Isolation of Vermamoeba vermiformis and associated bacteria in hospital water

Pagnier, Isabelle; Valles, Camille; Raoult, Didier; Scola, Bernard La

doi:10.1016/j.micpath.2015.02.006

Cited by 69 publications

(49 citation statements)

References 42 publications

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“…Based upon the range of target cells utilized in this study, we strongly suspect that the S. maltophilia T4SS can modulate the death program of a wide range of cellular targets, including killing other mammalian cells that are part of the immune system (e.g., neutrophils) or other bacteria that inhabit its niches, whether planktonic in nature or coinfecting plant, animal, or human hosts. In regard to the proapoptotic effect that the K279a VirB/D4 T4SS has on macrophages, it is tempting to speculate that this function evolved as a result of S. maltophilia interacting with predatory protozoans (amoebae) in nature (113)(114)(115)(116)(117). Despite demonstrating the importance of the S. maltophilia T4SS in influ- encing the death of other cells, we do not believe that this is the only function of this VirB/D4 T4SS, given what is known about T4SS in general (35)(36)(37).…”

Section: Discussionmentioning

confidence: 99%

Stenotrophomonas maltophilia Encodes a VirB/VirD4 Type IV Secretion System That Modulates Apoptosis in Human Cells and Promotes Competition against Heterologous Bacteria, Including Pseudomonas aeruginosa

et al. 2019

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Stenotrophomonas maltophilia is an emerging opportunistic and nosocomial pathogen. S. maltophilia is also a risk factor for lung exacerbations in cystic fibrosis patients. S. maltophilia attaches to various mammalian cells, and we recently documented that the bacterium encodes a type II secretion system which triggers detachment-induced apoptosis in lung epithelial cells. We have now confirmed that S. maltophilia also encodes a type IVA secretion system (VirB/VirD4 [VirB/D4] T4SS) that is highly conserved among S. maltophilia strains and, looking beyond the Stenotrophomonas genus, is most similar to the T4SS of Xanthomonas. To define the role(s) of this T4SS, we constructed a mutant of strain K279a that is devoid of secretion activity due to loss of the VirB10 component. The mutant induced a higher level of apoptosis upon infection of human lung epithelial cells, indicating that a T4SS effector(s) has antiapoptotic activity. However, when we infected human macrophages, the mutant triggered a lower level of apoptosis, implying that the T4SS also elaborates a proapoptotic factor(s). Moreover, when we cocultured K279a with strains of Pseudomonas aeruginosa, the T4SS promoted the growth of S. maltophilia and reduced the numbers of heterologous bacteria, signaling that another effector(s) has antibacterial activity. In all cases, the effect of the T4SS required S. maltophilia contact with its target. Thus, S. maltophilia VirB/D4 T4SS appears to secrete multiple effectors capable of modulating death pathways. That a T4SS can have anti- and prokilling effects on different targets, including both human and bacterial cells, has, to our knowledge, not been seen before.

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Section: Discussionmentioning

confidence: 99%

Stenotrophomonas maltophilia Encodes a VirB/VirD4 Type IV Secretion System That Modulates Apoptosis in Human Cells and Promotes Competition against Heterologous Bacteria, Including Pseudomonas aeruginosa

et al. 2019

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“…As a result, the simultaneous presence of V. vermiformis and A. fumigatus in the same environments can lead to increased fungal population. Some authors have reported that V. vermiformis is frequently recovered from drinking water or hospital water (Rohr et al 1998;Thomas et al 2006;Loret and Greub 2010;Pagnier et al 2015). In an Australian report on microfungal contaminants in municipal water, Aspergillus was the third genus recovered in the water samples (Sammon et al 2010).…”

Section: Discussionmentioning

confidence: 99%

“…Vermamoeba vermiformis is one of the most common FLA to have been isolated from different water systems (Rhoads et al 2015;Montalbano Di Filippo et al 2015;Lu et al 2015;Armand et al 2016). It is also frequently recovered from hospital water networks as shown by several authors (Rohr et al 1998;Thomas et al 2006;Ovrutsky et al 2013;Pagnier et al 2015). Acanthamoeba, another genus of FLA commonly found in soil and water, has, as V. vermiformis, a two-staged life cycle: an actively feeding, dividing trophozoite form corresponding to the period of metabolic activity of the amoeba and a dormant cyst that can resist hostile environmental conditions such as nutrient depletion, osmotic stress, temperature changes, pH variations and water disinfection (Critchley and Bentham 2009;Fouque et al 2012).…”

Section: Introductionmentioning

confidence: 98%

Vermamoeba vermiformis-Aspergillus fumigatus relationships and comparison with other phagocytic cells

et al. 2016

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Free living amoebae (FLA) are protists ubiquitously present in the environment. Aspergillus fumigatus is a mould responsible for severe deep-seated infections, and that can be recovered in the same habitats as the FLA. By conducting coculture experiments and fungal incubation with amoebal supernatants, we report herein that Vermamoeba vermiformis, a FLA present in hospital water systems, promotes filamentation and growth of A. fumigatus. This finding is of particular importance to institutions whose water systems might harbor FLA and could potentially be used by immunocompromised patients. Also, the relationships between V. vermiformis and A. fumigatus were compared to those between this fungus and two other phagocytic cells: Acanthamoeba castellanii, another FLA, and macrophage-like THP-1 cells. After 4 h of coincubation, the percentages of the three phagocytic cell types with adhered conidia were similar, even though the types of receptors between FLA and macrophagic cell seemed different. However, the percentage of THP-1 with internalized conidia was considerably lower (40 %) in comparison with the two other cell types (100 %). Thus, this study revealed that interactions between A. fumigatus and these three phagocytic cell types show similarities, even though it is premature to extrapolate these results to interpret relationships between A. fumigatus and macrophages.

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“…Water treatment processes, nutrients, disinfection residuals, DBPs, and the abiotic factors of distribution systems and on-premises plumbing (e.g., stagnation of water, temperature) have significant impacts on the microbial community of tap water and associated water quality (Wang et al, 2018). Moreover, free-living amoebae and some other protozoa present in distribution systems protect certain bacterial pathogens from disinfectants and support intracellular growth of pathogens like Legionella (Balczun and Scheid, 2017;Lu et al, 2014;Pagnier et al, 2015).…”

Section: Water Microbiologymentioning

confidence: 99%

Faster and safer: Research priorities in water and health

Setty¹,

Loret²,

Courtois³

et al. 2019

International Journal of Hygiene and Environmental Health

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The United Nations' Sustainable Development Goals initiated in 2016 reiterated the need for safe water and healthy lives across the globe. The tenth anniversary meeting of the International Water and Health Seminar in 2018 brought together experts, students, and practitioners, setting the stage for development of an inclusive and evidence-based research agenda on water and health. Data collection relied on a nominal group technique gathering perceived research priorities as well as underlying drivers and adaptation needs. Under a common driver of public health protection, primary research priorities included the socioeconomy of water, risk assessment and management, and improved monitoring methods and intelligence. Adaptations stemming from these drivers included translating existing knowledge to providing safe and timely services to support the diversity of human water needs. Our findings present a comprehensive agenda of topics at the forefront of water and health research. This information can frame and inform collective efforts of water and health researchers over the coming decades, contributing to improved water services, public health, and socioeconomic outcomes.

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Isolation of Vermamoeba vermiformis and associated bacteria in hospital water

Cited by 69 publications

References 42 publications

Stenotrophomonas maltophilia Encodes a VirB/VirD4 Type IV Secretion System That Modulates Apoptosis in Human Cells and Promotes Competition against Heterologous Bacteria, Including Pseudomonas aeruginosa

Stenotrophomonas maltophilia Encodes a VirB/VirD4 Type IV Secretion System That Modulates Apoptosis in Human Cells and Promotes Competition against Heterologous Bacteria, Including Pseudomonas aeruginosa

Vermamoeba vermiformis-Aspergillus fumigatus relationships and comparison with other phagocytic cells

Faster and safer: Research priorities in water and health

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