Active Surveillance for Carbapenem-Resistant Enterobacterales (CRE) Colonization and Clinical Course of CRE Colonization among Hospitalized Patients at a University Hospital in Thailand

Development of a risk prediction model for subsequent infection after colonization with carbapenem-resistant Enterobacterales: a retrospective cohort study

BACKGROUND

Colonization of carbapenem-resistant Enterobacterale (CRE) is considered as one of vital preconditions for infection, with corresponding high morbidity and mortality. It is important to construct a reliable prediction model for those CRE carriers with high risk of infection.

METHODS

A retrospective cohort study was conducted in two Chinese tertiary hospitals for patients with CRE colonization from 2011 to 2021. Univariable analysis and the Fine-Gray sub-distribution hazard model were utilized to identify potential predictors for CRE-colonized infection, while death was the competing event. A nomogram was established to predict 30-day and 60-day risk of CRE-colonized infection.

RESULTS

879 eligible patients were enrolled in our study and divided into training (n = 761) and validation (n = 118) group, respectively. There were 196 (25.8%) patients suffered from subsequent CRE infection. The median duration of subsequent infection after identification of CRE colonization was 20 (interquartile range [IQR], 14-32) days. Multisite colonization, polymicrobial colonization, catheterization and receiving albumin after colonization, concomitant respiratory diseases, receiving carbapenems and antimicrobial combination therapy before CRE colonization within 90 days were included in final model. Model discrimination and calibration were acceptable for predicting the probability of 60-day CRE-colonized infection in both training (area under the curve [AUC], 74.7) and validation dataset (AUC, 81.1). Decision-curve analysis revealed a significantly better net benefit in current model. Our prediction model is freely available online at https://ken-zheng.shinyapps.io/PredictingModelofCREcolonizedInfection/ .

CONCLUSIONS

Our nomogram has a good predictive performance and could contribute to early identification of CRE carriers with a high-risk of subsequent infection, although external validation would be required.

Prevalence of intestinal colonization and nosocomial infection with carbapenem-resistant Enterobacteriales in children: a retrospective study

Objective

We investigated the epidemiological surveillance of the intestinal colonization and nosocomial infection of carbapenem-resistant Enterobacteriales (CRE) isolates from inpatients, which can provide the basis for developing effective prevention.

Methods

A total of 96 CRE strains were collected from 1,487 fecal samples of hospitalized children between January 2016 and June 2017, which were defined as the "CRE colonization" group. In total, 70 CRE clinical isolates were also randomly selected for the comparison analysis and defined as the "CRE infection" group. The antimicrobial susceptibility of all strains was determined by the microdilution broth method. Polymerase chain reaction (PCR) was used to analyze carbapenemase genes, plasmid typing, and integrons. Multilocus sequence typing was further used to determine clonal relatedness.

Results

In the "CRE colonization" group, Klebsiella pneumoniae was mostly detected with a rate of 42.7% (41/96), followed by Escherichia coli (34.4%, 33/96) and Enterobacter cloacae (15.6%, 15/96). The ST11 KPC-2 producer, ST8 NDM-5 producer, and ST45 NDM-1 producer were commonly present in carbapenem-resistant K. pneumoniae (CRKPN), carbapenem-resistant E. coli (CRECO), and carbapenem-resistant E. cloacae (CRECL) isolates, respectively. In the "CRE infection" group, 70% (49/70) of strains were K. pneumoniae, with 21.4% E. cloacae (15/70) and 5.7% E. coli (4/70). The ST15 OXA-232 producer and ST48 NDM-5 producer were frequently observed in CRKPN isolates, while the majority of NDM-1-producing CRECL isolates were assigned as ST45. Phylogenetic analysis showed that partial CRE isolates from intestinal colonization and nosocomial infection were closely related, especially for ST11 KPC-2-producing CRKPN and ST45 NDM-1-producing CRECL. Furthermore, plasmid typing demonstrated that IncF and IncFIB were the most prevalent plasmids in KPC-2 producers, while IncX3/IncX2 and ColE were widely spread in NDM producer and OXA-232 producer, respectively. Then, class 1 integron intergrase intI1 was positive in 74.0% (71/96) of the "CRE colonization" group and 52.9% (37/70) of the "CRE infection" group.

Conclusion

This study revealed that CRE strains from intestinal colonization and nosocomial infection showed a partial correlation in the prevalence of CRE, especially for ST11 KPC-2-producing CRKPN and ST45 NDM-1-producing CRECL. Therefore, before admission, long-term active screening of rectal colonization of CRE isolates should be emphasized.