Relationship between clinical efficacy of treatment of pulmonary Mycobacterium avium complex disease and drug-sensitivity testing of Mycobacterium avium complex isolates

• Published in: Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy Vol. 12; no. 4; pp. 195 - 202
• Main Authors: Kobashi, Yoshihiro, Yoshida, Kouichiro, Miyashita, Naoyuki, Niki, Yoshihito, Oka, Mikio
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01-08-2006
• Subjects: Anti-Bacterial Agents - adverse effects; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Antimicrobial susceptibility; Antitubercular Agents - adverse effects; Antitubercular Agents - pharmacology; Antitubercular Agents - therapeutic use; Clarithromycin - adverse effects; Clarithromycin - pharmacology; Clarithromycin - therapeutic use; Clinical efficacy; Drug sensitivity testing; Drug Therapy, Combination; Female; Humans; Lung Diseases - diagnostic imaging; Lung Diseases - drug therapy; Lung Diseases - microbiology; Male; Microbial Sensitivity Tests; Middle Aged; Mycobacterium avium; Mycobacterium avium complex; Mycobacterium avium Complex - drug effects; Mycobacterium avium Complex - isolation & purification; Mycobacterium avium-intracellulare Infection - diagnostic imaging; Mycobacterium avium-intracellulare Infection - drug therapy; Mycobacterium avium-intracellulare Infection - microbiology; Pulmonary disease; Quinolones - adverse effects; Quinolones - pharmacology; Quinolones - therapeutic use; Radiography; Treatment Outcome; Drug sensitivity testing; Pulmonary disease; Antimicrobial susceptibility; Mycobacterium avium complex; Clinical efficacy
• ISSN: 1341-321X; 1437-7780
• DOI: 10.1007/s10156-006-0457-8

We prospectively investigated the relationship between the clinical efficacy of treatment of pulmonary Mycobacterium avium complex (MAC) disease and drug-sensitivity testing of MAC isolates for antituberculous drugs, new quinolone antibiotics, and clarithromycin (CAM). Fifty-two patients who satisfied the diagnostic criteria of the American Thoracic Society (ATS) and who received treatment between April 1998 and December 2005, using combined therapy of rifampicin (RFP), ethambutol (EB), streptomycin (SM), and CAM, were enrolled in this study. The causative microorganisms isolated were Mycobacterium avium in 30 patients and M. intracellulare in 22 patients. Although separation of the two strains showed drug sensitivity testing to have slightly better minimal inhibitory concentrations (MIC) for M. intracellulare than for M. avium, there were no significant differences in the sputum eradication rate or clinical improvement between the two strains. The MICs of various antibiotics for the isolated MAC strains were as follows: RFP, 0.125–8µg/ml; CAM, 0.25–16µg/ml; SM, 2–128≦µg/ml; EB, 128≦µg/ml; levofloxacin (LVFX), 1–32µg/ml; sparfloxacin (SPFX), 0.5–16µg/ml; and gatifloxacin (GFLX), 0.25–8µg/ml. The isolated MAC strains showed the same excellent drug sensitivity test results for RFP, new quinolones, and CAM, but they showed resistant drug-sensitivity results for EB and SM. Regarding the relationship between clinical efficacy and the MICs of RFP, EB, CAM, and SM, there was a good relationship only for CAM. Although the ATS has not yet recommended routine drug susceptibility testing of CAM, we believe that drug susceptibility testing of CAM should be performed before the initial treatment is undertaken for pulmonary MAC disease.