Case reports involving coinfection with Avibacterium paragallinarum and Ornithobacterium rhinotracheale in broiler chickens and Avibacterium endocarditis in broiler breeding hens in Poland

ABSTRACT

The study describes three clinical cases of infection with Avibacterium spp.. In case no. 1, respiratory clinical signs and high mortality (0.7–4.2% daily; total 21.2%) in Ross 308 broiler chickens were shown to be caused by coinfection with sequence type 9 of O. rhinotracheale presumptive serotype A and A. paragallinarum presumptive serotype B. The identical (pulsed-field gel electrophoresis) restriction pattern (pulsotype) of seven A. paragallinarum isolates indicated that infectious coryza in broilers was caused by the same clone. In cases 2 and 3, sudden increased deaths in Ross 308 broiler breeders (especially males) with lesions in the endocardium (valvular or mural endocarditis) were shown to be caused by A. endocarditis. Among nine antibiotics tested, florfenicol was the only antibiotic to which all A. paragallinarum and O. rhinotracheale isolates were susceptible. Out of the eight antibiotics tested, 11 A. endocarditis isolates from both clinical cases of infective endocarditis were susceptible to penicillin, amoxicillin, doxycycline and florfenicol. The A. endocarditis isolates tested in both clinical cases had different PFGE patterns (pulsotypes), but identical within a case. The causes of infectious coryza and infective endocarditis in the cases presented have not been determined. In the prevention of infectious diseases in large-scale livestock farming, it is very important to follow the rules of biosecurity.

KEYWORDS:

• Avibacterium infections
• poultry
• endocarditis
• coinfections
• sudden deaths of poultry
• antibiotic resistance

Ethical statement

The samples from the dead birds were collected by a veterinarian as part of her work. According to Polish law (Law of 15 January 2015 on the protection of animals used for scientific or educational purposes), permission from the ethics commission is not required for this type of sample collection.

Acknowledgements

The authors want to acknowledge the Phibro Animal Health Corporation for providing FTA cards with reference serovars of A. paragallinarum.

Disclosure statement

No potential conflict of interest was reported by the authors.