Veterinary Archives, Vol. 76 No. 5, 2006.
Original scientific paper
Recognition of virulence parameters in phospholipase A producing Salmonella
Shammi Kapoor
Davinder Kumar Sharma
Shukriti Sharma
Mohinder Singh Kalra
Abstract
Thirty-two strains of Salmonella belonging to six serovars were subjected to antimicrobial drug sensitivity,
surface hydrophobicity assay, haemolytic activity assay, hydrolytic activity assay and enterotoxigenicity of
enzyme phospholipase A. The five strains that produced phospholipase A were resistant to most of the antibiotics.
Using various concentrations of ammonium sulphate for salt aggregation test, a high degree of correlation was
observed between phospholipase A production and hydrophobicity. The strain S30 (Salmonella Enteritidis)
producing the maximum phospholipase A was selected for studying the haemolytic and hydrolytic activities, as
well as enterotoxigenicity of phospholipase A fractions. The intracellular fraction of the enzyme phospholipase
A showed more haemolytic activity and hydrophobic activity than extracellular enzyme. The intracellular
enzyme was non-haemolytic to sheep RBC’s but hemolyzed all other mammalian erythrocytes. Enterotoxigenic
studies revealed maximal gut index with crude intracellular phospholipase A fraction (0.61) followed by crude
extracellular fraction (0.57). The purified fractions of the enzyme showed mild to moderate gut reaction as
compared to crude fractions, which gave moderate to marked reaction. The role of phospholipase A in exhibiting
virulence has been discussed.
Keywords
antibiogram; enterotoxigenicity; hydrophobicity; phospholipase A; virulence
Hrčak ID:
5151
URI
Publication date:
20.10.2006.
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