Publicação
Pseudomonadota on human skin : effects of antimicrobial agents
| Resumo: | Pseudomonadota are recognized as important harbours of antibiotic resistance, and some of them are also ubiquitous bacteria able to survive in multiple environments. The aim of this study was to understand if bacteria of the phylum Pseudomonadota that are common colonizers of a healthy human skin may be carriers of antibiotic resistance, and if their survival may be affected by the use of cosmetics or antimicrobial agents and if carbapenems resistance among Acinetobacter species is affected by phylogenomics. To answer this question, it was first done an analysis of the human healthy skin bacterial diversity based on metagenomic data available in public databases, and identified the most common Pseudomonadota genera and species. From this analysis, was identified the genus Acinetobacter as one of the most frequent in human skin, namely the species Acinetobacter johnsonii, Acinetobacter lwoffii and Acinetobacter junii. The genomes of those three species were collected from public databases (n=232) and compared in terms of antibiotic resistance and virulence profiles, aiming to understand if the resistance/virulence profiles were determined by the species or if other factors, such as the phylogeny or the strains origin (clinical, clinical associated, and environmental) may interfere. Based on this genome’s comparison it was possible to conclude that they are important carriers of antibiotic resistance genes. The strains from environmental origin presented a higher diversity of resistance genes, while the strains from clinical origin have poorer profiles of resistance but higher abundance. The blaNDM positive genomes (n=23) were processed to understand the genomic environment of the carbapenemase gene and if it varies according to the species or the strain origin. It was observed that the blaNDM gene was mainly associated to mobile genetic elements, namely the IS66 family, and associated with other genes of resistance (e.g. aminoglycosides, macrolides). Some Acinetobacter isolates in the laboratory culture collection, all from environmental origin, were tested for their tolerance to antiseptics (hydrogen peroxide, iodine, bleach, water) and cosmetics, using the disk diffusion method. For these isolates it was not possible to infer any correlation between the antibiotic resistance profile and the tolerance to cosmetic compounds, but it was observed some variance between strains in the tolerance to hydrogen peroxide. In the future, it would be interesting to extend these tests to strains from different origins (e.g. skin isolates) and test higher concentration of the cosmetics. |
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| Autores principais: | Murugesan, Saravanan |
| Assunto: | Origin Species Carbapenems resistance Filogenomics Phenotypic Origem Espécie Resistência aos cabapenemos Filogenómica Fenotípica |
| Ano: | 2025 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Católica Portuguesa |
| Idioma: | inglês |
| Origem: | Veritati - Repositório Institucional da Universidade Católica Portuguesa |
| Resumo: | Pseudomonadota are recognized as important harbours of antibiotic resistance, and some of them are also ubiquitous bacteria able to survive in multiple environments. The aim of this study was to understand if bacteria of the phylum Pseudomonadota that are common colonizers of a healthy human skin may be carriers of antibiotic resistance, and if their survival may be affected by the use of cosmetics or antimicrobial agents and if carbapenems resistance among Acinetobacter species is affected by phylogenomics. To answer this question, it was first done an analysis of the human healthy skin bacterial diversity based on metagenomic data available in public databases, and identified the most common Pseudomonadota genera and species. From this analysis, was identified the genus Acinetobacter as one of the most frequent in human skin, namely the species Acinetobacter johnsonii, Acinetobacter lwoffii and Acinetobacter junii. The genomes of those three species were collected from public databases (n=232) and compared in terms of antibiotic resistance and virulence profiles, aiming to understand if the resistance/virulence profiles were determined by the species or if other factors, such as the phylogeny or the strains origin (clinical, clinical associated, and environmental) may interfere. Based on this genome’s comparison it was possible to conclude that they are important carriers of antibiotic resistance genes. The strains from environmental origin presented a higher diversity of resistance genes, while the strains from clinical origin have poorer profiles of resistance but higher abundance. The blaNDM positive genomes (n=23) were processed to understand the genomic environment of the carbapenemase gene and if it varies according to the species or the strain origin. It was observed that the blaNDM gene was mainly associated to mobile genetic elements, namely the IS66 family, and associated with other genes of resistance (e.g. aminoglycosides, macrolides). Some Acinetobacter isolates in the laboratory culture collection, all from environmental origin, were tested for their tolerance to antiseptics (hydrogen peroxide, iodine, bleach, water) and cosmetics, using the disk diffusion method. For these isolates it was not possible to infer any correlation between the antibiotic resistance profile and the tolerance to cosmetic compounds, but it was observed some variance between strains in the tolerance to hydrogen peroxide. In the future, it would be interesting to extend these tests to strains from different origins (e.g. skin isolates) and test higher concentration of the cosmetics. |
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