四环素和青霉素在铜绿假单胞菌中的蓄积动力学研究及能量抑制剂(CCCP)的影响

为证实国内临床分离的铜绿假单胞菌多重耐药菌株中是否存在与其多重耐药有关的主动外排机制 ,本文研究了 3H-四环素和 3H-青霉素在临床多重耐药菌 (2 1、2 6、2 8、435及 M12 5 1)、敏感菌 (172、2 2 3及K799/6 1)以及体外诱导的多重耐药突变株 (172 o c和 2 2 3o c)中的蓄积动力学及能量抑制剂 (Carbonylcyanide m- chlorophenylhydrazone,CCCP)的影响。结果表明两种药物无论是在耐药还是敏感菌中 ,胞内均可在 5～ 10 min内达稳态浓度 ,而且耐药菌中的稳态浓度明显低于敏感菌。当加入 CCCP后 ,耐药菌中的药物浓度明显增加 ,而敏感菌则降低 ,提示在受试的临床耐药菌中存在主动外排机制 ;此外 ,两种抗菌药物在体外诱导多重耐药菌株中的蓄积研究及 CCCP的影响结果与临床耐药菌相似 ,提示获得性多重耐药与天然多重耐药在其多重耐药性产生方面具相同的主动外排机制。

Accumulation dynamics study of tetracycline and penicillin in Pseudomonas aeruginosa and the effect of CCCP

To identify if there was the mechanism of active efflux in domestic multiple resistant Pseudomonas aeruginosa strains, the accumulation of the 3H tetracycline and 3H penicillin in clinical multidrug resistant strains (21, 26, 28, 435 and M1251); susceptible strains (172, 223 and K799/61) as well as the in vitro induced multidrug resistant mutants (172o c and 223o c), and the effect of a proton conductor, carbonyl cyanide m chlorophenylhydrazone (CCCP) on it were assayed. Results indicated that the levels of the two agents reached a steady state in all of the susceptible and resistant strains within 5~10 min, and the level of the steady state in the cells of resistant strains was much lower than that of susceptible ones. After the addition of CCCP, the accumulation of antibiotic in resistant strains was increased remarkably while decreased slightly in susceptible ones. The data suggested that there was the mechanism of active efflux that pumed out the antibiotics in the clinical resistant isolates. In addition, the results of accumulation in the cells of the induced multiple resistant mutants and the effect of CCCP on it were similar to those of clinical resistant isolates. It predicted that the active efflux mechanism of acquired multiple resistance was the same to that of intrinsic ones.