In vitro Testing of the Efficacy of Organic Releasing Chlorine (Virusnip™) against Escherichia coli, Salmonella spp. Candida albicans and Trichophyton mentagophytes

Abstract

The antimicrobial activities of organic releasing chlorine disinfectant (Virusnip™) was evaluated and compared by semi-quantitative suspension-neutralization method under clean condition in vitro. The test organisms were clinical bacterial isolates of hemolytic Escherichia coli, Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Hadar, Salmonella Infantis, and Salmonella Virchow. Fungal isolates were Candida albicans and Trichophyton
mentagophytes. Four sets of Virusnip™ concentrations were prepared at 1:100, 1:200, 1:400 and 1:1000 for bacteria and 3 sets of 1:100, 1:200 and 1:400 for fungi. Each set of various concentrations was kept at room temperature for 1, 2 and 7 days before use. The assays were performed at room temperature and evaluated after 30 sec, 2 and 60 min contact time between bacterial suspension and Virusnip™ solution, and after 5, 30 and 60 min contact time between fungal suspension and Virusnip™ solution. The antimicrobial activities were calculated in percentage of reduction in viability of the test organisms. The result indicated that Virusnip™ solution kept for 7 days exhibited antibacterial
activity at 1:1000 concentration by 100% killing of E. coli within 2 min. Comparison of the antibacterial activity among Salmonella isolates after 2 min contact of all ages of Virusnip™ solution showed that S. Typhimurium and S. Hadar were completely destroyed at the lowest 1:400 concentration. Additionally, S. Infantis and S. Virchow except S. Enteritidis were destroyed at the lowest 1:200 concentration. At 1:1000 solution, some serovars required at least 60 min to be killed. The antifungal activity indicated that at least 1:200 of all ages solutions could destroy 100% T. mentagophytes within 5 min exposure. The highest dilution 1:400 of all ages of solution could completely reduce both two fungal isolates within 30 min.