Decreased hatchability problem in duck breeder farm was investigated and several bacterial agents were isolated. The total percentages of isolated bacteria from infertile duck eggs and dead in-shell-embryos were (10%) Enterobacter spp., (6.4% E. coli, (6%) Pseudomonas spp., (5.2% Salmonella spp., (4.4%) Proteus spp., (4.4%) Citrobacter spp., (4%) Klebsiella spp., and (2.8%) Staphylococcus spp. Trials for mycotic isolation gave negative results. Salmonella enteritidis serovar emek which was isoalted for the first time in Egypt during this study, showed homogenous surface protein profile, indicating the strong homology of the isolated strains. The major protein bands were 116.000, 84.000, 71.000, 55.000, 42.000 and 36.500 Kda. E. coli isolates shared a common molecular weight surface protein profile of 48.500, 48.000, 36.500, 26.600 Kda.