[Molecular typing of isolates from poultry production chains in four cities of Heilongjiang province].

To study the PFGE type of () strains isolated from poultry production chains (hatching, breeding, slaughter, distribution and retail) of four cities in Heilongjiang province. DNA collected from . strains in 2012 was digested by Ⅰ according to the standard PFGE protocol of US CDC. The PFGE patterns were then analyzed by BioNumerics software. The contamination of . 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 isolates and 55 pulsotypes from 65 isolates showed considerable diversity. The same pulsotypes of can be found between different food chains and cities. In contrast, no identical pulsotypes of were found between different food chain and cities. In these four cities, the above said two kinds of were from different sources. The source of contamination in HLJ2 city had been traced back to the chain of poultry hatching. The distribution of pulsetypes of the and 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.