title: Pulmonary Actinomyces graevenitzii infection presenting as organizing pneumonia diagnosed by PCR analysis.
abstract: We report what is believed to be the first case of pulmonary Actinomyces graevenitzii infection presenting as organizing pneumonia. Fever and night sweats developed in a 69-year-old male. The only abnormal laboratory data were an elevated erythrocyte sedimentation rate and C-reactive protein level. On chest images, multiple consolidations with air bronchograms were seen in the bilateral lungs. Histological examination from lung biopsy revealed a pattern of organizing pneumonia with microabscesses, but definitive diagnosis was not obtained because culture from lung specimen was negative. A. graevenitzii was eventually identified in the lung biopsy specimen by detection of an Actinomyces-specific PCR product followed by 16S rRNA gene sequencing. The patient was treated with high-dose ampicillin intravenously for 1 month, followed by oral amoxicillin and clarithromycin for 6 months, and recovered. We suggest that actinomycosis can present as organizing pneumonia, and identification of infection by PCR analysis and rRNA gene sequencing is a useful strategy in cases that are difficult to diagnose.
authors.affiliation: Department of Respiratory Medicine, National Centre for Global Health and Medicine, Tokyo, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Fujita
authors.affiliation: Department of Respiratory Medicine, National Centre for Global Health and Medicine, Tokyo, Japan.
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Iikura
authors.affiliation: Department of Respiratory Medicine, National Centre for Global Health and Medicine, Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Horio
authors.affiliation: Department of Microbiology, Gifu University Graduate School of Medicine, Gifu, Japan.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Ohkusu
authors.affiliation: Department of Respiratory Medicine, National Centre for Global Health and Medicine, Tokyo, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kobayashi
mesh_terms: D000190:Actinomyces / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D000196:Actinomycosis / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology*; D000368:Aged; D000658:Amoxicillin / Q000008:administration & dosage; D000667:Ampicillin / Q000008:administration & dosage; D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D001431:Bacteriological Techniques / Q000379:methods; D001706:Biopsy; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D017291:Clarithromycin / Q000008:administration & dosage; D018549:Cryptogenic Organizing Pneumonia / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology / Q000473:pathology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D006651:Histocytochemistry; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013902:Radiography, Thoracic; D017422:Sequence Analysis, DNA; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D000667:Ampicillin; D000658:Amoxicillin; D002097:C-Reactive Protein; D017291:Clarithromycin