Objective: To analyze the clinical features and differential diagnosis of pulmonary infection with Mycobacterium massiliense (M. massiliense).
Methods: The clinical manifestations and laboratory test results of our patient were analyzed and the strain isolated from the patient was tested by bacteriological and molecular methods. The partial gene fragments of rpoB and hsp65 were amplified by PCR, sequenced and compared with GeneBank database in NCBI for identification of Mycobacterium species.
Results: The patient was a 72 year old female, who had been admitted to hospital several times because of recurrent respiratory symptoms which had failed to improve upon treatment. This time, pulmonary infection with M. massiliense was confirmed by clinical manifestation and laboratory results. M. massilence isolated from the sputum of our patient was confirmed by bacteriological and molecular methods. The results of specific segments of rpoB and hsp65 tested by PCR and sequence analysis, and compared with that of mycobacterium in NCBI, showed that the DNA homology was 100% and 99% respectively. The results of drug sensitivity test showed that this strain was resistant to multiple drugs. According to the results of drug susceptibility tests and the condition of the patient, therapy with cefoxitin sodium and amikacin was used and the drugs were effective.
Conclusions: The clinical manifestations and the chest imaging of pulmonary infection with M. massiliens were similar to those of Mycobacterium tuberculosis, which can be differentiated by laboratory tests.