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

Abstract

Verona-Integron-encoded-Metallo-b-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.

Examining the influence of environmental factors onAcanthamoeba castellaniiandPseudomonas aeruginosain co-culture

“…Interestingly, PA B80425 did not remain at elevated levels on day 7 and instead showed another reduction in growth compared to mono-culture suggesting that it is less robust than the other strains when in the presence of amoebae. The environmental isolates all survived at a greater concentrations in co-culture than in mono-culture over all 4 time points suggesting that these particular strains, at least, were well-prepared for co-culture with amoebae which is not surprising as both P. aeruginosa and A. castellanii are likely to share environmental niches and A. castellanii has been shown to aid in the extracellular survival of other bacterial species [49, 50]. Raw survival counts for P. aeruginosa are provided in S1 Fig.…”

“…aeruginosa and A. castellanii are likely to share environmental niches and A. castellanii has been shown to aid in the extracellular survival of other bacterial species [49,50]. Raw survival counts for P. aeruginosa are provided in S1 Fig.…”

Vermamoeba vermiformis resides in water-based heater–cooler units and can enhance Mycobacterium chimaera survival after chlorine exposure

“…We used the in-vitro disinfection protocol with chlorine (hypochlorous acid) as described earlier [10] to investigate whether, in the presence of V. vermiformis, M. chimaera is protected against disinfectant. This procedure was necessary because the Puristeril340, used for disinfection of the HCUs, cannot be neutralized effectively, which is necessary to investigate the survival of M. chimaera.…”

A. castellanii and P. aeruginosa mutually exacerbate damage to corneal cells during coinfection

“…Pseudomonas aeruginosa is an opportunistic pathogen that is commonly found in a wide range of environmental habitats, including soil, water, plants, and animals ( 10 ). P. aeruginosa has been demonstrated to be associated with a range of infections, including urinary tract infections, pneumonia, wound infections, and sepsis ( 11 ). Corneal infection is one of the prominent clinical manifestations associated with P. aeruginosa infections and is often attributed to factors such as contact lens use or eye injury ( 12 ).…”

“…A. castellanii and P. aeruginosa are widespread pathogenic microorganisms that cause certain human diseases ( 18 , 19 ). Experimental evidence suggests that A. castellanii can interfere with the efficacy of hospital disinfection with chlorine, which leads to increased bacterial survival ( 11 ). Animal studies have indicated that bacterial presence participates in the development of AK ( 20 ).…”