Objective: To analyze the sequence characteristics of the serogroup 1 Legionella pneumophila (Lp1) strains isolated from the cooling tower water in Zhejiang province by sequence-based typing (SBT).
Methods: 61 strains of Lp1 isolated from cooling tower water in ten cities of Zhejiang Province from 2005 to 2011 were genotyped by SBT method. The nucleotide polymorphism of the sequencing results was analyzed by DnaSP 5.0, and the SBT results were cluster analyzed using SplitsTree and eBURST software.
Results: All 61 isolates of Lp1 were resolved into 11 STs, and 5 new STs were found in this study. The ST with the largest number of isolates was ST1 (n=50), and these ST-1 strains were found in 10 cities. The nucleotide polymorphism (Pi) of these seven housekeeping genes ranged from 0.01095 (mip) to 0.05355 (pilE). The STs of the Lpl isolates were clustered to four clonal complexes (CC), and ST-1, ST-149, ST-154 were the three main clonal complexes (CC).
Conclusion: Genetic diversity was shown in the serogroup 1 Legionella pneumophila strains isolated from cooling tower water in Zhejiang province.