1472-2Evaluation of the inflammatory response induced by Staphylococcus aureus in a murine model of infection
Autores:Hugo Santana (UFBA - Universidade Federal da Bahia) ; Lício Fábio Almeida Andrade Ferreira (UFBA - Universidade Federal da Bahia) ; Lucas Teixeira Graia (UFBA - Universidade Federal da Bahia) ; Ítalo Sousa Pereira (UFBA - Universidade Federal da Bahia) ; Tiana Baqueiro Figueiredo (UFBA - Universidade Federal da Bahia) ; Lucas Miranda Marques (UFBA - Universidade Federal da Bahia) ; Robson Amaro Augusto da Silva (UFBA - Universidade Federal da Bahia)


Staphylococcus aureus has great importance in the clinical practice due to infection that can lead to disease as folliculitis and pyoderma. Studies have evaluated the inflammatory response developed by the host organism against the pathogen in different animal models. Our study aimed to evaluate the inflammatory response to infection by different strains of S. aureus in an intradermal murine model of infection. BALB / c mice were infected intradermally with 107 isolates of ATCC and MRSA 112 strains of S. aureus in the ear to characterize the inflammatory response. The animals were euthanized 6, 24, 48 and 96 hours after infection and the profile of cell recruitment as well as the systemic response to infection was evaluated. Cytokine production was assessed by ELISA. Intradermal neutrophilic infiltrate was observed in the ear in animals infected with two strains of S. aureus. However, a higher neutrophils infiltrate was observed in MRSA infected mice. The animals infected by the strain MRSA showed culture-positive samples of the draining lymph nodes 48 hours after infection, while the strain ATCC only showed positive culture 96 hours after infection. Animals infected with MRSA strains show absolute and relative neutrophilia compared to animals infected with strain ATCC. In the draining lymph nodes of the infection site was observed a kinetic of cell proliferation in animals infected with different strains tested. Infected animals produced more IL-10 and TNF-&alpha in the control group. Our results indicate that there is a difference in the kinetics of migration between different strains of S. aureus to the draining lymph node in the intradermic infection model, modulation in neutrophils migration to the lesion site and this can be important for the development of immune response against different strains of S. aureus.

Palavras-chave:  Staphylococcus, bacteria, neutrophils, intradermal, model