RESUMO
The problem of antibiotic resistance is a global critical public health concern. In light of the threat of returning to the pre-antibiotic era, new alternative approaches are required such as quorum-sensing (QS) disruption and virulence inhibition, both of which apply no discernible selective pressure on bacteria, therefore mitigating the potential for the development of resistant strains. Bearing in mind the significant role of QS in orchestrating bacterial virulence, disrupting QS becomes essential for effectively diminishing bacterial virulence. This study aimed to assess the potential use of sub-inhibitory concentration (0.25 mg/mL) of glyceryl trinitrate (GTN) to inhibit virulence in Serratia marcescens and Pseudomonas aeruginosa. GTN could decrease the expression of virulence genes in both tested bacteria in a significant manner. Histopathological study revealed the ability of GTN to alleviate the congestion in hepatic and renal tissues of infected mice and to reduce bacterial and leukocyte infiltration. This study recommends the use of topical GTN to treat topical infection caused by P. aeruginosa and S. marcescens in combination with antibiotics.
RESUMO
BACKGROUND: Hepatitis C virus (HCV) is characterized by a high degree of nucleotide sequence variability between genotypes. This variability extends to functional and immunological determinants. Serological tests using antigenic segments derived from the HCV polyprotein have been used for the diagnosis of HCV infection. However, available diagnostic Kits do not necessarily take type variability into consideration and are not optimized for HCV genotype 4a (HCV4a), the predominant genotype in Egypt. AIM: The aim of this study was to express some HCV4a-derived polypeptides in order to identify those with immunodiagnostic utility. MATERIALS AND METHODS: Six sequential/overlapping genomic segments encoding 100-266 amino acid peptides from the core (peptide 1), envelope 1 (E1; peptide 2), envelope 2 (E2; peptides 4, 5, and 6), and E1/E2 (peptide 3) regions of the HCV4apolyprotein were selected for in vitro expression as glutathione S-transferase-fusion proteins. The immunoreactivity of the expressed peptides was evaluated against sera from HCV-infected/uninfected individuals using dot blot, western blot, and enzyme-linked immunosorbent assay. RESULTS: The expressed polypeptides were recognized by HCV-infected sera from 20 patients, while showing no immunoreactivity toward uninfected serum. Peptide 1 derived from the core protein was found to be the most immunoreactive. CONCLUSION: Expressed polypeptides hold good potential for use in the development of improved HCV immunodiagnostics.
