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

T-W Wan; Y Tomita; N Saita; K Konno; Y Iwao; W-C Hung; L-J Teng; T Yamamoto

doi:10.1016/j.nmni.2016.05.011

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

New Microbes New Infect. 2016 May 26:13:17-21. doi: 10.1016/j.nmni.2016.05.011. eCollection 2016 Sep.

Authors

T-W Wan¹, Y Tomita², N Saita³, K Konno³, Y Iwao⁴, W-C Hung⁵, L-J Teng⁶, T Yamamoto⁴

Affiliations

¹ 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.
² Developmental Therapeutics Branch, Centre for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
³ Konno Hospital, Fukuoka, Japan.
⁴ Department of Epidemiology, Genomics, and Evolution, International Medical Education and Research Centre, Niigata, Japan.
⁵ Department of Microbiology and Immunology, Kaohsiung Medical University, Kaohsiung, Taiwan.
⁶ Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, Taipei, Taiwan.

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.

Keywords: Community-associated methicillin-resistant Staphylococcus aureus; ST121/agr4 lineage; elderly community-acquired pneumonia; fatal aspiration pneumonia; influenza.