Banca de DEFESA: SIVONEIDE MARIA DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : SIVONEIDE MARIA DA SILVA
DATE: 21/07/2021
TIME: 09:00
LOCAL: Remoto
TITLE:

Investigation of resistance genes and factors associated with biofilm formation of Providencia stuartii

KEY WORDS:

Antimicrobials. Bacterial infections. Enterobacteriaceae.

PAGES: 110
BIG AREA: Ciências Biológicas
AREA: Bioquímica
SUMMARY:

Providencia stuartii is a species of Enterobacteriaceae that causes different infections mainly due to its intrinsic resistance to antimicrobials, ability to acquire new genes and biofilm formation. Thus, this study addressed the main mechanisms of resistance and virulence of human pathogens, especially P. stuartii, through two approaches: review of the state-of-the-art on this topic; and experimental analysis, investigating genes associated with resistance and biofilm in 28 P. stuartii isolates obtained from a public hospital in Recife, PE. For experimental analysis, initially, the taxonomic identity was confirmed by mass spectrometry. As for the susceptibility, phenotype, followed by molecular assays were performed to investigate the aac(6')-Ib-cr and bla_KPC resistance genes. In sequence, genetic diversity and the biofilm-associated fimH and mrkD genes were investigated. To confirm biofilm formation, staining, microscopy and hydrocarbon adhesion methods were used. Finally, a review of the virulence factors of pathogenic bacteria was carried out. As a first result, a book chapter was obtained that includes: aminoglycosides and inactivating enzymes. From an experimental point of view, the following results were obtained: all isolates were confirmed as P. stuartii and resistant to fluoroquinolones, most of them resistant to beta-lactams. This study demonstrated the first report in Brazil of the aac(6')-Ib-cr gene, present in 16 isolates and confirmed the spread of bla_KPC in 14, of which 11 had both genes. All isolates formed biofilm and were mostly hydrophilic. However, they did not show the fimH and mrkD genes, which are associated with biofilm in enterobacteria, thus revealing the particularities of this species. The data obtained indicate that the therapeutic options for P. stuartii are limited, as in addition to the natural resistance to antimicrobials and the potential for the acquisition of new genes, mechanisms not yet known may be responsible for its biofilm formation. The review study also showed that this species represents a human pathogen with significant virulence factors such as the efficient toxin production system, reinforcing the need for additional studies to eventually prevent infections caused by this bacteria.

BANKING MEMBERS:
Externa à Instituição - HORTENCIA FARIAS DE ANDRADE
Externa à Instituição - LÍVIA CAROLINE ALEXANDRE DE ARAÚJO - UFPB
Presidente - 2380850 - MARIA BETANIA MELO DE OLIVEIRA
Interna - 1133984 - PATRICIA MARIA GUEDES PAIVA
Interno - 1960817 - THIAGO HENRIQUE NAPOLEAO