Prevalence of pks genotoxin among hospital-acquired Klebsiella pneumoniae

Abstract

The pks genotoxic K. pneumoniae has recently triggered a widespread alarm. DNA damage and higher virulence have been linked to colibactin, a genotoxin expressed by the pks genomic island. Little is known about its molecular epidemiology in clinical isolates from Egypt. Therefore, this study was conducted to determine the prevalence and the microbiological and clinical features of pks harboring hospital-acquired K. pneumoniae isolates from Egypt. Eighty-seven hospital-acquired K. pneumoniae isolates from various specimen types were screened for pks colibactin island markers clbB, clbQ, clbA, and clbN by PCR. The pks-positive hvKp isolates were classified to one of the capsular types K1 and K2 using multiplex-PCR targeting K-serotype wzi and rmpA genes. The prevalence of pks+ strains was 27.6% (24/87). K1 capsular type, phenotypic, and genotypic hypervirulent isolates were significantly higher among pks+ strains than pks− strains (P < 0.001), while pks+ K. pneumoniae strains were found to be significantly less resistant to 8 of the antibiotic compounds tested than pks− strains. Carriage of K1 capsular type and mucoviscosity-associated rmp A gene and diabetes mellitus were identified to remain independent risk factors having a substantial association to pks-positivity by multivariate regression analysis. In conclusion, Hospital-acquired K. pneumoniae isolates in Egypt had an increased prevalence of the pks colibactin genotoxin. The significant occurrence of hypervirulent determinants in pks+ K. pneumoniae highlighted the genotoxin's possible pathogenicity combined with its distribution in several specimen types, which necessitates clinical attention and epidemic tracking.