EDUARDO MILTON RAMOS SANCHEZ
Projetos de Pesquisa
Unidades Organizacionais
LIM/38 - Laboratório de Epidemiologia e Imunobiologia, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Emergence of livestock-associated Mammaliicoccus sciuri ST71 co-harbouring mecA and mecC genes in Brazil(2023) MOURA, Guilherme S. de; CARVALHO, Eneas de; SANCHEZ, Eduardo M. Ramos; SELLERA, Fabio P.; MARQUES, Michele F. S.; HEINEMANN, Marcos B.; VLIEGHER, Sarne De; SOUZA, Fernando N.; MOTA, Rinaldo A.The discovery and tracking of antimicrobial resistance genes are essential for understanding the evolution of bacterial resistance and restraining its dispersion. Mammaliicoccus sciuri (formerly Staphylococcus sciuri) is the most probable evolutionary repository of the mecA gene, that later disseminated to S. aureus. In this study, we describe the first double mecA/mecC homologue-positive non-aureus staphylococci and mammaliicocci (NASM) from the American continent, also representing the first report of mecC-positive NASM in Brazil. Two clonally related methicillin-resistant M. sciuri strains co-carrying mecA and mecC genes were isolated from the teat skin swab and milk sample collected from an ewe's left udder half. Both M. sciuri strains belonged to the sequence type (ST) 71. Besides mecA and mecC genes, the M. sciuri strains carried broad resistomes for clinically important antimicrobial agents, including & beta;-lactams, tetracyclines, lincosamide, streptogramin, streptomycin, and aminoglycosides. Virulome analysis showed the presence of the clumping factor B (clfB), ATP-dependent protease ClpP (ClpP) and serine-aspartate repeat proteins (sdrC and sdrE) virulence-associated genes. Phylogenomic analysis revealed that these M. sciuri strains are part of a globally disseminated branch, associated with farm and companion animals and even with food. Our findings suggest that M. sciuri is likely to emerge as a pathogen of global interest, carrying a broad repertoire of antimicrobial resistance genes with a remarkable co-presence of mecA and mecC genes. Finally, we strongly encourage to monitor M. sciuri under the One Health umbrella since this bacterial species is spreading at the human-animal-environment interface.
- The bovine leukemia virus infection prolongs immunosuppression in dairy cows during the periparturient period by sustaining higher expression of immunological checkpoints in T cells(2023) NASCIMENTO, Alice Maria Melo do; SOUZA, Carolina Menezes Suassuna de; OLIVEIRA, Ana Claudia Dumont; BLAGITZ, Maiara Garcia; SANCHEZ, Eduardo Milton Ramos; LIBERA, Alice Maria Melville Paiva Della; LEITE, Ricardo de Miranda Henriques; FERNANDES, Artur Cezar de Carvalho; SOUZA, Fernando NogueiraBovine leukemia virus (BLV) is caused by a deltaretrovirus and has been associated with immunosuppression as well as comorbidities such as bovine mastitis, the costliest disease in the dairy sector. However, no previous study has explored at the synergistic immunosuppressive effect of the peripartum period with an immunosuppressive viral disease such as BLV. Thus, our study explored the effect of BLV infection in the periparturient period on the expression of PD-1 and CTLA-4 in blood T lymphocytes, and the impact of BLV infection on the rate of new intramammary infections during the early lactation. Here, we found that BLV-infected dairy cows always had a statistically significant higher expression of CTLA-4 and PD-1 in blood T cells. Furthermore, our findings indi-cated that BLV infection prolongs immunosuppression in dairy cows during the periparturient period by sus-taining higher expression of immunological checkpoints in T cells. In addition, BLV-infected dairy cows have a higher rate of new intramammary infections during early lactation. Thus, our study provides new insights of the immunosuppressive effect of BLV on the most critical period of the cows' life with marked detrimental effect on protective T-cell immunity and comorbidities, such as bovine mastitis.
- Bovine-associated staphylococci and mammaliicocci trigger T-lymphocyte proliferative response and cytokine production differently(2023) SOUZA, Fernando N.; SANTOS, Kamila R.; FERRONATTO, Jose A.; SANCHEZ, Eduardo M. Ramos; TOLEDO-SILVA, Bruno; HEINEMANN, Marcos B.; VLIEGHER, Sarne De; LIBERA, Alice M. M. P. DellaWe examined whether distinct staphylococcal and mammaliicoccal species and strains trigger B-and T-lymphocyte proliferation and interleukin (IL)-17A and interferon (IFN)-gamma production by peripheral blood mononuclear cells in nulliparous, primiparous, and multiparous dairy cows. Flow cytometry was used to measure lymphocyte proliferation with the Ki67 anti-body, and specific monoclonal antibodies were used to identify CD3, CD4, and CD8 T lymphocyte and CD21 B lymphocyte populations. The supernatant of the peripheral blood mononuclear cell culture was used to measure IL-17A and IFN-gamma production. Two distinct, inactivated strains of bovine-associated Staphylococcus aureus [one causing a persistent intramammary infec-tion (IMI) and the other from the nose], 2 inactivated Staphylococcus chromogenes strains [one causing an IMI and the other from a teat apex), as well as an inactivated Mammaliicoccus fleurettii strain originat-ing from sawdust from a dairy farm, and the mitogens concanavalin A and phytohemagglutinin M-form (both specifically to measure lymphocyte proliferation) were studied. In contrast to the ""commensal"" Staph. aureus strain originating from the nose, the Staph. aureus strain causing a persistent IMI triggered proliferation of CD4+ and CD8+ subpopulations of T lymphocytes. The M. fleurettii strain and the 2 Staph. chromogenes strains had no effect on T-or B-cell proliferation. Fur-thermore, both Staph. aureus and Staph. chromogenes strains causing persistent IMI significantly increased IL-17A and IFN-gamma production by peripheral blood mononuclear cells. Overall, multiparous cows tended to have a higher B-lymphocyte and a lower T-lymphocyte proliferative response than primiparous and nulliparous cows. Peripheral blood mononuclear cells of multipa-rous cows also produced significantly more IL-17A and IFN-gamma. In contrast to concanavalin A, phytohemagglu-tinin M-form selectively stimulated T-cell proliferation.