Second seminar
-
Upload
raed-najeeb-alkhursan -
Category
Science
-
view
127 -
download
0
Transcript of Second seminar
Occurrence of fungi in poultry feed with cultural and molecular detection of their aflatoxigenic
activityM.Sc. Student
Raed Najeeb Kadhim
SupervisorsProf.Dr. Mohammed H.Khudor Prof.Dr.Basil A.Abbas
Mycotoxins
• low-molecular-weight natural products produced as secondary metabolites by fungi.
• Lack of visible appearance of fungus does not negate presence of mycotoxins. Toxins can remain in the organism after fungus has been removed.
• Mycotoxins greatly resist decomposition and even temperature treatments, such as cooking and freezing.
• Resistant to breakdown in an animal’s digestive system.
Aspergillus
• Found in soil, plant debris, and indoor air environment•Aspergillus flavus is The most important species which cause aspergillosis in animals as well as in man and in birds. •Aspergillus flavus causes mycotic abortion in cattle and sheep.Ingestion of high amounts of aflatoxin may induce lethal effects, also cause sinusitis, cerebral aspergillosis, meningitis, pulmonary aspergillosis, cutaneous aspergillosis and hepatosplenic aspergillosis.•Produces many toxins as aflatoxins (B1, B2, ,G1,G2, M1, M1) Gliotoxin, Sterigmatocystin, and Methoxy Sterigmatocystin.
Some important mycotoxins
Today 300 - 400 mycotoxins are known
Common mycotoxins
Aflatoxin
Deoxynivalenol
Zearalenone
Fumonisin
Ochratoxin
Aflatoxins
• Produced by Aspergillus. flavus, A.parasiticus and A. oryzae.• There are types: aflatoxins B1 (AFB1) and B2(AFB2),G1(AFG1),G2(AFG2),M1(AFM1) andM2(AFM2). •Aflatoxin B1 occurs most frequently and is most toxic and carcinogenic.
AfB1 metabolism
• The main metabolizing organ for aflatoxin is the liver, but this can also occurs directly at the site of absorption, in the blood or in several extra-hepatic organs.
•Oral route is the main contamination means, inhalation may also occur as a result of people or animals being exposed to the grain’s dust.
•AfB1 is efficiently absorbed by duodenum.
Collection of samples of poultry feed
Culturing on PDA,MEA& SDA
Isolation
Identification
Morphological by culture Microscopically Molecular Cultural
method (on CAM medium
PCR UV NH4 Sol.
Light Microscope
A. flavus
Sequences analysis
The Aim of Study
1 Study the occurrence of mycoflora in poultry feed.
Determination of aflatoxigenic A.flavus. Compatible homology aflatoxigenic A.flavus strains with other strains in the gene bank.
Figure(12): Agarose gel electrophoretic of PCR products obtained from DNA of fungal isolates showing amplicons for aflR primer. Lanes: M-
100bp standard, Lanes1–7: A. flavus (aflatoxin producer) amplicon corresponding to 798 bp .
Table(5):Detection of aflatoxigenic and nonaflatoxigenic A.flavus isolates from poultry feed by three methods