Yajko D M, Nassos P S, Sanders C A, Hadley W K
Department of Laboratory Medicine, University of California, San Francisco General Hospital Medical Center.
Am Rev Respir Dis. 1989 Nov;140(5):1198-203. doi: 10.1164/ajrccm/140.5.1198.
The murine macrophage continuous cell line J774 was used to measure the ability of antimicrobial agents, either singly or in combination, to kill intracellular Mycobacterium avium complex. All of 14 strains of M. avium complex, isolated from patients with AIDS, grew inside J774 cells during an incubation period of 7 days. The susceptibility of macrophage-ingested M. avium complex to antimicrobial agents was determined by comparing the number of colony-forming units (cfu) of M. avium complex inside untreated macrophages at the time of drug addition with the number of cfu present in macrophages after treatment with drugs for 7 days. Simultaneous experiments were carried out in broth medium without macrophages in order to compare killing of free mycobacteria with killing of macrophage-ingested mycobacteria. Antimicrobial agents (rifampin, rifabutin [Ansamycin], ethambutol, ciprofloxacin, clofazimine, isoniazid, and amikacin) were tested using concentrations that are achievable in the serum of patients. Among drugs known to penetrate macrophages, there was 96.2% agreement in susceptibility test results between the broth experiments and the J774 experiments when single drugs were tested, but only 74% agreement when combinations of drugs were tested. Killing of M. avium complex inside J774 cells by any single drug was uncommon. However, killing in J774 cells occurred against 10 of 11 (91%) strains with the combination of rifabutin + ethambutol + ciprofloxacin and against all of seven strains tested with the combination of rifabutin + ethambutol + amikacin. Interpretive criteria of in vitro susceptibility data need to be developed so that these interpretations correlate with a predictable clinical response in patients.
小鼠巨噬细胞连续细胞系J774用于测定抗菌药物单独或联合使用时杀死细胞内鸟分枝杆菌复合群的能力。从艾滋病患者中分离出的14株鸟分枝杆菌复合群菌株，在7天的培养期内均能在J774细胞内生长。通过比较加药时未处理巨噬细胞内鸟分枝杆菌复合群的菌落形成单位（cfu）数量与药物处理7天后巨噬细胞内cfu数量，来确定巨噬细胞摄取的鸟分枝杆菌复合群对抗菌药物的敏感性。同时在无巨噬细胞的肉汤培养基中进行实验，以比较游离分枝杆菌的杀灭情况与巨噬细胞摄取的分枝杆菌的杀灭情况。使用患者血清中可达到的浓度测试抗菌药物（利福平、利福布汀[安莎霉素]、乙胺丁醇、环丙沙星、氯法齐明、异烟肼和阿米卡星）。在已知能穿透巨噬细胞的药物中，单药测试时肉汤实验和J774实验的药敏试验结果一致性为96.2%，但联合用药测试时一致性仅为74%。任何单一药物在J774细胞内杀死鸟分枝杆菌复合群的情况都不常见。然而，利福布汀+乙胺丁醇+环丙沙星联合使用时，对11株菌株中的10株（91%）在J774细胞内有杀灭作用，利福布汀+乙胺丁醇+阿米卡星联合使用时，对所有7株测试菌株在J774细胞内均有杀灭作用。需要制定体外药敏数据的解释标准，以便这些解释与患者可预测的临床反应相关。
