title: Emerging ST121/agr4 community-associated methicillin-resistant Staphylococcus aureus (MRSA) with strong adhesin and cytolytic activities: trigger for MRSA pneumonia and fatal aspiration pneumonia in an influenza-infected elderly.
abstract: The pathogenesis of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) pneumonia in influenza-infected elderly individuals has not yet been elucidated in detail. In the present study, a 92-year-old man infected with influenza developed CA-MRSA pneumonia. His CA-MRSA was an emerging type, originated in ST121/agr4 S. aureus, with diversities of Panton-Valentine leucocidin (PVL)(-)/spat5110/SCCmecV(+) versus PVL(+)/spat159((etc.))/SCCmec (-), but with common virulence potentials of strong adhesin and cytolytic activities. Resistance to erythromycin/clindamycin (inducible-type) and gentamicin was detected. Pneumonia improved with the administration of levofloxacin, but with the subsequent development of fatal aspiration pneumonia. Hence, characteristic CA-MRSA with strong adhesin and cytolytic activities triggered influenza-related sequential complications.
authors.affiliation: Department of Epidemiology, Genomics, and Evolution, International Medical Education and Research Centre, Niigata, Japan; Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: T-W
authors.initials: TW
authors.lastname: Wan
authors.affiliation: Developmental Therapeutics Branch, Centre for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Tomita
authors.affiliation: Konno Hospital, Fukuoka, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Saita
authors.affiliation: Konno Hospital, Fukuoka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Konno
authors.affiliation: Department of Epidemiology, Genomics, and Evolution, International Medical Education and Research Centre, Niigata, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Iwao
authors.affiliation: Department of Microbiology and Immunology, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: W-C
authors.initials: WC
authors.lastname: Hung
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: L-J
authors.initials: LJ
authors.lastname: Teng
authors.affiliation: Department of Epidemiology, Genomics, and Evolution, International Medical Education and Research Centre, Niigata, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
keywords: Community-associated methicillin-resistant Staphylococcus aureus; ST121/agr4 lineage; elderly community-acquired pneumonia; fatal aspiration pneumonia; influenza