Antibiotic resistance (AR) is the resistance mechanism pattern in bacteria that evolves over some time, thus protecting the bacteria against antibiotics. AR is due to bacterial evolution to make itself fit to changing environmental conditions in a quest for survival of the fittest. AR has emerged due to the misuse and overuse of antimicrobial drugs, and few antibiotics are now left to deal with these superbug infections. To combat AR, vaccination is an effective method, used either therapeutically or prophylactically. In the current study, an in silico approach was applied for the design of multi-epitope-based vaccines against Providencia rettgeri, a major cause of traveler’s diarrhea. A total of six proteins: fimbrial protein, flagellar hook protein (FlgE), flagellar basal body L-ring protein (FlgH), flagellar hook-basal body complex protein (FliE), flagellar basal body P-ring formation protein (FlgA), and Gram-negative pili assembly chaperone domain proteins, were considered as vaccine targets and were utilized for B- and T-cell epitope prediction. The predicted epitopes were assessed for allergenicity, antigenicity, virulence, toxicity, and solubility. Moreover, filtered epitopes were utilized in multi-epitope vaccine construction. The predicted epitopes were joined with each other through specific GPGPG linkers and were joined with cholera toxin B subunit adjuvant via another EAAAK linker in order to enhance the efficacy of the designed vaccine. Docking studies of the designed vaccine construct were performed with MHC-I (PDB ID: 1I1Y), MHC-II (1KG0), and TLR-4 (4G8A). Findings of the docking study were validated through molecular dynamic simulations, which confirmed that the designed vaccine showed strong interactions with the immune receptors, and that the epitopes were exposed to the host immune system for proper recognition and processing. Additionally, binding free energies were estimated, which highlighted both electrostatic energy and van der Waals forces to make the complexes stable. Briefly, findings of the current study are promising and may help experimental vaccinologists to formulate a novel multi-epitope vaccine against P. rettgeri.

The coronavirus pandemic has affected more than 150 million people, while over 3.25 million people have died from the coronavirus disease 2019 (COVID-19). As there are no established therapies for COVID-19 treatment, drugs that inhibit viral replication are a promising target; specifically, the main protease (M^pro) that process CoV-encoded polyproteins serves as an Achilles heel for assembly of replication-transcription machinery as well as down-stream viral replication. In the search for potential antiviral drugs that target M^pro, a series of cembranoid diterpenes from the biologically active soft-coral genus Sarcophyton have been examined as SARS-CoV-2 M^pro inhibitors. Over 360 metabolites from the genus were screened using molecular docking calculations. Promising diterpenes were further characterized by molecular dynamics (MD) simulations based on molecular mechanics-generalized Born surface area (MM-GBSA) binding energy calculations. According to in silico calculations, five cembranoid diterpenes manifested adequate binding affinities as M^pro inhibitors with ΔG_binding < −33.0 kcal/mol. Binding energy and structural analyses of the most potent Sarcophyton inhibitor, bislatumlide A (340), was compared to darunavir, an HIV protease inhibitor that has been recently subjected to clinical-trial as an anti-COVID-19 drug. In silico analysis indicates that 340 has a higher binding affinity against M^pro than darunavir with ΔG_binding values of −43.8 and −34.8 kcal/mol, respectively throughout 100 ns MD simulations. Drug-likeness calculations revealed robust bioavailability and protein-protein interactions were identified for 340; biochemical signaling genes included ACE, MAPK14 and ESR1 as identified based on a STRING database. Pathway enrichment analysis combined with reactome mining revealed that 340 has the capability to re-modulate the p38 MAPK pathway hijacked by SARS-CoV-2 and antagonize injurious effects. These findings justify further in vivo and in vitro testing of 340 as an antiviral agent against SARS-CoV-2.

The effects of the learning environment on academic performance can be investigated according to a broad range of factors using a diversity of approaches. Many differences in academic performance have been associated with the sex of the student. Objectives: This study aims to understand the impact of absenteeism on the final grades earned by full-time medical laboratory sciences undergraduate students and whether this is affected by sex. Academic performance was analyzed using students’ final grades from two consecutive semesters (January to April and September to December 2019). The differences between male (n = 43) and female (n = 72) students were evaluated by Pearson’s correlation. During the semester, all teaching and assessment methods were standardized across both course sections to avoid confounding effects derived from the teaching method. Academic performance was assessed both objectively (multiple-choice questions) and subjectively (short essay questions). The mean scores of male and female students during two semesters were significantly different (p = 0.0180). To correlate marks with absenteeism, the correlation coefficient (r) was negative, which indicates an inverse correlation between absence rate and scores. Interestingly, a statistically significant correlation between absenteeism and final grades was found in the male sample population (p = 0.0011 for the first semester; p = 0.0255 for the second semester) that was not observed for their female counterparts (p = 0.2041; p = 0.1537). The results indicate that academic performance among women is not solely dependent on class attendance but likely involves other factors such as self-learning, and group discussion. The mean scores of female medical sciences students were significantly higher than the male students for two consecutive semesters. Male overall scores seem to be conditional on the instructor’s explanation. This sex-based variation in academic performance revealed by taking absenteeism rate into account warrant further investigation.

Walnuts are one of the healthiest foods in the world because they are one of the best sources of beneficial nutrients, minerals, and antioxidants. They also contain key sources of energy. Despite several traditional uses, the leaves of Juglans regia L. have received little attention regarding phytochemical and pharmacological potential. Thus, the current study intended to find the walnut genotypes with the greatest antioxidant, anticancer, and antifungal activity. The total polyphenolic, flavonoid, and flavanol contents of leaves from 14 walnut genotypes were determined. Genotypes that accumulate flavonoid/flavonol contents (99.8–111.93 mg/g quercetin equivalent (QE) and 101.67–111.83 mg/g QE) showed significantly higher ferric reducing antioxidant potential (FRAP) activity (128.2–148.1 μM Fe²⁺/g dry weight (DW)] than other genotypes. Maximum divergence in the quercetin content (0.8–1.23 mg/g) of walnut genotypes was obtained by cluster analysis. The active component, quercetin, was measured using RP-HPLC. Moreover, the extracts were investigated for antifungal and anticancer assays. We report the significant antifungal potential of walnut leaf genotypes against Candida glabrata, Candida albicans, and Candida tropicalis, with 57.7–93.6%, 26.8–51.5%, and 26.8–51.5% inhibition, respectively. The most significant antiproliferative effect was shown by Opex Culchry, which exhibited 9.4% cell viability at a concentration of 25 µL (0.75 mg) against lung (A549) cell lines. Chenovo exhibited 2.9, 6.2, and 2.2% cell viability, Opex Culchry exhibited 2, 1.5, and 2.4% cell viability, and Sulieman showed 7.6, 0.9, and 7% cell viability against the colon (HCT116) cell lines. The results showed that walnut leaves possess enormous potential as antioxidants, and as anticancer and antifungal agents.

Background and aim: Despite the fact that the chikungunya viral infection is a neglected disease, complications such as hemorrhagic fever, arthritis, and lymphopenia remain a health concern. The aim of this study was to determine the prevalence of the chikungunya virus in the Southern Region, Saudi Arabia. Enzyme immunoassay and polymerase chain reaction have been compared between samples.Materials and methods: Forty samples from two southern hospitals in Saudi Arabia were collected between December 2019 and February 2020 and screened for chikungunya virus IgG antibodies and for viral RNA. Selection criteria were based on hematological parameters and rheumatological profiles such as rheumatoid factor, c-reactive protein, anti-nuclear antibody, and anti-cyclic citrullinated peptide (anti-CCP) of out-patients.Results: One confirmed case of chikungunya virus was detected using the ELISA test. However, no viral RNA was detected in any of the samples. This suggests that the virus is cleared rapidly in patients.Conclusion: Chikungunya is a neglected viral disease in Saudi Arabia. Future work should focus on detailed investigation of this viral infection and its vectors.

The current COVID-19 pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Globally, this pandemic has affected over 111 million individuals and posed many health and economic challenges. Much research effort is dedicated to discovering new treatments to address the associated challenges and restrict the spread of SARS-CoV-2. Since SARS-CoV-2 is a positive-strand RNA virus, its replication requires the viral RNA-dependent RNA polymerase (RdRp) enzyme. In this study, we report the discovery of new potential RdRp enzyme inhibitors based on computer modeling and simulation methodologies. The antiviral ZINC database was utilized for covalent docking virtual screening followed by molecular inter-action analyses based on reported hot spots within the RdRp binding pocket (PDB: 7BV2). Eleven molecules, ZINC000014944915, ZINC000027556215, ZINC000013556344, ZINC000003589958, ZINC000003833965, ZINC000001642252, ZINC000028525778, ZINC000027557701, ZINC000013781295, ZINC000001651128 and ZINC000013473324, were shown to have the highest binding interactions. These molecules were further assessed by molecular dynamics (MD) simu-lations and absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies. The results showed that all 11 molecules except ZINC000027557701 formed stable complexes with the viral RdRp and fell within the accepted ADMET parameters. The identified molecules can be used to design future potential RdRp inhibitors.