Study on chicken Shigella Boydii by random amplified polymorphic DNA

【Objective】 The evolutionary position of chicken Shigella boydii was determined.【Method】 The genetic diversity among strains of chicken Shigella boydii,S.Pullorum,Enteroinvasive E.coli and Shigella Dysenteriae was studied by random amplified polymorphic DNA(RAPD) with 6 random primers,and some special PCR products were cloned and sequenced,Further evolutionary relationships among chicken Shigella boydii and other related strains were examined based on sequences.【Result】 Four efficient primers were selected from six 10 bp random primers.64 RAPD bands were identified and 3 of them were common in all three species tested and 61 of them were polymorphic between any two strains.The percentage of polymorphism was 95.3%.The primer P2 could be used to differentiate chicken Shigella boydii and S.Pullo-rum from four bacterial strains.The result showed that the common rate of the amplified bands between Shigella boydii and Shigella dysenteriae was 66.7%,Shigella boydii and Enteroinvasive E.coli was 44.4%,but the amplified bands produced by Shigella and S.Pullorum was much different from each other when primer P6 was used,so the primer p6 could be used to differentiate the three species.The results for sequenced PCR products and examined evolutionary relationships showed that the chicken Shigella boydii may be a new species or subspecies from human.【Conclusion】 The chicken Shigella boydii may be a new species or subspecies from human.