Molecular Characterization of
Toxigenic Aspergillus
flavus Isolated from Sick Broiler Lungs and Risk Factors
Analysis
Md Zulfekar Ali1, Saba Sana2*, Ali Ahmad
Sheikh2 and Zoya Maheen2
1Animal
Health Research Division, Bangladesh Livestock Research Institute,
Bangladesh
2Institute of Microbiology, University of Veterinary and
Animal Sciences Lahore, Pakistan
Abstract
Brooder’s pneumoniais a respiratory disease of poultry caused by fungi of genus
Aspergillus. Aspergillus flavus is a
toxigenic fungus, which sporulates easily in poor quality bedding and
contaminates indoor air. The objective of present study is to isolate
A. flavus from diseased birds,
characterize toxigenic potential/variability and analysis of the risk factors
associated with brooder’s pneumonia caused by
A. flavus. Litter, air and morbid Cobb 500 strain from poultry farm
(n=10) were selected for sampling. Moisture contents detected in bedding of saw
dust and rice husk were 73 to 46.4 and 20.06 to 23.26% respectively. Poultry
farms used saw dust were found more contaminated (CFU/30minutes 80±2.6 to
160±6.0) in comparison to those having rice husk (CFU/30minutes 28±3a
50±2.6b) as bedding material.
A. flavus was isolated from lungs of all infected birds and identified based
upon colony and microscopic morphology. Infected lung tissues containing fungal
plaques were processed for histopathological examination. Tissue was found
necrotized and contaminated with fungal hyphae. Purified
A. flavus species were evaluated for
aflatoxins (Total aflatoxins and AFB1) production potential by Enzyme
linked immunosorbent assay (ELISA). All species were found toxigenic with
production of total aflatoxin ranged from 1.51 to 8.77ppm and AFB1
from 0.33 to 3.0 ppm. Molecular analysis by Multiplex Polymerase chain reaction
(PCR) revealed genetic variability in aflatoxins biosynthetic pathway.
AflR gene was amplified in all species
with 1032bps amplicon size. Multiplex
PCR amplified the omt-A gene in 40, ver-1 in 70 and nor-1
in 60 percent toxigenic isolates. It is concluded that toxigenic A. flavus
is emerging as major pathogen in Brooder’s pneumonia associated with poor
litter quality.
To Cite This Article:
Ali MZ, Sana S, Sheikh AA and Maheen Z 2022.
Molecular characterization of toxigenic
Aspergillus flavus isolated from sick broiler lungs and risk
factors analysis. Pak Vet J, 42(2): 194-200.
http://dx.doi.org/10.29261/pakvetj/2022.037