To analyze and compare the drug resistance and molecular epidemiological characteristics of carbapenem resistant Klebsiella pneumoniae (CRKP) infection in pediatric and adult hospitalized patients.

Twenty-eight CRKP strains from pediatric ward and 58 CRKP strains from respiratory intermediate care unit (RICU) and emergency intensive care unit (EICU) were collected in the Peking University International Hospital from January 2015 to April 2018. VITEK 2 Compact automatic bacterial identification instrument, Kirby-Bauer method, and agar diffusion gradient method were used for identification and drug sensitivity test. WHONET 5.6 was used for data analysis; and modified carbapenem inactivation method was used to detect carbapenemase; multilocus sequence typing (MLST) was used for molecular genetic analysis of CRKP; repetitive element palindromic-polymerase chain reaction (REP-PCR) was used to analyze homology; polymerase chain reaction (PCR) amplification was used to detect the five drug resistance genes including KPC, NDM, IMP, OXA-48, and VIM.

The drug susceptibility results showed that 86 strains of CRKP were all multi-drug resistant. There were great differences in the drug resistance rates of quinolones, amikacin, furantoin and tobramycin in the department of pediatrics, EICU and RICU. KPC-2 (15/28) was the dominant gene in the strains from pediatric department, and 98.2% (57/58) of CRKP strains from department of EICU and RICU carried KPC-2 gene. Eighty-six strains of CRKP were classified into 7 types of STs by MLST. The types of STs from pediatric department were scattered, with ST11 (57.1%, 16/28) as the main type; while the ST11 (100%) was the only one STs type in EICU and RICU department. In this study, 7 types were found by REP-PCR homology analysis, the most common type was type A, and the types identified by REP-PCR in pediatric department were diverse; only one type was found in RICU and EICU.

There is a difference in the resistance rate of CRKP strains to certain drugs between pediatric department and adult wards. Most of CRKP strains in the study are ST11 type carrying KPC-2. Different from the adult intensive care unit, there are certain genetic polymorphisms among pediatric CRKP strains.

Klebsiella pneumoniae; Carbapenem resistance; Pediatrics; Respiratory intensive care unit; Emergency intensive care unit