCl的MICt/MICc比，CIP,GEN,对于用LA-LA处理的SA,TET在0.5-0.8之间。用LA-LA处理的ST和用LA-NaCl处理的SA表现出最高的变异系数。在用LA-LA处理的ST处观察到最低的相对适合度(0.5)。用LA-LA处理的ST和SA显示出最低的ζ电位。运输者-，毒素-抗毒素系统-，伴侣蛋白-，与SOS反应相关的基因在用LA-LA处理的ST和SA时受到抑制。运输者-，毒素-抗毒素系统-，在LA-NaCl处理的SA中过表达与伴侣蛋白相关的基因，NaCl-LA,和NaCl-NaCl。结果表明，ST和SA用LA-LA治疗，LA-NaCl,NaCl-LA,NaCl-NaCl可诱导侧支敏感性和交叉抗性。
