Résumé
The aim of the research is to investigate the genetic characteristics of Legionella pneumophila serogroup1 (LP1)in Sichuan Province.The sequence-based typing (SBT) and multiple-locus VNTR analysis (MLVA) were used to describe the genetic polymorphism of 42 strains which were isolated from 1989-2016 in Sichuan Province,China.According to the reference,PCR was used to detect the 8-VNTR loci and 7 housekeeping genes respectively.The VNTR results were determined by using capillary electrophoresis,and the SBT results were sequenced and compared with the database of EWGLI.Results showed that totally 42 stains were divided into 8 MLVA types with the advantage types were M08 (47.6 ％) and M07 (23.8 ％).Twelve ST types were obtained with 3 main clonal complex and 2 singleton,including 2 novel ST types,among those,ST1 was the predominant type,accounting for 52.3 ％,following by ST630 (14.2 ％).In conclusion,our results demonstrated MLVA and SBT were both applied to the research for molecular epidemiological investigation of LP1 and showed the high genetic polymorphism and the regional specificity.The results also suggest that the isolates are a potential threat to the public,effective control and prevention strategies are urgently needed.
Résumé
The aim of the research is to investigate the genetic characteristics of Legionella pneumophila serogroup1 (LP1)in Sichuan Province.The sequence-based typing (SBT) and multiple-locus VNTR analysis (MLVA) were used to describe the genetic polymorphism of 42 strains which were isolated from 1989-2016 in Sichuan Province,China.According to the reference,PCR was used to detect the 8-VNTR loci and 7 housekeeping genes respectively.The VNTR results were determined by using capillary electrophoresis,and the SBT results were sequenced and compared with the database of EWGLI.Results showed that totally 42 stains were divided into 8 MLVA types with the advantage types were M08 (47.6 ％) and M07 (23.8 ％).Twelve ST types were obtained with 3 main clonal complex and 2 singleton,including 2 novel ST types,among those,ST1 was the predominant type,accounting for 52.3 ％,following by ST630 (14.2 ％).In conclusion,our results demonstrated MLVA and SBT were both applied to the research for molecular epidemiological investigation of LP1 and showed the high genetic polymorphism and the regional specificity.The results also suggest that the isolates are a potential threat to the public,effective control and prevention strategies are urgently needed.