title: Diagnosis of fulminant pneumonia caused by Legionella pneumophila serogroup 8 with the sequence analysis of the 16S rRNA gene.
abstract: Pneumonia is the fourth leading cause of death in Japan. Accurate and rapid detection of the causative pathogen(s) is necessary and important for appropriate antimicrobial treatment, especially in patients with rapidly progressive pneumonia or immunocompromised patients. Conventional methods, such as cultivations, detection of urinary antigens or PCR amplification of specific genes, inevitably require the precise presumption of potential pathogens in each case, and pneumonia caused by unanticipated microorganisms might lead to inadequate antimicrobial treatments and unfortunate consequences. We herein report an immunocompromised female patient (69 years old) with fulminant pneumonia caused by Legionella (L.) pneumophila serogroup 8. Ordinary cultivation methods and urinary antigen detection failed to identify the causative organisms. Accordingly, DNA was extracted from the bronchoalveolar lavage fluid and used for the PCR-based cloning of the bacterial 16S rRNA gene. Sequencing analysis of the isolated clones revealed the predominance of L. pneumophila. Based on this information, the patient received an appropriate and successful antimicrobial treatment. In addition, L. pneumophila serogroup 8 was identified with culturing the bronchoalveolar lavage fluid and serotyping with L. pneumophila antisera. The 16S rRNA gene sequencing analysis can reveal the potential pathogens without any presumption about the organism, and can evaluate the kinds and ratio of bacterial species in each specimen. In conclusion, this cultivation-independent method is a potential diagnostic modality for pneumonia, especially in patients with rapidly progressive pneumonia or those who are immunocompromised.
authors: Department of Respiratory Medicine, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan. namihei@med.uoeh-u.ac.jp
authors: Toshinori
authors: T
authors: Kawanami
authors: Kazuhiro
authors: K
authors: Yatera
authors: Kazumasa
authors: K
authors: Fukuda
authors: Kei
authors: K
authors: Yamasaki
authors: Masamizu
authors: M
authors: Kunimoto
authors: Shuya
authors: S
authors: Nagata
authors: Chinatsu
authors: C
authors: Nishida
authors: Hiroshi
authors: H
authors: Ishimoto
authors: Midori
authors: M
authors: Ogawa
authors: Hatsumi
authors: H
authors: Taniguchi
authors: Hiroshi
authors: H
authors: Mukae
mesh_terms: D000368:Aged; D000890:Anti-Infective Agents / Q000627:therapeutic use; D001483:Base Sequence; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D005260:Female; D006801:Humans; D007564:Japan; D016952:Legionella pneumophila / Q000235:genetics*; D007877:Legionnaires' Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000382:microbiology; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011859:Radiography; D017422:Sequence Analysis, DNA; D012703:Serotyping; D016896:Treatment Outcome
chemical_list: D000890:Anti-Infective Agents; D012336:RNA, Ribosomal, 16S