Banca de DEFESA: VERONICA KAREN CASTRO PÉREZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE: VERONICA KAREN CASTRO PÉREZ
DATA: 22/03/2019
HORA: 14:00
LOCAL: Sala DMV08 (Prédio da preventiva)
TÍTULO:

DETECTION OF VIRULENCE AND ANTIMICROBIAL RESISTANCE GENES IN S.aureus ISOLATED FROM BOVINE MASTITIS IN BRASIL

PALAVRAS-CHAVES:

mastitis, virulence factors, antimicrobial resistance, zoonosis

PÁGINAS: 1
GRANDE ÁREA: Ciências Agrárias
ÁREA: Medicina Veterinária
RESUMO:

Bovine mastitis is a disease with the greatest impact on dairy cattle production worldwide. Staphylococcus aureus is one of the major causative agents of mastitis. Besides the veterinary importance, this pathogen also has relevance in human health, due to its zoonotic potential. S. aureus presents several virulence factors involved in almost all infection processes, as well as resistance to several antimicrobials. Thus, the present study aims to evaluate the virulence factors and genetic mechanisms of drug resistance in 404 samples of S. aureus isolated from cows with mastitis, as well as to verify the association of these characteristics with the antimicrobial resistance profile. Identification of the virulence and resistance genes was done by monoplex and multiplex PCR. The phenotypic identification of slime production was performed in TSB broth with Red Congo and sucrose and incubated at 37 ° C for 48 hours. The association between the presence of virulence factors and the antimicrobial resistance and year of isolation was calculated by univariate analysis using the chi-square and Fisher's exact tests. As a result, 100% (404/404) of the isolates were confirmed as S. aureus. Moreover, 83.66 % (338/404) isolates formed biofilm, it was observed in them that they are more likely to be resistant to penicillin in comparison to the susceptible strains. The presence hemolysins genes hla and hlb was found in 26.69% (110/412) isolates. Of the samples tested 81.82% (90/110) had both hla and hlb genes. In addition, 12.73% (14/110) of the isolates had only the hla gene, but not hlb and only one isolate 1/110, had the hlb gene but not the hla gene. In contrast, none of the 110 isolates tested for the identification of enterotoxin genes sea, seb, sec, sed and see were found. We can conclude that there is a high frequency of S. aureus strains isolated from mastitis, biofilm forming and that there is an association between the biofilm producing strains and penicillin resistance. These results may help us to understand the distribution of enterotoxin and hemolysin genes, as well as biofilm production and drug resistance association among bovine mastitis isolates, important for the epidemiology of the disease in cattle and in human population.

MEMBROS DA BANCA:
Presidente - ELAINE MARIA SELES DORNELES
Interno - ALESSANDRO DE SÁ GUIMARÃES - EMBRAPA
Interno - GERALDO MARCIO DA COSTA
Externo à Instituição - ANDREY PEREIRA LAGE - UFMG
Externo à Instituição - JAMILI MARIA SUHET MUSSI - SIM
Externo à Instituição - MARCOS BRYAN HEINEMANN - USP