Author
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Ziprin, Richard |
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Kubena, Leon |
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Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 7/24/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: It has been reported that up to sixty percent of the crops of market age birds contain Campylobacter. However, this number may not represent true colonization but only transient presence of the organism. In our present studies we have studied colonization of crops in newly hatched chicks by wild-type and mutant strains of C. jejuni. Groups of 15 day-of-hatch Leghorn chicks were orally gavaged with 10**8 CFUs of the wild-type strain on day-of-hatch or with an equivalent number of mutant C. jejuni, which had been previously shown to be ineffective colonizers of the cecum. Three birds from each challenged group were killed by cervical dislocation on days 1, 3, 5, 7, and 9 after inoculation. There was a 2-4 hour feed withdrawal period before sacrifice, then crops were aseptically removed placed in individual plastic bags containing 5 ml of sterile water, and placed in a Stomacher device. The C. jejuni concentration in the resultant suspension was determined by standard plate count methods, using Campy-Cefex agar. We observed an initial rapid drop in Campylobacter concentrations present in the crop during the first 24 hrs after challenge, then a stable concentration of approximately 10**5 CFUs was established through days 7 to 9. Mutant strains lacking an ability to colonize cecum were found to persist in the crop. Concentrations of these mutant strains in the crop, were usually below that of the wild-type but were still between 10**3 to 10**5 CFUs. These results indicate that the bacterial factors necessary for colonization of the crop are not the same as those needed for colonization of the cecum. |
