Transmission characteristics of drug-resistant bacteria in ICU environment based on metagenomic sequencing technology

OBJECTIVE To explore the application value of metagenomic next-generation sequencing (mNGS) in monitoring drug-resistant bacteria in environment of 3 intensive care units(ICUs), reveal the transmission characteristics of drug-resistant bacteria and provide a basis for optimizing infection control.

METHODS Object surface and air samples were selected from the surgical intensive care unit (SICU), emergency intensive care unit (EICU) and neurology intensive care unit (NICU) of a three-A general hospital. Combined with conventional culture and mNGS technology, the distribution of microbial communities, resistance genes and virulence factors were analyzed, and the transmission pathways were explored through phylogenetic tree and redundancy analysis (RDA).

RESULTS The culture results showed that drug-resistant bacteria were detected on the object surfaces of 3 ICUs, mainly including Acinetobacter spp. carrying OXA-23 carbapenemase, Enterobacteriaceae carrying KPC carbapenemase and Pseudomonas spp.. Only NICU detected drug-resistant bacteria in the air samples, mainly linezolid-resistant Staphylococcus spp.. mNGS revealed the presence of complex bacterial communities in the environment, with object surface samples in NICU exhibiting the highest diversity and detecting IC2 type Acinetobacter baumannii consistent with global prevalence. RDA showed significant differences in the object surface and air sample communities across different ICUs. Analysis of resistance genes and virulence genes showed that object surface samples in SICU carried multiple β-lactamase genes and iron uptake related virulence genes, while samples in NICU were enriched with virulence genes related to the synthesis of A. baumannii pili. Only NICU detected drug-resistant bacteria carrying bla_OXA, bla_KPC and bla_SHV in the air sample.

CONCLUSIONS mNGS can accurately identify the distribution characteristics of drug resistance strains from ICU environment and their association with potential transmission, which is complementary to the conventional culture method. Its application helps establish an active monitoring system for drug-resistant bacteria in ICU environment, and improve the accuracy and timeliness of hospital-associated infection prevention and control.