IN-VITRO ACTIVITY OF THREE CHEMICAL AGENTS AGAINST DIFFERENT SPECIES OF ASPERGILLUS

Aspergillosis is caused by ubiquitous and opportunist moulds of the genus Aspergillus, which contaminate the atmosphere by liberating thousands of conidia in the air, making it extremely important to use air filters and to implement proper programs of antisepsis and disinfection for the prevention of this disease. This study evaluated the in-vitro effectiveness of the chemical agents iodophor, quaternary ammonia and chlorexidine against A.fumigatus (8), A. niger (8), A.flavus (6) and A. terreus (1). Successive dilutions of disinfectants/antiseptics (log sub(2)) were prepared in RPMI for the test, and the suspension was adjusted until a final concentration of 5 x 10 super(4) UFC/mL. The microdilution test was done in agreement with NCCLSM-38 adapted for chemical agents, with microplates incubation at 35 C in constant agitation. The visual results were evaluated after 96 hours, and all Aspergillus spp. isolates used were resistant to iodophor at all concentrations tested. Quaternary ammonia and chlorexidine showed effectiveness against Aspergillus spp. isolates, except for one A. fumigatus and one A. terreus. According to these results the use of quaternary ammonia and chlorexidine is indicated for the prevention of aspergillosis, while the use of iodophor is questionable.Original Abstract: A aspergilose e causada por fungos ubiquos e oportunistas do genero Aspergillus, que liberam milhares de conidios no ar, contaminando o ambiente, sendo de extrema importancia a utilizacao de filtros de ar e programas corretos de anti-sepsia e desinfeccao para prevencao da enfermidade. Este estudo avaliou a eficacia "in vitro" dos agentes quimicos, iodoforo, amonia quaternaria e clorexidina, frente a isolados de Aspergillus fumigatus (8), Aspergillus niger (8), Aspergillus fumis (6) e Aspergillus terreus (1). Para o teste foram preparadas diluicoes sucessivas dos desinfetantes/antisepticos (log sub(2)) em caldo RPMI, e os inoculos foram ajustados ate uma concentracao final de 5 x 10 super(4) UFC/mL. Foi realizada a tecnica de microdiluicao em caldo de acordo com NCCLSM-38, adaptada para agentes quimicos, com incubacao das microplacas a 35 C em agitacao constante. A leitura visual dos resultados foi realizada apos 96 horas, e os isolados de Aspergillus spp. utilizados foram resistentes ao iodoforo nas concentracoes testadas. A amonia quaternaria e a clorexidina mostra-ram-se eficazes contra os isolados de Aspergillus spp., com excecao de um A. fumigatus e um A. terreus. Com