Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, SA, Australia.
Luoda Pharma Pty Ltd, Caringbah, NSW, Australia.
J Vet Pharmacol Ther. 2020 Sep;43(5):499-507. doi: 10.1111/jvp.12871. Epub 2020 May 18.
The objective of this study was to determine the minimum inhibitory concentrations (MICs) and pharmacodynamic profiles of four ionophores (lasalocid, monensin, narasin and salinomycin) against staphylococcal isolates from clinical cases of human and veterinary staphylococcal infections, and to determine the effect of methicillin resistance on the antimicrobial activity of ionophores. Broth microdilution MIC testing was used to determine antimicrobial activity against 156 staphylococcal isolates of human and veterinary origin. Pharmacodynamic profiles were examined using time-kill kinetics profiles against an ATCC type strain of Staphylococcus aureus and a clinical isolate of methicillin-resistant Staphylococcus pseudintermedius. All tests were performed in accordance with CLSI guidelines. All four ionophores demonstrated antimicrobial activity against methicillin-resistant staphylococci at concentrations similar to those observed for methicillin-susceptible isolates of the same species. Testing of human and veterinary MRSA isolates also showed that MIC values were not influenced by the host origin of the isolates. Pharmacodynamic profiles were similar for both isolates tested across all four ionophores, with similar reductions in viable cell counts being observed over an 18- to 24-hr period. Lasalocid, monensin, narasin and salinomycin all demonstrated antimicrobial activity against staphylococcal isolates of human and veterinary origins, with activity being unaffected by methicillin resistance status, although some Staphylococcus species-specific effects were observed that require further investigation.
本研究旨在测定四种离子载体（拉沙洛西、莫能菌素、那拉菌素和盐霉素）对来自人类和兽医金黄色葡萄球菌感染临床病例的分离株的最小抑菌浓度（MIC）和药效学特征，并确定耐甲氧西林对离子载体抗菌活性的影响。采用肉汤微量稀释 MIC 试验测定了 156 株来自人类和兽医来源的金黄色葡萄球菌分离株的抗菌活性。使用时间杀菌动力学曲线对 ATCC 金黄色葡萄球菌标准株和耐甲氧西林金黄色葡萄球菌中间亚种临床分离株进行了药效学特征研究。所有试验均按照 CLSI 指南进行。四种离子载体均对耐甲氧西林金黄色葡萄球菌表现出抗菌活性，其浓度与相同物种的耐甲氧西林敏感分离株相似。对人类和兽医耐甲氧西林金黄色葡萄球菌分离株的检测还表明，宿主来源并不影响 MIC 值。四种离子载体对两种分离株的药效学特征相似，在 18 至 24 小时的观察期内，活菌计数均有相似程度的减少。拉沙洛西、莫能菌素、那拉菌素和盐霉素对来自人类和兽医来源的金黄色葡萄球菌分离株均具有抗菌活性，其活性不受耐甲氧西林状态的影响，但观察到一些特定于金黄色葡萄球菌的影响，需要进一步研究。
