Role of periodontal pathogens in atherosclerotic plaque development and progression: An overview

Atherosclerosis is a progressive disease marked by the accumulation of lipids and fibrous components in the large arteries. It is one of the primary causes of heart disease and stroke. Periodontal diseases encompass conditions like gingivitis and periodontitis, which are multifactorial diseases associated with dysbiotic plaque biofilms that trigger an immune-inflammatory host response, eventually resulting in the destruction of periodontal tissues. Links between periodontal disease and atherosclerosis may be based on direct invasion of periodontal pathogens or inflammatory mechanisms triggered by bacteria related to periodontal lesions, locally or systemically, that may impact the initiation of the atherosclerotic lesion. The presence of periodontal pathogens within an atheromatous lesion implies hematogenous dissemination. The invasion of atheroma by periodontal pathogens results in changes in the proatherogenic and proinflammatory properties of endothelial cells, leading to endothelial dysfunction, which is a hallmark of atherosclerosis. Clinical and epidemiological studies have offered sufficient evidence of periodontitis having an adverse effect on systemic health, including atherosclerosis; however, a direct causal effect has not yet been proved. This review aims to analyse scientific results regarding the mechanism by which periodontal pathogens may cause atherosclerosis as well as to describe the role of Porphyromonas gingivalis in atherosclerotic plaque development and progression

Protection of Litopenaeus vannamei against White Spot Syndrome Virus using bacterially expressed recombinant envelope proteins VP39 and VP28

White spot syndrome virus (WSSV) is a highly virulent shrimp pathogen, causing huge economic loss to the aquaculture industry. We investigated the efficacy of recombinant VP39 protein against WSSV infection in Litopenaeus vannamei by intramuscular and oral administration, and also compared the efficacy with recombinant VP28 (rVP28). The VP39 is a 283 amino acid protein encoded by the structural gene vp39 which acts as an important mediator for virus entry to the host. Shrimp orally vaccinated with rVP39 and rVP28 showed a cumulative mortality of 50% and 60% respectively following challenge, and this indicates that rVP39 had a better protective effect against WSSV infection compared with rVP28. Vaccination by intramuscular injection with rVP39 and rVP28 resulted in survival rate of 60% and 50%, respectively. The transcriptional profiling of viral genes of vaccinated shrimp with recombinant viral proteins of VP28 showed higher transcriptional levels than VP39. The transcriptional level of rVP39 vaccinated animals was delayed by 6 days after WSSV infection, while the delay was only 4 days in the case of rVP28. These results indicate that vaccination delays the transcription of envelope genes of WSSV in shrimp. The present study could demonstrate the importance of VP39 as a prominent candidate for vaccination against WSSV

Genetic Diversity of the Legionella pneumophila dotA Gene Detected on Surfaces of Respiratory Therapy Equipment

Legionellosis is a neglected disease due to the absence of well-defined clinical symptoms and difficulties in isolating the causal organism. Legionella spp. is known to colonize the lumen of respiratory therapy equipment(RTE) and evade conventional detection by entering the viable but non-culturable state. Monitoring these surfaces for Legionella pneumophila in addition to routine monitoring of water could aid in decreasing incidences of hospital-acquired infections by this pathogen. In this study swabs of different respiratory therapy equipment were tested for the presence of Legionella by conventional culture-based methods versus molecular detection of culture-independent template by polymerase chain reaction (PCR). Genetic diversity of the genes amplified were studied using bioinformatic tools. The dotA genes were genetically diverse indicating no clonality. This communication highlights that the persistence of virulence genes like dotA on abiotic surfaces can result in the mobilization of these genes to other species and give rise to virulent forms especially in a healthcare setting

Role of oral microbiota in irreversible pulpitis - Current strategies and future perspectives

Irreversible pulpitis is an inflammation of the tooth pulp caused by an opportunity-driven invasion of the pulp space by oral microbiota typically prevalent in the oral cavity. Microbial organisms are extensively recognised to be the fundamental cause of endodontic infections and treatment failures. Previously, bacterial species responsible for these infections were largely recognised using conventional microbial culture techniques, lending credence to the widely held belief that anaerobic Gram-negative bacteria frequently enter the pulp space and trigger endodontic infections. The advent of novel technologies grants the advantage of detecting and studying microbial populations via an amalgamation of the modern "Omics" techniques and meticulous bioinformatics analysis, additionally detecting the metatranscriptome, metaproteome and metabolome along with the metagenome. Amongst these analytical strategies, metagenomic analyses are essentially pragmatic for investigating the oral microbiome. Metagenomics favor not only assessment of microbial composition in diseased conditions, but also contributes to detection of novel, potentially pathogenic species inclusive of non-viable bacteria. The present review describes current knowledge of root canal microbiome, including its composition and functional attributes, the novel strategies available for detection of microbiome as well as challenges associated and provides some crucial pointers for areas of future research

Exploring the Pathogenic Potential of Vibrio vulnificus Isolated from Seafood Harvested along the Mangaluru Coast, India

It has been observed that not all strains of Vibrio vulnificus are virulent. Determining the virulence of strains that are frequently present in seafood is of significance for ensuring seafood safety. This study is an attempt to predict the virulence of seafood-borne V. vulnificus isolated along the Mangaluru Coast, India. The isolates tested possessed a vcgC gene sequence with high similarity to that in the clinical strain. Transcriptional analysis of core virulence genes in seafood isolate E4010 showed the phenomenon of contact-mediated expression of rtxA1 which correlated well with the actin disintegration and cytotoxicity. These results suggest that the seafood isolates tested in this study possess a functional RtxA1 which could help in initiating the infection. However, other putative virulence genes such as vvpE encoding an extracellular protease, vvhA encoding hemolysin, flp encoding tad pilin and ompU encoding fibronectin-binding protein were also constitutively expressed. Virulence-associated attributes such as cytotoxicity and adherence matched the response of the clinical strain (p > 0.05). On the other hand, the environmental strains showed higher serum sensitivity compared with the clinical strain. These findings show that the part of virulence attributes required for the disease process might be intact in these isolates

PCR-based evidence showing the presence of Vibrio vulnificus in wound infection cases in Mangaluru, India

Vibrio vulnificus is a Gram-negative, opportunistic human pathogen capable of causing life-threatening septicaemia, wound infections, and gastroenteritis, especially in immunocompromised individuals. Two cases of V. vulnificus-associated wound infection occurring in diabetic patients are reported here. The pathogen was detected by PCR targeting species-specific marker gyrB and virulence markers, including repeats in toxin (rtxA) and hemolysin (vvhA), but the causative agent could not be cultured. Genotyping based on the virulence-correlated gene revealed that the V. vulnificus detected in this study belonged to the vcg-C type, which is commonly associated with clinical cases. This report highlights the clinical applicability of PCR-based methods in the detection of V. vulnificus in culture-negative cases. Such methods may add a very useful clinical dimension to currently used diagnostic practices. Keywords: Vibrio vulnificus, Wound infection, Polymerase chain reaction, Diagnosi

Quorum sensing regulation of virulence gene expression in Vibrio harveyi during its interaction with marine diatom Skeletonema marinoi

Communication between species from different kingdoms may be as important as intra-kingdom communication. It has recently been confirmed that co-existing bacteria and phytoplankton in aquatic ecosystems do cross-talk. This study examined the signs of possible cross signalling between V. harveyi, one of the predominant bacterial species of the marine ecosystem and a dominant diatom species, S.marinoi, to understand communication over species borders. It is known that V.harveyi employ quorum sensing for cell-to-cell communication, bioluminescence (luxR), and the regulation of the virulence gene (vhp, chiA). Former studies have also shown, this kind of interactions being disrupted by compounds secreted by a few algal species existing in the aquatic ecosystem. We investigated the QS communication by quantifying the expression levels of virulence regulator luxR and virulence factors metalloprotease (vhp) and chitinase (chiA) in four different V. harveyi strains grown in the presence of S. marinoi strain. Results obtained in this study indicate that quorum sensing was activated in strains of V. harveyi analysed but did not regulate the expressions of vhp and chiA virulence factors. This observation suggests that the existence of S. marinoi did not interfere with the QS behavior of V. harveyi and its interaction with marine diatom; it may be due to the commensalism relationship

Unveiling the acid stress response of clinical genotype Vibrio vulnificus isolated from the marine environments of Mangaluru coast, India

Gastric acidity is one of the earliest host defences faced by ingested organisms, and successful pathogens need to overcome this hurdle. The objective of this study was the systematic assessment of acid stress response of Vibrio vulnificus isolated from coastal regions of Mangaluru. Acid shock experiments were carried out at pH 4.0 and pH 4.5 with different experimental conditions expected to produce a varied acid response. Exposure to mild acid before the acid shock was favourable to the bacteria but was dependent on cell population and pH of the media and was independent of the strains tested. Lysine dependent acid response was demonstrated with reference to the previously identified lysine decarboxylase system. Additionally, the results showed that inoculation into the oyster provided some level of protection against acid stress. Increased expression of Lysine/Cadaverine related genes were observed upon the addition of ground oyster which was accurately determined by quantitative real-time PCR proving the phenomenon observed. The potential role of ornithine was analysed with regard to acid stress, but no change in the survival pattern was observed. These findings highlight the physiology of bacteria in acid stress.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Genome analysis of clinical genotype Vibrio vulnificus isolated from seafood in Mangaluru Coast, India provides insights into its pathogenicity

AbstractVibrio vulnificus an opportunistic human pathogen native to marine/estuarine environments, is one of the leading causes of death due to seafood consumption and exposure of wounds to seawater worldwide. The present study involves the whole genome sequence analysis of an environmental strain of V. vulnificus (clinical genotype) isolated from seafood along the Mangaluru coast of India. The sequenced genome data was subjected to in-silico analysis of phylogeny, virulence genes, antimicrobial resistance determinants and secretary proteins using suitable bioinformatics tools. The sequenced isolate had an overall genome length of 4.8 Mb and GC content of 46% with 4,400 coding DNA sequences. The sequenced strain belongs to a new sequence type (Multilocus sequence typing) and was also found to branch with a phylogenetic lineage that groups the most infectious strains of V. vulnificus. The seafood isolate had complete genes involved in conferring serum resistance yet showed limited serum resistance. The study identified several genes against the antibiotics that are commonly used in their treatment, highlighting the need for alternative treatments. Also, the secretory protein analysis revealed genes associated with major pathways like ABC transporters, two-component systems, quorum sensing, biofilm formation, cationic antimicrobial peptide (CAMP) resistance and others that play a critical role in the pathogenesis of the V. vulnificus. To the best of our knowledge, this is the first report of a detailed analysis of the genomic information of a V. vulnificus isolated from the Indian subcontinent and provides evidence that raise public health concerns about the safety of seafood

Genome analysis of clinical genotype <i>Vibrio vulnificus</i> isolated from seafood in Mangaluru Coast, India provides insights into its pathogenicity

Vibrio vulnificus an opportunistic human pathogen native to marine/estuarine environment, is one of the leading causes of death due to seafood consumption and exposure of wounds to seawater worldwide. The present study involves the whole genome sequence analysis of an environmental strain of V. vulnificus (clinical genotype) isolated from seafood along the Mangaluru coast of India. The sequenced genome data was subjected to in-silico analysis of phylogeny, virulence genes, antimicrobial resistance determinants, and secretary proteins using suitable bioinformatics tools. The sequenced isolate had an overall genome length of 4.8 Mb and GC content of 46% with 4400 coding DNA sequences. The sequenced strain belongs to a new sequence type (Multilocus sequence typing) and was also found to branch with a phylogenetic lineage that groups the most infectious strains of V. vulnificus. The seafood isolate had complete genes involved in conferring serum resistance yet showed limited serum resistance. The study identified several genes against the antibiotics that are commonly used in their treatment, highlighting the need for alternative treatments. Also, the secretory protein analysis revealed genes associated with major pathways like ABC transporters, two-component systems, quorum sensing, biofilm formation, cationic antimicrobial peptide (CAMP) resistance, and others that play a critical role in the pathogenesis of the V. vulnificus. To the best of our knowledge, this is the first report of a detailed analysis of the genomic information of a V. vulnificus isolated from the Indian subcontinent and provides evidence that raises public health concerns about the safety of seafood.</p