BACKGROUND AND OBJECTIVE

Nontuberculous mycobacteria (NTM) lung disease appears like tuberculosis infection but is resistant to primary anti-tuberculosis drugs. Hence, patients whose sputum sample tests positive for acid-fast bacilli (AFB) and bacterial culture for several times should be assessed for colonization or infection with NTM in a damaged lung secondary to TB. In such cases, though drug-resistant TB may be adequately treated, treatment may need to be directed towards the NTM as well. In NTM therapy, the duration and choice of treatment agent is based upon the specific organism and disease extent. This study used one-step multiplex PCR (mPCR) assay for rapid differentiation of solid cultures in Ogawa medium as Mycobacterium tuberculosis (MTB) and/or NTM.

A total of 80 stocked isolates obtained from the Lung Center of the Philippines from January to December 2018 were screened for NTM in terms of growth in Ogawa medium, acid fastness, and MPT64 TB antigen test result. These were from sputum specimens of multidrug-resistant tuberculosis (MDR-TB) patients. DNA was extracted from cultures (n=55) grown in Ogawa medium and one-step mPCR was performed to identify NTM to the species level.

Out of 80 samples screened, a total of 55 isolates were identified as NTM. One-step mPCR identified 12.73% (7/55) as M. abscessus, 34.55% (19/55) as M. massiliense, 1.82% (1/55) as M. kansasii, and 50.91% (28/55) were identified only up to genus Mycobacteria spp. Neither M. avium complex nor M. intracellulare was identified among the samples tested.

One-step mPCR was able to identify isolates as MTB or NTM coinciding with the initial screening using MPT64 TB antigen test. Multiplex PCR has given a more specific identificati on to the species level. The use of mPCR in identifying MTB and clinically significant NTM’s is suitable for the adequate treatment of mycobacterial infection.

Humans ; Child ; Nontuberculous Mycobacteria ; Lung Diseases

China/epidemiology* ; Humans ; Mycobacterium Infections, Nontuberculous/microbiology* ; Nontuberculous Mycobacteria/classification* ; Transients and Migrants

Humans ; Nontuberculous Mycobacteria ; Peritoneal Dialysis/adverse effects* ; Peritonitis/etiology*

HIV ; HIV Infections/drug therapy* ; Humans ; Mycobacterium Infections, Nontuberculous ; Nontuberculous Mycobacteria

BACKGROUND: Pulmonary infection with nontuberculous mycobacteria (NTM) is increasing in South Korea. Since treatment strategy differs by NTM species, accurate identification is necessary. In this study, using Mycobacterium pulmonary isolates recently recovered from a general hospital in Seoul, the prevalence of NTM isolates was investigated. METHODS: A total of 483 Mycobacterium pulmonary strains isolated between May and November 2018 from an 814-bed general hospital in South Korea were analyzed. Bacterial species were identified based on nucleotide sequences of the 16S–23S rDNA internal transcribed spacer and the rpoB gene. RESULTS: From a total of 1,209 pulmonary specimens from patients suspected to be infected with mycobacteria, 324 deduplicate strains were isolated, comprising 90 Mycobacterium tuberculosis and 229 NTM strains. Among the NTM isolates, 61.5% (n=144) were Mycobacterium avium complex (MAC), including 92 M. avium and 52 Mycobacterium intracellulare, while 8.1% (n=19) represented Mycobacterium abscessus, including 10 M. abscessus subsp. abscessus and 9 M. abscessus subsp. massiliense. In addition, 12 (5.1%) Mycobacterium lentiflavum, 12 (5.1%) Mycobacterium gordonae, 6 (2.6%) Mycobacterium kansasii, and 5 (2.1%) Mycobacterium fortuitum were identified. In addition, Mycobacterium mucogenicum (n=2), Mycobacterium septicum (n=1), Mycobacterium colombiens (n=1), Mycobacterium asiaticum (n=1), and Mycobacterium celatum (n=1) were identified. CONCLUSION: Among the recently recovered Mycobacterium pulmonary strains, more than half were identified as NTM, and MAC was the most prevalent NTM, followed by M. abcessuss.
Base Sequence ; DNA, Ribosomal ; Hospitals, General ; Humans ; Korea ; Mycobacterium ; Mycobacterium avium Complex ; Mycobacterium fortuitum ; Mycobacterium kansasii ; Mycobacterium tuberculosis ; Nontuberculous Mycobacteria ; Prevalence ; Seoul ; Tertiary Care Centers ; Tertiary Healthcare

An inflammatory myofibroblastic tumor (IMT) is a solid tumor of unknown etiology frequently affecting children and young adults and commonly affecting the lung or orbital region. We present a case involving a 41-year-old man who had an IMT combined with Mycobacterium tuberculosis infection in the retroperitoneum. He presented with only pain in the right lower abdomen without accompanying symptoms; a retroperitoneal mass was found on computed tomography. The tumor had invaded the end of the ileum and was attached to the omentum, so mass excision could not be performed. The tumor was completely excised surgically and had histological features diagnostic of an IMT. Histologic findings of the omentum were positive for Ziehl-Nielsen staining for acid-fast bacilli and for a positive polymerase chain reaction for M. tuberculosis. The patient had no apparent immune disorder. These findings made this case exceptional because IMTs, which are mostly due to atypical mycobacteria, have been found mainly in immunocompromised patients.
Abdomen ; Adult ; Child ; Humans ; Ileum ; Immune System Diseases ; Immunocompromised Host ; Inflammation ; Lung ; Mycobacterium tuberculosis ; Myofibroblasts ; Nontuberculous Mycobacteria ; Omentum ; Orbit ; Polymerase Chain Reaction ; Tuberculosis ; Young Adult

No abstract available.
Nontuberculous Mycobacteria*

The pathogen Mycobacterium avium complex (MAC) is the most common cause of nontuberculous mycobacterial pulmonary disease worldwide. The decision to initiate long-term antibiotic treatment is difficult for the physician due to inconsistent disease progression and adverse effects associated with the antibiotic treatment. The prognostic factors for the progression of MAC pulmonary disease are low body mass index, poor nutritional status, presence of cavitary lesion(s), extensive disease, and a positive acid-fast bacilli smear. A regimen consisting of macrolides (clarithromycin or azithromycin) with rifampin and ethambutol has been recommended; this regimen significantly improves the treatment of MAC pulmonary disease and should be maintained for at least 12 months after negative sputum culture conversion. However, the rates of default and disease recurrence after treatment completion are still high. Moreover, treatment failure or macrolide resistance can occur, although in some refractory cases, surgical lung resection can improve treatment outcomes. However, surgical resection should be carefully performed in a well-equipped center and be based on a rigorous risk-benefit analysis in a multidisciplinary setting. New therapies, including clofazimine, inhaled amikacin, and bedaquiline, have shown promising results for the treatment of MAC pulmonary disease, especially in patients with treatment failure or macrolide-resistant MAC pulmonary disease. However, further evidence of the efficacy and safety of these new treatment regimens is needed. Also, a new consensus is needed for treatment outcome definitions as widespread use of these definitions could increase the quality of evidence for the treatment of MAC pulmonary disease.
Amikacin ; Body Mass Index ; Clofazimine ; Consensus ; Disease Progression ; Ethambutol ; Humans ; Lung ; Lung Diseases ; Macrolides ; Mycobacterium avium Complex* ; Mycobacterium avium* ; Mycobacterium* ; Nontuberculous Mycobacteria ; Nutritional Status ; Recurrence ; Rifampin ; Sputum ; Treatment Failure ; Treatment Outcome

Mycobacterium abscessus is the second most important pathogen in pulmonary disease caused by nontuberculous mycobacteria (NTM), following Mycobacterium avium. Mycobacterium abscessus is classified into three subspecies: M. abscessus subsp. abscessus, M. abscessus subsp. massiliense, and M. abscessus subsp. bolletii. Mycobacterium abscessus is the most difficult to treat NTM due to its resistance to many antibiotics. Treatment should include an initial regimen of 2–3 injectable and oral antibiotics for several weeks or months, followed by inhaled amikacin and 1–3 oral antibiotics, depending on the subspecies and drug susceptibility patterns, including macrolide susceptibility. The continuation phase should be continued for a minimum of 12 months after culture conversion. Suitable injectable antibiotics include amikacin, imipenem, cefoxitin, and tigecycline, while oral antibiotics include macrolides (azithromycin or clarithromycin), clofazimine, linezolid, and moxifloxacin. Surgery can be a useful adjunctive therapy for some patients with refractory disease. However, the overall treatment prognosis is still unsatisfactory. Therefore, novel and more effective interventions are required for the treatment of M. abscessus pulmonary disease.
Amikacin ; Anti-Bacterial Agents ; Cefoxitin ; Clofazimine ; Humans ; Imipenem ; Linezolid ; Lung Diseases ; Macrolides ; Mycobacterium avium ; Mycobacterium ; Nontuberculous Mycobacteria ; Prognosis