Related Experiment Video
Updated: Dec 28, 2025
Multiplex PCR Assay for Typing of Staphylococcal Cassette Chromosome Mec Types I to V in Methicillin-resistant Staphylococcus aureus
Published on: September 5, 2013
mecA-related structure in methicillin-resistant coagulase-negative staphylococci from street food in Taiwan
Tsung-Ying Yang1, Wei-Wen Hung2, Lin Lin3
1Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan.
Abstract:
Antibiotic-resistant patterns, a mecA homologue complex, and staphylococcal cassette chromosome mec (SCCmec) were analysed in samples of ready-to-eat (RTE) street food in Taiwan. RTE food samples (270) were collected in three densely populated Taiwanese cities between June and November 2014. Among 14 strains being identified as methicillin-resistant coagulase-negative staphylococci (MRCoNS), genetic diversities was determined by PFGE analysis. SCCmec types IV, V, VIII and TXG-24 were detected in 9, and mecASs (a mecA homologue) detected in 8. The mecASs gene complex from S. sciuri subsp. sciuri TXG-24 was found to be closely related to those found in both S. sciuri subsp. sciuri (ATCC29062) and S. sciuri subsp. rodentium (ATCC700061). SCCmecTXG24 carries a class A mec complex, a ccrA5B3-like gene complex, a heavy metal gene complex, and an IS1216 mobile element carrying tet(S). Matching identity to ccrA5 was 84.5% for ccrA in S. pseudintermedius KM241. Matching identify to ccrB3 was 92.1% for ccrB in S. pseudintermedius AI16. Similar ccrA and SCCmec boundary sequences suggest that SCCmec is easily transmitted to coagulase-negative staphylococci (CoNS). Based on MRCoNS strains identified in this research, Taiwanese RTE food products likely carry multiple antibiotic resistance genes that can be transmitted to hospitals and other clinical settings.
Insights
Ready-to-eat street food in Taiwan harbors methicillin-resistant coagulase-negative staphylococci (MRCoNS). These strains carry mobile antibiotic resistance genes, including staphylococcal cassette chromosome mec (SCCmec), posing a public health risk for transmission to clinical settings.
Area of Science:
- Microbiology
- Food Safety
- Genetics
Background:
- Antibiotic resistance is a growing global health concern.
- Ready-to-eat (RTE) street food can be a potential vehicle for pathogen transmission.
- Coagulase-negative staphylococci (CoNS) are opportunistic pathogens, and methicillin-resistant strains (MRCoNS) are of particular concern.
Purpose of the Study:
- To investigate antibiotic resistance patterns, mecA homologues, and staphylococcal cassette chromosome mec (SCCmec) elements in MRCoNS from Taiwanese RTE street food.
- To determine the genetic diversity of MRCoNS strains.
- To assess the potential for transmission of antibiotic resistance genes.
Main Methods:
- Collection of 270 RTE street food samples from three Taiwanese cities.
- Identification and characterization of MRCoNS strains.
- Pulsed-field gel electrophoresis (PFGE) for genetic diversity analysis.
- Detection of SCCmec types and mecA homologues (e.g., mecASs).
Main Results:
- Fourteen MRCoNS strains were identified.
- SCCmec types IV, V, VIII, and a novel type TXG-24 were detected.
- The mecASs gene complex, a mecA homologue, was found in eight strains.
- SCCmecTXG24 contained a class A mec complex, a ccrA5B3-like gene complex, a heavy metal resistance gene complex, and an IS1216 mobile element carrying tet(S).
- Sequence analysis indicated potential for SCCmec transmission among CoNS.
Conclusions:
- Taiwanese RTE street food is a reservoir for MRCoNS carrying diverse antibiotic resistance genes.
- The presence of mobile genetic elements like SCCmec facilitates the spread of antibiotic resistance.
- Findings highlight the risk of transmitting antibiotic-resistant genes from food environments to clinical settings.
