In vitro activity of disinfectants against Aspergillus spp.

Fungi of the Aspergillus genus are widespread and contaminate the environment. Thousands of conidia are released from each phialide and dispersed in the air every day. These fungi are considered important mycose-causing agents in hospitals. Due to this, research to determine prevalent fungi from the Aspergillus genus in hospital environments, and an adequate disinfection program in these areas is are needed. This study evaluated the susceptibility of Aspergillus spp. isolated from a veterinary environment against four disinfectants. Successive dilutions of disinfectants (log2) were used according to CLSI M38-A2 microdilution technique adapted to chemical agents against 18 isolates of this genus. After 72 hours of incubation, the Minimum Inhibiting Concentration and Minimum Fungicidal Concentration capable of inhibiting 50% and 90% of the isolates were determined. Chlorexidine-cetrimine, benzalconium chloride and a chlorophenol derivative proved to be effective against all isolates with a lower MIC than that suggested by the manufacturer, except for the A. flavus strain. Sodium hypochlorite was ineffective against three A. fumigatus, three A. flavus and one A. niger isolate. These results demonstrated that all studied disinfectants were effective against environmental isolates, with the exception of sodium hypochlorite, which showed lower effectiveness.