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Acute toxicity and anti-enterotoxigenic activity of pigment extracted from Micrococcus roseus
Mahmoud Yolmeh1, Morteza Khomeiri2, Ezzatollah Ghaemi3
1Department of Food Science and Nutrition, Faculty of Food Engineering, University of Campinas, Rua Monteiro Lobato, 80, Cidade Universitária Zeferino Vaz, Campinas, SP, CEP: 13083-862, Brazil. yolmeh@unicamp.br.
Abstract:
Microbial pigments are considered as one of the main sources of natural types, and the attention to them is increasing in the food and pharmaceutical industries. This study aimed to investigate the effects of pigments extracted from Micrococcus roseus (PEM) on the gene expression of a and b staphylococcal enterotoxins (sea and seb) and their acute toxicity. Real-time PCR was used to study the anti-enterotoxigenic activity of PEM against Staphylococcus aureus at sub-inhibitory concentrations. In addition, the acute toxicity of PEM was evaluated on albino mice through alkaline phosphatase (ALP), aspartate aminotransferas (AST), and alanine aminotransferase (ALT) of liver and its histopathological changes. Based on the results, the expression of sea and seb was decreased in the presence of PEM at sub-inhibitory concentrations. The 2-∆∆CT was measured 0.02 and 0.01 for the expression of sea and seb of S. aureus grown in the MHB containing 16 mg/ml PEM. The results showed that the expression of seb is more sensitive to PEM compared to the expression of sea. After treatment of mice with PEM for two weeks, the condition of mice was normal, and the results of liver enzymatic activities and histopathological changes showed insignificant difference compared to the control sample.
Insights
Pigments from Micrococcus roseus (PEM) significantly reduce the expression of staphylococcal enterotoxins (sea and seb) at sub-inhibitory levels. PEM also demonstrated low acute toxicity in mice, indicating its safety for potential applications.
Area of Science:
- Microbiology
- Biotechnology
- Toxicology
Background:
- Microbial pigments are gaining importance in food and pharmaceutical industries.
- Natural pigments offer alternatives to synthetic compounds.
- Staphylococcal enterotoxins pose significant health risks.
Purpose of the Study:
- To evaluate the impact of Micrococcus roseus pigments (PEM) on the gene expression of staphylococcal enterotoxins (sea and seb).
- To assess the acute toxicity of PEM in a mammalian model.
Main Methods:
- Real-time PCR was employed to quantify the expression levels of sea and seb genes.
- Sub-inhibitory concentrations of PEM were used against Staphylococcus aureus.
- Acute toxicity was assessed in albino mice by monitoring liver enzymes (ALP, AST, ALT) and histopathological changes.
Main Results:
- PEM significantly decreased the gene expression of both sea and seb in Staphylococcus aureus.
- The expression of seb was found to be more sensitive to PEM than sea.
- Mice treated with PEM showed no significant adverse effects on liver enzymes or tissue structure compared to controls.
Conclusions:
- Micrococcus roseus pigments exhibit anti-enterotoxigenic properties by downregulating sea and seb gene expression.
- PEM demonstrates a favorable safety profile, with low acute toxicity.
- These findings suggest PEM as a promising natural agent for controlling staphylococcal enterotoxin production.
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