Transcript Fungi in Drinking Water Distribution Systems

Fungi in Drinkable Water Distribution System
Seham Alsurayhi
Mycology
M, 6:30 PM
Outline
• The history of fungal water studies.
• Sources and type of fungi found in water.
• Fungal Water Biofilms.
• How Filamentous Fungi Affect Water Quality.
• The impact on human health.
• Removal or controlling fungi in water.
• Summary.
The history of fungal water studies:
• The issue of fungi in water was observed between 1960s-1970s, people starting noticing
the bad taste and smell as well as health problems.
• Between 1980s-1990s more health problems reported in Finland,
Sweden and other countries worldwide.
• Researchers became curious to Know more about fungi occurrence in drinking water,
result from different countries show the fungal occurrence to vary between 7.5-89%.
• Greatest concerns for the water consumers is not just fungal alone, but pathogenic
microorganisms that may cause epidemiological and sanitary risks.
Sources and type of fungi found in water:
Fungi can enter drinking water distribution systems through several contamination
pathways including:
• During water treatment.
• Deficiencies in stored water facilities
cross-connections.
Sources and type of fungi found in water:
• Mains breaks and intrusions.
• During mains installation and maintenance.
* According to studies filamentous fungi are those that survive in water, and these
fungi all belong to hyphomycetes and oomycetes classes of fungi. For example,
Alternaria alternate numerous members of Penicillium species, Aspergillus niger,
Aspergillus fumigatus, Epiccocum nigrum, and a variety of molds belonging to
Cladosporium species.
Aspergillus fumigatus
Penicillium brevicompacum
Penicillium Trichoderma
Surveys of fungi in drinking water
Country, Place, Year
Period of time
Type of water
Main isolation method
Most frequent fungal isolates
United Kingdom, 1996
Autumn and Spring
Surface water and network
Membrane filtration, Direct
plating and Bating
Aspergillus, Cladosporium, Epicoccum,
Penicillium and Trichoderma
Greece, Thessaloniki, 1998
One collection (126
samples)
Tap water (hospital and
community)
Membrane filtration
Penicillium, Aspergillus and Acremonium
Greece, 85 haemodialysis units, 1998
One collection (255
samples)
Municipal water supplies of
haemodialysis centres
Membrane filtration
Penicillium and Aspergillus
Germany, North Rhine-Westphalia,
1998/9
12 months
Drinking water
Pour-plating
Acremonium, Exophiala, Penicillium and
Phialophora
Norway, 14 networks, 2002/3
December, June and
September
Drinking water (surface and
groundwater)
Membrane filtration
Penicillium, Trichoderma and Aspergillus
Portugal, Braga, 2003/4
12 months
Tap water
Membrane filtration
Penicillium and Acremonium
Pakistan, Karachi, 2007
One collection (30
samples)
Water (and fruit juice)
Direct plating
Aspergillus niger and A. clavatus
Australia, Queensland, 2007/8
18 months
Municipal water
Membrane filtration
Cladosporium, Penicillium, Aspergillus and
Fusarium
Fungal Water Biofilms:
• Biofilms are an important habitat for fungi in drinking water. Their development is
influenced by many factors including temperature, nutrient concentration, pipe material and
water flow rate.
• Biofilms are communities of microorganisms that are attached to a surface.
• Filamentous fungi find their way into water distribution systems through biofilms formed
on a water distribution pipe.
A fungal biofilm living on a surface
Five stages of biofilm development:
1) Initial reversible attachment of free-swimming micro- organisms to
surface.
2) Permanent attachment
3) Maturation I
4) Maturation II
5) Dispersion
How Filamentous Fungi Affect Water Quality :
Fungi, through their biofilms, negatively affect quality of products in water distribution
systems:
1- they can feed on metallic pipes thereby creating pores on the pipes and causing water
leakage and contamination.
2- fungi obviously contaminate water distribution systems when biofilms are formed
internally, in situations where they are formed externally on a pipe, the microorganisms can
penetrate the water system through the holes resulting in contaminated water.
3- Moreover, contamination may occur when other impurities enter a pipeline through the
openings.
4- The presence of fungi in water can alter the taste and smell of water. Organic acids
produced by fungal metabolic processes can increase the rate of corrosion of water pipes.
The impact on human health:
• Fungi present in drinking water may cause severe fungal infections in
Immunosuppressed patients.
• Many species of genus Aspergillus are found in water are causative agents of
kidney, liver disorders, allergy, burns, Otitis media and increase risk of invasive
infections.
• Also, that Penicillium spp. is frequently found in fresh water and its implication in
allergy, asthma or other respiratory problems has been cited in many previous
research studies.
• Filamentous fungi produce toxins and consumption of water infected by fungi may
cause allergic reactions.
Removal or controlling fungi in water:
• Removal of fungi from drinkable water would entail application of appropriate
physical, chemical, or biological technique that eliminates formation of biofilms.
• Biofilms can be removed using sanitizers; however, once they are formed, the
biofilms are not easy to eliminate due to the fact that the EPSs are resistant to
sanitizers and so shield the microorganisms from sanitizers. for example, Chlorine is
known to be relatively ineffective at controlling biofilms.
• The most dependable approach, that may be employed to prevent establishment of
biofilms, is by all the time observing hygiene. The initiative involves monitoring of
pipelines in order to detect and remove, as early as possible.
Summary:
•Studies of fungi in drinking water have demonstrated that fungi are relatively common in water
distribution systems.
• Fungi can enter drinking water distribution systems through several contamination pathways.
• Studies of filamentous fungi that cause contamination of water distribution system and their relation
to biofilm formation.
• The presence of fungi in water affect water quality through alters the taste and smell of water.
• Filamentous fungi produce toxins and cause allergic reactions also, cause severe fungal infections in
Immunosuppressed patients.
• Controlling fungi in water by using appropriate technique to eliminate formation of biofilms.
References:
• Siqueira, V. M., Oliveira, H., Santos, C., Paterson, R. R. M., Gusmão, N. B., & Lima, N. (2011). Filamentous fungi in drinking
water, particularly in relation to biofilm formation. International journal of environmental research and public health, 8(2),
456-469.
• Hageskal, G., Lima, N., & Skaar, I. (2009). The study of fungi in drinking water. Mycological research, 113(2), 165-172.
• Arvanitidou, M., Kanellou, K., Constantinides, T. C., & Katsouyannopoulos, V. (1999). The occurrence of fungi in hospital
and community potable waters. Letters in applied microbiology, 29(2), 81-84.
• Hageskal, G., Gaustad, P., Heier, B. T., & Skaar, I. (2006). Occurrence of moulds in drinking water.
• De Toni, P. S. A., & Reilly, K. (2011). A REVIEW OF FUNGI IN DRINKING WATER AND THE IMPLICATIONS FOR HUMAN
HEALTH.
• Warris, A., Voss, A., Abrahamsen, T. G., & Verweij, P. E. (2002). Contamination of hospital water with Aspergillus fumigatus
and other molds. Clinical infectious diseases, 34(8), 1059-1060.