Clinical relevance of Mycobacterium szulgai in The Netherlands.
BACKGROUND
The clinical relevance of Mycobacterium szulgai isolates is unknown, and available literature focuses on case reports of M. szulgai disease. We assessed the clinical relevance of M. szulgai isolated from patients in The Netherlands.


METHODS
We reviewed medical files for all 21 patients in The Netherlands from whom M. szulgai was isolated during 1999-2006, applying the diagnostic criteria of the American Thoracic Society for nontuberculous mycobacterial infection. Random amplified polymorphic DNA genotyping was performed using IS986, OPA-2, and OPA-18 as primers.


RESULTS
Of the 21 patients, 16 (76%) met the American Thoracic Society diagnostic criteria and were thus likely to have M. szulgai disease. Pulmonary M. szulgai disease was the most common presentation, with extrapulmonary disease restricted to patients with an impaired systemic immunity. Although treatment regimens varied in content and duration, the outcomes were mostly favorable. Both overtreatment and undertreatment were noticed. Random amplified polymorphic DNA genotyping revealed a higher degree of interpatient variability, with limited intrapatient variability, suggesting persisting monoclonal infection and good reproducibility. No genotype was associated with clinical relevance.


CONCLUSIONS
Clinical isolation of M. szulgai generally represents true disease and demands careful follow-up. Extrapulmonary disease occurs in patients with impaired immunity. Adherence to diagnostic guidelines can be improved.
van Ingen
Jakko
J
Department of Pulmonary Diseases, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands. j.vaningen@ulc.umcn.nl
Boeree
Martin J
MJ
de Lange
Wiel C M
WC
de Haas
Petra E W
PE
Dekhuijzen
P N Richard
PN
van Soolingen
Dick
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000995:Antitubercular Agents / Q000627:therapeutic use; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D007538:Isoniazid / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*; D009426:Netherlands; D009170:Nontuberculous Mycobacteria / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D019105:Random Amplified Polymorphic DNA Technique
D000995:Antitubercular Agents; D004269:DNA, Bacterial; D007538:Isoniazid