TDK conference 2014

Pasteurellosis in rabbits is caused by a Gram-negative coccobacillus, namely Pasteurella multocida, and the disease is considered one of the most important pathological conditions of rabbits, equally affecting livestock, pets and laboratory animals.

Defense against pasteurellosis has long been an important issue among farmers and veterinarians alike. Protection begins with prevention, and its very first step includes maintaining appropriate hygiene. After the onset of clinical infections, however, antibacterial drugs should make up the first line of treatment. Unfortunately, the use of most antibacterial compounds is contraindicated in rabbits. Furthermore, spreading of bacterial resistance also serves as a limiting factor for antibacterial treatments.

The question arises whether antibacterials can be replaced by substances that equal to antibiotics in their effectiveness or have ability to prevent the infection.

In our experiment, we investigated the effects of beta-glucans (polysaccharides, produced by various fungal species, consisting of a backbone structure of β-(1-3)-linked β-D-glucopyranosyl units and β-(1-6)-linked side chains) and the Echinacea (purple coneflower, Echinacea purpurea herbal grist) in New Zealand white rabbits infected with P. multocida. We hypothesized that the immunostimulatory effects of beta-glucans and Echinacea could subsitute for antibacterial treatments of pasteurellosis.

Seven treated groups were examined: control, infected control, antibacterials, small dose (5 mg/kg) and high dose (50 mg/kg) beta-glucans, small dose (10 mg/kg) and high dose (100 mg/kg) Echinacea.

The observed clinical signs (based on inspection, auscultation, rectal temperature and body weight), pathological findings and the results of histopathological examinations suggested that in case of severe P. multocida infection, neither beta-glucan nor Echinacea can substitute for antibacterial treatments. However, death of individual animals in the beta-glucan-treated groups occurred considerably later, than in the infected controls.