The potency of herbal extracts and its green synthesized nanoparticle formulation as antibacterial agents against Streptococcus mutans associated biofilms.

This study aims to determine the effects of the extracts of Streblus asper, Cymbopogon citratus, Syzygium aromaticum and its formulation of green synthesized silver nanoparticle (AgNPs) on Streptococcus mutans growth and biofilm formation. The ethanolic extracts of S. asper, C. citratus, S. aromaticum, and a mix of the three herbs demonstrated antibacterial activity against S. mutans isolates by reducing bacterial biofilm formation and decreasing bacterial cell surface hydrophobicity. The formulated AgNPs from the ethanolic extracts could enhance the antibacterial activities of the plant extracts. Molecular docking found the best interaction between luteolin isolated from C. citratus and glucosyltransferase protein (GtfB), assuming the promising anti-biofilm activity. The scanning electron microscopy revealed morphological changes in the biofilm structure and a significant decrease in the biofilm area of the AgNPs treated. The study suggested that the extracts and its application could be used as natural alternative agents with multi-action against S. mutans infections.

Effectiveness of an online educational video intervention to improve the knowledge and behavior of contact lens care during the COVID-19 pandemic: A pre-test/post-test design.

Objective: To assess the effectiveness of an online educational video in improving contact lens (CL) care knowledge and behavior. Methods: Participants completed a 47-item questionnaire on their CL hygiene knowledge and wear and care behavior. A 5-min CL educational video was shown, and participants completed a post-test. After 2 months, the same questionnaire was used to determine knowledge retention and behavioral changes. Descriptive statistics and McNemar's tests were performed. Results: The mean age of the 132 enrolled participants was 24 years, and 61% were female. The knowledge scores significantly improved after watching the educational video (p < 0.001). Two months after the intervention, the participants reported changes in their hygienic behavior (p < 0.001). Conclusions: Online video-based learning is an effective educational tool for improving the knowledge and behavior of CL care. Practice implications: Patient education via online videos is an innovative and successful strategy that raises awareness, increases patient knowledge, and encourages preventative health behavior to avoid CL-related complications.

Bacterial microbiota of the contact lens surface and associated care behaviours.

Introduction: Contact lens (CL) wear has been reported to cause changes to the microbiome of the ocular surface. More insight into the alteration of this microenvironment can help to understand the pathogenesis of CL-related eye infections. Knowledge of the relationship between the CL wearer's behaviours and pathogens would help health care providers focus on each step of proper CL care. This study aims to determine the behaviours that might be associated with the community of bacteria on CL. Methods: A cross-sectional design was performed using anonymous questionnaires to obtain demographic data and assess hygiene practices among volunteering wearers. The CLs used were collected to evaluate the prevalence of pathogenic bacteria associated with ocular infections by PCR and microbiota analysis. Results: The bacterial microbiota study revealed a total of 19 genera and 26 isolated strains from 20 eligible CLs. Enterobacter, Staphylococcus, and Achromobacter were the main genus in this subject population. Staphylococcus pasteuri and Achromobacter agilis were the most common pathogens at 65% and 35%, respectively. Enterobacter mori, a nonpathogenic organism, was found to be the most predominant strain, accounting for 27.51% of the total bacterial constituents. The risk behaviour of CL wear that was significantly associated with A. agilis contamination was cleaning the CL case with tap water (P value = 0.04). Conclusions: This is the first study focusing on the association between the culture selected microbial community on the CL surface and compehensive behavioural characteristics. Environmental contamination was the main source of microbes found on CL surfaces. An emphasis in patient education should be placed on careful handling during the CL care routine and managing the hygiene of the surroundings.

Rub and Rinse Contact Lenses Before Wearing as a Protective Regimen Against Contact Lens-Related Eye Infections.

Purpose: Data on contact lens (CL) users in Thailand are limited, and previous reports have mainly focused on young populations. This study aims to determine demographic data, hygienic behaviour, and complications related to the usage of CLs in the general population. Methods: This was a cross-sectional survey conducted from November 2020 to March 2021 using an anonymous questionnaire. Information on the demographic traits of the participants, characteristics of CL use, and CL care behaviours was collected. The responses were summarised and presented as a total behaviour score. Regression analysis was performed to evaluate the potential risk factors for a history of CL-related eye infections. Results: A total of 134 CL wearers were recruited. Of all the participants, 83.58% were female and 16.42% were male. The average age was 31.14±10.69 years old. The total behaviour score showed that 62.69% of the population had good CL behaviour, while 37.31% exhibited poor CL behaviour. More than 50% of participants practised appropriate CL handling. Common unfavourable behaviours (>50%) reported were not using CL care solution to clean the storage case, not rubbing and rinsing the lens before storage, exposure to water during wear, use of makeup around the ocular area, and missing annual eye exams. Other less common but important instances of mishandling included using tap water to clean the lenses, topping off old CL solution, and exceeding the recommended planned-replacement period. However, no behaviours were significantly associated with a history of CL-related eye infections. Rubbing and rinsing CLs before wearing them was found to be a protective factor against a history of eye infections. Conclusion: Rubbing and rinsing CLs before wearing should be mentioned as an additional recommendation for the user.

Atomistic insight and modeled elucidation of conessine towards Pseudomonas aeruginosa efflux pump.

Drug-resistant Pseudomonas aeruginosa efflux pump extrudes antibiotics from cells for survival. Efflux pump inhibitor (EPI) thus becomes an interesting alternative to handle the drug-resistant bacteria. Conessine, a natural steroidal alkaloid from Holarrhena antidysenterica, previously exhibited efflux pump inhibitory potential. Our molecular docking and molecular dynamics (MD) studies provided atomistic information as well as the interaction of conessine with bacterial MexB efflux pump in phospholipid bilayer membrane to further the previous experimental report. Herein, the binding site and proposed mode of action of conessine were identified compared to known/commercial EPIs such as PAßN or designed-synthetic P9D. Our results explained conessine binding mode of action as an effective agent against the MexB efflux pump. The MD simulation also suggested that conessine was able to affect glycine loop (G-loop) flexibility, and the reduced G-loop flexibility due to conessine could hinder an antibiotics extrusion. In addition, our study suggested the conessine core structure buried in a hydrophobic region in the efflux pump similar to other known EPIs. Our finding could cope as a key for the design and development of the conessine derivative as novel EPI against P. aeruginosa.Communicated by Ramaswamy H. Sarma.