Comparative study of antibiofilm activity of lime juice and lithium dioxide nanoparticles against Salmonella isolated from local cheese

Abstract

Thirty specimens of fresh white cheeses, presented for sale in different markets at different cities of Iraq were analyzed microbiologically in this study. Isolates of Salmonella, included in the specimens collected from November 2017 to January 2018, were investigated. Capacity for biofilm producing was demonstrated by two method, Tissue culture plate method (TCP) and Congo red agar (CRA).After that the antibiofilm activity of lime extract and LiO2NPs was studied as each one of them alone and then the synergistic effect was done by TCP method. The results showed that all Salmonella isolates produce biofilm but in different degrees. The results also displayed that Lime extract and LiO2NPs had antibiofilm effect against Salmonella when used alone and when the combination done between each one of these materials. In conclusion, it was observed that the specimens of fresh white cheese included in this study contained microbial contamination at a health-threatening level but we can eliminate this contamination by using lime extract and LiO2NPs.