Molecular typing of Salmonella isolates from poultry production chains in four cities of Heilongjiang province / 中华流行病学杂志

ABSTRACT

Objective To study the PFGE type of Salmonella (S.) strains isolated from poultry production chains (hatching,breeding,slaughter,distribution and retail) of four cities in Heilongjiang province.Methods DNA collected from S.strains in 2012 was digested by Xba Ⅰ according to the standard PFGE protocol of US CDC.The PFGE patterns were then analyzed by BioNumerics software.Results The contamination of S.appeared most serious during the process of slaughtering (13.84％).PFGE was used to determine the genetic relationships between these isolates from poultry production chains,89 pulsotypes from 150 S.enteritidis isolates and 55 pulsotypes from 65 S.indiana isolates showed considerable diversity.The same pulsotypes ofS.enteritidis can be found between different food chains and cities.In contrast,no identical pulsotypes of S.indiana were found between different food chain and cities.In these four cities,the above said two kinds of S.were from different sources.The source of S.contamination in HLJ2 city had been traced back to the chain of poultry hatching.Conclusions The distribution of pulsetypes of the S.enteritidis and S.indiana isolates was from different regions and the dominant bands were also different between the chains of poultry production.Cross contamination existed in slaughterhouses and contamination can be traced back to the poultry hatching.