Bacteriological incidence in pneumonia patients with pulmonary emphysema: a bacterial floral analysis using the 16S ribosomal RNA gene in bronchoalveolar lavage fluid

Abstract

Pulmonary emphysema is an important radiological finding in chronic obstructive pulmonary disease patients, but bacteriological differences in pneumonia patients according to the severity of emphysematous changes have not been reported. Therefore, we evaluated the bacteriological incidence in the bronchoalveolar lavage fluid (BALF) of pneumonia patients using cultivation and a culture-independent molecular method. Japanese patients with community-acquired pneumonia (83) and healthcare-associated pneumonia (94) between April 2010 and February 2014 were evaluated. The BALF obtained from pneumonia lesions was evaluated by both cultivation and a molecular method. In the molecular method, ~600 base pairs of bacterial 16S ribosomal RNA genes in the BALF were amplified by polymerase chain reaction, and clone libraries were constructed. The nucleotide sequences of 96 randomly selected colonies were determined, and a homology search was performed to identify the bacterial species. A qualitative radiological evaluation of pulmonary emphysema based on chest computed tomography (CT) images was performed using the Goddard classification. The severity of pulmonary emphysema based on the Goddard classification was none in 47.4% (84/177), mild in 36.2% (64/177), moderate in 10.2% (18/177), and severe in 6.2% (11/177). Using the culture-independent molecular method, Moraxella catarrhalis was significantly more frequently detected in moderate or severe emphysema patients than in patients with no or mild emphysematous changes. The detection rates of Haemophilus influenzae and Pseudomonas aeruginosa were unrelated to the severity of pulmonary emphysematous changes, and Streptococcus species – except for the S. anginosus group and S. pneumoniae – were detected more frequently using the molecular method we used for the BALF of patients with pneumonia than using culture methods. Our findings suggest that M. catarrhalis is more frequently detected in pneumonia patients with moderate or severe emphysema than in those with no or mild emphysematous changes on chest CT. M. catarrhalis may play a major role in patients with pneumonia complicating severe pulmonary emphysema.

Lung Macrophage Phenotypes and Functional Responses: Role in the Pathogenesis of COPD

“…Berenson et al reported that the severity of COPD (FEV 1% predicted) correlated with impaired LM phagocytosis for nontypeable Haemophilus influenzae (NTHi) and Moraxella catarrhalis [ 28 ]. Moreover, studies using clone library analysis of the 16 s RNA gene sequence have reported that H. influenzae and M. catarrhalis were more frequently identified as causative bacteria for pneumonia and/or exacerbations of COPD as well as disease progression [ 29 ]. Similarly, Streptococcus pneumoniae , which also causes acute COPD exacerbations, had been associated with the progression of emphysema possibly by inducing LMs to produce MMP-12 [ 30 ].…”

“…Therefore, the defective phagocytic and efferocytic functions of LMs in COPD could contribute to the colonization of the airways with various bacteria, specifically those known to cause acute exacerbations and pneumonia during COPD. Consequently, these infections have been related to the progression of COPD [ 29 ].…”

Anti-PcrV titers in non-cystic fibrosis patients with Pseudomonas aeruginosa respiratory tract infection

“…People with structural lung abnormalities, such as cystic fibrosis, bronchiectasis, DPB, idiopathic pulmonary fibrosis, and emphysema, have a high incidence of P. aeruginosa airway tract colonization or infection (Poletti et al, 2006;Yamazaki et al, 2016;Naito et al, 2017;Kadowaki et al, 2015;Arancibia et al, 2002). In the present study, three participants in the PA group had DPB and 10 had radiological findings of bronchiolitis, which may reflect P. aeruginosa colonization of their bronchioles, and all participants in the PA group had structural lung abnormalities.…”

“…Previous chest CT scans were reviewed retrospectively and evaluated. In order to evaluate structural lung abnormalities related to P. aeruginosa infection, the following radiological patterns were sought: bronchiolitis (small nodules <5 mm in diameter, arranged in a centrilobular fashion), bronchiectasis (1.5 times as wide as a nearby vessel and a lack of bronchial tapering on sequential slices), traction bronchiectasis, and emphysema (Poletti et al, 2006;Yamazaki et al, 2016;Naito et al, 2017;Kadowaki et al, 2015).…”

Chronic Pseudomonas aeruginosa Infection as the Pathogenesis of Chronic Obstructive Pulmonary Disease

“…of <35%, systemic steroid use, and antibiotic therapy within the preceding 3 months increased the risk of P. aeruginosa colonization [13,23,24]. The detection rates of H. influenza and P. aeruginosa were reported not to be associated with the severity of emphysematous changes [26,27]. However, chronic P. aeruginosa infection was recently reported to be associated with severe obstruction in COPD patients [28].…”