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.

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.

In Silico Evaluation of Bioactive Compounds of Artemisia pallens Targeting the Efflux Protein of Multidrug-Resistant Acinetobacter baumannii (LAC-4 Strain).

Acinetobacter baumannii (A. baumannii) is one of the major representative aetiologies of recalcitrant nosocomial infections. Genotypic and phenotypic alterations in A. baumannii have resulted in a significant surge in multidrug resistance (MDR). Of all the factors responsible for the development of antimicrobial resistance (AMR), efflux protein pumps play a paramount role. In pursuit of a safe alternative for the prevention and control of A. baumannii infections, bioactive compounds from the aerial parts of the medicinal plant Artemisia pallens were studied. GC-MS analysis of the ethanol extract of A. pallens detected five major compounds: lilac alcohol A, spathulenol, lilac alcohol C, n-hexadecanoic acid, and vulgarin. In silico examinations were performed using the Schrödinger suite. Homology modelling was performed to predict the structure of the efflux protein of A. baumannii-LAC-4 strain (MDR Ab-EP). The identified bioactive compounds were analysed for their binding efficiency with MDR Ab-EP. High binding efficiency was observed with vulgarin with a glide score of -4.775 kcal/mol and stereoisomers of lilac alcohol A (-3.706 kcal/mol) and lilac alcohol C (-3.706 kcal/mol). Our molecular dynamic simulation studies unveiled the stability of the ligand-efflux protein complex. Vulgarin and lilac alcohol A possessed strong and stable binding efficiency with MDR Ab-EP. Furthermore, validation of the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of the ligands strongly suggested that these compounds could serve as a lead molecule in the development of an alternate drug from A. pallens.

Virulence of Acinetobacter baumannii in proteins moonlighting.

The diverse function of the moonlighting proteins in Acinetobacter baumannii is highly associated with its virulence that had spurred renewed attention in recent years. The existing and newly formed hypothetical moonlighting proteins, evolve without jeopardizing the structural constraints of their original roles. It is yet uncertain and undefined to lucidly describe the functions of the moonlighting proteins in A. baumannii albeit its overwhelming evidences on few proteins. This commentary thus highlights the expression and occurrence of potent moonlighting proteins in A. baumannii, rendering virulence to the strains and the reasons to target the same portraying an active arena of research.

Intracellular survival and innate immune evasion of Burkholderia cepacia: Improved understanding of quorum sensing-controlled virulence factors, biofilm, and inhibitors.

Burkholderia cepacia complex (Bcc) are opportunistic pathogens implicated with nosocomial infections, and high rates of morbidity and mortality, especially in individuals with cystic fibrosis (CF). B. cepacia are naturally resistant to different classes of antibiotics, and can subvert the host innate immune responses by producing quorum sensing (QS) controlled virulence factors and biofilms. It still remains a conundrum as to how exactly the bacterium survives the intracellular environment within the host cells of CF patients and immunocompromised individuals although the bacterium can invade human lung epithelial cells, neutrophils, and murine macrophages. The mechanisms associated with intracellular survival in the airway epithelial cells and the role of QS and virulence factors in B. cepacia infections in cystic fibrosis remain largely unclear. The current review focuses on understanding the role of QS-controlled virulence factors and biofilms, and provides additional impetus to understanding the potentials of QS-inhibitory strategies against B. cepacia.

4-hydroxy-3-methoxybenzaldehyde causes attrition of biofilm formation and quorum sensing-associated virulence factors of Streptococcus mutans.

OBJECTIVE: The present study investigated the effects of 4-hydroxy-3-methoxybenzaldehyde (4-H-3-MB) against Streptococcus mutans (S. mutans) using an in vitro cariogenic biofilm model. DESIGN: The antimicrobial susceptibility of biofilm-forming S. mutans was evaluated by disc diffusion method. In vitro investigations were performed using crystal violet staining assay (biofilm assay), exopolysaccharide (EPS) assay, acid production, growth curve analysis, optical microscopic, and FE-SEM analyses to determine the antibiofilm activity of 4-H-3-MB. RESULTS: S. mutans (SDC-05) was resistant to ampicillin, piperacillin/tazobactam and ceftriaxone, whereas the other strains of S. mutans (SDC-01, 02, 03 and SDC-04) were sensitive to all the antibiotics tested. 4-H-3-MB showed promising antibiofilm activity on S. mutans UA159 (79.81 %, 67.76 % and 56.31 %) and S. mutans SDC-05 (77.00 %, 59.48 % and 48.22 %) at the lowest concentration of 0.2, 0.1, 0.05 mg/ml. 4-H-3-MB did not inhibit bacterial growth even at concentrations 0.2 mg/ml. Similarly, 4-H-3-MB led to significant attrition in exopolysaccharide (EPS) and acid production by S. mutans UA159 and S. mutans (SDC-05) at the concentration of 0.2, 0.1 mg/ml, respectively. Optical microscopy and FE-SEM analysis 4-H-3-MB reduced the biofilm thickness of S. mutans UA159 and S. mutans SDC-05 relative to the untreated specimens. CONCLUSION: 4-H-3-MB significantly inhibited biofilm formation by S. mutans in a dose-dependent manner. Hence, our findings indicate that the active principle of 4-H-3-MB could be used as a biofilm inhibiting agent against S. mutans.

Letter to the editor regarding, "Beneath the surface: A systematic review on intraoperative imaging techniques for deep margin assessment in oral squamous cell carcinoma".

Surgical methods for oral squamous cell carcinoma have the potential to improve patient outcomes with the integration of modern imaging tools for deep margin evaluation. This articlesummarises the potential benefits of MRI, FMI, and ultrasound modalities for improving surgical accuracy, based on a wide range of research. Theuses of intraoperative imaging in oral pathology are also covered, along with difficulties including ethical and technological constraints. Important insights to direct future research and implementation efforts in the field of oral cancer surgery are provided, which also examines implications for clinical education and innovation.

Understanding the biofilm development of Acinetobacter baumannii and novel strategies to combat infection.

Acinetobacter baumannii (A. baumannii) is a Gram-negative, nonmotile, and aerobic bacillus emerged as a superbug, due to increasing the possibility of infection and accelerating rates of antimicrobial agents. It is recognized as a nosocomial pathogen due to its ability to form biofilms. These biofilms serve as a defensive barrier, increase antibiotic resistance, and make treatment more difficult. As a result, the current situation necessitates the rapid emergence of novel therapeutic approaches to ensure successful treatment outcomes. This review explores the intricate relationship between biofilm formation and antibiotic resistance in A. baumannii, emphasizing the role of key virulence factors and quorum sensing (QS) mechanisms that will lead to infections and facilitate insight into developing innovative method to control A. baumannii infections. Furthermore, the review article looks into promising approaches for preventing biofilm formation on medically important surfaces and potential therapeutic methods for eliminating preformed biofilms, which can address biofilm-associated A. baumannii infections. Modern advances in emerging therapeutic options such as antimicrobial peptide (AMPs), nanoparticles (NPs), bacteriophage therapy, photodynamic therapy (PDT), and other biofilm inhibitors can assist readers understand the current landscape and future prospects for effectively treating A. baumannii biofilm infections.

Functional biomes beyond the bacteriome in the oral ecosystem.

Selective constraint and pressures upon the host tissues often signifies a beneficial microbiome in any species. In the context of oral microbiome this displays a healthy microbial cosmos resisting the colonization and helps in rendering protection. This review highlights the endeavors of the oral microbiome beyond the bacteriome encompassing virome, mycobiome, protozoa and archaeomes in maintaining the oral homeostasis in health and disease. Scientific data based on the peer-reviewed publications on the microbial communities of the oral microbiome were selected and collated from the scientific database collection sites of web of science (WOS), pubmed central, Inspec etc., from 2010 to 2021 using the search key words like oral microbiome, oral microbiota, oral virome, oral bacteriome, oral mycobiome and oral archaeome. Data excluded were from conference proceedings, abstracts and book chapters. The oral homeostasis in both the health and disease conditions, mostly is balanced by the unrevealed virome, mycobiome, oral protozoa and archaeome. The review documents the need to comprehend the diversity that prevails among the kingdoms in order to determine the specific role played by each domain. Oral microbiome is also a novel research arena to develop drug and targeted therapies to treat various oro-dental infections.

Evaluation of Antimicrobial and Antibiofilm Activity of Citrus medica Fruit Juice Based Carbon Dots against Pseudomonas aeruginosa.

Pseudomonas aeruginosa (P. aeruginosa) is one of the common immortal pathogens that cause intense chronic infections in low-immunity patients, significantly evading the immune system and suppressing the respiratory system. This work reports on the synthesis of prominent members of the carbon family, carbon quantum dots (CQDs), from a natural carbon precursor, Citrus medica (C. medica) fruit, and their inhibiting property against P. aeruginosa. CQDs synthesized by the conventional hydrothermal method with an average particle size of 4.5 nm exhibit renowned antimicrobial properties. To enhance the properties of the CQDs, nitrogen was doped using ammonium hydroxide as a nitrogen source, and absorption and fluorescence studies and the elemental composition of CQDs were also reported. CQDs potentially inhibited the growth of bacteria at the lowest concentration level of 1.25% (v/v). Similarly, CQDs moderately inhibited biofilm formation at the concentration level of 0.07% (v/v) for both clinical and control strains of P. aeruginosa. A fluorescence microscopy study revealed that the treated strain shows a moderately reduced biofilm formation when compared to the control strain of P. aeruginosa PAO1.

Biofilm-Associated Agr and Sar Quorum Sensing Systems of Staphylococcus aureus Are Inhibited by 3-Hydroxybenzoic Acid Derived from Illicium verum.

Biofilm-producing Staphylococcus aureus (S. aureus) is less sensitive to conventional antibiotics than free-living planktonic cells. Here, we evaluated the antibiofilm activity of Illicium verum (I. verum) and one of its constituent compounds 3-hydroxybenzoic acid (3-HBA) against multi-drug-resistant S. aureus. We performed gas chromatography-mass spectroscopy (GC-MS) to identify the major constituents in the methanolic extract of I. verum. Ligand-receptor interactions were studied by molecular docking, and in vitro investigations were performed using crystal violet assay, spreading assay, hemolysis, proteolytic activity, and growth curve analysis. The methanolic extract of I. verum inhibited S. aureus at 4.8 mg/mL, and GC-MS analysis revealed anethole, m-methoxybenzaldehyde, and 3-HBA as the major constituents. Molecular docking attributed the antibiofilm activity to an active ligand present in 3-HBA, which strongly interacted with the active site residues of AgrA and SarA of S. aureus. At a subinhibitory concentration of 2.4 mg/mL, the extract showed biofilm inhibition. Similarly, 3-HBA inhibited biofilm activity at 25 µg/mL (90.34%), 12.5 µg/mL (77.21%), and 6.25 µg/mL (62.69%) concentrations. Marked attrition in bacterial spreading was observed at 2.4 mg/mL (crude extract) and 25 µg/mL (3-HBA) concentrations. The methanol extract of I. verum and 3-HBA markedly inhibited ß-hemolytic and proteolytic activities of S. aureus. At the lowest concentration, the I. verum extract (2.4 mg/mL) and 3-HBA (25 µg/mL) did not inhibit bacterial growth. Optical microscopy and SEM analysis confirmed that I. verum and 3-HBA significantly reduced biofilm dispersion without disturbing bacterial growth. Together, we found that the antibiofilm activity of I. verum and 3-HBA strongly targeted the Agr and Sar systems of S. aureus.