Isolation and Identification of Pathogenic Bacteria Showing Resistance against Disinfectants

Successive use and misuse of disinfectant against certain microbes may trigger resistance, causing the problem of ineffectiveness of disinfectant due to development of resistance strains. Ultimately, it is speculated to raise public health issues worldwide. Keeping in view the said problem an experiment was designed to test the efficacy of different disinfectants against some pathogenic bacteria isolated from selected restaurants and cafeterias kitchen. A total of 45 isolates were purified and identified. Amongst them, three isolates; Klebsiella pneumoniae, Macrococcus caseolyticus, Staphylococcus sciuri were selected for their pathogenicity while Terribacillus halophilus were selected for significant tolerance to high temperature and salt regimes. Different parameters including Minimum Inhibitory Concentrations (MIC) and Minimum bactericidal concentration (MBC) were determined for disinfectant; sodium hypochlorite, benzalkonium chloride and chloroxylenol. MIC values was: 2500μg/ml to 5000μg/ ml for sodium hypochlorite; 0.54μg/ml to 17.3μg/ml for Benzalkonium chloride; 18.7μg/ml to 150μg/ ml for chloroxylenol. MBC values was: 5000μg/ml to 33320μg/ml for sodium hypochlorite; 8.6μg/ ml to 138μg/ml for Benzalkonium chloride; 75μg/ml to 300μg/ml for chloroxylenol. Conclusively, K.pneumoniae showed high resistance to sodium hypochlorite and benzalkonium chloride compared to other bacteria used in this study. Among the studied, Staphylococcus sciuri were the most tolerant and resistance to chloroxylenol.