Biofilms have become a major issue in different spheres of medicine and industry. Source of the issue revolves around increasing resistance of microorganisms towards conventional antibiotics which is even more elevated within biofilms that are difficult to eradicate by means of biocides and antibiotics. Multiple approaches were applied to deal with this issue amongst which green nanotechnology gave promising results and the search for molecules that “freeze bacteria” in the planktonic state. Since silver was used as an antimicrobial agent since ancient times. Considering this a study which deals with the effect of sub-inhibitory concentrations of silver nitrate and silver nanoparticles on biofilm forming capacity of bacteria would yield valuable information to evaluate the effect these substances have on the phenotypical expression of biofilm formation in bacteria as potential biofilm gene expression

Aim To develop an online biofilm calculation tool (Biofilm Classifier), which calculates the optical density cut off value and accordingly determines the biofilm forming categories for the tested isolates by standardized formulas, as well as to compare the results obtained by Biofilm Classifier to manual calculations and the use of predefined values. Methods The biofilm forming capacity of tested strains was evaluated using tissue culture plate method in 96 well plates, and optical density (OD) value of the formed biofilm was measured on an ELISA Microplate reader at 595 nm on a total of 551 bacterial isolates from clinical specimen. Results Comparative analysis indicated that the manual calculation was 100% in accordance with results obtained by the designed software as opposed to the results obtained by use of predefined values for biofilm categorization. When using predefined values compared to manual biofilm categorization for the determination of biofilm positive and biofilm negative strains the specificity was 100%, sensitivity 97.81%, positive predictive value 100%, negative predictive value 96.04% and accuracy 98.57%. Conclusion Considering obtained results, the use of the designed online calculator would simplify the interpretation of biofilm forming capacity of bacteria using tissue culture plate method.

Aim To develop an online biofilm calculation tool (Biofilm Classifier), which calculates the optical density cut off value and accordingly determines the biofilm forming categories for the tested isolates by standardized formulas, as well as to compare the results obtained by Biofilm Classifier to manual calculations and the use of predefined values. Methods The biofilm forming capacity of tested strains was evaluated using tissue culture plate method in 96 well plates, and optical density (OD) value of the formed biofilm was measured on an ELISA Microplate reader at 595 nm on a total of 551 bacterial isolates from clinical specimen. Results Comparative analysis indicated that the manual calculation was 100% in accordance with results obtained by the designed software as opposed to the results obtained by use of predefined values for biofilm categorization. When using predefined values compared to manual biofilm categorization for the determination of biofilm positive and biofilm negative strains the specificity was 100%, sensitivity 97.81%, positive predictive value 100%, negative predictive value 96.04% and accuracy 98.57%. Conclusion Considering obtained results, the use of the designed online calculator would simplify the interpretation of biofilm forming capacity of bacteria using tissue culture plate method.

Spices, which are plant substances used to enhance flavor are at the same time, the most commonly used natural antimicrobial agents in food. Besides this they have shown to effect the biofilm forming capacity of bacteria at different concentrations. In our study we tested the antibacterial effect of different w/V solutions of commercially available spices: cinnamon, curcuma and ginger and investigated their effect on biofilm formation of Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 19433. The results of our study indicate that cinnamon had an antibacterial effect on gram positive bacteria, ginger only on E.coli and curcuma did not exhibit any antibacterial properties. Results of the effect of different w/V solutions of spices on biofilm formation of the tested bacteria indicate that the spices had different effects on the tested bacteria and that the applied spice w/V solution did modify biofilm formation of bacteria. Hereby it is evident that the finding of novel antimicrobial compounds should be accompanied by biofilm formation studies since biofilms represent the natural state of bacteria and as such must be taken into consideration. Keywords— Spices, Antimicrobial Effect, Antibiofilm Effect

Forensic botany refers to the application of plant biology disciplines in crime investigations. Since plants are widespread in most habitats, they often provide valuable clues in criminal investigations. Hence, the primary role of forensic botany is to establish a connection between the victim or suspect and the crime scene. The forensic applications of forensic botany include many aspects including recognition of plant evidence at the crime scene, collection and preservation of plant evidence, maintenance of the chain of custody, and a testimony for the admissibility of this evidence in court. For the development of new efficient methods for plant identification and individualization, the initial step is optimization of DNA isolation from plant material. The aim of this work is to optimize the DNA isolation protocol of different leaf and non-leaf plant tissues, including pollen grains, using the salting out method from Taraxacum officinale, a species of the Asteraceae family. Since the species is very common in ecosystems with antropogenic influence, the need to optimize the DNA isolation protocol is of high importance. The efficiency of the isolation protocol was evaluated using spectrophotometry (concentration and purity) and gel electrophoresis. The results demonstrate that salting out can be used for the isolation of DNA from Taraxacum officinale. However, optimization is required, depending on the part of the plant from which DNA is extracted.