Assessing residential activity in a home plumbing system simulator: monitoring the occurrence and relationship of major opportunistic pathogens and phagocytic amoebas

Frontiers in Microbiology

Microbiology

Megan Urbanic¹  Min Tang¹  Darren Lytle²  Daniel Williams²  Christy Muhlen²  Hodon Ryu²  Laura Boczek²  Morgan McNeely²  Vicente Gomez-Alvarez² 

[1] Oak Ridge for Science and Education Research Fellow at U.S. Environmental Protection Agency, Cincinnati, OH, United States;Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH, United States;

关键词: Legionella pneumophila;    premise plumbing;    microbial communities;    opportunistic pathogens;    free-living amoeba;   

DOI  :  10.3389/fmicb.2023.1260460

 received in 2023-07-17, accepted in 2023-09-28,  发布年份 2023

来源: Frontiers

【 摘 要 】

Opportunistic premise plumbing pathogens (OPPPs) have been detected in buildings’ plumbing systems causing waterborne disease outbreaks in the United States. In this study, we monitored the occurrence of OPPPs along with free-living amoeba (FLA) and investigated the effects of residential activities in a simulated home plumbing system (HPS). Water samples were collected from various locations in the HPS and analyzed for three major OPPPs: Legionella pneumophila, nontuberculous mycobacterial species (e.g., Mycobacterium avium, M. intracellulare, and M. abscessus), and Pseudomonas aeruginosa along with two groups of amoebas (Acanthamoeba and Vermamoeba vermiformis). A metagenomic approach was also used to further characterize the microbial communities. Results show that the microbial community is highly diverse with evidence of spatial and temporal structuring influenced by environmental conditions. L. pneumophila was the most prevalent pathogen (86% of samples), followed by M. intracellulare (66%) and P. aeruginosa (21%). Interestingly, M. avium and M. abscessus were not detected in any samples. The data revealed a relatively low prevalence of Acanthamoeba spp. (4%), while V. vermiformis was widely detected (81%) across all the sampling locations within the HPS. Locations with a high concentration of L. pneumophila and M. intracellulare coincided with the highest detection of V. vermiformis, suggesting the potential growth of both populations within FLA and additional protection in drinking water. After a period of stagnation lasting at least 2-weeks, the concentrations of OPPPs and amoeba immediately increased and then decreased gradually back to the baseline. Furthermore, monitoring the microbial population after drainage of the hot water tank and partial drainage of the entire HPS demonstrated no significant mitigation of the selected OPPPs. This study demonstrates that these organisms can adjust to their environment during such events and may survive in biofilms and/or grow within FLA, protecting them from stressors in the supplied water.

【 授权许可】

Unknown   
Copyright © 2023 Gomez-Alvarez, Ryu, Tang, McNeely, Muhlen, Urbanic, Williams, Lytle and Boczek.