Mycobacterium riyadhense Pulmonary Infection, France and Bahrain

4 showed susceptibility to amikacin, ciprofl oxacin, clarithromycin, and doxycycline but resistance to cefoxitin, sulfamethoxazole, rifampin (MIC >16 μg/mL) and intermediate-resistance to imipenem (MIC 8–16 μg/mL). According to the American Thoracic Society diagnostic criteria for NTM lung disease (9), patient 1 fulfi lled all criteria and patient 3 fulfi lled the radiographic and microbiological criteria. These fi ndings suggest that M. conceptionense can cause lung disease. For the other patients, colonization with M. conceptionense is a more plausible explanation (Table). These 4 recent cases of M. conceptionense infection are in accordance with the increasing prevalence of NTM (10). Increasing prevalence might be the result of technical advances in NTM identifi cation, including use of liquid media and sequencing, or the result of a local outbreak or contamination event. We consider contamination to be an unlikely cause because specimens were completely separated from each other during collection and testing. Isolates from different patients yielded distinct randomly amplifi ed polymorphic DNA patterns. In conclusion, M. conceptionense is not a rare NTM species in South Korea and can cause pulmonary disease.