The study of fungi in drinking water

Abstract

The occurrence of fungi in drinking water has received increased attention in the last decades, and fungi are now generally accepted as drinking water contaminants. The knowledge about the occurrence and diversity of fungi in water has increased considerably from a low knowledge base. However, the relevance of waterborne fungi for water quality and human health is poorly understood and still conflicting. Scientific reports on effective treatment against fungi in water are also few. This article presents a review of the literature on fungal water studies, including some general results, and considerations of significance, limits, contradictions, precautions, and practical consequences.

Freshwater Fungal Infections

“…7,9 Nonetheless, microscopic fungi are present in freshwater communities, although they exist in relatively lower concentrations, are rarely planktonic (free-living) and are even more rarely pathogenic. 4,9,10 Most are parasitic of planktonic algae or rotifers or are surface colonizers. 9 Like Legionella pneumophila and other bacteria, fungi may be associated with or be harbored by free-living amoebas in freshwater, including tap and potable water.…”

“…16 Depending on the municipality, or private water source owner, a variety of methods may be used to remove potentially harmful microorganisms from the water supply. 17 In the United States, where drinking water is considered "among the safest in the world," 17 the most common methods to treat community water supplies (particularly when the source is surface water, which is generally more prone to significant contamination then groundwater) 10 include coagulation and flocculation (positively charged chemicals are added to bind with negatively charged dirt and other particulate matter), sedimentation of these now larger particles, filtration using natural and artificial filters, and disinfection with chemicals such as chlorine or chloramine (often done as the final step in water purification). 17 Nevertheless, pathogenic fungi can still enter drinking water in developed nations, including all types of treated tap and bottled water.…”

“…17 Nevertheless, pathogenic fungi can still enter drinking water in developed nations, including all types of treated tap and bottled water. 10 Pathogenic fungi generally associated with tap water or that have the potential for concern include Candida albicans, Candida parapsilosis, Aspergillus, Fusarium, Exophiala dermatitidis and microsporidia. 10,18 Chaetomium species have been found frequently in tap water; however, potentially serious infections of immunocompromised patients likely originated from a source other than drinking water.…”

“…10 Pathogenic fungi generally associated with tap water or that have the potential for concern include Candida albicans, Candida parapsilosis, Aspergillus, Fusarium, Exophiala dermatitidis and microsporidia. 10,18 Chaetomium species have been found frequently in tap water; however, potentially serious infections of immunocompromised patients likely originated from a source other than drinking water. 19 The presence of some fungal contaminants in drinking water may be related to their establishment of biofilms in portions of the water distribution system upstream from household or commercial establishment plumbing systems.…”

“…19 The presence of some fungal contaminants in drinking water may be related to their establishment of biofilms in portions of the water distribution system upstream from household or commercial establishment plumbing systems. 10 Hageskal et al provided an informative review of the methodological challenges and difficulty in interpretation of microbiological assessments for drinking water contamination by fungi. 10 There are several examples of isolations of potentially pathogenic fungi from municipal water, including sites in Portugal, 20 Norway, 21,22 Brazil 6 and the Netherlands.…”