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The effect of dazomet on salmonellas on artificially contaminated eggs
Abstract:
Salmonellas were isolated from the surface of only 1 of 21 artificially contaminated eggs after they had been treated with dazomet. By comparison salmonellas were isolated from the surface of 13 of the 21 untreated eggs. Penetration by the salmonellas through the shells to the shell membranes resulted from the immersion of warm eggs in a cold suspension of salmonella cells. While the dazomet treatment reduced the incidence of salmonellas within the shells and shell membranes, elimination of salmonellas from all eggs was not achieved. However, the numbers of surviving salmonellas on the eggs were small; a count of 4 per shell being recorded compared to greater than 110,000 per shell of the untreated eggs. The failure to achieve complete elimination of salmonellas within the shell and membranes appeared to be due to inadequate penetration of the fumigant to these structures.
Insights
Dazomet treatment significantly reduced surface salmonellas on eggs, but did not fully eliminate internal contamination. Inadequate fumigant penetration limited complete eradication of salmonella in eggs.
Area of Science:
- Food safety
- Microbiology
- Veterinary public health
Background:
- Salmonella contamination in eggs poses a significant public health risk.
- Effective decontamination methods are crucial for preventing foodborne illnesses.
- Understanding pathogen penetration mechanisms is key to developing control strategies.
Purpose of the Study:
- To evaluate the efficacy of dazomet fumigation in reducing Salmonella contamination on and in artificially contaminated eggs.
- To investigate the penetration of Salmonella into eggs under specific conditions.
- To identify factors limiting the complete elimination of Salmonella by dazomet.
Main Methods:
- Artificial contamination of eggs with Salmonella.
- Treatment of eggs with dazomet fumigant.
- Isolation and enumeration of Salmonella from egg surfaces, shells, and membranes.
- Comparison of treated and untreated (control) eggs.
Main Results:
- Dazomet treatment reduced Salmonella isolation from egg surfaces from 13/21 to 1/21 untreated eggs.
- Salmonella penetration into shells and membranes occurred when warm eggs were immersed in cold Salmonella suspensions.
- While dazomet reduced internal Salmonella incidence, complete elimination was not achieved.
- Surviving Salmonella counts were significantly lower in dazomet-treated eggs (4 per shell) compared to untreated eggs (>110,000 per shell).
Conclusions:
- Dazomet fumigation is effective in reducing Salmonella contamination on egg surfaces and significantly lowers internal counts.
- Inadequate penetration of the fumigant to the shell and membrane structures appears to be the reason for incomplete Salmonella elimination.
- Further research into optimizing fumigant delivery or alternative methods is needed for complete Salmonella eradication in eggs.
