In-vitro and In-vivo Inhibition of Aspergillus fumigatus by Pseudomonas fluorescens Used as a Microbial Antagonist

O.O. Agarry and B.I. Osho

The potential inhibitory effect of Pseudomonas fluorescens from cassava starch and flour was studied by using: (I) in-vitro inhibition assays with Aspergillus fumigatus and (ii) the in-vivo A. fumigatus rats model of infection. In-vitro activity against A. fumigatus revealed a moderate capacity of the bacterium in inhibiting the growth of the fungus. In-vivo experiments were performed by oral administration of P. fluorescens to 12 -14 week-old rats previously infected with A. fumigatus. Toxicological data of rat plasma showed that the bacterium had liver improvement functions. Alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities of the rats dosed with P. fluorescens alone were lower (2.65 and 20.67 IU/L) than the control. Moreover, no significant (P>0.05) rise was observed with the plasma albumin, globulin and total protein. There was a reduction in the count of A. fumigatus in rats dosed with both organisms after 7 days of feeding trials. The weight gain by rats in the treated group compared favourably with the control. Histopathological data confirmed protection of the liver, spleen, and kidney while the stomach and small intestine had partial erosion of the mucus membranes.