OBJECTIVE To explore the occurrence, clinical and drug resistance characteristics of intestinal colonization by carbapenem-resistant Enterobacteriaceae (CRE) in elderly patients, and to provide basis for the clinical diagnosis and treatment, prevention and control of healthcare-associated infection.

METHODS Faeces samples from elderly patients with long-term repeated hospitalization in intensive care unit, oncology, geriatrics departments of Chongzhou people′s hospital were actively screened from Jan. 2023 to Jan. 2024 for CRE strains, which were further analyzed for colonization rate, clinical characteristics and antimicrobial resistance.

RESULTS Totally 53 intestinal colonized CRE strains were isolated from 810 patients with a colonization rate of 6.54%, of which 12 developed subsequent infections. Of the CRE strains, Klebsiella pneumoniae accounted for 54.72%, Escherichia coli 37.74%, Enterobacter cloacae 3.77%, Proteus mirabilis 1.89%, and Citrobacter freundii 1.89%. The CRE causing subsequent infection were mainly K. pneumoniae (58.33%), E. coli (33.33%) and P. mirabilis (8.33%). The drug susceptibility results showed that 53 strains showed similar drug resistance, which were cephalosporins, piperacillin-tazobactam and carbapenem antibiotics resistant in vitro, but were certain sensitive to other antibiotics with the highest to tigecycline. Totally 51 out of 53 CRE strains produced carbapenemase, 56.61% for metallobase, 35.85% for serinase, and 3.77% for both.

CONCLUSION It is suggested that intestinal CRE screening should be strengthened for elderly patients, especially for patients with histories of basic diseases and invasive operations, and effective prevention and control measures should be taken as soon as possible to reduce the cross-transmission and -infection.