Isolation and Identification of Microorganisms in Eggs of a Commercial Ostrich Breeder Farm

Contamination of hatching eggs with pathogenic microorganisms decrease hatchability and may cause a financial loss in industrial bird production. The aim of this study was to evaluate the microbiological status of a commercial ostrich farm and its relationship to the hatchery management. Microbial sampling was done from the organs of two dead embryos, cloacae of seven newly hatched chicks and one mature female ostrich, the content of five infertile eggs, the incubation room and incubator machines, the ingredients of diet, and the shell surface of 62 eggs which were laid during a reproductive season. Various selective and differential media included MacConkey agar, blood agar, Sabouraud's dextrose agar, nutrient agar, and PPLO agar, etc. were used for isolation and identification of the microorganisms. Different types of fungi and bacterial contamination were found on the shell surface of the eggs, which Gram-positive bacilli were isolated in 74% of these eggs (46/62). From the organs of two dead embryos Gram-positive bacilli, Gram-positive cocci, Staphylococcus epidermidis, Rhodotorula spp., Helminthosporium spp., and Aspergillus nidulans were isolated. Most of the ingredients of the diet contained Mucor spp. and a wide range of bacterial species. Finally, the effect of applying the formaldehyde gas was evaluated by McNemar's test, that results showed this method was very useful for reduction of microbial load of the eggshell in a high rate contamination. Comparison of microbial communities isolated from dead embryos and the egg-shells' surface showed that microorganisms in different parts of the farm could lead to contamination of the eggs which penetrated into the eggs. So implementing sanitation and disinfection of hatching eggs for improvement of hatchability rate is recommended.