Heifets L, Lindholm-Levy P
National Jewish Center for Immunology, Denver, CO 80206.
Am Rev Respir Dis. 1992 May;145(5):1223-5. doi: 10.1164/ajrccm/145.5.1223.
Previously, we reported that pyrazinamide has very poor bactericidal activity against M. tuberculosis growing in broth at pH 5.6. In the present study, cultivation at pH 4.8 to 5.0 in 7H12 broth prevented an increase in the number of viable bacteria, but the cultures remained metabolically active. The presence of 50 micrograms/ml pyrazinamide in semidormant cultures led to a sharp decline in the number of viable bacteria, by more than 1,000-fold. This unfavorable environment probably made the bacilli especially vulnerable to pyrazinamide, whose mode of action remains unclear. To distinguish this effect of pyrazinamide on the semidormant bacteria from its mostly bacteriostatic activity against actively multiplying bacteria, we suggest interpreting the in vitro effect as "sterilizing."
此前，我们报道过吡嗪酰胺对在pH 5.6的肉汤中生长的结核分枝杆菌杀菌活性很差。在本研究中，在7H12肉汤中于pH 4.8至5.0培养可防止活菌数量增加，但培养物仍保持代谢活性。在半休眠培养物中存在50微克/毫升吡嗪酰胺会导致活菌数量急剧下降，超过1000倍。这种不利环境可能使杆菌对吡嗪酰胺特别敏感，其作用方式尚不清楚。为了将吡嗪酰胺对半休眠细菌的这种作用与其对活跃繁殖细菌的主要抑菌活性区分开来，我们建议将体外作用解释为“杀菌”。
