Kei Yamasaki

Significance of Anaerobes and Oral Bacteria in Community-Acquired Pneumonia

Background Molecular biological modalities with better detection rates have been applied to identify the bacteria causing infectious diseases. Approximately 10–48% of bacterial pathogens causing community-acquired pneumonia are not identified using conventional cultivation methods. This study evaluated the bacteriological causes of community-acquired pneumonia using a cultivation-independent clone library analysis of the 16S ribosomal RNA gene of bronchoalveolar lavage specimens, and compared the results with those of conventional cultivation methods. Methods Patients with community-acquired pneumonia were enrolled based on their clinical and radiological findings. Bronchoalveolar lavage specimens were collected from pulmonary pathological lesions using bronchoscopy and evaluated by both a culture-independent molecular method and conventional cultivation methods. For the culture-independent molecular method, approximately 600 base pairs of 16S ribosomal RNA genes were amplified using polymerase chain reaction with universal primers, followed by the construction of clone libraries. The nucleotide sequences of 96 clones randomly chosen for each specimen were determined, and bacterial homology was searched. Conventional cultivation methods, including anaerobic cultures, were also performed using the same specimens. Results In addition to known common pathogens of community-acquired pneumonia [Streptococcus pneumoniae (18.8%), Haemophilus influenzae (18.8%), Mycoplasma pneumoniae (17.2%)], molecular analysis of specimens from 64 patients with community-acquired pneumonia showed relatively higher rates of anaerobes (15.6%) and oral bacteria (15.6%) than previous reports. Conclusion Our findings suggest that anaerobes and oral bacteria are more frequently detected in patients with community-acquired pneumonia than previously believed. It is possible that these bacteria may play more important roles in community-acquired pneumonia.

High-resolution CT scoring system-based grading scale predicts the clinical outcomes in patients with idiopathic pulmonary fibrosis.

BackgroundThe 2011 idiopathic pulmonary fibrosis (IPF) guidelines are based on the diagnosis of IPF using only high-resolution computed tomography (HRCT). However, few studies have thus far reviewed the usefulness of the HRCT scoring system based on the grading scale provided in the guidelines. We retrospectively studied 98 patients with respect to assess the prognostic value of changes in HRCT findings using a new HRCT scoring system based on the grading scale published in the guidelines.MethodsConsecutive patients with IPF who were diagnosed using HRCT alone between January 2008 and January 2012 were evaluated. HRCT examinations and pulmonary function tests were performed at six-month intervals for the first year after diagnosis. The HRCT findings were evaluated using the new HRCT scoring system (HRCT fibrosis score) over time. The findings and survival rates were analyzed using a Kaplan-Meier analysis.ResultsThe HRCT fibrosis scores at six and 12 months after diagnosis were significantly increased compared to those observed at the initial diagnosis (p < 0.001). The patients with an elevated HRCT fibrosis score at six months based on a receiver operating characteristic (ROC) curves analysis had a poor prognosis (log-rank, hazard ratio [HR] 2.435, 95% CI 1.196-4.962; p = 0.0142). Furthermore, among the patients without marked changes in %FVC, those with an elevated score above the cut-off value had a poor prognosis (HR 2.192, 95% CI 1.003-4.791; p = 0.0491).ConclusionsOur data demonstrate that the HRCT scoring system based on the grading scale is useful for predicting the clinical outcomes of IPF and identifying patients with an adverse prognosis when used in combination with spirometry.

Bacteriological Assessment of Healthcare-Associated Pneumonia Using a Clone Library Analysis

Background The causative pathogens of healthcare-associated pneumonia (HCAP) remain controversial, and the use of conventional cultivation of sputum samples is occasionally inappropriate due to the potential for oral bacterial contamination. It is also sometimes difficult to determine whether methicillin-resistant Staphylococcus aureus (MRSA) is a true causative pathogen of HCAP. Methods We evaluated the bacterial diversity in bronchoalveolar lavage fluid (BALF) using molecular and cultivation methods in 82 HCAP patients. BALF specimens were obtained from the lesions of pneumonia using bronchoscopy. The bacterial flora was analyzed according to the clone library method using amplified fragments of the 16S ribosomal RNA gene with universal primers. In addition, sputum cultures and the above specimens were assessed. Results Eighty (97.6%) of the 82 BALF samples obtained from the patients with HCAP showed positive polymerase chain reaction results. The predominant phylotypes detected in the BALF in this study included bacteria common in cases of community- and hospital-acquired pneumonia. In addition, the phylotypes of streptococci and anaerobes were detected in 19 (23.2%) and 8 (9.8%) cases, respectively. In particular, phylotypes of streptococci were highly detected among the patients 75 of age or older. Staphylococcus aureus was cultured in 23 (28.0%) cases using conventional cultivation methods and detected in only 6 (7.3%) cases as predominant phylotypes according to the clone library method. Conclusions The clone library analysis of BALF in the HCAP patients detected heterogeneous bacteria and a high incidence of streptococci compared with that observed using cultivation methods. In addition, the results of our study may indicate a lower incidence of MRSA than previously expected in HCAP patients.

Relationship between the ratios of CD4/CD8 T-lymphocytes in the bronchoalveolar lavage fluid and lymph nodes in patients with sarcoidosis

BACKGROUND Evaluating the ratio of CD4/CD8 T-lymphocytes in the bronchoalveolar lavage fluid (BALF) is important for understanding the clinical and pathological conditions of patients with sarcoidosis. However, few studies have thus far demonstrated the usefulness of evaluating the relationship between the ratios of CD4/CD8 T-lymphocytes in the mediastinal lymph nodes and BALF. This study aimed to investigate and identify the relationships between CD4/CD8 T-lymphocyte ratio in the mediastinal lymph nodes and BALF in patients with sarcoidosis. METHODS Thirty-three consecutive patients with sarcoidosis with enlarged mediastinal and/or hilar lymphadenopathy were enrolled in the study, and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and bronchoalveolar lavage (BAL) were simultaneously performed. The CD4/CD8 T-lymphocyte ratios in the mediastinal lymph nodes and BALF were evaluated using immunohistochemistry and flow cytometry, respectively. RESULTS The interobserver variability in the CD4/CD8 ratio in the mediastinal lymph nodes as determined by immunostaining was low, and the pathological and cytological profiles of T-lymphocytes in the mediastinal and/or hilar lymph nodes and BALF were correlated in patients with sarcoidosis. Additionally, the CD4/CD8 T-lymphocyte ratios in BALF were significantly higher than those in the mediastinal lymph nodes. Importantly, non-caseating granulomas were detected at a high rate by using EBUS-TBNA. CONCLUSIONS Performing EBUS-TBNA in patients with sarcoidosis allows correct diagnosis as well as the estimation of the ratio of CD4/CD8 T-lymphocytes in BALF.

Evaluation of a rapid immunochromatographic ODK0501 assay for detecting Streptococcus pneumoniae antigens in the sputum of pneumonia patients with positive S. pneumoniae urinary antigens.

BACKGROUND A novel, rapid and noninvasive test (ODK0501, RAPIRUN(®)Streptococcus pneumoniae) uses polyclonal antibodies to detect C polysaccharide of S. pneumoniae derived from sputum samples using an immunochromatographic assay. We evaluated its usefulness in Japanese patients with pneumonia who exhibited positive urinary antigen tests for S. pneumoniae (BinaxNOW(®)S. pneumoniae). PATIENTS AND METHODS Forty adult patients with pneumonia treated between May 2011 and August 2013 were enrolled. Bacterial cultures, Gram staining and ODK0501 assays of sputum as well as urinary antigen tests for S. pneumoniae using urine samples obtained from the same patients were performed upon admission, the fourth day after starting antimicrobial treatment and at the end of the antimicrobial treatment. RESULTS Twenty-seven of the 40 patients were positive for ODK0501, while a negative result for ODK0501 was associated with low-quality sputum samples according to the Geckler classification of sputum. The sensitivity and specificity of the ODK0501 assay in the 40 patients were 90.9% and 61.1%, respectively, based on the culture results. The results obtained with this kit were more favorable than those observed on Gram staining. The ODK0501 assay also showed a rapid reaction to the disappearance of S. pneumoniae in the sputum samples, while approximately 80% of the patients exhibited persistent positive results on the urinary antigen detection tests at the end of treatment. CONCLUSIONS The ODK0501 test is a noninvasive, rapid and accurate tool for diagnosing respiratory infections caused by S. pneumoniae, although good quality sputum must be obtained prior to adequate treatment with antibiotics.

Disseminated Mycobacterium abscessus Complex Infection Manifesting as Multiple Areas of Lymphadenitis and Skin Abscess in the Preclinical Stage of Acute Lymphocytic Leukemia.

A 37-year-old woman was admitted to a hospital due to a prolonged fever and a rash on her legs. She had systemic lymphadenitis and a skin abscess on her left leg. Pathological findings of a left leg skin biopsy revealed abscess formation with granulomatous dermatitis, Mycobacterium abscessus complex was cultured from the resected left supraclavicular lymph node, and disseminated M. abscessus complex infection was diagnosed. She was treated with combination treatment with antimicrobials and percutaneous drainage, and her clinical findings improved. Four months later, she developed acute lymphocytic leukemia. Leukemia is a risk factor for disseminated M. abscessus complex infection, even before developing leukemia.

Possible role of anaerobes in the pathogenesis of nontuberculous mycobacterial infection

Recent advances in cultivation‐independent molecular biological modalities for detecting bacterial species have indicated that several bacterial species may play a role in the pathogenesis of certain infectious diseases. The aim of this study was to evaluate the role of bacterial flora in the pathogenesis of nontuberculous mycobacteriosis (NTM) using a bacterial floral analysis of bronchoalveolar lavage fluid (BALF) with 16S rRNA gene sequencing in patients with bronchiectasis.

Possible familial case of Birt–Hogg–Dubé syndrome complicated with lung cancer: A possible link between these two disease entities

A 65-year-old Japanese woman was introduced to our hospital for an examination of multiple pulmonary cystic lesions and a pulmonary nodule in the left lower lobe. She had a smoking history of 25 pack-years, and her two younger brothers had suffered from pneumothorax; one of them additionally had lung cancer with pulmonary multiple cystic lesions. A surgical biopsy specimen obtained from her left lower lobe revealed adenocarcinoma surrounded by a single epithelial layer that was covered with collagen fibers. The pathological features were compatible with the findings of the cystic lesions in the patients with Birt-Hogg-Dubé syndrome (BHDS). A diagnosis of BHDS was eventually made according to the detection of a folliculin gene mutation. This is the first report of a possible familial case of BHDS complicated with primary lung cancer. We herein reviewed the previously reported cases of BHDS with lung cancer and other tumors and discussed a potential mechanism of tumorigenesis and carcinogenesis in the lung in the patients with BHDS.

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

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.

Prevalence of sinusitis and efficacy of intranasal corticosteroid treatment on asthmatic symptoms in asthmatic patients with rhinosinusitis: a pilot study.

Prevalence of sinusitis on sinus computed tomography (CT) in asthmatic patients and efficacy of intranasal corticosteroid treatment on asthmatic symptoms in asthmatic patients with rhinosinusitis on sinus CT is unclear.