Clinical Molecular Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae Among Pediatric Patients in Jiangsu Province, China

Abstract

Purpose: The continuous emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a serious public health problem globally, especially for children, but data on CRKP infection in pediatric patients are limited. This study aimed to identify epidemiological and molecular patterns of CRKP among pediatric patients in Jiangsu province, China.

Patients and methods: CRKP were consecutively collected from the Children's Hospital of Nanjing Medical University in China from July 2018 to May 2019. Then, CRKP strains were performed for further study: antimicrobial susceptibility testing, drug-resistance determinants screening and homology analysis.

Results: We collected 94 CRKP from 94 children. Overall, bla _KPC-2 (79.8%) was the predominant carbapenemase gene, followed by bla _NDM-1(14.9%), bla _IMP-4 (5.3%) and bla _NDM-5(4.3%). Notably, two isolates coharbored bla _KPC-2 and bla _IMP-4, and two isolates coharbored bla _KPC-2 and bla _NDM-5. MLST analysis revealed that 14 distinct sequence types (STs) were identified, of which ST11 was the most common sequence type identified. Moreover, two novel STs, ST4854 and ST4855, were detected in this study. PFGE revealed that a predominant cluster consisting of KPC-2-producing CRKP ST11 clone isolates was identified and was distributed mainly in the pediatric intensive care unit (PICU) and cardiac intensive care unit (CCU). Moreover, this is the first report to identify the dissemination of ST716 CRKP coproducing KPC-2 and IMP-4 clones.

Conclusion: Clonal dissemination of KPC-2-producing CRKP ST11 was observed in multiple departments. Moreover, two novel STs (ST4854 and ST4855) were identified, which indicates an increased diversity of CRKP strains. To our knowledge, this is the first report that identified the dissemination of Klebsiella pneumoniae coproducing KPC-2 and IMP-4 clones among children, which represents a significant health risk to pediatric patients. Active surveillance and effective control measures are urgently needed to prevent further transmission of these strains among children.

Keywords: KPC-2; Klebsiella pneumoniae; ST11; carbapenemase; children; clonal dissemination.

Figure 1

Minimum spanning trees of 94 CRKP isolates. Each node represents a single ST. The size of the nodes was proportional to the number of strains within the represent ST. The color distribution represents distribution of carbapenemase genes among different STs.

Figure 2

Dendrogram of PFGE profiles of 71 CRKP ST11 isolates. The UPGMA algorithm was performed to construct a dendrogram based on the dice similarity coefficient. Strains were classified as the same clone cluster when their dice similarity index was ≥80%.

Figure 3

Dendrogram of PFGE profiles of 23 CRKP non-ST11 strains. The UPGMA algorithm was performed to construct dendrogram based on the dice similarity coefficient. Strains were classified as the same clone cluster when their dice similarity index was ≥80%.