Occult hepatitis B virus infection and current perspectives on global WHO 2030 eradication.

The current World Health Organization (WHO) Hepatitis Elimination Strategy suffers from lack of a target for diagnosing or expunging occult HBV infection. A sizable segment of the global population has an undetected HBV infection, particularly the high-risk populations and those residing in countries like India with intermediate endemicity. There is growing proof that people with hidden HBV infection can infect others, and that these infections are linked to serious chronic hepatic complications, especially hepatocellular carcinoma. Given the current diagnostic infrastructure in low-resource settings, the WHO 2030 objective of obliterating hepatitis B appears to be undeniably challenging to accomplish. Given the molecular basis of occult HBV infection strongly linked to intrahepatic persistence, patients may inexplicably harbour HBV genomes for a prolonged duration without displaying any pronounced clinical or biochemical signs of liver disease, and present histological signs of moderate degree necro-inflammation, diffuse fibrosis, and hence the international strategy to eradicate viral hepatitis warrants inclusion of occult HBV infection.

Molecular Docking Analysis of Hydroxyclavicol and Eugenol From Betel Leaves Against Outer Membrane Protein (OmpH) of Dialister pneumosintes.

Introduction Dialister pneumosintes is an obligate anaerobic non-spore-forming Gram-negative bacilli. As a part of polymicrobial film, the activated virulence factor causes oral diseases like gingivitis and periodontitis. Decreased susceptibility of clinical strains of D. pneumosintes to different antibiotics including piperacillin and metronidazole raises concerns. There has been significant interest in the utility of plant phytocompounds as potent antibacterial agents.  Aim The study aimed to look at the potential of two phytocompounds, eugenol and hydroxychavicol, for their ability to inhibit outer membrane protein (OmpH) of D. pneumosintes using computational tools. Results The study showed effective inhibition of the OmpH of D. pneumosintes by both eugenol and hydroxychavicol. The high probability to be active (Pa) value indicated the probability of true positive for the tested compounds for their predicted biological activity. There was strong reciprocity between the drug-likeliness and its binding affinity for the target protein, indicating an inhibitory nature. Conclusion The tested phytocompounds hydroxychavicol and eugenol showed potential inhibition of the OmpH protein of D. pneumosintes indicating its potential use as inhibitory compounds of the pathogen and future directions for the treatment of periodontitis and gingivitis.

Study on Biofilm Formation Among Enterococcus Isolates and Association With Their Antibiotic Resistance Patterns.

Background Enterococci are a part of the normal intestinal flora of humans. They have emerged as one of the leading causes of nosocomial infection. The evolved antibiotic resistance mechanisms coupled with the virulence properties of enterococci have made it a successful pathogen. Aim This study aimed to determine the ability of biofilm formation among the clinical enterococci isolates and the antimicrobial resistance pattern of the strains. Materials and methods Clinical samples of patients who attended Saveetha Medical College and Hospital, Chennai, India, over six months. Identification and characterization of Enterococcus species were done using various biochemical tests. Antibiotic susceptibility patterns for each isolate were performed using the Kirby- Bauer disc diffusion method. Results The formation of biofilm formation was detected using the microtiter plate method. In total, 90 Enterococcus species were isolated; Enterococcus faecalis were 63 (70%), Enterococcus faecium were 25 (28%) and Enterococcus gallinarum were 2 (2%)independently. E. faecalis displayed advanced resistance rates compared to other Enterococcus species. Resistance against penicillin was found in 42 strains (47%) and resistance to ampicillin was observed in 39 strains (43%). This was followed by resistance to high-level gentamicin in 35 strains (39%) and resistance to ciprofloxacin in 32 strains (36%). Resistance to vancomycin and linezolid also were noted in some strains. Conclusion Our results indicate that E. faecalis exhibits an increasing rate of antimicrobial resistance but lower biofilm conformation. The unique traits of E. faecalis raise concerns for the associated infections, especially hospital-acquired infections.

In Silico Molecular Docking of Phytochemicals of Murraya koenigii Against Streptococcus mutans.

Background The curry leaf tree, Murraya koenigii, is a tropical to subtropical tree in the family Rutaceae that is native to Asia. The plant parts are shown to have potential antimicrobial, antioxidant, antifungal, antidiarrheal, antidiabetic, anticancer, and anti-inflammatory properties. Streptococcus mutans is a facultative anaerobic, Gram-positive cocci, a common inhabitant of the human oral cavity that forms biofilms, contributing to dental caries. Aim The study aimed to analyze the inhibitory potential of phytocompounds in M. koenigii against the oral pathogen S. mutans. Materials and methods The protein and ligand were prepared, and molecular docking was carried out using the Hex protein docking server. The PyMOL program was used to view, analyze, and annotate the docked complex. The interaction of the drug, including the mechanism of action, and predicted adverse effects were predicted using the Way2Drug PASS Online server. The absorption, distribution, metabolism, excretion, and toxicity properties of the drug candidates were analyzed using the SwissADME online server. Results The study identified O-methyl murrayamine, koenigine, koenigicine, and murrayone as having inhibitory potential against the glycosyltransferase protein of S. mutans. Among the four compounds analyzed for docking, koenigicine had the lowest E-score, indicating a strong interaction with the receptor. Among the four compounds analyzed, murrayone had a high topological polar surface area score, while all four compounds had similar bioavailability scores. Conclusion This study concluded that O-methyl murrayamine, koenigine, koenigicine, and murrayone exhibit potent inhibitory potential against S. mutans. M. koenigiileaf extract can be used in toothpaste as an antibacterial agent to protect teeth against dental caries. These findings are important for the potential use of the above compound to act as an anticariogenic agent in oral health applications.

Genomic surveillance of omicron B.1.1.529 SARS-CoV-2 and its variants between December 2021 and March 2023 in Tamil Nadu, India-A state-wide prospective longitudinal study.

A state-wide prospective longitudinal investigation of the genomic surveillance of the omicron B.1.1.529 SARS-CoV-2 variant and its sublineages in Tamil Nadu, India, was conducted between December 2021 and March 2023. The study aimed to elucidate their mutational patterns and their genetic interrelationship in the Indian population. The study identified several unique mutations at different time-points, which likely could attribute to the changing disease characteristics, transmission, and pathogenicity attributes of omicron variants. The study found that the omicron variant is highly competent in its mutating potentials, and that it continues to evolve in the general population, likely escaping from natural as well as vaccine-induced immune responses. Our findings suggest that continuous surveillance of viral variants at the global scenario is warranted to undertake intervention measures against potentially precarious SARS-CoV-2 variants and their evolution.

Evaluation of Antibacterial Efficacy of Two Commercially Available Probiotics as Intracanal Medicament against Enterococcus faecalis: An In Vitro Study.

AIM: This study was performed to evaluate the antibacterial efficacy of two commercially available probiotics (BIFILAC and VSL 3) as intracanal medicament against Enterococcus faecalis in endodontic therapy. MATERIALS AND METHODS: Microorganisms from commercially available probiotics (BIFILAC and VSL 3) were extracted via the manufacturer's recommendations and mixed by weight. About 30 microliters were then placed on sterile discs. The pathogenic test organism was E. faecalis set to a 1 McFarland standard challenge. A two-probiotic disc template on blood agar plates was inoculated with E. faecalis and incubated at 37°C for 48 hours and 1 week respectively. Phase-1 of the study was conducted by a disc diffusion assay test to evaluate zones of inhibition (ZOI) in millimeters (mm). Phase-2 was conducted by mixing 9 mL of 30% poloxamer 407 and MRS broth in a test tube, together with the two probiotic mixtures and E. faecalis, set at a 2 McFarland standard. Serial dilutions up to 108 were done and the mixture was placed inside root canals and incubated at 37ºC for 36 hours and evaluated for colony-forming unit (CFU)/mL counts. RESULTS: The results of phase-1 showed that probiotics Lactobacillus rhamnosus and Bifidobacterium species are effective in fighting against E. faecalis with the acceptable zone of inhibition. The results of phase-2 showed that both the probiotics are effective against E. faecalis with a reduction in the number of CFU after probiotic usage. CONCLUSION: Commercially available probiotics can be used effectively as an intracanal medicament to fight against E. faecalis, Poloxamer 407 is a promising vehicle for delivering probiotics inside the root canal system. Further in vitro and in vivo studies are needed to determine the full potential of "Bacteriotherapy" with an application of probiotics. CLINICAL SIGNIFICANCE: If probiotics are proved to be an effective intracanal medicament against E.faecalis they can be used as an alternative to calcium hydroxide as intracanal medicament with no side effects to the host.

PARP in the neuropathogenesis of cytomegalovirus infection - Possible role and therapeutic perspective.

Cytomegalovirus infects the majority of the population globally. Congenital CMV infection acquired through primary maternal infection in pregnancy is the most common intrauterine infection with a high mortality rate due to severe long-term neurodevelopmental sequelae. The demyelination and neuroinflammation during CMV infection have been attributed to altered immune response and ROS-mediated apoptosis. PARP-1 protein is linked to apoptotic neuronal loss with subsequent neurotoxicity and CNS injury as a result of PARP hyperactivation. PARP-1 play a critical role in the establishment of latency including EBV, HHV-8 and HIV. Research on PARP inhibitors recently shows significant progress against neurodegenerative diseases such as Alzheimer's disease and cancer therapy including malignant lymphoma and hepatitis B virus-induced hepatocellular carcinoma. The role of PARP1 in the neuropathogenesis of CMV and the potential of PARP inhibitors in the prevention of neurological sequelae is still elusive. Further studies on the role of PARP on the neuropathogenesis of CMV infection can help thwart neurodegeneration through the potential development of PARP inhibitors such as small molecule inhibitors.

Host cell responses against the pseudomonal biofilm: A continued tale of host-pathogen interactions.

In biofilm formation, pathogens within the bacterial community coordinate a cell-cell communication system called quorum sensing (QS). This is achieved through various signalling pathways that regulate bacterial virulence and host immune response. Here, we reviewed the host responses, key clinical implications, and novel therapeutic approaches against the biofilms of P. aeruginosa. Given the high degree of intrinsic antibiotic resistance and biofilm formation by the pathogen, the ensuing treatment complications could result in high morbidity and mortality rates worldwide. Notwithstanding the availability of intervention strategies, there remains a paucity of effective therapeutic options to control biofilmogenesis. This review discusses the basic understanding of QS-associated virulence factors and several key therapeutic interventions to foil the biofilm menace of P. aeruginosa.

Emerging Trends of Nanotechnology and Genetic Engineering in Cyanobacteria to Optimize Production for Future Applications.

Nanotechnology has the potential to revolutionize various fields of research and development. Multiple nanoparticles employed in a nanotechnology process are the magic elixir that provides unique features that are not present in the component's natural form. In the framework of contemporary research, it is inappropriate to synthesize microparticles employing procedures that include noxious elements. For this reason, scientists are investigating safer ways to produce genetically improved Cyanobacteria, which has many novel features and acts as a potential candidate for nanoparticle synthesis. In recent decades, cyanobacteria have garnered significant interest due to their prospective nanotechnological uses. This review will outline the applications of genetically engineered cyanobacteria in the field of nanotechnology and discuss its challenges and future potential. The evolution of cyanobacterial strains by genetic engineering is subsequently outlined. Furthermore, the recombination approaches that may be used to increase the industrial potential of cyanobacteria are discussed. This review provides an overview of the research undertaken to increase the commercial avenues of cyanobacteria and attempts to explain prospective topics for future research.

In silico design of a multi-epitope Chimera from Aedes aegypti salivary proteins OBP 22 and OBP 10: A promising candidate vaccine.

BACKGROUND & OBJECTIVES: The emergence and re-emergence of arboviruses such as dengue, Chikungunya and Zika viruses causing morbidity and mortality around the globe are of serious concern. A safe and effective vaccine is essential to control viral transmission. The salivary proteins of the mosquito that aid in blood probing, feeding and development are immunogenic. We aimed to report a multi-epitope candidate vaccine chimera from Aedes aegyptii mosquito salivary proteins OBP 22 and OBP 10 that could confer protection against all pathogens transmitted by the vector. METHODS: Linear and conformation B-cell epitopes and MHC class-I and class-II binding T- cell epitopes were predicted using bioinformatic tools. Selected B- and T-cell epitopes were chosen for designing a multiepitope vaccine construct. The chimeric construct was analyzed for its immunogenicity, TAP and proteasomal cleavage, allergenicity, and structural validation for its suitability to be used as a candidate vaccine. Molecular docking was carried out to analyze the binding interactions with TLRs molecules. RESULTS: A chimeric multiepitope vaccine was designed with the best-selected combination of immunogenic B-cell epitope, cytotoxic and helper T-cell and gamma interferon inducing epitopes with suitable adjuvant and linkers. The interacting residues between the candidate vaccine and the TLR molecules have been identified. INTERPRETATION & CONCLUSION: The proposed multiepitope candidate vaccine was designed from the mosquito salivary protein OBP 22 and OBP 10. The candidate vaccine was found promising for the protection against arboviruses. Further clinical validation is warranted to prove its efficacy, safety and immunogenicity for its potential use.

Standardization of an in-house multiplex real-time polymerase chain reaction for the simultaneous detection of Toxoplasma gondii, Rubella virus, cytomegalovirus, herpes simplex Virus 1 and 2, and Treponema pallidum infection among pregnant women.

BACKGROUND: An in-house multiplex real-time polymerase chain reaction (PCR) was developed in two cocktails for the identification of six Toxoplasma gondii, Rubella virus, cytomegalovirus, herpes simplex virus (1 and 2), and Treponema pallidum (syphilis) (TORCH-S) agents, which causes congenital infection among pregnant women. OBJECTIVE: Standardization and validation of an in-house multiplex real-time PCR assay for the detection of TORCH-S infection. METHODS: This study was conducted from February 2017 to February 2019. Primers specific for T. gondii, Rubella virus, cytomegalovirus, herpes simplex virus (1 and 2), and T. pallidum were designed using Primer3 software (https://bioinfo.ut.ee/primer3-0.4.0/). The primer sequences obtained were subjected to BLAST analysis using BLAST database. Synthetic DNA was obtained to use as positive control templates for all the six TORCH-S agents. The lower limit of the detection was performed using plasmid construct for each virus serially diluted from 10-1 to 10-9. RESULTS: An in-house multiplex real-time PCR was standardized and validated in two cocktails for TORCH-S agents, cocktail-1 (HSV1, rubella, and T. gondii), and cocktail-2 (HSV2, CMV, and T. pallidum). The lower limit of the detection for HSV1, rubella, and Toxoplasma were 60.7 copies/10 µl input, 76.4 copies/10 µl input, and 34.4 copies/10 µl input and for HSV2, CMV, and T. pallidum were 80.8 copies/10 µl input, 166 copies/10 µl input, and 43.7 copies/10 µl input, respectively. CONCLUSION: TORCH-S infection is one of the significant reasons for irregular pregnant outcomes. It is absolutely important to screen TORCH-S infection for women who had the histories of abnormal pregnancies to prevent birth defects and perinatal complications. This multiplex real-time PCR assay provides a rapid, sensitive, and specific technique to detect these six TORCH-S agents.

Comparative Evaluation of Antifungal Activity of Octenidine: An In Vitro Confocal Laser Study.

AIM: The aim of this study was to evaluate the antifungal efficacy of a novel endodontic irrigant octenidine against conventional irrigants sodium hypochlorite and EDTA on Candida albicans growth in the young and old population by calculating the number of colonies formed and by qualitative identification of dead/viable fungi by Confocal laser scanning microscopy (CLSM) method. MATERIALS AND METHODS: The total number of samples used in the study was eighty samples after decoronation of the crown portion the middle third of root canal. Each group was subdivided into four subgroups with various irrigation protocols: (A) 17% EDTA + 5.25% NaOCl, (B) 100% Octenisept, (C) 17% EDTA + 5.25% NaOCl + 1% clotrimazole, and (D) phosphate buffer saline. After completion of irrigation ATCC samples (90028) of C. albicans were inoculated with 5 mL of peptone water each and incubated at 37°C for 72 hours to attain the turbidity corresponding to 0.5 McFarland standards CFU. Eight samples were analyzed for the formation of candidal colonies, and two samples for the assessment of viability of Candida by confocal laser scanning microscope in each subgroup. RESULTS: Comparison of antifungal efficacy of endodontic irrigants employed in the young and old populations revealed a significant reduction in the mean values of CFU and the mean values of percentage of non-viable microorganism by CLSM method. A positive relationship was revealed in the younger population which had a better antifungal efficacy than the older population in all the irrigant subgroups evaluated in the study. CONCLUSION: All the endodontic irrigants employed in our study had a good antifungal efficacy against Candida albicans. Octenisept had a maximum antifungal efficacy, while phosphate saline showed the least efficacy in both age groups, which was quantitatively evaluated by CFU method, and the same was confirmed through qualitative evaluation by CLSM method. CLINICAL SIGNIFICANCE: Candida albicans plays a major role in the establishment and pathogenesis of failed root canal treatment. Age-related changes alter the adhesion potential of dentin, in turn influence the outcome of endodontic therapy. Octenidine, a novel antifungal agent, can be substituted over the conventionally used EDTA and NaOCl with less adverse effects.

B cell epitopes in the intrinsically disordered regions of neuraminidase and hemagglutinin proteins of H5N1 and H9N2 avian influenza viruses for peptide-based vaccine development.

Avian influenza viruses (AIV) are very active in several parts of the globe and are the cause of huge economic loss for the poultry industry and also human fatalities. Three dimensional modeling was carried out for neuraminidase (NA) and hemagglutinin (HA) proteins of AIV. The C-score, estimated TM-Score, and estimated root-mean-square deviation (RMSD) score for NA of H5N1 were -1.18, 0.57 ± 0.15, and 9.8 ± 7.6, respectively. The C-score, estimated TM-Score, and estimated RMSD score for NA of H9N2 were -1.43, 0.54 ± 0.15, and 10.5 ± 4.6, respectively. The C-score, estimated TM-Score, and estimated RMSD score for HA of H5N1 were -0.03, 0.71 ± 0.12, and 7.7 ± 4.3, respectively. The C-score, estimated TM-Score, and estimated RMSD score for HA of H9N2 were -0.57, 0.64 ± 0.13, and 8.9 ± 4.6, respectively. Intrinsically disordered regions were identified for the NA and HA proteins of H5N1 and H9N2 with the use of PONDR program. Linear B cell epitope was predicted using BepiPred 2 program for NA and HA of H5N1 and H9N2 avian influenza strains. Discontinuous epitopes were predicted by Discotope 2 program. The linear epitopes that were considered likely to be immunogenic and within the intrinsically disordered region for the NA of H5N1 was TKSTNSRSGFEMIWDPNGWTGTDSSFSVK, and for H9N2 it was VGDTPRNDDSSSSSNCRDPNNERGAP. In the case of HA of H5N1, it was QRLVPKIATRSKVNGQSG and ATGLRNSPQRERRRKK; for H9N2 it was INRTFKPLIGPRPLVNGLQG and SLKLAVGLRNVPARSSR. The discontinuous epitopes of NA of H5N1 and H9N2 were identified at various regions of the protein structure spanning from amino acid residue positions 90 to 449 and 107 to 469, respectively. Similarly, the discontinuous epitopes of HA of H5N1 and H9N2 were identified in the amino acid residue positions 27 to 517 and 136 to 521, respectively. This study has identified potential and highly immunogenic linear and conformational B-cell epitopes towards developing a vaccine against AIV both for human and poultry use.

Identification of B- and T-cell epitopes on HtrA protein of Orientia tsutsugamushi.

Orientia tsutsugamushi, a cause of scrub typhus is emerging as an important pathogen in several parts of the tropics. The control of this infection relies on rapid diagnosis, specific treatment, and prevention through vector control. Development of a vaccine for human use would be very important as a public health measure. Antibody and T-cell response have been found to be important in the protection against scrub typhus. This study was undertaken to predict the peptide vaccine that elicits both B- and T-cell immunity. The outer-membrane protein, 47-kDa high-temperature requirement A was used as the target protein for the identification of protective antigen(s). Using BepiPred2 program, the potential B-cell epitope PNSSWGRYGLKMGLR with high conservation among O. tsutsugamushi and the maximum surface exposed residues was identified. Using IEDB, NetMHCpan, and NetCTL programs, T-cell epitopes MLNELTPEL and VTNGIISSK were identified. These peptides were found to have promiscuous class-I major histocompatibility complex (MHC) binding affinity to MHC supertypes and high proteasomal cleavage, transporter associated with antigen processing prediction, and antigenicity scores. In the I-TASSER generated model, the C-score was -0.69 and the estimated TM-score was 0.63 ± 0.14. The location of the epitope in the 3D model was external. Therefore, an antibody to this outer-membrane protein epitope could opsonize the bacterium for clearance by the reticuloendothelial system. The T-cell epitopes would generate T-helper function. The B-cell epitope(s) identified could be evaluated as antigen(s) in immunodiagnostic assays. This cocktail of three peptides would elicit both B- and T-cell immune response with a suitable adjuvant and serve as a vaccine candidate.

Design of peptide epitope from the neuraminidase protein of influenza A and influenza B towards short peptide vaccine development.

Influenza viruses A and B are important human respiratory pathogens causing seasonal, endemic and pandemic infections in several parts of the globe with high morbidity and considerable mortality. The current inactivated and live attenuated vaccines are not effective. Therefore, it is of interest to design universal influenza virus vaccines with high efficacy. The peptide GQSVVSVKLAGNSSL of pandemic influenza, the peptide DKTSVTLAGNSSLCS of seasonal influenza and the peptide DILLKFSPTEITAPT of influenza B were identified as potential linear cell mediated epitopes. The epitopes predicted by BepiPred (B-cell epitope designer) program was subjected to docking experiment-using HexDock and CABS dock programs. The epitopes of pandemic H1N1 influenza A gave similar score of high affinity in docking. The epitope DKTSVTLAGNSSLCS of seasonal influenza A and epitope DILLKFSPTEITAPT of influenza B had high binding energy. It is further observed that the peptides GQSVVSVKLAGNSSL (pandemic influenza), DKTSVTLAGNSSLCS (seasonal influenza) DILLKFSPTEITAPT (influenza B) are found to interact with some known MHC class II alleles. These peptides have high-affinity binding with known MHC class II alleles. Thus, they have the potential to elicit cell immune response. These vaccines have to be further evaluated in animal models and human volunteers. These findings have application in the development of peptide B-cell epitope vaccines against influenza viruses.

Detection of parvovirus B19 in selected high-risk patient groups & their phylogenetic & selection analysis.

Background & objectives: Human parvovirus B19V (B19V) is known to be associated with erythema infectiosum commonly in children, aplastic crisis, especially in persons with underlying haemolytic disorders, hydrops fetalis in pregnancies and arthritis. This cross-sectional study was aimed to determine the presence of B19V infection in childhood febrile illnesses, association of B19V with arthropathies and in adult patients with end-stage renal disease (ESRD) on dialysis. The genetic diversity among the sequences was also analysed. Methods: A nested polymerase chain reaction (nPCR) assay was used for B19V DNA targeting VP1/VP2 region and used for testing 618 patients and 100 healthy controls. Phylogenetic analysis on nucleotide and amino acid sequences was carried out to compare our sequences with other Indian strains and global strains. Results: Among 618 samples tested, seven (1.13%) were found positive. The phylogenetic analysis revealed that all the seven sequences belonged to genotype 1 and showed low genetic diversity. The clustering pattern of seven sequences was similar both by nucleotide and by predicted amino acid sequences. The fixed effects likelihood analysis showed no positive or negatively selected sites. Interpretation & conclusions: Seven samples (4 from non-traumatic arthropathies, 2 from patients with ESRD and 1 from febrile illness patient) were found positive by nPCR. When our seven sequences were compared with global strains, the closest neighbour was other Indian strains followed by the Tunisian strains.