Clonal dissemination of KPC-2-producing Klebsiella pneumoniae ST11 and ST48 clone among multiple departments in a tertiary teaching hospital in Jiangsu Province, China

Abstract

Background: The world-wide prevalence of carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a threat to the public health. The objective of this study was to determine the epidemiological and molecular patterns of KPC-producing Klebsiella pneumoniae (K. pneumoniae) clinical isolates.

Methods: In this study, a total of 82 non-duplicated CRKP isolates were analyzed for the prevalence of resistant determinants including carbapenemase, extended spectrum β-lactamase (ESBLs), and AmpC as well as integrons and cassette regions by polymerase chain reaction (PCR) and DNA sequencing. The genetic relatedness was investigated by pulsed field gel electrophoresis (PFGE) and multi-locus sequencing typing (MLST).

Results: Overall, bla _KPC-2 (n=75) was the predominant carbapenemase gene, followed by high prevalence of bla _SHV (92.7%) and bla _CTX-M (90.2%). PFGE and MLST analysis revealed that 65 out of 68 KPC-2-producing CRKP belonged to the ST11 clone and were distributed mainly in the department of neurology ICU. Moreover, first report on clonal dissemination of KPC-2-producing CRKP ST48 clone and NDM-5-producing CRKP ST337 clone was also identified. Class I integron were detected in 17 (20.7%) of 82 isolates with aadA2 being the most common cassette. And a novel cassette array of integron, aac(6')-II-bla _CARB/PSE-1 was identified.

Conclusions: All in all, KPC-2-producing CRKP ST11 and ST48 clone were widely disseminated in multiple departments of our hospital, which triggers the need for active surveillance and implementation of infection control measures.

Keywords: Carbapenemases; KPC-2; Klebsiella pneumoniae (K. pneumoniae); NDM-5; clonal dissemination.

Figure 1

Dendrogram of PFGE profiles of XbaI-digested DNA restriction fragments from 68 carbapenem-resistant Klebsiella pneumoniae ST11 isolates. The UPGMA algorithm was performed to conduct dendrogram based on the Dice similarity coefficient. Isolates were categorized to be of the same cluster when their dice similarity index was ≥80%. NRICU, neurology ICU; EGICU, emergency ICU; NS, neurosurgery; CMICU, critical care medicine ICU; NR, neurology; RA, respiratory; UL, urology; BMTC, bone marrow transplantation center; GT, gastroenterology; OT, otolaryngology; OL, oncology; OR, orthopaedics; GA, geriatrics.

Figure 2

Dendrogram of PFGE profiles of XbaI-digested DNA restriction fragments from 14 carbapenem-resistant Klebsiella pneumoniae non-ST 11 isolates. The UPGMA algorithm was performed to conduct dendrogram based on the Dice similarity coefficient. Isolates were categorized to be of the same cluster when their dice similarity index was ≥80%. NRICU, neurology ICU; EGICU, emergency ICU; CMICU, critical care medicine ICU; NICU, neonatal ICU; NS, neurosurgery; GA, geriatrics, NR, neurology; CD, cardiology.