Recombinant auto-bioluminescentto monitor the progression ofinfection in the embryonated chicken eggs.

Abstract

Avian pathogenic(APEC) infections in poultry adversely affect health and production, with public health implications. This study assessed the potential of bioluminescence imaging for real-time, noninvasive tracking of microbial progression in 12-day-old chicken embryos inoculated with an APEC strain or its derivatives integrated either withABCDE oroperon. Eggs were imaged daily for bioluminescence detection, with dead embryos sampled immediately and survivors killed at 5-days post-inoculation (dpi). The eggs were opened, and egg contents were imaged for bioluminescence. Yolks were sampled forisolation and quantification. The results showed lethality rates of 100%, 93.3%, and 80% in embryos inoculated with native strain,ABCDE, orrespectively. Bioluminescence analysis showed increased bioluminescence signal strength over time preceding embryo death. Surviving embryos exhibited a sequential reduction in signal strength. A strong positive correlation was found between bioluminescence signal intensityand, withAPEC-infected eggs showing a higher luminoscore thanABCDE-APEC. Theload in yolks of APEC-inoculated eggs showed a positive trend over time. Overall, bioluminescence imaging ofoperon-labelled bacteria enabled more efficient real-time detection and monitoring of. Multiple imaging sessions on the same embryo throughout the experiment allowed precise monitoring of infection progression without sequential culling. This offers a controlled platform for evaluating antimicrobial treatment efficacy in anmodel that closely resembles anchicken model. It can also be used to study infection patterns of other pathogens, especially those that pose risks to public health.Bioluminescence imaging enabled real-time, noninvasive tracking of a bioluminescent APEC infection in embryonated chicken eggs over time.Bioluminescence signals showed contrasting patterns for dead and surviving embryos.The-APEC showed a higher luminoscore thanABCDE-APEC in inoculated embryonated chicken eggs.Thebioluminescent signal from intact eggs effectively reflects thesignal following the take out of yolk and embryo.