Rapidly growing mycobacteria (RGM) have emerged as important human pathogens that can cause a variety of diseases. Thirty isolates of the pathogenic RGM were recovered from patients who attended King Chulalongkorn Memorial Hospital during 1997 and 2003. There were 16 isolates of Mycobacterium chelonae, ten isolates of M. fortuitum and four isolates of M. abscessus. Clinical data was available in only nine patients (five males and four females) including six M. chelonae, two M. abscessus, and one M. fortuitum. The mean age was 37 years (range: 13-62 years). The associated conditions were present in five patients including two diabetes, one
HIV infection, one pregnancy, one SLE and one
chronic renal failure. A wide spectrum of clinical features was observed. These included two chronic pulmonary
infections, two post-traumatic
wound infections, two disseminated
infections, one
lymphadenitis, one
keratitis and respiratory colonization. AFB staining was positive in six patients (66.67%). The MIC of one M. chelonae and one M. abscessus were determined by Epsilon test. For M. chelonae, the MIC of
clarithromycin,
amikacin,
ciprofloxacin,
sulfamethoxazole and
imipenem were 0.25, 2.0, 1.00, > 64, and 0.54 microg/ml, respectively. For M. abscessus, the MIC of
clarithromycin,
amikacin,
ciprofloxacin,
tetracycline and
sulfamethoxazole were 0.016, 0.016, 0.038, > 16 and 0.002 microg/ml, respectively. Six of eight patients (75%) were initially treated with four first-line antituberculous drugs (
isoniazid,
rifampicin,
pyrazinamide and
ethambutol) before obtaining the culture result. Of these, three patients with pulmonary and disseminated
infections improved after a prolonged course of these combinations. The patients improved after switching to specific anti-RGM
antibiotics. One patient died after 10 months of
therapy of four anti-tuberculous drugs. One patient with post-traumatic
wound infection was cured with surgical
debridement and
dicloxacillin. One patient improved
after treatment as acute
bronchitis with oral
amoxicillin. An extensive review of the literature of RGM
infections in Thailand is also presented.