Molecular Characterization and Identification of Aflatoxigenic Fungi Associated with Poultry Feed in Port Harcourt, Rivers State

The contamination of livestock feeds by aflatoxigenic fungi poses
significant health and economic risks, affecting both animal productivity and
human food safety. This study investigated the occurrence, molecular
characterization, and aflatoxigenic potential of fungal contaminants in
commercial poultry feeds obtained from Rumuolumeni, Mile III, and Choba
in Port Harcourt, Rivers State. About nine feed samples (starter, grower, and
finisher) were aseptically collected and analyzed using standard
microbiological methods. Ten grams of each sample were serially diluted
and inoculated on Potato Dextrose Agar (PDA) supplemented with
chloramphenicol to isolate fungal species. Distinct colonies were purified
and identified based on morphology and molecular characteristics. DNA
was extracted using the CTAB method, and the Internal Transcribed Spacer
(ITS) region was amplified with ITS1/ITS4 primers. The resulting PCR
products were sequenced, analyzed via BLAST on the NCBI database, and
phylogenetically compared using MEGA 11 software. Aflatoxin production
was confirmed through culture on YES agar, methanol extraction,
immunoaffinity
purification,
and
High-Performance
Liquid
Chromatography (HPLC) quantification. Results revealed that all feed
samples were contaminated with fungi, with Aspergillus flavus, A. niger, A.
fumigatus, Penicillium, Fusarium, and Rhizopus species identified. Molecular
analysis confirmed A. flavus as the predominant aflatoxigenic fungus,
clustering with known aflatoxin-producing lineages (bootstrap 85–92%).
HPLC analysis showed that A. flavus isolates produced Aflatoxins B₁, B₂, G₁,
and G₂, with B₁ being the most dominant and toxic (45.6–60.2 µg/kg). It is
concluded that poultry feeds in the study area are significantly contaminated
with aflatoxigenic A. flavus, posing serious food and feed safety concerns.
The study recommends strict quality control during feed production, proper
storage conditions, and routine screening for aflatoxins to safeguard animal
and public health.