Molecular studies on antibiotic resistant genes of Aeromonas species isolated from fish Detection of some virulence genes in A.hydrophila and A.caviae isolated from fresh water fishes at Qalubia Governorate Detection of some virulence genes of avian pathogenic E.Coli by polymerase chain reaction. Current status of E.Coli sergroups affecting broiler in Kaliobia governorate Molecular characterization and antimicrobial Resistance Gene of E.coli and salmonella Kentucky isolated from Turkey in Egypt Phenotypic and genotypic characterization of antibiotic resistant strains of flavobacterium columnare isolated from Nile Tilapia (oreochromis niloticus). Diagnostic tools for Mycotic pneumonia in large ruminant using autofluerescence character of fungi and detection of virulence genes of Aspergillus fumigatus using PCR. cryptococcosis in small ruminants with special references to convetional and molecular methods of diagnosis Antibiotic Resistance genes in Streptococus iniae isolated from diseased (oreochromis niloticus). Virulence- associated genes profiling of Streptococus iniae isolated from diseased Nile Tilapia (oreochromis niloticus). Characterization of some antimicrobial genes of Escherichia coli recovred from pet animals and human with urinary tract infections.