Infection of Shell Eggs With Yersinia Enterocolitica

Area of Science:

• Food safety
• Microbiology
• Food science

Background:

• Yersinia enterocolitica is a foodborne pathogen.
• Shell eggs are a potential vehicle for Yersinia transmission.
• Understanding egg penetration by Yersinia is crucial for food safety.

Purpose of the Study:

• To determine if Yersinia enterocolitica can penetrate and infect shell eggs.
• To investigate the effect of iron on Yersinia enterocolitica penetration into eggs.
• To assess Yersinia enterocolitica penetration under different inoculation techniques.

Main Methods:

• Shell eggs were inoculated with Yersinia enterocolitica using temperature or pressure differentials.
• Eggs were stored at 10°C for up to 14 days.
• Iron supplementation (20 ppm) was tested.

Main Results:

• No Yersinia enterocolitica was detected immediately after inoculation.
• After 7 days of storage, 14% of eggs without iron supplementation contained Yersinia enterocolitica.
• After 14 days, 100% of eggs examined contained Yersinia enterocolitica, with counts exceeding log 6.0 CFU/ml.

Conclusions:

• Yersinia enterocolitica can penetrate and proliferate within shell eggs during refrigerated storage.
• Iron supplementation did not significantly inhibit Yersinia enterocolitica penetration.
• Refrigerated storage of contaminated eggs poses a significant risk for Yersinia enterocolitica proliferation.