Computational analysis suggests that virulence of Chromobacterium violaceum might be linked to biofilm formation and poly-NAG biosynthesis

Abstract

Groups of genes that produce exopolysaccharide with a N-acetyl-D-glucosamine monomer are in the genome of several pathogenic bacteria. Chromobacterium violaceum, an opportunistic pathogen, has the operon hmsHFR-CV2940, whose proteins can synthesize such polysaccharide. In this work, multiple alignments among proteins from bacteria that synthesize such polysaccharide were used to verify the existence of amino acids that might be critical for pathogen activity. Three-dimensional models were generated for spatial visualization of these amino acid residues. The analysis carried out showed that the protein HmsR preserves the amino acids D135, D228, Q264 and R267, considered critical for the formation of biofilms and, furthermore, that these amino acids are close to each other. The protein HmsF of C. violaceum preserves the residues D86, D87, H156 and W115. It was also shown that these residues are also close to each other in their spatial arrangement. For the proteins HmsH and CV2940 there is evidence of conservation of the residues R104 and W94, respectively. Conservation and favorable spatial location of those critical amino acids that constitute the proteins of the operon indicates that they preserve the same enzymatic function in biofilm synthesis. This is an indicator that the operon hmsHFR-CV2940 is a possible target in C. violaceum pathogenicity.

Analyses of Seven New Genomes of Xanthomonas citri pv. aurantifolii Strains, Causative Agents of Citrus Canker B and C, Show a Reduced Repertoire of Pathogenicity-Related Genes

“…The hmsHFR-hp genes (XAC1813-1810) are involved in adaptation and virulence, and have been reported respectively to be homologous to E. coli genes pgaABCD (Wang et al, 2004). Mutations in genes from this operon in members of the genera Chromobacterium , Yersinia , and Xanthomonas have resulted in reduction of biofilm formation and consequent reduction in virulence induction (Becker et al, 2009; Abu Khweek et al, 2010; Wang et al, 2012). Therefore, the absence of XAC1810-XAC1819 in the genomes of strains XauB and XauC might contribute to less efficient tissue adhesion processes and biofilm formation, and reduce cell-to-cell aggregation dependent of adhesin and exopolysaccharides molecules; this in turn would lead to reduction in tissue colonization capabilities in these strains.…”

Nutrients Removal from Aquaculture Wastewater by Biofilter/Antibiotic-Resistant Bacteria Systems

“…These interactions are also dependent on the physicochemical characteristics of the fluid (e.g., pH, temperature) in which the substrate is introduced [44]. The ability of both strains to form biofilms on various substrates is due to the synthesis of different molecules, such as the synthesis of three alginate exopolysaccharides, Psl and Pel [45] by P. aeruginosa and N-acetyl-D-glucosamine monomer by C. violaceum [46].…”

Evolutionary Trajectories in Plant-Associated Pseudomonas and Xanthomonas Strains

“…The hmsHFR-hp genes (XAC1813-1810) are involved in adaptation and virulence, and have been reported respectively to be homologous to E. coli genes pgaABCD (Wang et al, 2004). Mutations in genes from this operon in members of the genera Chromobacterium, Yersinia, and Xanthomonas have resulted in reduction of biofilm formation and consequent reduction in virulence induction (Becker et al, 2009;Abu Khweek et al, 2010;. Therefore, the absence of XAC1810-XAC1819 in the genomes of strains XauB and XauC might contribute to less efficient tissue adhesion processes and biofilm formation, and reduce cell-to-cell aggregation dependent of adhesin and exopolysaccharides molecules; this in turn would lead to reduction in tissue colonization capabilities in these strains.…”