Co-Infection of Escherichia coli, Enterococcus faecalis and Chlamydia psittaci Contributes to Salpingitis of Laying Layers and Breeder Ducks

Abstract

Salpingitis is manifested as hemorrhagic follicular inflammation exudations and peritonitis, leading to reduced egg production and high culling of breeder flocks. From 2018 to 2021, increasing salpingitis during egg peak is threatening the poultry industry post-artificial insemination, both in breeder layers and breeder ducks across China. In our study, Escherichia coli (E. coli), Enterococcus faecalis (E. faecalis) and Chlamydia psittaci (C. psittaci) were isolated and identified from the diseased oviducts using biochemical tests and PCR. To identify and isolate pathogenicity, we inoculated the isolates into laying hens via an intravaginal route. Later, laying hens developed typical salpingitis after receiving the combination of the aforementioned three isolates (1 × 105 IFU/mL of C. psittaci and 1 × 106 CFU/mL of E. faecalis and E. coli, respectively), while less oviduct inflammation was observed in the layers inoculated with the above isolate alone. Furthermore, 56 breeder ducks were divided into seven groups, eight ducks per group. The birds received the combination of three isolates, synergic infection of E. coli and E. faecalis, and C. psittaci alone via vaginal tract, while the remaining ducks were inoculated with physiological saline as the control group. Egg production was monitored daily and lesions of oviducts and follicles were determined post-infection on day 6. Interestingly, typical salpingitis, degenerated follicles and yolk peritonitis were obviously found in the synergic infection of three isolates and the birds inoculated with C. psittaci alone developed hemorrhagic follicles and white exudates in oviducts, while birds with E. faecalis or E. coli alone did not develop typical salpingitis. Finally, higher E. coli loads were determined in the oviducts as compared to E. faecalis and C. psittaci infection. Taken together, the combination of E. coli and E. faecalis, and C. psittaci could induce typical salpingitis and yolk peritonitis both in laying hens and breeder ducks. Secondary infection of E. coli and E. faecalis via artificial insemination is urgently needed for investigation against salpingitis.

A Novel Intranasal Vaccine With PmpGs + MOMP Induces Robust Protections Both in Respiratory Tract and Genital System Post Chlamydia psittaci Infection

“…Chlamydia psittaci SZ18-1 strains (GenBank MK751470.1) were isolated from breeder ducks with egg drop and severe salpingitis (13). The strain was propagated onto BGMK cells at 37 • C in a flow of 5% CO 2 for 72 h. Live elementary bodies (EBs) were harvested and purified by density gradient centrifugation, and inclusion-forming units (IFUs) were determined by Chlamydia immunofluorescence assay (IMAGEN TM ; Oxoid, Cambridge, UK).…”

Animal Chlamydiae: A Concern for Human and Veterinary Medicine

“…After identifying Escherichia coli , Enterococcus faecalis , and C. psittaci in the oviducts of diseased hens and ducks, Fang and colleagues inoculated laying hens with isolates of these bacteria. These hens developed salpingitis, which was more severe in animals infected with all three bacteria compared with corresponding single infections [ 13 ]. Interestingly, in breeder ducks, a single infection with C. psittaci but not a single infection with E.a coli or E.s faecalis had a negative impact on duck oviduct health, and co-infection led to salpingitis.…”

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): antimicrobial‐resistant Enterococcus faecalis in poultry

“…Parameter 4 -Experimentally susceptible domestic species (or family/order) Salpingitis (infection of the avian reproductive system) has experimentally been produced by Fang et al (2021) in layers and breeder ducks. For full manifestations of salpingitis, a co-infection including E. faecalis, Escherichia coli (E. coli) and Chlamydia psittaci was needed.…”