engleski

Prevalence of Gallibacterium anatis and Escherichia coli on broiler breeder farms in Croatia

Gallibacterium anatis and Escherichia coli are some of the most common causative agents of peritonitis, folliculitis and salpingitis, as well as upper respiratory tract disorders in poultry. They can act as primary pathogens or appear in coinfection with other microorganisms such as Mycoplasma spp., IBV or each other. Less prominent clinical symptoms and pathomorphological lesions usually follow Gallibacterium infections, while colibacillosis is recognized by more severe lesions. The infection can be subclinical, but usually causes great production decrease and high mortality rates. In this study, we wanted to determine the prevalence of G. anatis and E. coli on two broiler breeder farms to assess the epizootiological situation in Croatia. During this epizootiological survey, poultry carcasses and swabs from live animals were brought from two broiler breeder farms to the Department of Poultry Diseases with Clinic where necropsy was done. During examination, 200 swab samples were taken from pharynx, peritoneum, liver, oviduct and bone marrow of 128 animals in total. Samples were then plated on 5% sheep blood agar and incubated aerobically at 37°C for 24 hours. Identification was done by Gram staining, biochemical tests and MALDI-TOF spectrometry method. Afterwards, the isolates were stored in BHI at -80°C for further analyses. Altogether 15, 5% of the samples from both farms were positive for G. anatis. From that, 93, 5% of isolates originated from the pharynx, while only 6, 5% originated from the peritoneum. In contrast, 38% of the samples from both farms were positive for E. coli and even 62, 5% of the isolates originated from oviduct. Coinfection of G. anatis and E. coli was present only in two cases, but the flocks were previously positive for Mycoplasma synoviae and 793B IBV strains were detected. This data confirms the assumption about G. anatis being an opportunistic pathogen and demonstrates higher prevalence of E. coli on the examined broiler breeder farms. Since the isolates are usually farm specific and often multidrug resistant, therapy is not always successful and the use of autogenous vaccines with adjustment of the immunoprophylaxis program for every flock individually is recommended.

Gallibacterium anatis, Escherichia coli, broiler breeder, autogenous vaccine, poultry

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