Effect Of Sound Stress Research Articles

Cryptococcus neoformans Virulence Attributes can be Modulated by Sound Stress

Sound waves are a prime component making up the environment, and they are present in almost all niches on the planet. In times of increasing noise pollution, the effect of sound stress on humans, animals, and microorganisms is well known. However, the possibility of this kind of pressure in the environment, affecting pathogenic fungi, which live in the background as saprophytes, has not been explored. Fungi can develop attributes and become virulent due to adaptation to selective pressure or stress. In this context, our group has become interested in evaluating the impact of sound stress on the fungus Cryptococcus neoformans, a pathogen that has high phenotypic plasticity. C. neoformans strain H99 was chosen for all assays. The yeasts were cultivated at 30°C, exposed or not to the frequency of 8 kHz. We observed morphological changes in these cells, such as the expression of phenotype virulence attributes: capsule expansion and melanin production. We also analyzed the number of viable cells after exposure, and we observed the yeast’s susceptibility to antifungals. After the treatment with 8 kHz, the cells showed a significant increase in the capsule expansion, an acceleration of the melanin production, and a slight reduction in the number of viable cells. Finally, tests performed with the antifungals showed a decrease in inhibition halo on the plate test. Our results are innovative and suggest that stress caused by sound could incite increased virulence in this fungus.

Rise in thymocyte number and thymulin serum level induced by noise

A high level of noise is known to induce important changes in the immune system. In this work, the effect of sound stress on the circulating level of thymulin and on the cellularity of the thymus gland was studied. The experiments were done in RK mice exposed to a noise level of 100 dB for a period of 1 h. Following the noise exposure, the animals were bled at different times for thymulin titration, or killed in order to evaluate the number of cells and the weight of each thymus. The results indicate that young mice exposed to the stressor stimulus show an increase in serum thymulin titre, and at the same time they show an increment in thymus weight and in thymocyte number compared to control. These results support a new argument in favour of the theory of a central nervous system control on the thymus function.

Effect of sound stress on the migration of prethymic stem cells.

Effect of sound stress on the migration of prethymic stem cells.

Effect of sound stress on ovulation, estrus, and conception in beef heifers

Effect of sound stress on ovulation, estrus, and conception in beef heifers