Related Experiment Video
Updated: Apr 6, 2026
Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Discovery, evolution, and environmental co-selection of novel msrA-harboring plasmids in multidrug-resistant
Feng Zhang1, Shiyu Ma1, Jiaxu Gao1
1College of Food and Bioengineering, Zhengzhou University of Light Industry, Key Laboratory of Cold Chain Food Processing and Safety Control, Ministry of Education, Zhengzhou, 450001, China.
Abstract:
The escalating prevalence of antimicrobial resistance in food-related pathogens constitutes a critical challenge to global public health and food safety. To elucidate the mechanisms underlying the high erythromycin resistance rate observed in our previous surveillance of Staphylococcus in retail foods, we conducted a comprehensive genomic investigation of msrA-positive Staphylococcus from a nationwide retail food collection in China. We identified 102 msrA-positive isolates, all of which exhibited a multidrug-resistant (MDR) phenotype, with a significantly higher prevalence in aquatic products (13.95%), identifying this food category as a high-risk reservoir for transmitting resistant bacteria to consumers. Genomic typing revealed the dominance of the S. aureus ST15-t085 lineage (58.0%), which exhibited a specific ecological adaptation to retail aquatic products. We characterized 12 novel msrA-harboring plasmids (pMsrA-I to pMsrA-XII), with the dominant Type A plasmids carrying a coupled msrA-mphC cassette that confers synergistic high-level resistance. Structural analysis demonstrated that IS431R serves as a key driver of plasmid evolution, mediating the capture of resistance clusters. Notably, these plasmids also harbor genes conferring tolerance to heavy metals and food preservatives, physically linked to the antimicrobial resistance regions. This genetic linkage suggests that routine disinfection and environmental residues in retail food processing environments likely drive the co-selection of these multidrug-resistant plasmids. Furthermore, these isolates harbored both the plasmids and chromosomal biofilm-associated genes, as well as the neglected enterotoxin gene seh (15.7%), highlights a dual threat of environmental persistence and pathogenicity. These findings underscore the urgent need for targeted surveillance of novel resistance plasmids in the retail food market to mitigate the spread of these multidrug-resistant pathogens.
Insights
Antimicrobial resistance in food is a major public health threat. This study found multidrug-resistant Staphylococcus, particularly in aquatic foods, carrying novel plasmids linked to heavy metals and preservatives, driving resistance spread.
Area of Science:
- Food safety and public health
- Genomics and molecular biology
- Antimicrobial resistance mechanisms
Background:
- Rising antimicrobial resistance in foodborne pathogens poses a global threat.
- Previous surveillance indicated high erythromycin resistance in retail food Staphylococcus.
- Understanding resistance mechanisms is crucial for public health and food safety.
Purpose of the Study:
- To investigate the genomic basis of high erythromycin resistance in Staphylococcus from Chinese retail foods.
- To identify the prevalence and characteristics of resistance genes and plasmids.
- To explore potential drivers and implications of multidrug resistance in food environments.
Main Methods:
- Genomic investigation of msrA-positive Staphylococcus isolates from a nationwide retail food collection in China.
- Prevalence analysis across different food categories, especially aquatic products.
- Plasmid characterization, including novel msrA-harboring plasmids and their genetic elements.
- Analysis of co-selection pressures, such as heavy metals and food preservatives.
Main Results:
- 102 msrA-positive Staphylococcus isolates were identified, all exhibiting multidrug resistance (MDR).
- Aquatic products showed a significantly higher prevalence (13.95%), indicating a high-risk reservoir.
- Dominance of the S. aureus ST15-t085 lineage adapted to retail aquatic products.
- Characterization of 12 novel msrA-harboring plasmids, some with synergistic resistance cassettes.
- Plasmids linked to heavy metal and preservative resistance genes, suggesting co-selection by environmental factors.
- Presence of the enterotoxin gene seh in 15.7% of isolates, indicating potential pathogenicity.
Conclusions:
- Aquatic products are a significant reservoir for multidrug-resistant Staphylococcus carrying novel resistance plasmids.
- Environmental factors like disinfectants and residues likely drive the co-selection and spread of MDR plasmids.
- The co-occurrence of antimicrobial resistance, heavy metal tolerance, and pathogenicity genes poses a dual threat.
- Urgent need for targeted surveillance of resistance plasmids in retail food markets to control pathogen spread.
Related Concept Videos
01:25Clinical Significance of Antibiotic Resistance
01:25Mechanism of Antibiotic Resistance in MRSA
01:29Staphylococcal Skin Infections
00:57Antibiotic Selection
01:24Evolution of New Traits in Microbes
01:29Microbes in Food Production