Bactericidal Activity and Physiological Effects of Combined Application of Poly-Hexamethylene Biguanide Hydrochloride and 1-bromo-3-chloro-5, 5-dimethylimidazolidine-2, 4-dione on Staphylococcus aureus

Abstract

Abstract-Poly-hexamethylene biguanide hydrochloride (PHMB) and 1-bromo-3-chloro-5,5-dimethylimidazolidine-2,4-dione (BCDMH) are widely used for surface disinfection. Here, we examined the bactericidal effects of the mixture of PHMB and BCDMH (named PB) combined in different ratios on S. aureus, and studied effects of temperature, pH and bovine serum albumin (BSA , as organic interferent) on PB bactericidal activity with suspension quantitative germicidal method. We also observed surface structure changes and ATP level in S. aureus treated with PB with scanning electron microscope and multi-function microplate reader, respectively. The results showed that mixture of 10 mg/L PHMB and 10 mg/L BCDMH could meet the bactericidal requirements according to Technical Standard for Disinfection (China 2002), producing similar bactericidal activity to those exhibited by 320 mg/L PHMB and 60 mg/L BCDMH, separately. The results showed that PB was competent to kill bacteria quickly and bactericidal activity increased with time within 12 min. Temperature had no significant effect on PB bactericidal activity. PB offered satisfied bactericidal activity within 3.0 to 5.0 pH range. BSA significantly reduced bactericidal activity of PB. In addition, PB treatment could result in protuberance on S. aureus surface, and bring about a rapid decline in intracellular ATP level.

Fungicidal, Corrosive, and Mutational Effects of Polyhexamethylene Biguanide Combined with 1-Bromo-3-chloro-5,5-dimethylimidazolidine-2,4-dione

“…PB is a combined disinfectant established in our laboratory, and it is formed with PHMB and BCDMH. We have studied the PB bactericidal effects on E. coli , Pseudomonas aeruginosa (unpublished data), and S. aureus [ 7 ]. The related results showed that PB has relatively optimal bactericidal activity at relatively low concentration [ 7 ].…”

“…We have studied the PB bactericidal effects on E. coli , Pseudomonas aeruginosa (unpublished data), and S. aureus [ 7 ]. The related results showed that PB has relatively optimal bactericidal activity at relatively low concentration [ 7 ]. In this study, we try to examine its fungicidal, metal corrosive, and mutational effects.…”

“…So far, the combination of PHMB and BCDMH is not well-characterized. Our previous studies have shown that the bactericidal activity of the combination of PHMB and BCDMH (PB) against Escherichia coli and Staphylococcus aureus was significantly greater than that of either PHMB or BCDMH alone [ 7 ]. Therapy for Candida infections is a challenge as one of the most cunning and adaptive organisms that exists [ 8 ].…”