Diversity of hypervirulent Klebsiella pneumoniae clones causing cryptogenic liver abscesses and metastatic complications in Argentina.

Abstract

Cryptogenic liver abscesses (CLA) caused by hypervirulent Klebsiella pneumoniae (hvKP) strains are emerging in western countries. The aim of the study was to describe the clinical characteristics of patients from Argentina with hvKP-related CLA and the analysis of isolated strains. A retrospective chart review of 15 patients hospitalized in 8 hospitals of Argentina between October 2015 and November 2018 was performed. PCR for genes associated with capsular and multilocus sequence (MLST) determination and virulence factors were done in 8 hvKP isolates from these patients. We found that the mean age was 60 years and 73% were men; 40% had diabetes. Sixty percent had bacteremia and 73% had ≥1 metastatic foci of infection. There was no in-hospital death but 2 patients with endophthalmitis required eye enucleation. From the 8 studied isolates, 4 belonged to K1 and 4 to K2 serotypes, the rpmA and iroB genes were present in all of them, and 7 and 5 also harbored the iucA and the rmpA2 gene, respectively. MSLT analysis showed that most of the K1 serotypes belonged to ST23 while a diverse MLST pattern was seen with K2 strains. In addition, the four hvKP strains associated to metastatic complications, belonging to three distinct sequence types, were positive to the rpmA, iroB and iuc virulence genes. We could show an important morbidity associated with this syndrome in Argentina, a significant diversity in the hvKP clones causing CLA in Argentina, and the potential utility of the rpmA and iroB genes as predictors of virulence.