Abstract

The activity of dichloroxylenol (1.2% w/v), a commercial disinfectant formulation called Tiscol, on Staphylococcus aureus Oxoid 701/1 Lot 610254 and clinical isolates ofEscherichia coli and Salmonella typhi was carried out using the kill kinetics and the Kesley – Sykes procedures. The study demonstrates that the effectiveness of dichloroxylenol (1.2% w/v) against the test bacteria was time and concentration dependent and markedly affected by the presence of organic matter. Dichloroxylenol (1.2% w/v) also showed slightly greater activity against S. aureus Oxoid 701/1 Lot 610254 than against Escherichia coli and Salmonella typhi, indicating a probable role for cell wall in the susceptibility of bacteria to dichloroxylenol (1.2% w/v). The kesley – Sykes results suggest that in conditions of high contamination or presence of organic matter such as food, blood or tissue particles, dichloroxylenol (1.2% w/v) at or above 6% v/v can be appropriate in disinfection.   

Key words: Dichloroxylenol (1.2% w/v), Kill kinetics, Kesley – Sykes method.