Abundance of antibiotic-resistant bacteria and resistance genes in hospital environment

OBJECTIVE To analyze the types, distribution and dissemination of antibiotic-resistant bacteria and resistance genes in the hospital environment, providing support for controlling their spread.

METHODS Samples were collected from the surfaces of environmental objects and dust accumulated on air conditioning return air vent filters in a hospital in Wuxi City. Metagenomic methods were used to quantitatively analyze the abundance of antibiotic-resistant bacteria and resistance genes in the hospital environmental media.

RESULTS A total of 6 antibiotic-resistant bacterial genera were detected (Pseudomonas, Bacillus, Enterococcus, Rahnella, Carnobacterium and Ewingella). Pseudomonas almost distributed throughout the surveyed areas(8 departments in total), while Bacillus was mostly found in non-critical infection areas. Bacillus had the highest number of species (19 species), including Bacillus cereus and Bacillus subtilis. Pseudomonas had the widest distribution (14 species), primarily consisting of Pseudomonas J380 strain and Pseudomonas MYb193 strain. The hepatology outpatient department had the highest number of detected species, mainly Bacillus. A total of 42 types of resistance genes from 12 major categories were detected, including amides (lmrB), aminoglycosides (aadK, AAC(6)-Ii), macrolides (clbA, msrC, CRP, ErmD), β-lactams (BPU-1), sulfonamides (sul2), penicillins (BLA1), etc., as well as multidrug-resistant genes (mexB, D, F, K, Q, W, blt, bmr, mphL, msrC). There were relatively more types of resistance genes in the tuberculosis ward, hepatology outpatient department and outpatient hall, with mexF widely present in the surveyed departments. Additionally, 52 types of virulence genes were detected.

CONCLUSION Hospitals should pay attention to the pollution characteristics of antibiotic-resistant bacteria and resistance genes in the hospital environment, providing references for clinical rational drug use, disinfection measures, and the spread of environmental drug-resistant bacteria and resistance genes.