Outbreak of Pseudomonas aeruginosa producing VIM carbapenemase in an intensive care unit and its termination by implementation of waterless patient care

Abstract

Background Long-term outbreaks of multidrug-resistant Gram-negative bacilli related to hospital-building water systems have been described. However, successful mitigation strategies have rarely been reported. In particular, environmental disinfection or replacement of contaminated equipment usually failed to eradicate environmental sources of Pseudomonas aeruginosa. Methods We report the investigation and termination of an outbreak of P. aeruginosa producing VIM carbapenemase (PA-VIM) in the adult intensive care unit (ICU) of a Swiss tertiary care hospital with active case finding, environmental sampling and whole genome sequencing (WGS) of patient and environmental strains. We also describe the implemented control strategies and their effectiveness on eradication of the environmental reservoir. Results Between April 2018 and September 2020, 21 patients became either infected or colonized with a PA-VIM strain. For 16 of them, an acquisition in the ICU was suspected. Among 131 environmental samples collected in the ICU, 13 grew PA-VIM in sink traps and drains. WGS confirmed the epidemiological link between clinical and environmental strains and the monoclonal pattern of the outbreak. After removing sinks from patient rooms and implementation of waterless patient care, no new acquisition was detected in the ICU within 8 months after the intervention. Discussion Implementation of waterless patient care with removal of the sinks in patient rooms was successful for termination of a PA-VIM ICU outbreak linked to multiple environmental water sources. WGS provides highly discriminatory accuracy to investigate environment-related outbreaks.

An interventional quasi-experimental study to evaluate the impact of a rapid screening strategy in improving control of nosocomial extended-spectrum beta-lactamase-producing Enterobacterales and carbapenemase-producing organisms in critically ill patients

“…We observed a non-statistically significant increase in CPO acquisition rates during the control period, but not regarding nEcESBL-PE. This increase was confounded by an outbreak of VIM-producing P. aeruginosa from April 2018 to September 2020 related to an environmental reservoir, with a peak observed in August 2020 [ 15 ]. However, similar conclusions were observed regarding acquisition rates after exclusion of non-fermentative bacteria.…”

“…Timing and adequacy of prescription for screening and CP were monitored by a dedicated nurse. Environmental cleaning was temporarily modified during a P. aeruginosa outbreak, focusing on controlling the aquatic reservoir (disinfection and suppression of ICU sinks in September 2020) [ 15 ].…”

Detection of Pseudomonas aeruginosa Serogroup G Using Real-Time PCR for Novel Target Genes Identified Through Comparative Genomics

“…Researchers believed that a certain correlation exists between O antigen serotype and toxin secretion. P. aeruginosa may secrete four toxins, including ExoS (exoenzyme S), ExoT (exoenzyme T), ExoU (cytotoxin), and ExoY (Catho et al, 2021). However, some clinical isolates belonging to the serogroup G do not secrete any of the four toxins (Koch et al, 2014;Kuo et al, 2020;Catho et al, 2021).…”

“…It is a versatile opportunistic pathogen that thrives in moist environments, such as soil and water, causing water-borne diseases and nosocomial infections (Falkinham et al, 2015). In recent decades, the number of P. aeruginosa-related water-borne illnesses has increased dramatically (Catho et al, 2021;Petitjean et al, 2021). P. aeruginosa infection may cause a variety of diseases, including those of the respiratory tract (predominantly cystic fibrosis), circulatory system (bacteremia and sepsis), central nervous system, heart (endocarditis), ears (including otitis external), eyes, bones, gastrointestinal tract, urinary tract, and skin (Carmeli et al, 2016;Lee et al, 2017;Morand and Morand, 2017).…”

“…P. aeruginosa infection may cause a variety of diseases, including those of the respiratory tract (predominantly cystic fibrosis), circulatory system (bacteremia and sepsis), central nervous system, heart (endocarditis), ears (including otitis external), eyes, bones, gastrointestinal tract, urinary tract, and skin (Carmeli et al, 2016;Lee et al, 2017;Morand and Morand, 2017). The epidemiology, virulence, and drug resistance of P. aeruginosa are closely related to its serotype (Ayi, 2015;Catho et al, 2021).…”