The Microbiological Contamination of Egg Shells and Egg Packing Materials ,

THE microbiology of egg shells and egg packing materials has received inadequate attention. In England, Haines (1938) found levels of bacterial contamination ranging from 1.30×104—8.0×106 (incubation, 20°C.) and 3.5×104–1.6×106 (incubation, 37°C.) on the shells of 130 eggs, the majority of which were procured from a farm. Rosser (1942) reported average counts of 7.0×104 organisms per shell of Canadian market eggs and 1.03×105 per shell of eggs obtained from a farm. Forsythe et al. (1953) found an average of 6.3×104 (range, 1.0×104—1.0×106) microorganisms on the shells of eggs produced on an experimental poultry farm. Haines (1938) examined 100 isolates from shells and found that gram-negative bacteria (38%), bacilli (30%), and gram-positive cocci (25%) were the most prevalent contaminants. He concluded that eggs were exposed to contamination from a wide variety of sources, the chief ones being feces, manure, and soil. The present study was undertaken with the object…