title: Pathogen prevalence and microbial levels associated with restricted shell eggs.
abstract: Restricted shell eggs that do not meet quality standards for retail but maintain acceptable quality for inclusion in further processed eggs are often diverted to further processing. A study was conducted to characterize the microbiological populations present on and in these eggs. On a single day, restricted eggs were collected from three shell egg processing plants a total of three times (replicates). Six shells or egg contents were combined to create a pool. Ten pools of shells and contents were formed for each plant per replicate. Shells and membranes were macerated in 60 ml of diluent. Contents were stomacher blended to form a homogeneous mixture. Total aerobic microorganisms and Enterobacteriaceae were enumerated. The prevalence of Salmonella, Campylobacter, and Listeria was determined by cultural methods. Average aerobic counts were 4.3 log CFU/ml for the shells and 2.0 log CFU/ml for the contents. There were plant x replicate differences for both (P < 0.05 and P < 0.01, respectively). The average Enterobacteriaceae level associated with the shell was 2.4 log CFU/ml and less than 0.1 log CFU/ml for the egg contents, with 36.7% of the samples being positive. One shell sample (0.5% of total samples) was Campylobacter positive. Two shell samples (1.1% of total samples) were Salmonella positive. Twenty-one percent of samples were positive for Listeria (33 shells and 5 contents). Although current pasteurization guidelines are based on Salmonella lethality, the results of this study reiterate the need to revisit the guidelines to determine the effectiveness for other pathogenic species.
authors: U.S. Department of Agriculture, Agricultural Research Service, Egg Safety and Quality Research Unit, Athens, Georgia 30605, USA. deana.jones@ars.usda.gov
authors: D R
authors: DR
authors: Jones
authors: M T
authors: MT
authors: Musgrove
mesh_terms: D000818:Animals; D002167:Campylobacter / Q000254:growth & development / Q000302:isolation & purification; D002645:Chickens; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004528:Egg Shell / Q000382:microbiology; D004531:Eggs / Q000382:microbiology* / Q000592:standards; D004755:Enterobacteriaceae / Q000302:isolation & purification*; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling / Q000379:methods / Q000592:standards; D005516:Food Microbiology; D005525:Food-Processing Industry / Q000379:methods / Q000592:standards; D006801:Humans; D008087:Listeria / Q000254:growth & development / Q000302:isolation & purification; D012475:Salmonella / Q000254:growth & development / Q000302:isolation & purification