| 초록 |
Staphylococcus aureus is a key member in the human respiratory tract microbiome but also found in other habitats, such as on the skin and in soil. In the current study, we found that S. aureus inhibited biofilm formation by other respiratory tract bacteria when co-cultured. Subsequent analyses using Acinetobacter baumannii as a model biofilm former found this effect is primarily mediated by membrane vesicles (MVs) secreted by S. aureus. These MVs were found to coat the underlying surfaces and inhibit A. baumannii from adhering to the surface and, thus, reduced the biofilm formed by up to 93%. Parallel tests with two additional S. aureus, including one clinical isolate, gave similar results, suggesting that this activity is inherent to this strain. Evaluating the properties of the MVs-treated surfaces, we found they were more hydrophilic, which makes it difficult for the bacteria to adhere initially. This was confirmed as treating the substrate with oxygen plasma also rendered it hydrophilic and, likewise, reduced A. baumannii adherence and biofilm development by a comparable degree of 85 ~ 93%. Additional tests found the biofilm antagonism of S. aureus extended to other bacterial species representing both Gram-positive and Gram-negative strains, with 40~70% inhibition. In conclusion, the findings of this study describe a previously uncharacterized function of bacterial MVs and provide a new perspective on interspecies interactions occurring between S. aureus and other microbes. |
