Document Type : Original Article
1 Bacteriology, Immunology and Mycology Department, Fac. Vet. Med. Benha Univ. 2 Animal Health Research. Shibin el-kom branch. Agriculture Research Center
Animal Health Research. Shibin el-kom Branch.
Bacteriology, Immunology and Mycology Department, Fac. Vet. Med. Benha Univ.
Pseudomonas is a genus of Gram-negative bacteria belonging to the family Pseudomonadaceae. It is one of the psychrophilic bacteria that can thrive in low temperature milk in addition to producing heat-resistant spoiling enzymes due to presence of virulence genes. So, the aim of this study is to characterize the virulence potential of Pseudomonas species isolated from bulk tank milk. Four strains of pseudomonas species were identified as Pseudomonas aeruginosa, Pseudomonas fluorescence, Pseudomonas putida and Pseudomonas diminuta in the percentages of 16, 12, 4 and 4 (%,) respectively. The pathogenesis of Pseudomonas species is closely related to its virulence genes. In the present study, the virulence genes that were identified in the isolated samples were outer membrane lipoprotein L (oprL) and exotoxin S (exoS) virulence genes which detected in all studied strains, while exo polysaccharide synthesis locus (pslA) virulence gene was detected in 80% of the studied strains, on the other hand exotoxin A (toxA) virulence gene was detected in 70% of the studied strains. Moreover, elastase B (lasB) virulence gene was detected in 20% of the studied strains.