The Molecular Epidemiology Of Nosocomial Infection Caused By Carbapenem-resistant Klebsiella Pneumoniaes Isolates Recovered From Hospitalized Patients At A Children's Hospital In China

Objective To investigate the drug resistance phenotype,genotype and homology of carbapenem-resistant Klebsiella pneumoniae isolates recovered from childern or neonates at a children's hospital in China so as to verify if ther is an outbreak of hopital infection caused by these pathogens.Methods From October 2016 to April 2017,total 13 non-duplicate carbapenem-re sistant Klebsiella pneumonia straines were recovered from hospitalized patients at a children's hospital in Jinan,Shandong Province.The identification and antibiotic s usceptibility tests of these isolates were done by using VITEK-2 Compact system.The putative carbapenemases were determined by the imipene E-test strip tests and the modified Hodge test.The antimicrob ial resistance genes encoding the carbape nemases and extended-spectrum-?-lactamases were detected by using PCR and prod uct sequencing.The clonal relatedness of these strains was determined by multiloc us sequence typing?MLST?and pulsed-field gel electrophoresis?PFGE?,and were an alyzed by Dice similarity with BioNumerics?7.6?.Base on the MiSeq and MinION sequencing platform,the mobile elements,resistance genes,and other features of full plasmid sequence were annotated by INTEGRALL,ISfinder,ResFinder,Plasmi dFinder,and the Tn Number Registry online databases.Comparisons of the multipl e and paired sequences were conducted using MUSCLE 3.8.31 and BLASTN,resp ectively.Results These 13 isolates were highly resistant to most of available antibiotics,such as cephalosporins,aminoglycosides and carbapenems.The Hodge tests were positive in all isolates,while the imipenem-EDTA E-tests were negative in them.And all of these isolates carried bla_KPC-2PC-2 gene.Out of 13 K.pneumoniaes,12 were confirmed to belong to the sequence type 11?ST11?,and harbored blaKPC-2,blaCTX-M-65,blaSHV-12 and blaTEM-1B genes,and other one which belong to the sequence type 278?ST278?carried only a bla_KPC-2gene.The PFGE revealed that the eights ST11 K.pneumoniae?H2^H8 and H10?straines were clonally related and that the Dice similarity with BioNumerics were92.8%¹00%among them.Bioinformatics analysis of a plasmid pKPC-QL24 founed in K.pneumoniaes H4 strain indicated that it carirred the rmtB,bla_KPC-2,bla_SHV-12,bla_CTX-M-65and blaTEM-1B genes.Conclusion Our results showed that the clonal spread of carbapenem-resistant Klebsiella pneumonia ST11 haboring the rmtB,bla_KPC-2,bla _SHV-12,bla_CTX-M-65 and bla_TEM-1BEM-1B was the cause of an nosocomial outbreak in this children's hospital.Therefore,it should be pay attention to the monitoring of carbapenem-resistant Klebsiella pneumonias and the rational use of antibiotics.