Antibiofilm activity of 3,3'-diindolylmethane on Staphylococcus aureus and its disinfection on common food-contact surfaces

Attachment of Proteolytic Enzyme Inhibitors to Vascular Prosthesis-An Analysis of Binding and Antimicrobial Properties

Prosthetic infections are associated with high morbidity, mortality, and relapse rates, making them still a serious problem for implantology. Staphylococcus aureus is one of the most common bacterial pathogens causing prosthetic infections. In response to the increasing rate of bacterial resistance to commonly used antibiotics, this work proposes a method for combating pathogenic microorganisms by modifying the surfaces of synthetic polymeric biomaterials using proteolytic enzyme inhibitors (serine protease inhibitors-4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride and puromycin). While using techniques based on the immobilization of biologically active molecules, it is important to monitor the changes occurring on the surface of the modified biomaterial, where spectroscopic techniques (e.g., FTIR) are ideal. ATR-FTIR measurements demonstrated that the immobilization of both inhibitors caused large structural changes on the surface of the tested vascular prostheses (polyester or polytetrafluoroethylene) and showed that they were covalently bonded to the surfaces of the biomaterials. Next, the bactericidal and antibiofilm activities of the tested serine protease inhibitors were determined using the CLSM microscopic technique with fluorescent staining. During LIVE/DEAD analyses, a significant decrease in the formation of Staphylococcus aureus biofilm after exposure to selected concentrations of native inhibitors (0.02-0.06 mg/mL for puromycin and 0.2-1 mg/mL for 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride) was demonstrated.

Food safety culture maturity and its relation to company and employee characteristics

Three facets of food safety culture (FSC) (i.e., food safety management system (FSMS), human-organizational and human-individual building block), were diagnosed through a validated mixed-method assessment in twenty food processing companies. Many underdeveloped dimensions were detected in the FSMS and the human-organizational building block, while the human-individual building block was more mature. It was explored whether company (e.g., company size) and employee characteristics (e.g. leaders vs. non-leaders) are associated with FSC maturity (based on 1410 employee responses) through a cluster analysis and statistical (Mann-Whitney U and Kruskal-Wallis) tests. Results revealed significant differences (p-value <0.05) based on company characteristics (significant differences based on: size, belonging to a larger group, product type, place in the supply chain, training frequency, certificates, maturity of control and assurance activities) and employee characteristics (significant differences based on: leaders vs. non-leaders, daily direct contact with food or not, seniority, time since training and psychosocial well-being). These findings are useful to develop tailored food safety culture improvement interventions to enhance the maturity of food safety culture in food companies, as these might focus on lower perceiving (sub)groups of employees or lower perceiving (sub)groups of companies.

Investigation of some basil genotypes in terms of their effect on bacterial communication system, and antimicrobial activity

The exponential growth of multiresistant bacterial strains creates the need to explore new or combined strategies to combat bacterial resistance. Medicinal plant-derived compounds against pathogenic bacteria may provide new, simple approaches to developing more environmentally friendly antimicrobial agents. Many researchers focus on exploring novel or combined strategies for combating bacterial resistance. Aromatic plants containing essential oils, such as basil, are often used as therapeutic agents in the pharmaceutical industry. Recent research has shown that basil is effective against certain harmful food phytopathogenic bacteria and has antimicrobial and anti-quorum sensing properties, which were investigated in this study. Our results have shown that the essential oil and ethanol extract of basil exhibits both antibacterial activity and anti-quorum sensing activity against some Gram-negative and Gram-positive bacterial species. It has also been found to have antifungal effects on C. albicans. Among the tested microorganisms, the genotypes of PI 531396, PI 296390, PI 414199, PI 253157, PI 296391, PI 652071, midnight, and Dino cultivars have been found to be more effective than other genotypes. The highest effect on quorum sensing system was found in Moonlight and Dino cultivars, PI 296391, PI 414199, PI 652070, PI 172997 and PI 190100 genotypes. Dendrogram analysis has shown that there is a relationship between different genotypes depending on microorganisms and anti-quorum sensing activity. Ames 29184, PI 207498, and PI 379412 genotypes were in the same group. Biplot analyses were performed to determine the relationship between the studied properties, and the results showed that more than 47% of the total variation was in all forms.

Verbascoside: An Efficient and Safe Natural Antibacterial Adjuvant for Preventing Bacterial Contamination of Fresh Meat

Inappropriate and disproportionate antibiotic use contributes immensely to the development of antibiotic resistance in bacterial species associated with food contamination. Therefore, alternative strategies to treat multidrug-resistant (MDR) bacterial infections are urgently needed. In this study, verbascoside was shown to exhibit excellent antibacterial activity and synergistic effects in combination with cell wall synthesis-inhibiting antibiotics, indicating that it can be used as an adjuvant to restore or increase the activity of antibiotics against resistant pathogens. In a mechanistic study, higher concentrations of verbascoside resulted in a longer lag phase and a lower specific exponential-phase growth rate of bacteria. Furthermore, verbascoside exerted its antimicrobial activity through multiple mechanisms, including cell membrane dysfunction, biofilm eradication and changes in cell morphology. The promising antibacterial activity and in vitro safety assessment results suggested that verbascoside can be used as a food additive for fresh meat preservation. Treatment with medium and high doses of verbascoside caused significant bacterial death in meat samples, slowed the spoilage rate, and extended the shelf life. Collectively, verbascoside is expected to be useful as an antibiotic adjuvant to prevent or treat resistant bacteria-related infections and an alternative novel antimicrobial additive in the food industry.