Interception of Epoxide ring to quorum sensing system in Enterococcus faecalis and Staphylococcus aureus.

Quorum sensing inhibitor (QSI) has been attracting attention as anti-virulence agent which disarms pathogens of their virulence rather than killing them. QSI marking cyclic peptide-mediated QS in Gram-positive bacteria is an effective tool to overcome the crisis of antibiotic-dependent chemotherapy due to the emergence of drug resistance strain, e.g., methicillin resistant Staphylococcus aureus (MRSA) and Vancomycin resistant Enterococci (VRE). From a semi-large-scale screening thus far carried out, two Epoxide compounds, Ambuic acid and Synerazol, have been found to efficiently block agr and fsr QS systems, suggesting that the Epoxide group is involved in the mode of action of these QSIs. To address this notion, known natural Epoxide compounds, Cerulenin and Fosfomycin were examined for QSI activity for the agr and fsr systems in addition to in silico and SAR studies. As a result, most of investigated Epoxide containing antibiotics correlatively interfere with QSI activity for the agr and fsr systems under sublethal concentrations.

Antimicrobial resistance and genomic characterization of Salmonella enterica isolates from chicken meat.

This study investigated genotypic and phenotypic antimicrobial resistance profiles, phylogenic relatedness, plasmid and virulence composition of 39 Salmonella enterica strains isolated from chicken meat samples using whole genome sequencing (WGS) technology. Four distinct serotypes were identified; Salmonella Minnesota (16/39, 41%), Salmonella Infantis (13/39, 33.3%), Salmonella Enteritidis (9/39, 23.1%), and one isolate was detected for Salmonella Kentucky (1/39, 2.6%), with sequence types (STs) as followed: ST548, ST32, ST11, and ST198, respectively. Phenotypic resistance to tetracycline (91.2%), ampicillin (82.4%), sulfisoxazole (64.7%), and nalidixic acid (61.6%) was the most observed. Resistome analysis revealed the presence of resistance genes to aminoglycosides, ß-lactamase, sulfonamides, trimethoprim, phenicol, lincosamide, macrolides, and tetracyclines. Plasmidome showed the presence of eight incompatibility groups, including IncA/C2, IncFIB(K)_1_Kpn3, Col440I_1, IncR, IncX1, IncI1_1_Alpha, IncFIB(S)/IncFII(S), IncHI2/IncHI2A, IncX2 and ColpVC plasmids across the 39 genomes. Three resistance genes, sul2, tetA and blaCMY-2, were predicted to be located on IncA/C2 plasmid in S. Minnesota isolates, whereas all S. Infantis isolates were positive to IncFIB(K)_1_Kpn3 plasmid that carries bla CTX-M-65 gene. Eleven Salmonella pathogenicity islands and up to 131 stress and/or virulence genes were identified in the evaluated genomes. Phylogenetic analysis showed four phylogroups that were consistent with the identified ST profiles with a high level of inter-diversity between isolates. This is the first genomic characterization of Salmonella isolates from retail chicken meat in Saudi Arabia using WGS technology. The availability of Salmonella genomes from multiple geographic locations, including Saudi Arabia, would be highly beneficial in future source-tracking, especially during epidemiological surveillance and outbreak investigations.

Prevalence of Dry Eye Disease and Its Association With the Frequent Usage of Eye Cosmetics Among Women.

PURPOSE: Dry eye disease (DED) is defined as a disease of the tear film and ocular surface that leads to discomfort and visual disturbance. The diagnosis of DED mainly depends on the presenting clinical features. A delay in treatment may progress into chronic eye disease. This study aimed to estimate the prevalence of dry eye symptoms among eye cosmetic users in the Kingdom of Saudi Arabia. METHODS: This cross-sectional study involved adult Saudi females using eye cosmetics. The Ocular Surface Disease Index questionnaire was used to assess DED. RESULTS: A total of 207 responses were included in this study. DED symptoms were reported among those who used eye cosmetics suggesting their effect on the tear film and its stability. This study demonstrated that mascara is the most common cosmetic used, with a prevalence of 98.6%. The prevalence of dry eye syndrome (DES) was 71.6%, where 40.5%, 13.5%, and 17.6% had severe, moderate, and mild conditions, respectively. The frequency of using inner eyeliner significantly increased the prevalence of DES, in which those who used it daily accounted for 75%. In contrast, the results showed no correlation between the frequency of using mascara or external eyeliner and the prevalence of DES. CONCLUSION: The prevalence of DED among women who used eye cosmetics was much higher than its prevalence in the general population, which indicates that eye cosmetics are one of the risk factors in the development of DED. Also, the severity of DED was significantly higher in women who did not use a cleanser for removing cosmetics.

Assessment of disinfectant efficacy in reducing microbial growth.

The incidence of hospital- and community-acquired infections has been dramatically increased worldwide. Accordingly, hands hygiene and the use of disinfectants have been increased leading to the expansion in hand sanitizers production to meet public demand. This study was conducted to assess the efficiency of common disinfectants in the market of Riyadh, Saudi Arabia in inhibiting the microbial growth during the time of Coronavirus disease 2019 (COVID-19) pandemic. Five bacterial strains of commonly hospital-acquired infections (Pseudomonas aeruginosa, Escherichia coli, Salmonella enteritidis, Staphylococcus aureus, and Enterococcus faecalis) (ATCC reference strains and clinical isolates) were examined for their susceptibility against 18 disinfectants collected from the Saudi market. The tested 18 disinfectants were broadly clustered into different groups based on their active chemical composition as following: 12 products contained alcohol, 2 products had chlorhexidine, 3 products contained mixed concentration of alcohol/chlorhexidine and 1 product had a mixture of chlorhexidine/Hexamidine/Chlorocresol. By measuring the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC), our results revealed that all the 18 disinfectants have reduced the microbial growth of all the tested strains. Generally, the MICs and the MBCs for the clinical strains are higher than those of the reference strains. Taken together, our findings showed that all tested products have high disinfectants' killing rate against microbes of different origins, which suggest the high quality of these disinfectants and the good surveillance practice by the local authorities in Saudi Arabia.

The relationship between sleep quality, stress, and academic performance among medical students.

BACKGROUND: Sleep is essential for the body, mind, memory, and learning. However, the relationship between sleep quality, stress, and academic performance has not been sufficiently addressed in the literature. The aim of this study was to assess the quality of sleep and psychological stress among medical students and investigate the relationship between sleep quality, stress, and academic performance. MATERIALS AND METHODS: This cross-sectional study targeted all medical students in their preclinical years at a Saudi medical college in 2019. All students were asked to complete an electronic self-administered questionnaire comprising the Pittsburgh Sleep Quality Index (PSQI), the Kessler Psychological Distress Scale (K10), questions on the students' current overall grade point average, and other demographic and lifestyle factors. The associations between categorical variables were analyzed using Pearson's Chi-squared test at 0.05 significance level. RESULTS: The mean PSQI score was 8.13 ± 3.46; 77% of the participants reported poor quality of sleep and 63.5% reported some level of psychological stress (mean K10 score: 23.72 ± 8.55). Poor quality of sleep was significantly associated with elevated mental stress levels (P < 0.001) and daytime naps (P = 0.035). Stepwise logistic regression model showed that stress and daytime nap were associated with poor sleep quality. Whereas, poor sleep or stress did not show any significant association with academic performance. CONCLUSION: Poor sleep quality was significantly associated with elevated levels of strees. However, they did not show any statistically significant relationship with academic performance.