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Updated: May 28, 2026
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Quantifying the Cytotoxicity of Staphylococcus aureus Against Human Polymorphonuclear Leukocytes
Published on: January 3, 2020
Antimicrobial ointments and methicillin-resistant Staphylococcus aureus USA300
Masahiro Suzuki1, Kazuhiro Yamada, Miki Nagao
1Aichi Prefectural Institute of Public Health, Nagoya, Japan. masahiro_4_suzuki@pref.aichi.lg.jp
Emerging Infectious Diseases
|October 18, 2011
Summary
Methicillin-resistant Staphylococcus aureus (MRSA) USA300 strains showed resistance to common over-the-counter ointment antibiotics. This suggests widespread antibiotic use may favor the spread of the USA300 MRSA clone.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) is a significant public health concern.
- Over-the-counter (OTC) antibacterial ointments are widely accessible.
- The prevalence of specific MRSA clones, like USA300, is increasing.
Purpose of the Study:
- To determine the susceptibility of MRSA isolates to bacitracin and neomycin, common ingredients in OTC antibacterial ointments.
- To investigate if the USA300 clone exhibits unique resistance patterns to these topical antimicrobials.
Main Methods:
- Tested 259 MRSA isolates and 2 USA300 ATCC type strains.
- Assessed susceptibility to bacitracin and neomycin.
- Identified resistance patterns among different MRSA strains.
Main Results:
- Resistance to both bacitracin and neomycin was exclusively observed in the USA300 strains.
- No resistance was found in the other 259 MRSA isolates tested.
- This indicates a specific susceptibility profile for the USA300 clone.
Conclusions:
- The USA300 MRSA clone demonstrates resistance to commonly used OTC topical antibiotics.
- Widespread use of OTC antibacterial ointments may exert selective pressure favoring the proliferation of the USA300 clone.
- Further research is needed to understand the implications of this selection pressure on MRSA epidemiology.
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