A recently performed study has provided significant
data to clarify the intestinal microbial community diversity and dynamic change
of healthy and S. enteritidis orally infected ducklings.
Performed by a team of researchers from the Avian Disease Research Center at the College of Veterinary Medicine of Sichuan Agricultural University led by Professor Chen AC, the study* used the enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) method to yield valuable insights towards fully understanding the pathogenesis of S. enteritidis infection.
S. enteritidis remains one of the main causes of food-borne illness and as such is considered to be the most important pandemic zoonosis produced under natural conditions. Currently no treatment is used to modify the mortality and disease incidence.
ERIC-PCR bands of orally inoculated ducklings didn't show obvious change until 24 hours post inoculation. The numbers of the ERIC-PCR bands gradually decreased from 24 h to 72 h post inoculation and then, with the development of disease, the band numbers gradually increased to 6 d post inoculation.
The prominent bacteria had changed because of S. enteritidis infection and the DNAstar of the staple of ERIC-PCR showed that aerobe and facultative aerobe (Escherichia coli, Shigella, Salmonella) had become the predominant bacilli in intestine of ducklings orally infected with S. enteritidis.
In the view of the authors, to date no clear explanation has existed to elucidate the effect of orally S. enteritidis infection on intestinal microbial community diversity, and no mechanism has been found to explain this action.
The study used an elegant design which included two groups of ducklings. Ducklings in group 1 were used to perform the experiment. Those in group 2 were used to observe clinical signs and mortality.
Further research should explain the dynamic distribution regular pattern and the primary penetration sites of S. enteritidis.
* Cao SY, Wang MS, Cheng AC, Qi XF, Yang XY, Deng SX, Yin NC, Zhang ZH, Zhou DC, Zhu DK, Luo QH, Chen XY. Comparative analysis of intestinal microbial community diversity between healthy and orally infected ducklings with Salmonella enteritidis by ERIC-PCR. World J Gastroenterol. 2008; 14(7): 1120-1125