MOLECULAR DETECTION OF ASPERGILLUS NIGER GENES NIG1, CMDA AND MY-COTOXIN GENES FUM1, PKS FROM OTOMYCOSIS AMONG BREEDERS OF DOMESTIC CATS WITH SPECIAL EMPHASIS TO RISK FACTORS IN DIYALA GOVERNORATE, IRAQ

Document Type : Research article

Authors

1 Department of medicine, College of Veterinary Medicine, University of Diyala, Iraq

2 Department of pathology, College of Veterinary Medicine, University of Diyala, Iraq

Abstract

Aspergillus spp. is saprophytic opportunistic fungi that are a leading cause of otomycosis in human. Isolation of Aspergillus niger (A. niger) from external ear of domestic cats breeders (DCB), molecular characterization of A. niger by conventional polymerase chain reaction (PCR), detection of putative risk factors for infection with Aspergillus, detection of fumonisin and ochratoxin by PCR. One hundred and six external ear swabs were taken from DCB attended to private veterinary clinics and cultured on Sabouraud dextrose agar. Fungal growth was identified as A. niger according to cultural characteristics. All A. niger positive samples were subjected to confirmatory step by conventional PCR using species-specific PCR primer pairs for A. niger (NIG1) and calmodulin (Cmd A). Production of fumonisin and ochratoxin by A. niger confirmed by PCR using specific primers. A. niger was isolated from 10.38% ear swabs of DCB. Significant correlation was reported between age group, season, absence of earwax, using of antibiotics eardrops and isolation of A. niger.  No significant correlation was recorded between sex, education levels, economic status, swimming, exposure to trauma, diabetes miletus, occupation and isolation of A. niger. Fumonisin gene (FUM1) was detected in 63.64% (7/11) of A. niger isolated from ear of DCB. Ochratoxin gene (PKS) was not produced by any isolates of A.niger , 0% (0/11). Using of NIG1 and Cmd A has equal significance in molecular diagnosis of A. niger. Age group, season, absence of earwax, using of antibiotics eardrops have serious effect on infection of ear with A. niger among DCB. Fumonisin is the major mycotoxin produced from A. niger in otomycosis. A. niger ear infection represents significant problem among domestic cats breeders.

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