Barcs I
Department of Bacteriophages, B. Johan National Institute of Hygiene, Budapest, Hungary.
J Chemother. 1993 Aug;5(4):215-22. doi: 10.1080/1120009x.1993.11739235.
Lincosamide inactivation nucleotidylation (Lin) enzyme determined by the pBI109PGL plasmid of Staphylococcus epidermidis exhibits high level resistance to lincomycin but sensitivity to clindamycin by standard susceptibility methods. Substrate profile determination showed clindamycin to be a better substrate for the enzyme than lincomycin. In cultures of the plasmid-harboring strain, the level of clindamycin decreased below the inhibitory concentration in the first 4 hours of incubation but the level of lincomycin persisted longer. The initial extended inhibitory effect of clindamycin is due to better membrane penetrating ability, resulting in a higher intracellular concentration than that of lincomycin. Moreover, energy-dependent reduction in clindamycin uptake, probably due to active efflux of clindamycin but not of lincomycin, was observed. A therapeutic effect of clindamycin is not expected in infections caused by Lin-producer strains because the bacteriostatic effect of the drug is rapidly eliminated after administration.
由表皮葡萄球菌的pBI109PGL质粒所决定的林可酰胺失活核苷酸化（Lin）酶，通过标准药敏方法显示对林可霉素具有高水平耐药性，但对克林霉素敏感。底物谱测定表明，克林霉素是该酶比林可霉素更好的底物。在携带质粒的菌株培养物中，克林霉素的水平在孵育的前4小时内降至抑制浓度以下，但林可霉素的水平持续时间更长。克林霉素最初的延长抑制作用是由于其更好的膜穿透能力，导致细胞内浓度高于林可霉素。此外，观察到克林霉素摄取的能量依赖性降低，这可能是由于克林霉素的主动外排而非林可霉素的主动外排。对于由产生Lin的菌株引起的感染，预计克林霉素不会产生治疗效果，因为该药物的抑菌作用在给药后会迅速消除。
