The replacement of five consecutive amino acids in the cyt1a protein of bacillus thuringiensis enhances its cytotoxic activity against lung epithelial cancer cells

Cyt1A protein is a cytolytic protein encoded by the cyt gene of Bacillus thuringiensis subsp. israelensis (Bti) as part of the parasporal crystal proteins produced during the sporulation. Cyt1A protein is unique compared to the other endotoxins present in these parasporal crystals. Unlike ?-endotoxins, Cyt1A protein does not require receptors to bind to the target cell and activate the toxicity. It has the ability to affect a broad range of cell types and organisms, due to this characteristic. Cyt1A has been recognized to not only target the insect cells directly, but also recruit other endotoxins by acting as receptors. Due to these mode of actions, Cyt1A has been studied for its cytolytic activity against human cancer cell lines, although not extensively. In this study, we report a novel Cyt1A protein produced by a Bti strain QBT229 isolated from Qatar. When tested for its cytotoxicity against lung cancer cells, this local strain showed considerably higher activity compared to that of the reference Bti and other strains tested. The possible reasons for such enhanced activity were explored at the gene and protein levels. It was evidenced that five consecutive amino acid replacements in the ?8 sheet of the Cyt1A protein enhanced the cytotoxicity against the lung epithelial cancer cells. Such novel Cyt1A protein with high cytotoxicity against lung cancer cells has been characterized and reported through this study. -2018 by the authors. Licensee MDPI, Basel, Switzerland.Scopu

The Prevalence and Awareness of Cardiovascular Diseases Risk Factors among the Lebanese Population: A Prospective Study Comparing Urban to Rural Populations

Introduction. CVDs are largely driven by modifiable risk factors. This study sought to determine the awareness and prevalence of the modifiable CVDs risk factors among the Lebanese population. Methods. In a cross-sectional survey, 1000 participants aged ≥ 45 years were randomly selected from pharmacies and interviewed. The data was analyzed with SPSS version 21.0 software. Results. Differences between urban and rural areas include alcohol consumption (2.8% versus 1.7%; p=0.0001), cardioprotective vegetable servings (6.1% versus 2.3%; p=0.016), sedentary hours per day (18.6% versus 15.1%; p=0.002), and hypertension (38.5% versus 25.4%; p=0.001). The prevalence of overweight and obesity (77.3% versus 75.2%; p=0.468), smoking (39.3% versus 43.3%; p=0.232), diabetes (25.4% versus 21.4%; p=0.173), and dyslipidemia (25 versus 21.2%) was reported. Measurements revealed 19.3% of undiagnosed hypertension (12.4% versus 22.4%, p=0.001), 61.7% of hypertension (59.8% versus 62.6%; p=0.203), and 7.9% of undiagnosed diabetes (6.6% versus 8.6%; p=0.323). The declared awareness of CVDs risk factors was highest for smoking (91.5% versus 89.7%; p=0.339) and lowest for diabetes (54.4 versus 55.7%; p=0.692). Conclusion. This study has shown a high prevalence of modifiable CVDs risk factors in the Lebanese population ≥ 45 years, among which hypertension is the most prominent

The Replacement of five Consecutive Amino Acids in the Cyt1A Protein of Bacillus thuringiensis Enhances its Cytotoxic Activity against Lung Epithelial Cancer Cells

Cyt1A protein is a cytolytic protein encoded by the cyt gene of Bacillus thuringiensis subsp. israelensis (Bti) as part of the parasporal crystal proteins produced during the sporulation. Cyt1A protein is unique compared to the other endotoxins present in these parasporal crystals. Unlike δ-endotoxins, Cyt1A protein does not require receptors to bind to the target cell and activate the toxicity. It has the ability to affect a broad range of cell types and organisms, due to this characteristic. Cyt1A has been recognized to not only target the insect cells directly, but also recruit other endotoxins by acting as receptors. Due to these mode of actions, Cyt1A has been studied for its cytolytic activity against human cancer cell lines, although not extensively. In this study, we report a novel Cyt1A protein produced by a Bti strain QBT229 isolated from Qatar. When tested for its cytotoxicity against lung cancer cells, this local strain showed considerably higher activity compared to that of the reference Bti and other strains tested. The possible reasons for such enhanced activity were explored at the gene and protein levels. It was evidenced that five consecutive amino acid replacements in the β8 sheet of the Cyt1A protein enhanced the cytotoxicity against the lung epithelial cancer cells. Such novel Cyt1A protein with high cytotoxicity against lung cancer cells has been characterized and reported through this study

Study of the degradation process of ofloxacin with free chlorine by using ESI-LCMSMS: Kinetic study, by-products formation pathways and fragmentation mechanisms

International audienceThis study was conducted to gain a better understanding of the fate of fluoroquinolone antibacterial ofloxacin (OFX) which is the free available chlorine (FAC) in order to determine its effect during water chlorination process. The Direct reactions of FAC with OFX were quite rapid. A half-life of 7.7 s was measured under pseudo-first order conditions in the presence of an excess of total chlorine ([FAC]0 = 13 μM and [OFX]0 = 0.55 μM at pH 7.2 and 20 °C in buffered reagent water. Free chlorine reactions rates were of first-order type in both substrate and oxidant with specific second-order rate constants of 6.8 × 103 M-1 s-1. No induced back reactions or other interference by using thiosulfate to stop the chlorination reaction was shown. The seven products of the reaction were determined by using the LC/MS/MS analysis. Structures were investigated due to the explication of transitions obtained at different CID energies by LC-ESI-MS/MS. Pathways of the formations of these by-products were presented in this study and pathways of the fragmentations of pseudo molecular ions of the structures proposed were presented in supplementary files

OCCURRENCE OF 63 SELECTED PHARMACEUTICALS AND ISOLATION OF RESISTANT- BACTERIA STRAINS IN NATURAL WATER SOURCES IN LEBANON

A powerful analytical method was developed for the simultaneous determination of traces of 63 pharmaceuticals and their metabolites representing different therapeutic classes: antibiotics, stimulant, antidepressant, mucolytic, antiparasite and dyes using SPE-LC-ESI-MS/MS in water samples. 100 samples from rivers, lakes, fountain and artesian wells were collected for this study overall Lebanon. Monitoring programs show the presence of many antibiotics in several analyzed samples. Therefore, to evaluate if a relation may exist between finding antibiotics in water samples and resistant-bacterial strains; three bacteria (Escherichia coli, Enterococcus faecalis and Pseudomonas aeruginosa) were selected for isolation, then antimicrobial susceptibility was determined using disk diffusion method according to the recommendations of the European Committee on Antimicrobial Susceptibility Testing

Innovative SPE-LC-MS/MS technique for the assessment of 63 pharmaceuticals and the detection of antibiotic-resistant-bacteria: A case study natural water sources in Lebanon

A powerful analytical method for simultaneous determination of 63 pharmaceuticals and some metabolites in aqueous samples has been developed. The list of compounds amenable to the methods includes different therapeutic classes belonging to antibiotics, stimulants, antidepressants, mucolytics, and antiparasites. The method involves concentration and clean up by an offline solid phase extraction SPE followed by liquid chromatography coupled to tandem mass spectrometry (LC-ESI-MS/MS). The recovery of the target compounds from water samples was most efficient on Waters Oasis HLB SPE cartridge, while acetonitrile/water (60/40) was shown to be the most suitable solvent for desorbing the compounds from SPE. In addition, acidification of samples prior to SPE was optimized to enhance the recovery of the compounds. In terms of method validation, the recoveries of analytes ranged from 68% to 134%. Repeatability and intermediate precision were  10,000 ng L− 1 and 2000 ng L− 1, respectively. Moreover, bacterial analysis showed that the samples were contaminated by Escherichia coli (23%), intestinal Enterococcus (48%) and Pseudomonas aeruginosa (27%). Therefore, in order to evaluate if a correlation exists between finding antibiotics in water samples and the development of resistant-bacteria, an antimicrobial susceptibility test was conducted to the identified isolates using disk diffusion method. Multiple-antibiotic-resistant strains in both intestinal Enterococcus and E. coli were evident in many water samples, while P. aeruginosa was resistant to only one studied antibiotic

Oral Vancomycin Prophylaxis for the Prevention of Clostridium Difficile Infection: A Systematic Review and Meta-Analysis

Objective: Recently, oral vancomycin prophylaxis (OVP) has been suggested for the prevention of Clostridium difficile infection (CDI). We conducted a systematic review and meta-analysis to investigate the efficacy and safety of this approach. Design: Systematic review and meta-analysis. Methods: We conducted a computerized search of MEDLINE, EMBASE, and Cochrane databases from inception to March 2019 for publications investigating OVP for CDI prevention. Results were screened for eligibility. Relevant data were extracted and analyzed. Publication bias was assessed using the Egger test. Results: Ultimately, 8 retrospective studies and 1 prospective study examining 2174 patients, published between 2016 and 2019 were included in the review. OVP was associated with decreased CDI (odds ratio, 0.263; 95% confidence interval, 0.13-0.52) with considerable heterogeneity (I2 = 61%). Meta-regression showed that total daily dose of OVP correlated with CDI, explaining 100% of heterogeneity between studies. Furthermore, 3 studies evaluated the risk of vancomycin-resistant enterococci (VRE) infection after OVP and found no significant increase. Conclusion: Our results suggest that OVP might decrease CDI rates in at-risk populations, although this conclusion should be interpreted with caution. Higher daily doses of OVP might increase CDI. Although the use of OVP in high-risk patients may reduce CDI, this suggestion has yet to be validated by prospective blinded randomized controlled trials