Epidemiology and genotypic characteristics of carbapenem resistant Enterobacterales in Henan, China: a multicentre study

Abstract

Objectives: To identify the carbapenemase and colistin resistance genes and epidemiological status of carbapenem-resistant Enterobacterales (CRE) among 7 secondary and 11 tertiary hospitals in Henan province, China.

Methods: CRE isolates and clinical data of infected patients were collected from 7 secondary and 11 tertiary hospitals in Henan from July to September 2019 and analysed retrospectively. Polymerase chain reaction (PCR) and gene sequencing were performed to detect carbapenemase and colistin resistance genes; multilocus sequence typing was also performed.

Results: In total, 238 nonduplicate CRE isolates were collected mainly from the respiratory tract (54.20%) and blood (18.91%) of CRE-infected patients, half of them aged >65 years (45.80%). Carbapenem-resistant Klebsiella pneumoniae (CRKP) was the most common CRE (184 isolates, 77.31%) with constituent ratios of 84.38% and 72.54% in secondary and tertiary hospitals, respectively. In 184 CRKP isolates, bla_KPC-2 (89.13%) was the dominant carbapenemase gene, and ST11 (71.74%) was the most prevalent sequence type (ST), with constituent ratios of 83.95% and 62.14% in secondary and tertiary hospitals, respectively. In 29 carbapenem-resistant Escherichia coli (CREC) isolates, bla_NDM-5 (58.62%) and ST2 (31.03%) were prevalent. Four CRKP isolates and one CREC isolate were colistin-resistant and carried the plasmid-mediated mcr-1 gene.

Conclusion: Our results showed a wide spread of CRKP-ST11 with KPC-2 carbapenemase in the analysed 18 hospitals. The CRKP constituent ratio, CRKP-STs, and CREC carbapenemase genes between secondary and tertiary hospitals showed significant differences. The emergence of a colistin-resistant CRKP with plasmid-mediated resistance gene mcr-1 is of serious concern due to the limited treatment options.

Keywords: Carbapenemase; Colistin resistance; Enterobacterales; KPC-2; ST11; mcr-1.