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.