EGG-SHELL PENETRATION TENDENCY OF DIFFERENT SALMONELLA SEROTYPES BY ATTACHED RING COLOR METHOD

To investigate the extent of Salmonella penetration through the egg sh ell, 200 eggs were dipped in red (for 3 minutes) and then in green (fo r 6 minutes) aqueous bland food color solution for the detection of po sitive penetration test areas. Each egg with positive penetration area , 5 spots of 1 cm in diameter, was marked for the attachment of steel cylinders (1 cm in diameter and height). These cylinders were filled w ith the test strain of Salmonella. Among 19 serotypes S. pullorum and S. gallinarum were nonmotile while the other 17 were motile. Among a t otal of 180 eggs (900 points) maximum (30%) penetration was in area II I, where salmonellae invaded through cuticle, shell, inner and outer s hell membranes, followed by area II (14.77%) and area I (4.6%). It was very well evident that penetration of salmonellae to the contents of eggs was maximum, while in area II the penetration was to outer shell membrane and in the least cases through the cuticle and shell. Penetra tion in area I is not significant and to some extent in area II as wel l, while invasion in area III is highly significant.