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Updated: Feb 11, 2026
08:51
Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR RS-PCR
Published on: November 4, 2016
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Characterization of enterotoxin A-producing Staphylococcus aureus
Dong Chen1, Qifa Song2, Zhaojun Xu3
1Department of Clinical Laboratory, Sixth People's Hospital of Wenzhou, Wenzhou, Zhejiang Province, People's Republic of China.
Infection and Drug Resistance
|April 27, 2018
Summary
Wild-type Staphylococcus aureus strains show varied staphylococcal enterotoxin A (SEA) production. Phage types differed between clinical and environmental isolates, indicating distinct origins and potential transmission routes for SEA-producing bacteria.
Area of Science:
- Microbiology
- Food Safety
- Clinical Microbiology
Background:
- Staphylococcus aureus is a common pathogen that can produce staphylococcal enterotoxin A (SEA).
- SEA is a major cause of staphylococcal food poisoning.
- Understanding the characteristics of SEA-producing S. aureus is crucial for public health.
Purpose of the Study:
- To characterize wild-type Staphylococcus aureus isolates that produce staphylococcal enterotoxin A (SEA).
- To investigate the genetic diversity, enterotoxin gene profiles, and phage types of these isolates.
- To quantify SEA production levels and correlate them with transcriptional activity.
Main Methods:
- Identified 29 wild-type sea-positive S. aureus isolates from food and clinical samples.
- Quantified SEA production using enzyme-linked immunosorbent assay (ELISA) and sea mRNA levels.
- Determined phage type, genetic diversity via pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST).
Main Results:
- 22 isolates were from food sources, 7 from clinical patients.
- Identified five enterotoxin gene profiles and seven distinct sequence types (STs).
- SEA production varied significantly (0.1-33.5 ng/10^8 CFU), with 54.2% produced during the log growth phase. Four high-SEA producing isolates were identified.
- Phage typing revealed a distinction: ФMu3A phage in clinical isolates and ФSa3ms phage in environmental isolates.
Conclusions:
- Wild-type SEA-producing S. aureus strains exhibit diverse SEA production capacities.
- A clear distinction in phage types was observed between clinical and environmental isolates.
- These findings highlight the heterogeneity of SEA-producing S. aureus and potential differences in their origins and transmission.
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