The face of hypervirulent Klebsiella pneumoniae isolated from clinical samples of two Iranian teaching hospitals

Rahimeh Sanikhani,Azar Hadadi,Hamid Solgi,Fereshteh Shahcheraghi,Mohammad Moeinirad,Farzad Badmasti

doi:10.1186/s12941-021-00467-2

Abstract

Hypervirulent Klebsiella pneumoniae (hvKp) has emerged as a pathogen of global concern. In this study, both phenotypic and genotypic tests were used to detect hvKp. Antimicrobial resistance profiles and clonal relatedness of clinical isolates were also determined. We found that 34.2% (163/477) of the isolates were tellurite resistant, and among them 102 hvKp isolates detected with iucA or iutA or peg-344 as molecular markers. The blaSHV (80.4%), followed by blaCTX-M-15 (76.5%) and blaTEM (67.6%), blaOXA-48 (53.9%), and blaNDM-1 (32.3%) were detected, while blaKPC-1 was not present in any hvKp isolates. It was found that the majority of hvKp isolates belonged to capsular serotype K20 and ompK36 group C, which is related to clonal group (CG) 23 (e.g. ST23). A high percentage of multidrug-resistant hvKp (76.6%) and high resistance to imipenem (67%) indicated a serious problem that should be addressed in the clinical setting.

Highlights

Hypervirulent Klebsiella pneumoniae, an emerging pathotype of K. pneumoniae was first reported from Taiwan
Phenotypic tests In this study, 163 (34.2%) out of 477K. pneumoniae isolates were able to grow on tellurite-containing MH medium and were considered tellurite-resistant strains, so they were selected for the molecular identification test
Molecular identification of Hypervirulent Klebsiella pneumoniae (hvKp) Based on molecular identification, we found the iucA or iutA or peg-344 as hvKp molecular markers in 21.4% (102/477) of total K. pneumoniae and 62.6% (102/163) of tellurite-resistant isolates

Summary

Introduction

Hypervirulent Klebsiella pneumoniae (hvKp), an emerging pathotype of K. pneumoniae was first reported from Taiwan. It was identified as an important cause of pyogenic liver abscess [1, 2]. In hvKp isolates, pLVPK-like plasmids (Large Virulence Plasmid of K. pneumoniae) encoding virulence factor genes including capsular polysaccharide synthesis regulators (rmpA and rmpA2) and iron acquisition systems (iucA, iutA, and iro siderophore gene cluster), a metabolic transporter (peg-344) and heavy metal resistance genes (copper, silver, lead, and tellurite), have been identified [3, 4]. In addition to phenotypic methods, the presence of different virulence genes has been studied to increase the sensitivity and accuracy of hvKps identification. The genes of iucA, iutA, and peg-344 have been introduced as the best genetic diagnostic markers with the highest accuracy [18]

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