Emergence of hypervirulent Klebsiella pneumoniae isolates from some Iraqi hospitals

Hypervirulent Klebsiella pneumoniae (hvKp) is an emerging pathotype, which first appeared in Asian Pacific Rim but spread globally. This pathotype usually causes the acquired community infections, which infect healthy individuals. The infections by hvKp pathotype affect multiple sites or subsequently metastatically spreads, which required an urgent source control. The hvKp pathotype strains have increased their ability to infect endophthalmitis and central nervous system. Therefore, the rapid treatment is required to control these infections. This study aimed to detect hvKp in some of Iraqi hospitals and confirm the emergence of this pathotype. One hundred isolates of K. pneumoniae were collected during this study over the period from October 2021 to January 2022. Primary identification of these hvKp isolates was done by string and tellurite resistant tests. Later, the isolates that were positive for both string and tellurite tests (33%) were selected for molecular identification of this pathotype and siderophore production test. Two out of 33 of selected isolates (5.8%) were identified as hvKp in this study. These isolates contain four or five of suggested gene biomarkers borne on virulence plasmid (peg-344, iroB, iucA, prmpA, and prmpA2) to detect hvKp isolates. Furthermore, 19 isolates (57.57%) had one or more of these genes, which suggested that they have the potential to be hvKp. Out of 33 isolates, 17 isolates showed a PCR product for iucA gene (belongs to iuc operon encoding aerobactin) selected for siderophore production test. Two methods were used to measure production of siderophore. Most of the tested isolates showed a high level of siderophore production but hvKp isolate, which was positive for iucA and iroB showed the highest siderophore production.