Validation of AKACID plus as a room disinfectant in the hospital setting.

AKACID Plus, a novel polymeric guanidine with broad antimicrobial activity against multiantibiotic-resistant bacterial strains, was used in the present study as a room disinfectant. Disinfection of closed rooms experimentally contaminated with antibiotic-susceptible and multiresistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Escherichia coli was performed using AKACID Plus at concentrations of 0.1, 0.25, and 0.5% for 100 min. Bacterial suspensions were distributed on plastic and stainless steel plates and placed in a test room. Recovery of the test microorganisms was determined before nebulizing, 60 and 100 min after initiation, and 4 h after the end of room disinfection by a simple swab-rinse technique. The swab-rinse method demonstrated a dose- and time-dependent effectiveness of AKACID Plus in eradicating S. aureus, E. coli, and P. aeruginosa on plastic and stainless steel plates. Nebulized 0.5% AKACID Plus was successful in eliminating all hospital pathogens within 340 min. After the use of 0.25% AKACID Plus, MRSA was still detectable on microbial carrier plates. The test concentration of 0.1% AKACID Plus achieved a significant reduction of S. aureus and P. aeruginosa on plastic and stainless steel plates but was sufficient to eradicate only E. coli. These results suggest that nebulized AKACID Plus at a concentration of 0.5% is a potent substance for eradication of pathogenic organisms in the hospital setting.