|Nisbet, David - Dave|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/24/2003
Publication Date: 6/20/2003
Citation: Hume, M.E., Kubena, L.F., Edrington, T.S., Donskey, C.J., Moore, R.W., Ricke, S.C., Nisbet, D.J. 2003. Poultry digestive microflora biodiversity as indicated by denaturing gradient gel electrophoresis. Poultry Science. 82:1100-1107. Interpretive Summary: The types of intestinal bacteria present in chickens change as the chickens age and are affected by diet, stresses, and chemicals in the feed used to enhance growth. Traditional techniques for growing bacteria isolate all the bacteria present. Several DNA-based techniques have been developed, which rely on the use of DNA extracted from all the bacteria present in a sample. The DNA-based technique denaturing gradient gel electrophoresis (DGGE) was used in the present study to examine bacterial populations in the chicken intestine. The objective of the study was to examine changes in intestinal bacteria of different groups of chickens as they aged, feed withholding, and young chickens given chemicals in the feed to improve growth. Bacterial populations were shown to be affected by all of these parameters. Results indicated the usefulness of the DNA-based DGGE to detect changes and differences in intestinal bacterial populations in chickens.
Technical Abstract: Populations of digestive microflora in chickens change with age and are affected by diet, stresses, and performance enhancers. Culturing techniques used to profile a bacterial community may inadvertently select for some organisms, while excluding others. Several molecular-based techniques have been used to profile mixed microbial populations on the basis of DNA extracted from the entire community. Denaturing gradient gel electrophoresis was used in the present study to examine PCR-amplified fragments (amplicons) of a 16S ribosomal DNA variable region from predominant digestive bacteria. The objective of the study was to examine changes in digestive microbial communities of developing Leghorn chicks, molted Leghorn hens, and young broilers given a performance enhancer in feed; some groups were given a commercial competitive exclusion culture. Dendrograms of amplicon patterns indicated approximately 51% similarity correlation between Leghorn chicks less than 20 days old and chicks greater than 20 days old. Cecal communities in Leghorn chicks given competitive exclusion culture exhibited 21% correlation at all ages with those in control chicks. Non-molted and molted hens had 40% correlation between cecal communities, while diets with low calcium (0.8% (w/w) and excess zinc (2,800 mg/kg) had decreased population differences (90% correlation). The performance enhancer had a greater effect on broiler chicks at 10 days of age (56% and 73% correlation in two replicates of control vs. treated chicks) than in chicks at 3 days old (greater than 88% correlation). Results indicated the potential usefulness of the molecular-based DGGE to monitor changes and differences in digestive bacterial communities in chickens.