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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
Antimicrobial Activity of the Circular Bacteriocin AS-48 against Clinical Multidrug-Resistant Staphylococcus aureus
Cristina Velázquez-Suárez1,2, Rubén Cebrián3, Carmen Gasca-Capote4
1Department of Microbiology, Faculty of Sciences, University of Granada, Av. Fuente Nueva s/n, 18071 Granada, Spain.
Abstract:
The treatment and hospital-spread-control of methicillin-resistant Staphylococcus aureus (MRSA) is an important challenge since these bacteria are involved in a considerable number of nosocomial infections that are difficult to treat and produce prolonged hospitalization, thus also increasing the risk of death. In fact, MRSA strains are frequently resistant to all β-lactam antibiotics, and co-resistances with other drugs such as macrolides, aminoglycosides, and lincosamides are usually reported, limiting the therapeutical options. To this must be added that the ability of these bacteria to form biofilms on hospital surfaces and devices confer high antibiotic resistance and favors horizontal gene transfer of genetic-resistant mobile elements, the spreading of infections, and relapses. Here, we genotypically and phenotypically characterized 100 clinically isolated S. aureus for their resistance to 18 antibiotics (33% of them were OXA resistant MRSA) and ability to form biofilms. From them, we selected 48 strains on the basis on genotype group, antimicrobial-resistance profile, and existing OXA resistance to be assayed against bacteriocin AS-48. The results showed that AS-48 was active against all strains, regardless of their clinical source, genotype, antimicrobial resistance profile, or biofilm formation capacity, and this activity was enhanced in the presence of the antimicrobial peptide lysozyme. Finally, we explored the effect of AS-48 on formed S. aureus biofilms, observing a reduction in S. aureus S-33 viability. Changes in the matrix structure of the biofilms as well as in the cell division process were observed with scanning electron microscopy in both S-33 and S-48 S. aureus strains.
Insights
Bacteriocin AS-48 effectively combats methicillin-resistant Staphylococcus aureus (MRSA), including strains resistant to multiple antibiotics and those forming biofilms. Its activity is enhanced by lysozyme and it disrupts MRSA biofilms, offering a potential new therapeutic strategy.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) causes challenging nosocomial infections with limited treatment options.
- MRSA strains exhibit multi-drug resistance and form biofilms, complicating infection control and treatment.
- Biofilm formation by MRSA enhances antibiotic resistance and facilitates horizontal gene transfer.
Purpose of the Study:
- To evaluate the efficacy of bacteriocin AS-48 against clinically isolated Staphylococcus aureus strains.
- To investigate the activity of AS-48 against antibiotic-resistant and biofilm-forming MRSA.
- To assess the impact of AS-48 on established MRSA biofilms.
Main Methods:
- Genotypic and phenotypic characterization of 100 clinical Staphylococcus aureus isolates.
- Antimicrobial resistance profiling against 18 antibiotics.
- Assay of bacteriocin AS-48 activity against selected MRSA strains, alone and with lysozyme.
- Scanning electron microscopy to analyze AS-48 effects on MRSA biofilms.
Main Results:
- AS-48 demonstrated activity against all tested Staphylococcus aureus strains, irrespective of resistance profile or biofilm formation.
- AS-48's antimicrobial activity was enhanced in the presence of lysozyme.
- AS-48 reduced the viability of Staphylococcus aureus within pre-formed biofilms.
- Scanning electron microscopy revealed alterations in biofilm matrix structure and cell division.
Conclusions:
- Bacteriocin AS-48 is a promising agent against diverse Staphylococcus aureus strains, including resistant and biofilm-forming MRSA.
- AS-48, potentially combined with lysozyme, offers a novel therapeutic avenue for MRSA infections.
- AS-48 exhibits antibiofilm activity, suggesting its utility in preventing or treating biofilm-associated infections.
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