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Alternative treatment of serious and mild Pasteurella multocida infection in New Zealand White rabbits.

Palócz O, Gál J, Clayton P, Dinya Z, Somogyi Z, Juhász C, Csikó G - BMC Vet. Res. (2014)

Bottom Line: Immunisation is only variably effective.Four other groups were inoculated both in. and intramuscularly (im.), representing a supra-physiological challenge, and received either (1-3), (1-6) β-glucans, antibiotic or placebo. β-glucans given prophylactically were highly effective in protecting against physiological (in.) bacterial challenge.They were less effective in protecting against supra-physiological bacterial challenge (in. and im.), although they extended survival times.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Toxicology, Faculty of Veterinary Science, Szent István University, István u. 2, Budapest, 1078, Hungary. palocz.orsolya@aotk.szie.hu.

ABSTRACT

Background: Pasteurella multocida causes numerous economically relevant diseases in livestock including rabbits. Immunisation is only variably effective. Prophylactic antibiotics are used in some species but are contra-indicated in rabbits, due to their adverse effects on the rabbit microbiota. There is therefore a substantial need for alternative forms of infection control in rabbits; we investigated the effect of oral β-glucan on P. multocida infection in this species.

Results: Thirthy-five New Zealand White rabbits were randomly divided into five groups of seven animals. Three groups were inoculated with Pasteurella multocida intranasally (in.), a physiologically appropriate challenge which reproduces naturally acquired infection, and received either (1-3), (1-6) β-glucans or placebo. Four other groups were inoculated both in. and intramuscularly (im.), representing a supra-physiological challenge, and received either (1-3), (1-6) β-glucans, antibiotic or placebo. β-glucans given prophylactically were highly effective in protecting against physiological (in.) bacterial challenge. They were less effective in protecting against supra-physiological bacterial challenge (in. and im.), although they extended survival times. This latter finding has practical relevance to breeders as it extends the window in which heavily infected and symptomatic animals can be salvaged with antibiotics.

Conclusions: In our study, (1-3), (1-6) β-glucans were highly effective in protecting against a model of naturally acquired P. multocida infection and extended survival times in the supra-physiological model. Enrofloxacin was effective in protecting against supra-physiological infection. We are currently reviewing the use of combined prophylaxis.

No MeSH data available.


Related in: MedlinePlus

Representative photomicrographs of(a, c)lung tissue and(b, d)nasal mucosa from rabbits infected intranasally withP. multocida.(a) Lung from the positive control (untreated) animals showing interstitial inflammatory reaction, and (c) normal lung from the β-glucan treated animals. (b) Nasal mucosa from the positive control (untreated) animals showing epithelial necrosis and intensive heterophil granulocyte infiltration with submucosal edema. (d) Normal nasal mucosa from the β-glucan treated animals. Hematoxylin and eosin stain; magnification, 100×.
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Fig3: Representative photomicrographs of(a, c)lung tissue and(b, d)nasal mucosa from rabbits infected intranasally withP. multocida.(a) Lung from the positive control (untreated) animals showing interstitial inflammatory reaction, and (c) normal lung from the β-glucan treated animals. (b) Nasal mucosa from the positive control (untreated) animals showing epithelial necrosis and intensive heterophil granulocyte infiltration with submucosal edema. (d) Normal nasal mucosa from the β-glucan treated animals. Hematoxylin and eosin stain; magnification, 100×.

Mentions: In the animals exposed to physiological (in.) challenge, autopsy findings were relatively minor (see Additional file 1); nasal mucosa showed epithelial damage and inflammatory infiltration and the lungs were affected by interstitial pneumonia (Figure 3A-B), but macroscopic lesions did not develop. Tissues collected from the control and β-glucan treated groups were healthy and intact (Figure 3C-D). P. multocida was cultured back from all challenged rabbits nasal cavities. In the supra-physiological model (rabbits infected in. and im.), autopsy revealed congested heart accompanied with enlarged and congested blood vessels, necrotic foci in the liver, brown peritoneum, congested friable kidneys, and dark brown spleen. Trachea, lungs, and heart were congested, hyperemic and filled with blood. The lungs showed peribronchitis, severely congested vessels with vasculitis, marked alveolar collapse, diffused interstitial inflammatory reaction and intra-alveolar tissue destruction. Positive control and β-glucan animals showed similar pathology. The enrofloxacin treated group had milder symptoms; interstitial pneumonia and Pasteurella septicaemia occurred but necrotic lesions and macroscopical signs were not seen. P. multocida were cultured back from all inflammatory foci.Figure 3


Alternative treatment of serious and mild Pasteurella multocida infection in New Zealand White rabbits.

Palócz O, Gál J, Clayton P, Dinya Z, Somogyi Z, Juhász C, Csikó G - BMC Vet. Res. (2014)

Representative photomicrographs of(a, c)lung tissue and(b, d)nasal mucosa from rabbits infected intranasally withP. multocida.(a) Lung from the positive control (untreated) animals showing interstitial inflammatory reaction, and (c) normal lung from the β-glucan treated animals. (b) Nasal mucosa from the positive control (untreated) animals showing epithelial necrosis and intensive heterophil granulocyte infiltration with submucosal edema. (d) Normal nasal mucosa from the β-glucan treated animals. Hematoxylin and eosin stain; magnification, 100×.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4248437&req=5

Fig3: Representative photomicrographs of(a, c)lung tissue and(b, d)nasal mucosa from rabbits infected intranasally withP. multocida.(a) Lung from the positive control (untreated) animals showing interstitial inflammatory reaction, and (c) normal lung from the β-glucan treated animals. (b) Nasal mucosa from the positive control (untreated) animals showing epithelial necrosis and intensive heterophil granulocyte infiltration with submucosal edema. (d) Normal nasal mucosa from the β-glucan treated animals. Hematoxylin and eosin stain; magnification, 100×.
Mentions: In the animals exposed to physiological (in.) challenge, autopsy findings were relatively minor (see Additional file 1); nasal mucosa showed epithelial damage and inflammatory infiltration and the lungs were affected by interstitial pneumonia (Figure 3A-B), but macroscopic lesions did not develop. Tissues collected from the control and β-glucan treated groups were healthy and intact (Figure 3C-D). P. multocida was cultured back from all challenged rabbits nasal cavities. In the supra-physiological model (rabbits infected in. and im.), autopsy revealed congested heart accompanied with enlarged and congested blood vessels, necrotic foci in the liver, brown peritoneum, congested friable kidneys, and dark brown spleen. Trachea, lungs, and heart were congested, hyperemic and filled with blood. The lungs showed peribronchitis, severely congested vessels with vasculitis, marked alveolar collapse, diffused interstitial inflammatory reaction and intra-alveolar tissue destruction. Positive control and β-glucan animals showed similar pathology. The enrofloxacin treated group had milder symptoms; interstitial pneumonia and Pasteurella septicaemia occurred but necrotic lesions and macroscopical signs were not seen. P. multocida were cultured back from all inflammatory foci.Figure 3

Bottom Line: Immunisation is only variably effective.Four other groups were inoculated both in. and intramuscularly (im.), representing a supra-physiological challenge, and received either (1-3), (1-6) β-glucans, antibiotic or placebo. β-glucans given prophylactically were highly effective in protecting against physiological (in.) bacterial challenge.They were less effective in protecting against supra-physiological bacterial challenge (in. and im.), although they extended survival times.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology and Toxicology, Faculty of Veterinary Science, Szent István University, István u. 2, Budapest, 1078, Hungary. palocz.orsolya@aotk.szie.hu.

ABSTRACT

Background: Pasteurella multocida causes numerous economically relevant diseases in livestock including rabbits. Immunisation is only variably effective. Prophylactic antibiotics are used in some species but are contra-indicated in rabbits, due to their adverse effects on the rabbit microbiota. There is therefore a substantial need for alternative forms of infection control in rabbits; we investigated the effect of oral β-glucan on P. multocida infection in this species.

Results: Thirthy-five New Zealand White rabbits were randomly divided into five groups of seven animals. Three groups were inoculated with Pasteurella multocida intranasally (in.), a physiologically appropriate challenge which reproduces naturally acquired infection, and received either (1-3), (1-6) β-glucans or placebo. Four other groups were inoculated both in. and intramuscularly (im.), representing a supra-physiological challenge, and received either (1-3), (1-6) β-glucans, antibiotic or placebo. β-glucans given prophylactically were highly effective in protecting against physiological (in.) bacterial challenge. They were less effective in protecting against supra-physiological bacterial challenge (in. and im.), although they extended survival times. This latter finding has practical relevance to breeders as it extends the window in which heavily infected and symptomatic animals can be salvaged with antibiotics.

Conclusions: In our study, (1-3), (1-6) β-glucans were highly effective in protecting against a model of naturally acquired P. multocida infection and extended survival times in the supra-physiological model. Enrofloxacin was effective in protecting against supra-physiological infection. We are currently reviewing the use of combined prophylaxis.

No MeSH data available.


Related in: MedlinePlus