OBJECTIVE To analyze the distribution and clinical characteristics of carbapenem-resistant organisms (CRO) in the intestinal and respiratory tracts of high-risk ICU patients, and to evaluate the effectiveness of two screening methods: plate screening and Gene Xpert Carba (hereinafter referred to as Xpert Carba).

METHODS Intestinal samples (anal swabs, feces) and respiratory samples (sputum, lavage fluid) from 320 patients admitted to the ICU ward of the Fourth Affiliated Hospital of Soochow University from Apr.2023 to Dec.2024 were collected.Plate screening and Xpert Carba methods were used for active screening of CRO strains, and clinical data of patients were collected through electronic medical records.

RESULTS The plate screening results indicated that 70 out of 573 samples from 320 patients tested positive for CRO, with a positive rate of 12.22%(70/573).The positive rates for anal swabs, feces, sputum and lavage fluid were 9.26%(20/216), 10.39%(8/77), 13.02%(22/169) and 18.02%(20/111), respectively.There was no statistically significant difference in the positive rates among different sample types.The predominant CRO-positive organisms detected were Klebsiella pneumoniae in intestinal samples and Pseudomonas aeruginosa in respiratory samples.Among 361 intestinal and respiratory samples tested from 88 patients, plate screening and Xpert Carba screening showed the positive rates of 14.40%(52/361) and 6.37%(23/361), respectively.Analysis of the clinical characteristics of the 31 CRO-positive patients revealed that they were predominantly elderly (average age 69 years), with 51.61%(16/31) having a history of interdepartmental transfers and 48.39%(15/31) having surgerical history.The mechanical ventilation usage rate in the respiratory positive group (58.82%, 10/17) was higher than that in the intestinal positive group (0, 0/7) and the dual positive group (14.28%, 1/7).Compared with Xpert Carba, plate screening had lower screening costs, higher positive rates across different sample types and a broader range of detected bacterial species.

CONCLUSIONS The ICU ward is a high-prevalence area for CRO strains, with K.pneumoniae(from intestinal samples) and P.aeruginosa(from respiratory samples) showing the highest isolation rates.Plate screening boasts lower costs, higher detection rate and broader bacterial species coverage for active screening of CRO strains in the intestinal and respiratory tracts of high-risk ICU patients.