The efficacy of inactivated Escherichia coli autogenous vaccines against the E. coli peritonitis syndrome in layers

Abstract

Autogenous Escherichia coli vaccines to prevent the E. coli peritonitis syndrome (EPS) in laying hens are often used in the field, although their effectiveness has not been demonstrated yet. Therefore, in this study, which consisted of two experiments, their efficacy was assessed. In the first experiment, the EPS-inducing ability of three E. coli isolates originating from bone marrow of hens that died due to EPS and with different Pulsed-Field Gel Electrophoresis patterns, was examined by intravenous inoculation of the isolates in 17-week-old brown layers. Based on the results one isolate was chosen for the preparation of the vaccines and for homologous challenge and another one for heterologous challenge performed in the second experiment. In the named experiment, groups of laying hens which had been vaccinated intramuscularly at 14 and 18 weeks of age with inactivated vaccine either formulated as aqueous suspension or as water-in-oil emulsion were homologously or heterologously challenged per aerosol at 30 weeks of age. The vaccines contained ≥10 formaldehyde-inactivated colony-forming units (cfu) of E. coli per hen dose in 0.5 ml. The estimated E. coli challenge dose uptake ranged from 10 to 10 cfu per hen. Groups consisted of 18 hens each and were housed in separate isolators from 27 weeks of age. Control groups were included in this experiment, which was ended eight days after challenge. Vaccinations had no effect on body growth and both vaccine types induced (almost) complete protection against homologous challenge, while protection against heterologous challenge was inconclusive.

An Assessment of the Level of Protection Against Colibacillosis Conferred by Several Autogenous and/or Commercial Vaccination Programs in Conventional Pullets upon Experimental Challenge

“…In previous pathogenicity trials, our team confirmed, with O78 and O111 strains isolated from the same pullet-rearing farm and with the O18 reference strain, that the inoculation of 0.5 mL of a bacterial suspension at approximately 10 9 CFU/mL via the intratracheal route is a valid model for reproducing avian colibacillosis [ 40 ]. Under experimental conditions, the spectrum of protection conferred by immunization has been explored by different authors and is generally considered to reach almost full protection in homologous challenge conditions and rarely so with heterologous challenge [ 31 , 37 ].…”

“…), there are a limited number of publications reporting on their efficacy. Landman and Van Eck [ 37 ] reported on the protection provided by an autogenous vaccine prepared from an APEC strain isolated from the bone marrow of birds with egg peritonitis syndrome. The homologous experimental challenge demonstrated that pullets were almost fully protected, while the heterogenous challenge provided inconclusive results.…”

“…Autogenous vaccines are produced from pathogenic strains isolated from within the affected flock where the vaccine will be used. They are widely used in the field for colibacillosis control [ 36 , 37 ]. By nature, each autogenous vaccine is different, and reports on the impact of their usage are sporadic.…”

“…By nature, each autogenous vaccine is different, and reports on the impact of their usage are sporadic. As far as colibacillosis in layers/breeders is concerned, two reports have been published, with a negative [ 38 ] and a positive outcome [ 37 ]. However, to the authors’ knowledge, no publication has reported so far on the use of autogenous vaccines in a colibacillosis vaccination program, together with a commercial vaccine, evaluated by intratracheal challenge.…”

Tetratrichomonas gallinarum granuloma disease in a flock of free range layers

“…2004). Bacteriological analysis of femur bone marrow of four hens was performed to assess the presence of E. coli (Landman and Van Eck 2017b). Preparation of HE and Ziel–Neelsen stained tissue sections, culture of trichomonads from ceca in Diamond’s medium, and ISH for T. gallinarum and H. meleagridis were done as presented before (Landman et al.…”