Mycobacterium shinjukuense lung disease that was successfully treated with antituberculous drugs

Two Cases of Mycobacterium shinjukuense Pulmonary Disease With a Long-Term Response to Treatment With Clarithromycin, Rifampicin, and Ethambutol

Mycobacterium shinjukuense is a nontuberculous mycobacterium, and standard treatment for the infection has not been established. We report two cases of M. shinjukuense pulmonary disease in which two patients were treated with clarithromycin (CAM), rifampicin (RFP), and ethambutol (EB). Based on computed tomography (CT) findings, the patients experienced improvement with treatment. Reports of multiple cases of M. shinjukuense pulmonary disease treated with clarithromycin, rifampicin, and ethambutol are valuable, and they suggest that this regimen may be a new treatment option.

Mycobacterium shinjukuense infection successfully treated with clarithromycin, rifampicin, and ethambutol

We present the case of a 59-year-old woman diagnosed with Mycobacterium shinjukuense infection using mass spectrometry of bronchioalveolar lavage fluid. We initiated treatment with clarithromycin, rifampicin, and ethambutol based on the results of drug susceptibility testing, which improved lung opacities. Most previous cases were treated with the standard regimen for Mycobacterium tuberculosis. However, our regimen may provide a therapeutic option for this rare nontuberculous Mycobacterium infection.

Varying clinical presentations of nontuberculous mycobacterial disease : Similar to but different from tuberculosis

The incidence rate of pulmonary nontuberculous mycobacterial disease (PNTMD) in Japan is the highest among major industrialized nations. Although the typical clinical course and radiological manifestations of PNTMD are different from those of pulmonary tuberculosis (TB), confusion about these mycobacterial diseases leads to a diagnostic pitfall. Diagnostic challenges include the coexistence of Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM), false positives for NTM in MTB nucleic acid amplification tests, microbial substitution, and abnormal radiological manifestations caused by NTM. Features of extrapulmonary NTM diseases, such as pleurisy, vertebral osteomyelitis, and disseminated disease, are different from the corresponding tuberculous diseases. Moreover, the immunological background of the patient (status of human immunodeficiency virus infection with or without antiviral therapy, continuation or discontinuation of immunosuppressive therapy, use of immune checkpoint inhibitor, pregnancy and delivery, etc.) influences the pathophysiology of mycobacterial diseases. This review describes the varying clinical presentations of NTM disease with emphasis on the differences from TB. J. Med. Invest. 68 : 220-227, August, 2021.

Mycobacterium Shinjukuense Pulmonary Disease Progressed to Pleuritis after Iatrogenic Pneumothorax: A Case Report

Mycobacterium shinjukuense is a newly identified nontuberculous mycobacteria (NTM) and its gene sequence of 16S rRNA shows high homology to that of Mycobacterium tuberculosis. We present a case of M. shinjukuense pulmonary disease progressed to pleuritis after iatrogenic pneumothorax. The patient was initially diagnosed as tuberculosis based on a positive result for the 16S rRNA of an M. tuberculosis identification kit using scrapings from the cavitary nodule. We need to bear in mind that pneumothorax following bronchoscopy may induce NTM pleuritis and M. shinjukuense infection should be considered in the differential diagnosis of mycobacterial pulmonary disease with effusion.

Six Cases of Pulmonary Mycobacterium shinjukuense Infection at a Single Hospital

Mycobacterium shinjukuense lung disease was diagnosed in 3 men and 3 women [mean age: 77.0±12.2 (57-93) years]. On imaging, 3 patients with previous pulmonary tuberculosis exhibited a fibrocavitary pattern, while the other 3 patients showed nodular bronchiectasis. A test with a tuberculosis rRNA identification kit (TRC Rapid(®) M. TB) was falsely positive for M. tuberculosis due to DNA sequence similarity in 16SrRNA. M. shinjukuense was identified by the gene sequences of rpoB, 16S rRNA, and hsp65. The symptoms and imaging findings of most of the patients have improved with chemotherapy with low minimum inhibitory concentrations of anti-tuberculosis drugs.

Nontuberculous Mycobacterial Lung Disease Caused by Mycobacterium shinjukuense: The First Reported Case in Korea

Mycobacterium shinjukuense is a novel species of nontuberculous mycobacteria (NTM) that was first reported in Japan in 2011. It is a slow-growing NTM pathogen that can cause chronic pulmonary infections. There are only a few reported cases of M. shinjukuense infections, all of which are from Japan. We reported a case of chronic lung disease caused by M. shinjukuense. The organism was identified by 16S rRNA, rpoB, and hsp65 gene sequencing. To the best of our knowledge, this was the first confirmed case of lung disease caused by M. shinjukuense outside of Japan.

Microbiological features and clinical relevance of new species of the genus Mycobacterium

Nontuberculous mycobacteria (NTM) are present in the environment, mainly in water, and are occasionally responsible for opportunistic infections in humans. Despite the fact that NTM are characterized by a moderate pathogenicity, the diseases caused by NTM at various body sites are increasing on a worldwide level. Among over 150 officially recognized NTM species, only two or three dozen are familiar to clinicians, and even to most microbiologists. In this paper, approximately 50 new species described in the last 8 years are reviewed, and their role in human infections is assessed on the basis of reported clinical cases. The small number of reports concerning most of the "new" mycobacterial species is responsible for the widespread conviction that they are very rare. Their role is actually largely underestimated, mainly because they often remain unrecognized and misidentified. Aiming to minimize such bias, emphasis has been placed on more common identification pitfalls. Together with new NTM, new members of the Mycobacterium tuberculosis complex described in the last few years are also an object of the present review.