Clinical impact of methicillin-resistant staphylococcus aureus on bacterial pneumonia: cultivation and 16S ribosomal RNA gene analysis of bronchoalveolar lavage fluid. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Kawanami, Toshinori; Yatera, Kazuhiro; Yamasaki, Kei; Noguchi, Shingo; Fukuda, Kazumasa; Akata, Kentarou; Naito, Keisuke; Kido, Takashi; Ishimoto, Hiroshi; Taniguchi, Hatsumi; Mukae, Hiroshi
• Is Part Of: BMC infectious diseases. Volume 16:Issue 1(2016)
• Page Start: 1
• Page End: 9
• Publication Date: 2016-12
• Subjects: 16S rRNA gene -- Methicillin-resistant Staphylococcus aureus, MRSA -- Clone library -- Contamination -- Pneumonia -- Bronchoalveolar lavage, BALF -- Pneumonia; Communicable diseases -- Periodicals; Sexually Transmitted Diseases -- Periodicals; 616.905
• DOI: 10.1186/s12879-016-1493-3
• Languages: English
• ISSNs: 1471-2334

Abstract

Abstract Background Determining whether methicillin-resistantStaphylococcus aureus (MRSA) is a true causative pathogen or reflective of colonization when MRSA is cultured from the respiratory tract remains important in treating patients with pneumonia. Methods We evaluated the bacterial microbiota in bronchoalveolar lavage fluid (BALF) using the clone library method with a 16S ribosomal RNA (rRNA) gene analysis in 42 patients from a pneumonia registry who had MRSA cultured from their sputum or BALF samples. Patients were divided into two groups: those treated with (Group A) or without (Group B) anti-MRSA agents, and their clinical features were compared. Results Among 248 patients with pneumonia, 42 patients who had MRSA cultured from the respiratory tract were analyzed (Group A: 13 patients, Group B: 29 patients). No clones ofS. aureus were detected in the BALF of 20 out of 42 patients. Twenty-eight of 29 patients in Group B showed favorable clinical outcomes, indicating that these patients had non-MRSA pneumonia. Using a microflora analysis of the BALF, theS. aureus phylotype was predominant in 5 of 28 (17.9 %) patients among the detected bacterial phylotypes, but a minor population (the percentage of clones ≤ 10 %) in 19 (67.9 %) of 28 patients. A statistical analysis revealed no positive relationship between the percentage of clones of theS. aureus phylotype and risk factors of MRSA pneumonia. Conclusions The molecular method using BALF specimens suggests that conventional cultivation method results may mislead true causative pathogens, especially in patients with MRSA pneumonia. Further studies are necessary to elucidate these clinically important issues.