Comparative Study on the Anti-Biofilm Activity of LiO₂ Nanoparticles and Lime Juice against Shigella dysenteriae Isolated from Locally Made Cheese

Background: Nanoparticle is alternative method for treatment diseases and used as antibiofilm agent. Objective: Comparative Study of the Anti-Biofilm Activity of LiO₂ Nanoparticles and Lime Juice against Shigella dysenteriae isolated from Locally Produced Cheese. Methodology: In this study, thirty samples of fresh white cheese offered for sale in various marketplaces across several Iraqi towns were examined. Shigella isolates obtained from the samples collected between November 2022 and January 2023 were analyzed. Two methods—Congo red agar (CRA) and the tissue culture plate (TCP) method—were employed to evaluate the biofilm-forming ability of the isolates. The TCP method was further used to assess the synergistic effect after the antibiofilm activities of lime extract and LiO₂ nanoparticles (LiO₂-NPs) were tested separately. Results: Revealed that all Shigella isolates were capable of forming biofilms, although to varying degrees. The findings also indicated that lime extract and LiO₂-NPs, both individually and in combination, exhibited antibiofilm effects against Shigella. The fresh white cheese samples analyzed in this study were found to be microbially contaminated at levels potentially harmful to human health. However, this contamination may be mitigated through the application of alternative treatments such as lime extract and LiO₂-NPs, which demonstrated antibacterial activity against biofilm-producing isolates of Shigella dysenteriae. Conclusion: The findings of the current study demonstrated that lime extract and LiO₂-NPs, whether applied individually or in combination, exhibited significant antibiofilm activity against Shigella isolates. These results suggest that both agents have potential as alternative interventions to control bacterial contamination, particularly in dairy products.