Bacterial Causes of Death in Shell Embryos

Khafagy, Ahmed Refaat; El-kady, Magdy Fathy; Galal, Amira Fared; Eidaros, Nada Hussen

doi:10.21608/scvmj.2025.411028.1212

Bacterial Causes of Death in Shell Embryos

Document Type : Original Article

Authors

¹ Department of Bacteriology, Mycologyand ImmunologyDean of faculty of Veterinary MedicineAin shams University

² Department of poultry and rabbit diseases, Faculty of Veterinary Medicine, Beni suef University.

³ Veterinary Medicine Directorate, Dakahlia Governorate

⁴ Department of Bacteriology,Mycology and immunology Faculty of Veterinary Medicine, Suez canal University

10.21608/scvmj.2025.411028.1212

Abstract

Dead-in-shell embryos remains a major concern in chicken hatcheries indicating high bacterial contamination that implies the necessity to dispose them. The present study was planned to investigate the occurrence, frequency of bacteria isolated from deceased embryos collected from different hatcheries at several Egyptian governorates.
Three hundred fifty samples (350) collected from air sacs, yolk sacs, and internal organs of unhatched deceased chicks, in addition to swabs from egg nests and hatcheries, were submitted to bacteriological examination that revealed isolation of a total 261 bacterial isolates with a percentage of 74%. Staphylococcus aureus was the most prevalent with a total of 130 isolates (49.8%), followed by Salmonella with 66 isolates (25.2%), E. coli with 48 isolates (18.3%), and Klebsiella with 17 isolates (6.5%).
Molecular identification of Staphylococcus aureus isolates was confirmed by amplification of the h16S rRNA gene, meanwhile the invA gene in Salmonella isolates was evidenced by using specific primer through distinct bands of 300 bp and the phoA gene was detected by its specific primer in all E coli isolates.
The study put a thorough of light on bacterial causes of embryonic mortality and underscores the necessity of stringent cleanliness protocols in hatcheries.

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