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Subcutaneous Infection of Methicillin Resistant Staphylococcus Aureus MRSA
Published on: February 9, 2011
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Detection and analysis of methicillin-resistant human-adapted sequence type 398 allows insight into
Lei He1, Hong-Xiang Zheng2, Yanan Wang1
1Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, No. 160 Pujian Road, Shanghai, 200127, China.
Genome Medicine
|January 31, 2018
Summary
Highly virulent community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) ST398 evolved from susceptible strains without gaining new virulence factors. Low-level methicillin resistance, not specific genes, drives CA-MRSA development.
Area of Science:
- Microbiology
- Infectious Diseases
- Evolutionary Biology
Background:
- Severe infections caused by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) are a global health concern.
- The evolutionary pathways leading to highly virulent CA-MRSA remain poorly understood.
- Sequence type (ST) 398 is typically associated with livestock, with human isolates often being methicillin-susceptible or livestock-associated MRSA (LA-MRSA).
Purpose of the Study:
- To investigate the evolutionary history of CA-MRSA ST398 using whole genome sequencing.
- To analyze the virulence of CA-MRSA ST398 through phenotypic analyses and animal infection models.
- To determine the characteristics of methicillin resistance in diverse CA-MRSA strains.
Main Methods:
- Whole genome sequencing of CA-MRSA ST398 isolates compared to LA-MRSA and methicillin-susceptible ST398.
- Phenotypic analyses, including animal infection models, to assess virulence.
- Determination of methicillin resistance and mecA gene expression in various CA-MRSA strains.
Main Results:
- Severe and fatal infections were linked to ST398 CA-MRSA isolates with human-adapted genetic traits.
- Whole genome sequencing revealed evolution from methicillin-susceptible clones on multiple occasions.
- Isolates did not show increased virulence compared to susceptible predecessors; methicillin resistance was lower than in hospital-associated MRSA.
Conclusions:
- Highly virulent human-adapted ST398 CA-MRSA can emerge from methicillin-susceptible strains.
- CA-MRSA development is not necessarily linked to acquiring specific virulence genes.
- Staphylococcal cassette chromosome mec types conferring low-level resistance are crucial for CA-MRSA evolution, impacting diagnostic strategies.
Keywords:
Community-associated MRSALivestock-associated MRSAMethicillin resistanceST398Staphylococcus aureusVirulenceMore Related Videos
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