Antifungal resistance modulation of Aspergillus fumigatus isolates from brooder pneumonia affected birds by Eucalyptus globulus extracts

Abstract

Brooder pneumonia is a common respiratory problem during brooding period of poultry. It is most frequently caused by Aspergillus fumigatus. Use of azole drugs for treatment and prophylaxis results in resistance. The aim of this study was to determine whether the phytochemicals of Eucalyptus globulus are modulating resistance in Aspergillus fumigatus. Lung samples n = 50 of dead broiler chicks were collected from different farms of Lahore. Out of 50 lung samples 28 % (14) were considered positive for Aspergillus fumigatus after observing their macroscopic, microscopic characteristics and by performing PCR by amplifying ITS1-ITS4 gene (597 base pairs) and RodA gene (313 base pairs). Kirby-Bauer disc diffusion test was performed 14 isolates (100 %) were resistant towards both Fluconazole and Ketoconazole whereas 11 (78.57 %) were resistant towards Itraconazole. Eucalyptus globulus leaves were collected, and these were identified. Three solvent extracts were prepared. Maximum yield was of ethanolic extract. Antifungal activity was evaluated by agar well diffusion method. Highest antifungal activity was shown by Eucalyptus globulus Ethanol followed by chloroform and hexane extract showed no activity against any isolate then minimum inhibitory concentration of plant extracts that previously showed antifungal activity against isolates were evaluated by broth microdilution method. Modulation effect was checked by combining antifungal drug one by one with subinhibitory concentration of plant extract evaluated previously by broth microdilution method. 5 isolates were subjected into this experiment which are all sensitive towards Eucalyptus globulus ethanol and chloroform extracts tested previously in agar well diffusion test and MIC values were also evaluated. It was concluded that when Itraconazole was combined with E. globulus Ethanol extract then resistance was modified. Data of modulation was analyzed by One-way ANOVA and it reported P value of <0.05. It was synergistic inhibitory effect when Itraconazole was combined with Eucalyptus globulus Ethanol extract.