Spatiotemporal dynamics of multidrug resistant bacteria on intensive care unit surfaces

Alaric W D’Souza,Saadia Andleeb,Carey-Ann D Burnham,Sanket Patel,Robert F Potter,Gautam Dantas,Xiaoqing Sun,Danish Gul,Jennie H Kwon,Angela Shupe,Meghan Wallace

doi:10.1038/s41467-019-12563-1

Abstract

Bacterial pathogens that infect patients also contaminate hospital surfaces. These contaminants impact hospital infection control and epidemiology, prompting quantitative examination of their transmission dynamics. Here we investigate spatiotemporal and phylogenetic relationships of multidrug resistant (MDR) bacteria on intensive care unit surfaces from two hospitals in the United States (US) and Pakistan collected over one year. MDR bacteria isolated from 3.3% and 86.7% of US and Pakistani surfaces, respectively, include common nosocomial pathogens, rare opportunistic pathogens, and novel taxa. Common nosocomial isolates are dominated by single lineages of different clones, are phenotypically MDR, and have high resistance gene burdens. Many resistance genes (e.g., blaNDM, blaOXA carbapenamases), are shared by multiple species and flanked by mobilization elements. We identify Acinetobacter baumannii and Enterococcus faecium co-association on multiple surfaces, and demonstrate these species establish synergistic biofilms in vitro. Our results highlight substantial MDR pathogen burdens in hospital built-environments, provide evidence for spatiotemporal-dependent transmission, and demonstrate potential mechanisms for multi-species surface persistence.

Highlights

Bacterial pathogens that infect patients contaminate hospital surfaces
Similar numbers of the soil-associated opportunistic pathogen Pseudomonas stutzeri were recovered (28/ 289, 9.7%) as the common nosocomial pathogen P. aeruginosa (27/289, 9.3%). In addition to these expected nosocomial organisms, we identified a variety of other clinically relevant species such as Stenotrophomonas maltophila, Shewanella putrefaciens, and Providencia rettgeri. These results starkly contrast with USAH, where we only recovered six unique isolates, which MALDITOF MS identified as A. baumannii (4/6) and E. coli (2/6) (Fig. 2a)
While pathogenic bacteria that often cause healthcare-associated infections (HAIs) can be transferred via invasive medical procedures or directly between patients or healthcare providers, inanimate surfaces and shared equipment are an important reservoir for bacterial transmission[15,42]

Summary

Introduction

Bacterial pathogens that infect patients contaminate hospital surfaces. These contaminants impact hospital infection control and epidemiology, prompting quantitative examination of their transmission dynamics. We investigate spatiotemporal and phylogenetic relationships of multidrug resistant (MDR) bacteria on intensive care unit surfaces from two hospitals in the United States (US) and Pakistan collected over one year. Common nosocomial isolates are dominated by single lineages of different clones, are phenotypically MDR, and have high resistance gene burdens. Our results highlight substantial MDR pathogen burdens in hospital built-environments, provide evidence for spatiotemporal-dependent transmission, and demonstrate potential mechanisms for multispecies surface persistence. Global treatment of bacterial infections is increasingly compromised by evolution and transmission of multidrug-resistant organisms (MDROs) and their antibiotic resistance genes (ARGs) between multiple habitats[1].

Methods

Results

Conclusion