Use of aqueous compositions of polyacrylamide with zinc and copper cations as a possible way to reduce the risks of microbial contamination in objects in the hospital environment

Microbial contamination means that infectious agents are identified on objects in the hospital environment. This serious issue is the most significant for healthcare organizations. Covering abiotic surfaces with a thin polymer film can be a promising way to fight against microbial adhesion and colonization. This film acts as a depot of an antibacterial substance. In this study, our aim was to investigate antimicrobial effects of new water compositions of polyacrylamides (PAM) with CuSO4 and ZnSO4. We examined antibacterial activity of 5%-solutions of CuSO4 and ZnSO4 and their compositions with various PAM types in a concentration equal to 0.075 % against such reference cultures as Escherichia coli, Klebsiella pneumoniaе, Pseudomonas aeruginosa, and Staphylococcus aureus. We estimated use of PAM as a growth substrate as well as antimicrobial activity of the analyzed solutions and compositions in agar and liquid nutrient media. As a result, we established that bacterial cultures did not use PAM as sole nutrition source when growing in a liquid mineral medium and on PAM-films covering glass and plastic surfaces. More apparent inhibitory effects were produced on microorganisms cultivated on solid and liquid nutrient media by 5%-solution of ZnSO4. When PAM Praestol 857 and PAM Praestol were added to solutions of Cu2+ and Zn2+ cations, it resulted in an authentic increase in a diameter of a zone with inhibited bacterial growth in the agar medium. In the liquid medium, salts of both metals inhibited the growth and viability of all the analyzed microorganisms already in a concentration equal to 0.16 % or lower. Adding PAM Praestol 2530 led to a slight decrease in antibacterial efficiency of the examined metal salts whereas PAM Praestol 857 had practically no influence on bacteriostatic and bactericidal effects produced by them. Therefore, use of the obtained composite solutions where CuSO4 or ZnSO4, immobilized on a PAM matrix act as an antibacterial component seems a promising way to disinfect objects in the hospital environment. This can significantly reduce risks of hospital-acquired infections.