Genetic and Functional Analysis of the pks Gene in Clinical Klebsiella pneumoniae Isolates.

The gene cluster encodes colibactin, which can cause DNA damage and enhance the virulence in Escherichia coli. However, the role of the gene in Klebsiella pneumoniae has not been fully discussed. The aim of this study was to analyze the relationship between the gene cluster and virulence factors, as well as to assess antibiotic resistance and biofilm formation capacity in clinical isolates of Klebsiella pneumoniae. Thirty-eight of 95 clinical K. pneumoniae strains were positive. -positive strains usually infected emergency department patients, and -negative strains often infected hospitalized patients. The positive rates of K1 capsular serotype and hypervirulence genes (, , , , and ) were significantly higher in the -positive isolates than the -negative isolates ( < 0.05). The biofilm formation ability of -positive isolates was stronger than that of -negative isolates. Antibacterial drug susceptibility test showed the resistance of -positive isolates was weaker than that of -negative isolates. In conclusion, patients with -positive K. pneumoniae infection might have worse treatment outcomes and prognosis. -positive K. pneumoniae might have stronger virulence and pathogenicity. Clinical infection with -positive K. pneumoniae needs further attention. The infection rate with -positive K. pneumoniae has been increasing in recent years. Two previous surveys in Taiwan reported 25.6% gene islands and 16.7% -positive K. pneumoniae strains in bloodstream infections, and Chinese scholars also did a survey of K. pneumoniae bloodstream infections in Changsha, China, and found 26.8% -positive K. pneumoniae. In addition, it was found that the gene cluster might encode colibactin, which could be related to the virulence of K. pneumoniae. Studies confirmed that the prevalence of colibactin-producing K. pneumoniae was increasing. It is necessary to consider the clear relationship between the gene cluster and high pathogenicity in K. pneumoniae.