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Updated: Aug 23, 2025
A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
Published on: February 19, 2019
Molecular Characteristics and Distribution of Virulence Genes among Staphylococcus aureus Complex Isolates Derived
Min Yi Wong1,2, Yuan-Hsi Tseng1,3, Tsung-Yu Huang3,4
1Division of Thoracic and Cardiovascular Surgery, Chiayi Chang Gung Memorial Hospital, Puzi, Chiayi 613, Taiwan.
Abstract:
Staphylococcus aureus is a major human pathogen that produces various virulence factors which promote the binding of bacteria to tissues and medical devices such as vascular access devices, thereby developing a wide range of invasive infections. Vascular access serves as an entry site for S. aureus and elevates the risk of infection in the hemodialysis population. Nevertheless, the distribution of virulence genes in Staphylococcus spp. associated with vascular access infections (VAIs) has not been studied previously. In this study, we determined the relationship between the molecular characteristics and virulence profiles of S. aureus isolates obtained from VAIs. We collected isolates from patients with VAIs between August 2017 and December 2020 and further analyzed the molecular characteristics, antimicrobial resistance profiles, and virulence gene distribution in the isolates. Overall, 15 sequence types (STs), including a new ST (ST6892) and 19 spa types, were identified among the 56 isolates. Of the 53 S. aureus isolates, ST8, ST239, ST45, and ST59 were the predominant STs, whereas ST2250 was the only ST in 3 S. argenteus isolates. ST45-SCCmecIV-t026 (abbreviated as ST45-IV-t026), ST59-V-t437, and ST8-IV-t008 were the predominant clones that belonged to agr type I. All isolates harbored clfB and eno, whereas all S. aureus isolates harbored clfA. In addition, 10 Panton-Valentine leucocidin-positive isolates belonged to ST8 and ST59, with ST8-IV-t008 and ST59-V-t437 being the predominant clones. In brief, the distribution of virulence genes associated with STs may assist in the spread of molecular types of Staphylococcus spp.
Insights
Staphylococcus aureus vascular access infections (VAIs) show diverse virulence gene profiles linked to specific sequence types (STs). Understanding these molecular characteristics is key to combating invasive bacterial infections in hemodialysis patients.
Area of Science:
- Microbiology
- Infectious Diseases
- Molecular Epidemiology
Background:
- Staphylococcus aureus is a significant pathogen causing invasive infections, particularly in patients with vascular access devices.
- Vascular access devices serve as entry points for S. aureus, increasing infection risk in hemodialysis patients.
- The distribution of virulence genes in Staphylococcus species linked to vascular access infections (VAIs) remains understudied.
Purpose of the Study:
- To investigate the relationship between molecular characteristics and virulence gene profiles of S. aureus isolates from VAIs.
- To analyze the distribution of virulence genes in Staphylococcus species associated with vascular access infections.
Main Methods:
- Collection of S. aureus isolates from patients with VAIs between August 2017 and December 2020.
- Analysis of molecular characteristics, including sequence types (STs) and spa types.
- Assessment of antimicrobial resistance profiles and distribution of key virulence genes (e.g., clfA, clfB, eno, Panton-Valentine leucocidin).
Main Results:
- Fifty-six isolates were analyzed, revealing 15 sequence types (STs) and 19 spa types, including a novel ST (ST6892).
- Predominant S. aureus STs included ST8, ST239, ST45, and ST59. Staphylococcus argenteus isolates were identified as ST2250.
- Specific clones like ST45-IV-t026, ST59-V-t437, and ST8-IV-t008 were predominant and associated with agr type I. Panton-Valentine leucocidin was detected in 10 isolates belonging to ST8 and ST59.
Conclusions:
- The study highlights significant molecular diversity within Staphylococcus species causing VAIs.
- Specific sequence types are associated with distinct virulence gene profiles, potentially influencing infection pathways.
- Understanding the interplay between virulence genes and molecular types of Staphylococcus spp. is crucial for managing VAI spread.
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