Increased Incidence and Plasma-Biofilm Formation Ability of SCCmec Type IV Methicillin-Resistant Staphylococcus aureus (MRSA) Isolated From Patients With Bacteremia

Frontiers in Cellular and Infection Microbiology

Hinako Murakami¹  Masakazu Sasaki¹  Tadashi Maeda²  Daisuke Ono³  Kotaro Aoki⁴  Chiaki Kajiwara⁴  Tetsuo Yamaguchi⁴  Soichiro Kimura⁴  Masakaze Hamada⁴  Yoshikazu Ishii⁴  Kazuhiro Tateda⁵  Ayami Sato⁶ 

[1]Department of Clinical Laboratories, Toho University Omori Medical Center, Tokyo, Japan

[2]Department of General Medicine and Emergency Care, Toho University Omori Medical Center, Tokyo, Japan

[3]Department of Infectious Diseases and Infection Control, Saitama Medical Center, Saitama Medical University, Saitama, Japan

[4]Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan

[5]Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan

[6]Department of Clinical Laboratories, Toho University Omori Medical Center, Tokyo, Japan

[7]Department of Microbiology and Infectious Diseases, Toho University School of Medicine, Tokyo, Japan

[8]Department of Surgery, Toho University Sakura Medical Center, Chiba, Japan

关键词: Staphylococcus aureus;    mec;    Staphylococcus aureus;    biofilm;    plasma;    bloodstream infection;   

DOI  :  10.3389/fcimb.2021.602833

来源: Frontiers

【 摘 要 】

In Japan, Staphylococcal cassette chromosome mec (SCCmec) type IV methicillin-resistant Staphylococcus aureus (MRSA) is an increasingly prominent cause of bacteremia, but the virulence of most of these strains is unclear. We aimed to investigate the relationship between the molecular characteristics and the ability to form biofilms in the presence of blood plasma (plasma-biofilms) of MRSA strains isolated from bloodstream infections. In this study, the molecular characteristics and biofilms of MRSA strains isolated from blood cultures between 2015 and 2017 were analyzed by PCR-based assays, crystal violet staining, and confocal reflection microscopy methods. Among the 90 MRSA isolates, the detection rate of SCCmec type II clones decreased from 60.7 to 20.6%. The SCCmec type IV clone replaced the SCCmec type II clone as the dominant clone, with a detection rate increasing from 32.1 to 73.5%. The plasma-biofilm formation ability of the SCCmec type IV clone was higher than the SCCmec type II clone and even higher in strains harboring the cna or arcA genes. Plasma-biofilms, mainly composed of proteins, were formed quickly and strongly. Our study demonstrated the increased plasma-biofilm formation ability of SCCmec type IV strains.

【 授权许可】

CC BY