Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa
Background and Objectives: Antibiotics at sub-minimum inhibitory concentrations (sub-MIC) may alter bacterial virulence factors. The objective of this study was to investigate the effect of gentamicin at sub-MIC concentrations on the expression of genes involved in alginate production and biofilm fo...
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| Format: | Article |
| Language: | English |
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Tehran University of Medical Sciences
2021-12-01
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| Series: | Iranian Journal of Microbiology |
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| Online Access: | https://ijm.tums.ac.ir/index.php/ijm/article/view/3093 |
| _version_ | 1828139952308748288 |
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| author | Fateme Davarzani Zahra Yousefpour Navid Saidi Parviz Owlia |
| author_facet | Fateme Davarzani Zahra Yousefpour Navid Saidi Parviz Owlia |
| author_sort | Fateme Davarzani |
| collection | DOAJ |
| description | Background and Objectives: Antibiotics at sub-minimum inhibitory concentrations (sub-MIC) may alter bacterial virulence factors. The objective of this study was to investigate the effect of gentamicin at sub-MIC concentrations on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa.
Materials and Methods: The broth microdilution method was used to determine the MIC of gentamicin for three P. aeruginosa clinical isolates (P1-P3) and standard strains (PAO1 and 8821M). Alginate production and biofilm formation of the bacteria in the presence and absence of sub-MIC concentrations of gentamicin were measured using microtiter plate and carbazole assay, respectively. The real-time PCR method was used to determine the effect of gentamicin at sub-MIC concentrations on the expression level of genes involved in biofilm formation (pelA and pslA) and alginate production (algD and algU).
Results: Gentamicin at sub-MIC concentrations significantly reduced alginate production, biofilm formation, and the expression of alginate and biofilm-encoding genes in clinical isolate P1. This inhibitory effect was also observed on the alginate production of 8821M strain and biofilm formation of PAO1strain. In clinical isolates, P2 and P3, alginate production, biofilm formation, and the expression of alginate and biofilm-encoding genes were significantly increased in exposure to sub-MIC concentrations of gentamicin.
Conclusion: This study showed that different phenotypic changes in clinical isolates and standard strains of P. aeruginosa in exposure to sub-MIC concentrations of gentamicin are associated with changes in the expression of virulence genes. Further researches are required to understand the mechanisms involved in regulating the expression of virulence genes after exposure to sub-MIC concentrations of antibiotics. |
| first_indexed | 2024-04-11T19:00:53Z |
| format | Article |
| id | doaj.art-8d05fcf9378c47b686fb5c96e0f0d54a |
| institution | Directory Open Access Journal |
| issn | 2008-3289 2008-4447 |
| language | English |
| last_indexed | 2024-04-11T19:00:53Z |
| publishDate | 2021-12-01 |
| publisher | Tehran University of Medical Sciences |
| record_format | Article |
| series | Iranian Journal of Microbiology |
| spelling | doaj.art-8d05fcf9378c47b686fb5c96e0f0d54a2022-12-22T04:08:03ZengTehran University of Medical SciencesIranian Journal of Microbiology2008-32892008-44472021-12-01136Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosaFateme Davarzani0Zahra Yousefpour1Navid Saidi2Parviz Owlia3Molecular Microbiology Research Center (MMRC), School of Medicine, Shahed University, Tehran, IranMolecular Microbiology Research Center (MMRC), School of Medicine, Shahed University, Tehran, IranMolecular Microbiology Research Center (MMRC), School of Medicine, Shahed University, Tehran, IranMolecular Microbiology Research Center (MMRC), School of Medicine, Shahed University, Tehran, IranBackground and Objectives: Antibiotics at sub-minimum inhibitory concentrations (sub-MIC) may alter bacterial virulence factors. The objective of this study was to investigate the effect of gentamicin at sub-MIC concentrations on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa. Materials and Methods: The broth microdilution method was used to determine the MIC of gentamicin for three P. aeruginosa clinical isolates (P1-P3) and standard strains (PAO1 and 8821M). Alginate production and biofilm formation of the bacteria in the presence and absence of sub-MIC concentrations of gentamicin were measured using microtiter plate and carbazole assay, respectively. The real-time PCR method was used to determine the effect of gentamicin at sub-MIC concentrations on the expression level of genes involved in biofilm formation (pelA and pslA) and alginate production (algD and algU). Results: Gentamicin at sub-MIC concentrations significantly reduced alginate production, biofilm formation, and the expression of alginate and biofilm-encoding genes in clinical isolate P1. This inhibitory effect was also observed on the alginate production of 8821M strain and biofilm formation of PAO1strain. In clinical isolates, P2 and P3, alginate production, biofilm formation, and the expression of alginate and biofilm-encoding genes were significantly increased in exposure to sub-MIC concentrations of gentamicin. Conclusion: This study showed that different phenotypic changes in clinical isolates and standard strains of P. aeruginosa in exposure to sub-MIC concentrations of gentamicin are associated with changes in the expression of virulence genes. Further researches are required to understand the mechanisms involved in regulating the expression of virulence genes after exposure to sub-MIC concentrations of antibiotics.https://ijm.tums.ac.ir/index.php/ijm/article/view/3093Alginate;Biofilm;Gene expression;Gentamicin;Pseudomonas aeruginosa |
| spellingShingle | Fateme Davarzani Zahra Yousefpour Navid Saidi Parviz Owlia Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa Iranian Journal of Microbiology Alginate; Biofilm; Gene expression; Gentamicin; Pseudomonas aeruginosa |
| title | Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa |
| title_full | Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa |
| title_fullStr | Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa |
| title_full_unstemmed | Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa |
| title_short | Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa |
| title_sort | different effects of sub minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of pseudomonas aeruginosa |
| topic | Alginate; Biofilm; Gene expression; Gentamicin; Pseudomonas aeruginosa |
| url | https://ijm.tums.ac.ir/index.php/ijm/article/view/3093 |
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