Isolation, Identification, and Antimicrobial Evaluation of Secondary Metabolite from Serratia marcescens via an In Vivo Epicutaneous Infection Model.

Microbial secondary metabolites, which play a pivotal role in struggling with infectious diseases, are the new source for controlling bacterial contaminations and possess a strong antimicrobial potential. The present study is designed to evaluate the in vitro and in vivo bactericidal activities of prodigiosin against Staphylococcus aureus. For this purpose, Serratia marcescens was used to produce prodigiosin. Characterization of the prodigiosin was carried out using NMR. In addition, bioautographic detection of prodigiosin was detected by TLC. Antibacterial assays, in vivo epicutaneous infection tests, swap analyses, and histopathological examinations were determined. The results revealed that prodigiosin was detected by NMR and TLC. According to antimicrobial susceptibility tests, prodigiosin is an efficient bactericidal compound that demonstrated strong antibacterial activity toward S. aureus. In vivo, animal studies determined that the strong inhibition of S. aureus-caused epidermal infection occurs by prodigiosin at 48 h. Histopathological results showed that S. aureus + prodigiosin skin sections consist of improved and healthy tissues without any infection area compared with the S. aureus and control groups. The in vivo study verified the antibacterial results with swap analyses, and histopathological findings showed that prodigiosin is a promising microbial metabolite effective against S. aureus infection. This study proved that prodigiosin with excellent bioactivity exhibited antibacterial properties, which might possess massive potential for new therapeutic approaches using micro-organisms.

Optimization of the conditions of alkaline extraction of tomato peels and characterization of tomato peel extracts obtained under atmospheric and oxygen free conditions.

This study aims to optimize the extraction conditions to obtain the highest yield, to characterize tomato peel extract (TPE) under optimized conditions, and also to determine the effect of ambient oxygen on the properties of TPE. Optimisation were performed at three temperatures (60 °C, 80 °C, 100 °C) and three periods (2, 4, 6 h) by the response surface methodology. The properties of the extract under atmospheric and oxygen-free conditions (AC, OFC) were analysed to determine whether the characteristics of both extracts changed depending on the presence of oxygen; moreover, the morphological, chemical, thermal, biochemical, and antimicrobial properties were analysed. The maximum yield was 31.3% at 100 °C/6 h. A quadratic model was used to create the best fit. Both TPE samples exhibited similar morphological structure, similar weight losses at three stages of TGA curve, similar band assignments in FTIR spectra. GC-MS analysis showed that both samples mainly consisted of cutin in abundance of 70.45% and 68.14% for AC and OFC, respectively. OFC had higher total phenolic content possibly depending on the absence of oxygen. AC and OFC extracts exhibited substantial antimicrobial activity against S. aureus, E. coli, C. albicans, and A. brasiliensis with a MIC value of 100 µg TPE/ mL.

Evaluation of organic load-related efficacy changes in antiseptic solutions used in hospitals.

BACKGROUND: In this study, it was aimed to evaluate the change in antimicrobial efficacy related to the presence of the organic load of four different antiseptic solutions that are frequently used in hospitals. METHODS: Solutions of hydrogen peroxide, povidone-iodine, chlorhexidine digluconate, and ethyl alcohol were prepared, tested in terms of antimicrobial efficacy changes in the presence of organic substances, and evaluated according to EN 13727 and EN 13624 standards. RESULTS: Among the investigated solutions ethanol 70% solution showed the best results by providing a 5-log reduction on all test organisms without affecting by the type and concentration of organic substances. Solutions of hydrogen peroxide 3%, povidone-iodine 7.5%, and chlorhexidine digluconate 0.2% performed lower antimicrobial efficacy depending on the concentration of organic load. DISCUSSION: It is concluded that the antimicrobial efficacy of antiseptic solutions is significantly affected by the organic substances and thus the proper use of antiseptics has become important to achieve successful disinfection and prevention of antibacterial resistance.

Comparison of bactericidal and fungicidal efficacy of antiseptic formulations according to EN 13727 and EN 13624 standards

Background/aim: In this study, the antibacterial and antifungal properties of the five most commonly used antiseptic formulations were evaluated in terms of different contact times and organic conditions. Materials and methods: Solutions of chlorhexidine digluconate, povidone iodine, isopropyl alcohol, hydrogen peroxide, and tincture of iodine were prepared and tested according to European standards EN 13727 and EN 13624 with different parameters. Results: The results showed that isopropyl alcohol (70% v/v) and tincture of iodine (2%) had greater bactericidal and fungicidal activity against the four tested bacteria and two fungi in all conditions. Conclusion: When the results of the five different active substances were quantitatively evaluated regarding their bactericidal and fun-gicidal activities, it was found that contact time and organic load significantly affected the antiseptic efficacy.