Acanthamoeba castellanii interferes with adequate chlorine disinfection of multidrug-resistant Pseudomonas aeruginosa

M.J Sarink,J Pirzadian,W.A Van Cappellen,A.G.M Tielens,A Verbon,J.A Severin,J.J Van Hellemond

doi:10.1016/j.jhin.2020.09.019

M.J Sarink, J Pirzadian + Show 5 more

Open Access

https://doi.org/10.1016/j.jhin.2020.09.019

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Abstract

Verona-Integron-encoded-Metallo-β-lactamase-positive Pseudomonas aeruginosa (VIM-PA) is a cause of hard-to-treat nosocomial infections, and can colonize hospital water networks alongside Acanthamoeba. We developed an in-vitro disinfection model to examine whether Acanthamoeba castellanii can harbour VIM-PA intracellularly, allowing VIM-PA to evade being killed by currently used hospital disinfectants. We observed that A.castellanii presence resulted in significantly increased survival of VIM-PA after exposure to chlorine for 30 s or for 2 min. This undesirable effect was not observed after disinfection by 70% alcohol or 24% acetic acid. Confocal microscopy confirmed the presence of VIM-PA within A.castellanii pseudocysts. Our data indicate that A.castellanii contributes to persistent VIM-PA colonization of water systems after chlorine treatment.

Highlights

Multidrug-resistant strains of Pseudomonas aeruginosa (PA) are an important cause of nosocomial infections and are involved in hospital outbreaks worldwide [1]
This study developed an in-vitro disinfection model to determine the efficacy of Verona-Integron-encoded-Metallo-b-lactamase-positive Pseudomonas aeruginosa (VIM-PA) disinfection in the presence or absence of A. castellanii
Verona Integron-encoded Metallo-b-lactamase (VIM)-PA was incubated in phosphate-buffered saline (PBS) with or without A. castellanii trophozoites for 14 days preceding in-vitro disinfection in order to allow phagocytosis of the bacteria by A. castellanii trophozoites

Summary

Introduction

Multidrug-resistant strains of Pseudomonas aeruginosa (PA) are an important cause of nosocomial infections and are involved in hospital outbreaks worldwide [1]. PA infections are associated with increased morbidity and mortality in hospitalized patients [1]. Sarink et al / Journal of Hospital Infection 106 (2020) 490e494 antibiotics, resulting in resistance against the carbapenems, an important class of antibiotics for treatment of PA infections

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