Impact of psm-mec in Methicillin-Resistant Staphylococcus aureus (ST764) Strains Isolated from Keratitis Patients

Takashi Suzuki, Toshihiro Yamamoto, Chikara Kaito, Hitoshi Miyamoto, Yuichi Ohashi

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Staphylococcus aureus is a predominant pathogen in keratitis, and the rate of methicillin-resistant S. aureus (MRSA) is increasing. In our previous study, genotypes of MRSA isolates from keratitis cases were classified into ST5 or ST764 lineage by multi-locus sequence typing. In this study, we examined the virulence properties of these MRSA keratitis isolates and its virulence determinants. There was no difference in the prevalence of virulence genes, such as adhesion and toxins, between ST5 and ST764 isolates. All ST5 isolates carried the intact psm-mec gene, which suppresses exotoxin production and colony spreading, but promotes biofilm formation. In contrast, all ST764 isolates had one point mutation in the psm-mec gene. Biofilm production in ST5 isolates was significantly higher than that in ST764 isolates, whereas colony spreading, hemolytic activity, and production of alpha-phenol-soluble modulins were higher in ST764 than in ST5 isolates. The toxicity of ST764 supernatants to corneal epithelial cells was higher than that of ST5 supernatants. These results suggest that the point mutation in the psm-mec gene contributes to the difference in virulence properties between ST5 and ST764 isolates in MRSA keratitis.

Original languageEnglish
Pages (from-to)589-597
Number of pages9
JournalMicrobial Drug Resistance
Volume22
Issue number7
DOIs
Publication statusPublished - Oct 1 2016
Externally publishedYes

Fingerprint

Keratitis
Methicillin-Resistant Staphylococcus aureus
Virulence
Biofilms
Point Mutation
Genes
Exotoxins
Staphylococcus aureus
Epithelial Cells
Genotype

Keywords

  • MLST
  • MRSA
  • psm-mec
  • Staphylococcus aureus
  • virulence

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Pharmacology
  • Microbiology (medical)

Cite this

Impact of psm-mec in Methicillin-Resistant Staphylococcus aureus (ST764) Strains Isolated from Keratitis Patients. / Suzuki, Takashi; Yamamoto, Toshihiro; Kaito, Chikara; Miyamoto, Hitoshi; Ohashi, Yuichi.

In: Microbial Drug Resistance, Vol. 22, No. 7, 01.10.2016, p. 589-597.

Research output: Contribution to journalArticle

Suzuki, Takashi ; Yamamoto, Toshihiro ; Kaito, Chikara ; Miyamoto, Hitoshi ; Ohashi, Yuichi. / Impact of psm-mec in Methicillin-Resistant Staphylococcus aureus (ST764) Strains Isolated from Keratitis Patients. In: Microbial Drug Resistance. 2016 ; Vol. 22, No. 7. pp. 589-597.
@article{12867d88b19644d3b368e78127fbb1bb,
title = "Impact of psm-mec in Methicillin-Resistant Staphylococcus aureus (ST764) Strains Isolated from Keratitis Patients",
abstract = "Staphylococcus aureus is a predominant pathogen in keratitis, and the rate of methicillin-resistant S. aureus (MRSA) is increasing. In our previous study, genotypes of MRSA isolates from keratitis cases were classified into ST5 or ST764 lineage by multi-locus sequence typing. In this study, we examined the virulence properties of these MRSA keratitis isolates and its virulence determinants. There was no difference in the prevalence of virulence genes, such as adhesion and toxins, between ST5 and ST764 isolates. All ST5 isolates carried the intact psm-mec gene, which suppresses exotoxin production and colony spreading, but promotes biofilm formation. In contrast, all ST764 isolates had one point mutation in the psm-mec gene. Biofilm production in ST5 isolates was significantly higher than that in ST764 isolates, whereas colony spreading, hemolytic activity, and production of alpha-phenol-soluble modulins were higher in ST764 than in ST5 isolates. The toxicity of ST764 supernatants to corneal epithelial cells was higher than that of ST5 supernatants. These results suggest that the point mutation in the psm-mec gene contributes to the difference in virulence properties between ST5 and ST764 isolates in MRSA keratitis.",
keywords = "MLST, MRSA, psm-mec, Staphylococcus aureus, virulence",
author = "Takashi Suzuki and Toshihiro Yamamoto and Chikara Kaito and Hitoshi Miyamoto and Yuichi Ohashi",
year = "2016",
month = "10",
day = "1",
doi = "10.1089/mdr.2015.0315",
language = "English",
volume = "22",
pages = "589--597",
journal = "Microbial Drug Resistance",
issn = "1076-6294",
publisher = "Mary Ann Liebert Inc.",
number = "7",

}

TY - JOUR

T1 - Impact of psm-mec in Methicillin-Resistant Staphylococcus aureus (ST764) Strains Isolated from Keratitis Patients

AU - Suzuki, Takashi

AU - Yamamoto, Toshihiro

AU - Kaito, Chikara

AU - Miyamoto, Hitoshi

AU - Ohashi, Yuichi

PY - 2016/10/1

Y1 - 2016/10/1

N2 - Staphylococcus aureus is a predominant pathogen in keratitis, and the rate of methicillin-resistant S. aureus (MRSA) is increasing. In our previous study, genotypes of MRSA isolates from keratitis cases were classified into ST5 or ST764 lineage by multi-locus sequence typing. In this study, we examined the virulence properties of these MRSA keratitis isolates and its virulence determinants. There was no difference in the prevalence of virulence genes, such as adhesion and toxins, between ST5 and ST764 isolates. All ST5 isolates carried the intact psm-mec gene, which suppresses exotoxin production and colony spreading, but promotes biofilm formation. In contrast, all ST764 isolates had one point mutation in the psm-mec gene. Biofilm production in ST5 isolates was significantly higher than that in ST764 isolates, whereas colony spreading, hemolytic activity, and production of alpha-phenol-soluble modulins were higher in ST764 than in ST5 isolates. The toxicity of ST764 supernatants to corneal epithelial cells was higher than that of ST5 supernatants. These results suggest that the point mutation in the psm-mec gene contributes to the difference in virulence properties between ST5 and ST764 isolates in MRSA keratitis.

AB - Staphylococcus aureus is a predominant pathogen in keratitis, and the rate of methicillin-resistant S. aureus (MRSA) is increasing. In our previous study, genotypes of MRSA isolates from keratitis cases were classified into ST5 or ST764 lineage by multi-locus sequence typing. In this study, we examined the virulence properties of these MRSA keratitis isolates and its virulence determinants. There was no difference in the prevalence of virulence genes, such as adhesion and toxins, between ST5 and ST764 isolates. All ST5 isolates carried the intact psm-mec gene, which suppresses exotoxin production and colony spreading, but promotes biofilm formation. In contrast, all ST764 isolates had one point mutation in the psm-mec gene. Biofilm production in ST5 isolates was significantly higher than that in ST764 isolates, whereas colony spreading, hemolytic activity, and production of alpha-phenol-soluble modulins were higher in ST764 than in ST5 isolates. The toxicity of ST764 supernatants to corneal epithelial cells was higher than that of ST5 supernatants. These results suggest that the point mutation in the psm-mec gene contributes to the difference in virulence properties between ST5 and ST764 isolates in MRSA keratitis.

KW - MLST

KW - MRSA

KW - psm-mec

KW - Staphylococcus aureus

KW - virulence

UR - http://www.scopus.com/inward/record.url?scp=84990925113&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84990925113&partnerID=8YFLogxK

U2 - 10.1089/mdr.2015.0315

DO - 10.1089/mdr.2015.0315

M3 - Article

C2 - 26954266

AN - SCOPUS:84990925113

VL - 22

SP - 589

EP - 597

JO - Microbial Drug Resistance

JF - Microbial Drug Resistance

SN - 1076-6294

IS - 7

ER -