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Background Mycobacterial culture is the gold standard for the diagnosis of nontuberculous Mycobacterium (NTM) infections. However, this method is not suitable for detection of coinfection with different NTMs. Research Question The goal of this study was to determine if clone library analysis of BAL fluid (BALF) was useful for detection of NTM phylotypes, including multiple NTM phylotypes, in pulmonary NTM infections. Study Design and Methods BALF samples obtained from 120 patients with suspected pulmonary NTM infections were retrospectively evaluated by using the mycobacterial culture and clone library methods between July 2010 and August 2016. Results In total, 55 (45.8%) patients were diagnosed as NTM positive according to results of mycobacterial culture, and 52 patients were NTM positive as determined by using the clone library method. Furthermore, 45 (86.5%) and seven (13.5%) patients exhibited a single phylotype (mono-phylotype group) and multiple phylotypes of NTM (multi-phylotype group), respectively. Compared with the mono-phylotype group, the multi-phylotype group had a significantly higher incidence of adverse chest CT findings (P = .048). In addition, 11 patients who were NTM negative according to results of BALF mycobacterial culture were determined to be NTM positive according to the clone library method. Six of these 11 patients were eventually diagnosed as NTM positive by using mycobacterial culture results within 6.2 ± 2.1 months following the initial sample collection. Interpretation Coinfection multiple phylotypes could be associated with adverse clinical findings. In addition, patients who test positive for NTM genes but negative for mycobacterial culture may be diagnosed with NTM lung infection within 1 year of the initial sample collection. Further follow-up of these patients may facilitate early detection of NTM species.

Mycobacterial culture is the gold standard for the diagnosis of nontuberculous Mycobacterium (NTM) infections. However, this method is not suitable for detection of coinfection with different NTMs.The goal of this study was to determine if clone library analysis of BAL fluid (BALF) was useful for detection of NTM phylotypes, including multiple NTM phylotypes, in pulmonary NTM infections.BALF samples obtained from 120 patients with suspected pulmonary NTM infections were retrospectively evaluated by using the mycobacterial culture and clone library methods between July 2010 and August 2016.In total, 55 (45.8%) patients were diagnosed as NTM positive according to results of mycobacterial culture, and 52 patients were NTM positive as determined by using the clone library method. Furthermore, 45 (86.5%) and seven (13.5%) patients exhibited a single phylotype (mono-phylotype group) and multiple phylotypes of NTM (multi-phylotype group), respectively. Compared with the mono-phylotype group, the multi-phylotype group had a significantly higher incidence of adverse chest CT findings (P = .048). In addition, 11 patients who were NTM negative according to results of BALF mycobacterial culture were determined to be NTM positive according to the clone library method. Six of these 11 patients were eventually diagnosed as NTM positive by using mycobacterial culture results within 6.2 ± 2.1 months following the initial sample collection.Coinfection multiple phylotypes could be associated with adverse clinical findings. In addition, patients who test positive for NTM genes but negative for mycobacterial culture may be diagnosed with NTM lung infection within 1 year of the initial sample collection. Further follow-up of these patients may facilitate early detection of NTM species.

Background The frequencies of etiologic bacterial agents of intrapleural infections reported until now have been widely varied, largely depending on the implemented detective methods. The aims of this study were to evaluate bacterial etiologies of bacterial pleurisy using a cultivation-independent method. Methods Pleural fluids were collected from 42 febrile patients with hemipleural effusion. The bacterial flora was analyzed by a clone library method using amplified fragments of the 16S ribosomal RNA gene (rDNA) with universal primers in addition to conventional cultivation methods. Results Forty-two specimens were obtained from 26 patients with bacterial pleurisy, seven with mycobacterial pleurisy, and nine with other pleural effusions. In the 26 bacterial cases, 16 (61.5%) showed positive results for 16S rDNA sequencing analysis, of which 11 (42.3%) were also positive for cultivation method. In seven (43.8%) of the 16 polymerase chain reaction-positive cases, anaerobic phylotypes were predominantly detected. Anaerobic phylotypes (six of these seven cases) were not detected by cultivation method. In nine (34.6%) of the 26 bacterial pleural cases, the results from the clone library methods were not accordant with those of the cultivation method. In seven of these nine cases, the discrepancies between the two detection methods were due to the existence of anaerobes. Conclusion The clone library analysis using the 16S rDNA of pleural fluid showed a higher incidence of anaerobic bacteria in infectious pleurisy than that previously expected and provided additional bacterial information for cultivation methods.

Background Mucosa-associated lymphoid tissue (MALT) lymphoma constitutes approximately 90% of primary pulmonary lymphoma, and the diagnosis of pulmonary MALT lymphoma often requires invasive methods such as surgical lung biopsy. Chromosomal rearrangements involving MALT lymphoma translocation gene 1 (MALT1) have been reported to be specific for MALT lymphoma. The combination of BAL and cytologic approaches with molecular methods is useful for the diagnosis of lymphoproliferative disorders. Therefore, we examined the detection of MALT1 gene rearrangements in BAL fluid (BALF) cells for the diagnosis of MALT lymphoma. Methods We determined the percentage of BALF cells with MALT1 gene rearrangements by using the fluorescence in situ hybridization (FISH) method in 10 patients suspected to have pulmonary MALT lymphoma. Results MALT1 gene rearrangements in BALF cells were found in four of five cases with pulmonary MALT lymphoma (percentage of BALF cells with MALT1 gene rearrangements: 21.8% ± 6.8%). On the other hand, MALT1 gene rearrangements in BALF cells were negative in the five cases without pulmonary MALT lymphoma and one case with pulmonary MALT lymphoma. Conclusion These results suggest that the detection of MALT1 gene rearrangements in BALF cells is useful for the diagnosis of pulmonary MALT lymphoma, as it is a specific method that is less invasive than surgical biopsy. Because of the small number of patients in this study, further investigations are necessary to evaluate the detection rate of MALT1 gene rearrangements in BALF cells from patients with pulmonary MALT lymphoma.

The frequencies of etiologic bacterial agents of intrapleural infections reported until now have been widely varied, largely depending on the implemented detective methods. The aims of this study were to evaluate bacterial etiologies of bacterial pleurisy using a cultivation-independent method.Pleural fluids were collected from 42 febrile patients with hemipleural effusion. The bacterial flora was analyzed by a clone library method using amplified fragments of the 16S ribosomal RNA gene (rDNA) with universal primers in addition to conventional cultivation methods.Forty-two specimens were obtained from 26 patients with bacterial pleurisy, seven with mycobacterial pleurisy, and nine with other pleural effusions. In the 26 bacterial cases, 16 (61.5%) showed positive results for 16S rDNA sequencing analysis, of which 11 (42.3%) were also positive for cultivation method. In seven (43.8%) of the 16 polymerase chain reaction-positive cases, anaerobic phylotypes were predominantly detected. Anaerobic phylotypes (six of these seven cases) were not detected by cultivation method. In nine (34.6%) of the 26 bacterial pleural cases, the results from the clone library methods were not accordant with those of the cultivation method. In seven of these nine cases, the discrepancies between the two detection methods were due to the existence of anaerobes.The clone library analysis using the 16S rDNA of pleural fluid showed a higher incidence of anaerobic bacteria in infectious pleurisy than that previously expected and provided additional bacterial information for cultivation methods.