Bacterial sialoglycosidases in Virulence and Pathogenesis

Abstract

Human oral microbiome and dysbiotic infections have been recently evidently identified. One of the major reasons for such dysbiosis is impairment of the immune system. Periodontitis is a chronic inflammatory disease affecting the tissues that surround and support the teeth. In the United States., approximately 65 million people are affected by this condition. Its occurrence is also associated with many important systemic diseases such as cardiovascular disease, rheumatoid arthritis, and Alzheimer’s disease. Among the most important etiologies of periodontitis is Porphyromonas gingivalis, a keystone bacterial pathogen. Keystone pathogens can orchestrate inflammatory disease by remodeling a normally benign microbiota causing imbalance between normal and pathogenic microbiota (dysbiosis). The important characteristics of P. gingivalis causing dysbiosis are its virulence factors which cause effective subversion of host defenses to its advantage allowing other pathogens to grow. Some of the mechanisms involved in these processes are still not well-understood. However, various microbial strategies target host sialoglycoproteins for immune dysregulation. In addition, the enzymes that break down sialoglycoproteins and sialoglycans are the “sialoglycoproteases”, resulting in exposed terminal sialic acid. This process could lead to pathogen-toll like receptor (TLR) interactions mediated through sialic acid receptor ligand mechanisms. Assessing the function of P. gingivalis sialoglycoproteases, could pave the way to designing carbohydrate analogues and sialic acid mimetics to serve as drug targets.

Comparative Reverse Vaccinology of Piscirickettsia salmonis, Aeromonas salmonicida, Yersinia ruckeri, Vibrio anguillarum and Moritella viscosa, Frequent Pathogens of Atlantic Salmon and Lumpfish Aquaculture

“…Mass spectrometric analysis of extracellular products (ECP) from A. hydrophila that conferred 100% protection to catfish vaccinated with ECP when challenged with the pathogen two weeks post-vaccination showed several putative proteins that may serve as important immunogens, including chitinase, chitodextrinase, outer membrane protein 85, putative metalloprotease, extracellular lipase, hemolysin, and elastase [ 115 ]. Other enzymes like collagenase, lytic polysaccharide monooxygenase, sphingomyelin phosphodiesterase, methyltransferase, triacylglycerol lipase, exo-alpha-sialidase, deoxyribonuclease I, nucleotidyltransferase, class C beta-lactamase and SGNH/GDSL hydrolase family protein identified in this study as potential vaccine candidates have been implicated in the virulence of bacterial pathogen [ 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 ], and could be considered for a design of an effective polyvalent vaccine for finfish.…”

Production and Composition of Group B Streptococcal Membrane Vesicles Vary Across Diverse Lineages

“…Although sialidases have no known role in GBS pathogenesis ( Yamaguchi et al, 2016 ), these proteins were shown to be immunomodulatory in other bacterial species ( Aruni et al, 2011 ; Sudhakara et al, 2019 ) while simultaneously promoting biofilm production and metabolism of host sugars ( Hardy et al, 2017 ; Zaramela et al, 2019 ). The presence and abundance of sialidase was variable: the ST-1 and ST-17 MVs all contained sialidase, but the ST-12 MVs lacked it.…”

Remodeling of host glycoproteins during bacterial infection

“…Neuraminidases (sialidases) are well-known modifying enzymes that can cleave sialic acid from glycans. Many types of bacteria produce neuraminidase with various specificities ( 11 ). Streptococcus pneumoniae , a common cause of sepsis, can produce neuraminidase to induce rapid desialylation and clearance of platelets during systemic S. pneumo-niae infection ( 12 ).…”