Rapidly growing mycobacterial infections: spectrum of diseases, antimicrobial susceptibility, pathology and treatment outcomes.
OBJECTIVE
A series of cases infected with rapidly growing mycobacteria were studied to reveal the spectrum of disease, antimicrobial susceptibility, pathology, and treatment outcomes.


METHODS
The cases identified as rapidly growing mycobacterial infections in Ramathibodi Hospital from January 1993 to June 1999 were retrospectively studied.


RESULTS
There were 20 patients and most of the cases had no underlying disease. Only two cases were HIV-infected patients. The presenting clinical features were lymphadenitis (7), skin and subcutaneous abscess (7), eye infection (4), pulmonary infection (1), and chronic otitis media (1). Four of the seven cases with lymphadenitis had Sweet's syndrome. The organisms were Mycobacterium chelonae/abscessus group (17 cases) and Mycobacteriumfortuitum group (3 cases). The organisms were susceptible to amikacin, netilmicin and imipenem. The M. fortuitum group was susceptible to more antibiotics than the M. chelonaelabscessus group. Pathology of the infected tissue varied from non-specific findings to suppurative or caseous granuloma. The clinical responses corresponded to the antimicrobial susceptibility. Most of the patients had a good clinical outcome. A combination of two or more drugs was used for the medical treatment. Surgical resection was performed where possible to reduce the load of the organism, especially in cases with very resistant organisms.


CONCLUSIONS
Rapidly growing mycobacterial infections can occur in apparently normal hosts. Clinical syndrome is variable. The pathology is non-specific and culture is needed for definite diagnosis. Clinical responses varied but seemed to correlate with the in vitro susceptibility result. More studies are needed before one can deal with these infections more effectively.
Sungkanuparph
Somnuek
S
Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand.
Sathapatayavongs
Boonmee
B
Pracharktam
Roongnapa
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D004322:Drainage; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis / Q000188:drug therapy / Q000628:therapy; D016926:Mycobacterium chelonae / Q000187:drug effects; D019907:Mycobacterium fortuitum / Q000187:drug effects; D012189:Retrospective Studies; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents