Antimicrobial profile of the new biocide akacid

Abstract number: 1134_03_325

Buxbaum A., Kratzer C., Graninger W., Georgopoulos A.

Objectives:  

Akacid is a new member of the polymeric biguanide family of disinfectants. It was especially developed to enhance the antimicrobial activity of this class with significantly less toxicity. This paper describes the wide range of biocidal activity and low potential for induction of resistance of akacid.

Methods:  

A total of 370 recent clinical isolates from patients with documented infections in hospitals located in Austria was studied. The organisms tested by reference methods included: Staphylococcus aureus (98), S. epidermidis (9), Enterococcus faecalis (37), Klebsiella spp. (45), Escherichia coli (65), Salmonella spp. (6), Shigella spp. (2), Yersinia enterocolitica (1), Acinetobacter spp. (4), Helicobacter pylori (7), Proteus spp. (7), Pseudomonas aeruginosa (59), Stenotrophomonas maltophilia (4), Mycobacterium spp. (6), Legionella pneumophila (3), Candida spp. (10), Aspergillus spp. (7). Additionally, spores of Bacillus subtilis ATCC 6633 and B. anthracis CH10 (anthrax spores reg.no. G112/WET/ACT 36/47) were tested. Also, in-vitro selection of resistance to akacid was carried out on 30 strains.

Results:  

Akacid showed good activity against both gram-positive and gram-negative bacteria, regardless of their antibiotic resistance-profile. Generally, MICs of tested isolates were the same for antibiotic-sensitive and multiresistant strains. Potent activity was also observed against L. pneumophila, Mycobacterium spp. and against spores of B. subtilis and B. anthracis. Good antifungal efficacy could be recorded against Candida spp. and Aspergillus spp. Bactericidal action was observed at 1 × MIC,that is that MIC values equaled MBC values. The in-vitro selection of resistance test showed no increase in MIC values in any isolate after 30 passages.

Conclusions:  

This study clearly demonstrates the excellent antimicrobial properties of akacid. Akacid was highly active against bacteria (including Mycobacterium spp. and L. pneumophila), spores and fungi, without being affected by the resistance profile of the strains. These properties, together with a very low potential to select for resistance, make akacid a promising tool for the battle against rising resistance and therapeutic failures.