SPREAD OF STAPHYLOCOCCAL MOBILOME DUE TO DIFFERENT THERAPEUTIC APPROACHES
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| Year of publication | 2024 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Aim: Characterize staphylococcal mobilome induced by various agents, including antibiotic and phage therapy, and their combination. Background: Mobile genetic elements, like phages and chromosomal islands, represent a major force in the emergence of new pathogenic and drug-resistant Staphylococcus spp. strains. On the other hand, lytic phages can be used in the therapy of bacterial infections as an alternative or complement to antibiotics. With increasing knowledge of horizontal transfer, it is evident that some antibiotics, such as fluoroquinolones, can mobilize genetic elements, thereby spreading antibiotic resistance and virulence factors. Methods: A phage-inducible chromosomal island (PICI) and prophage E72 were transferred into the Staphylococcus epidermidis strain 1457 via transduction and lysogenization. The obtained strain 1457LA was treated with ciprofloxacin, lytic phage 812h1, and their combination. The optical density of the treated culture and titer of the induced and lytic phages were determined. DNA of strain 1457LA and from the released virions was extracted and sequenced. The amount of genetic elements released after each treatment was determined and compared. Results: 1457LA treatment with ciprofloxacin minimum inhibitory concentration did not lead to culture eradication, while almost 40% of the genomes detected in virions belonged to induced phage E72 and 60% to the PICI. After infection with phage 812h1, more than 99% of the genomes belonged to this lytic phage. In the case of the combined treatment, the genome of the lytic phage was present in 60 to 99.9% of the virions, depending on the input ratio of the phage. The genomes of PICI and E72 were approximately equally represented in the rest of the virions. The combined treatment resulted in the most significant decrease in culture density. Conclusions: Combination treatment resulted in a significant reduction in the amount of genetic elements released compared to antibiotic treatment and the highest decrease in culture optical density. |
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