scholarly journals Survival of Mycobacterium avium, Legionella pneumophila, Escherichia coli, and Caliciviruses in Drinking Water-Associated Biofilms Grown under High-Shear Turbulent Flow

2007 ◽  
Vol 73 (9) ◽  
pp. 2854-2859 ◽  
Author(s):  
Markku J. Lehtola ◽  
Eila Torvinen ◽  
Jaana Kusnetsov ◽  
Tarja Pitkänen ◽  
Leena Maunula ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Turbulent Flow ◽  
Mycobacterium Avium ◽  
Legionella Pneumophila ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
High Shear ◽  
Culture Methods

ABSTRACT Most of the bacteria in drinking water distribution systems are associated with biofilms. In biofilms, their nutrient supply is better than in water, and biofilms can provide shelter against disinfection. We used a Propella biofilm reactor for studying the survival of Mycobacterium avium, Legionella pneumophila, Escherichia coli, and canine calicivirus (CaCV) (as a surrogate for human norovirus) in drinking water biofilms grown under high-shear turbulent-flow conditions. The numbers of M. avium and L. pneumophila were analyzed with both culture methods and with peptide nucleic acid fluorescence in situ hybridization (FISH) methods. Even though the numbers of pathogens in biofilms decreased during the experiments, M. avium and L. pneumophila survived in biofilms for more than 2 to 4 weeks in culturable forms. CaCV was detectable with a reverse transcription-PCR method in biofilms for more than 3 weeks. E. coli was detectable by culture for only 4 days in biofilms and 8 days in water, suggesting that it is a poor indicator of the presence of certain waterborne pathogens. With L. pneumophila and M. avium, culture methods underestimated the numbers of bacteria present compared to the FISH results. This study clearly proved that pathogenic bacteria entering water distribution systems can survive in biofilms for at least several weeks, even under conditions of high-shear turbulent flow, and may be a risk to water consumers. Also, considering the low number of virus particles needed to result in an infection, their extended survival in biofilms must be taken into account as a risk for the consumer.

scholarly journals Protozoan Bacterivory and Escherichia coli Survival in Drinking Water Distribution Systems

1998 ◽  
Vol 64 (1) ◽  
pp. 197-202 ◽  
Author(s):  
I. Sibille ◽  
T. Sime-Ngando ◽  
L. Mathieu ◽  
J. C. Block
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Microbial Communities ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Trophic Relationships ◽  
Bacterial Cells ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

ABSTRACT The development of bacterial communities in drinking water distribution systems leads to a food chain which supports the growth of macroorganisms incompatible with water quality requirements and esthetics. Nevertheless, very few studies have examined the microbial communities in drinking water distribution systems and their trophic relationships. This study was done to quantify the microbial communities (especially bacteria and protozoa) and obtain direct and indirect proof of protozoan feeding on bacteria in two distribution networks, one of GAC water (i.e., water filtered on granular activated carbon) and the other of nanofiltered water. The nanofiltered water-supplied network contained no organisms larger than bacteria, either in the water phase (on average, 5 × 107bacterial cells liter−1) or in the biofilm (on average, 7 × 106 bacterial cells cm−2). No protozoa were detected in the whole nanofiltered water-supplied network (water plus biofilm). In contrast, the GAC water-supplied network contained bacteria (on average, 3 × 108 cells liter−1 in water and 4 × 107 cells cm−2 in biofilm) and protozoa (on average, 105cells liter−1 in water and 103 cells cm−2 in biofilm). The water contained mostly flagellates (93%), ciliates (1.8%), thecamoebae (1.6%), and naked amoebae (1.1%). The biofilm had only ciliates (52%) and thecamoebae (48%). Only the ciliates at the solid-liquid interface of the GAC water-supplied network had a measurable grazing activity in laboratory test (estimated at 2 bacteria per ciliate per h). Protozoan ingestion of bacteria was indirectly shown by adding Escherichia colito the experimental distribution systems. Unexpectedly, E. coli was lost from the GAC water-supplied network more rapidly than from the nanofiltered water-supplied network, perhaps because of the grazing activity of protozoa in GAC water but not in nanofiltered water. Thus, the GAC water-supplied network contained a functional ecosystem with well-established and structured microbial communities, while the nanofiltered water-supplied system did not. The presence of protozoa in drinking water distribution systems must not be neglected because these populations may regulate the autochthonous and allochthonous bacterial populations.

scholarly journals Mycobacterium avium Complex (MAC) in Water Distribution Systems and Household Plumbing in the United States

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3338
Author(s):  
Joseph O. Falkinham
Keyword(s):  
Drinking Water ◽  
Mycobacterium Avium ◽  
Distribution Systems ◽  
Water Distribution ◽  
Mycobacterium Avium Complex ◽  
Water Distribution Systems ◽  
Treatment Plant ◽  
The United States ◽  
Fecal Coliforms ◽  
Plate Count

Members of the Mycobacterium avium complex (MAC) are waterborne, opportunistic pathogens whose characteristics make urban water distribution systems and household plumbing ideal habitats for their survival, persistence and growth. Rather than contaminants, MAC are colonists of drinking water systems. MAC are normal inhabitants of natural soils and water, and enter drinking water treatment systems through surface sources. A proportion of MAC survive transmission through the treatment plant, and regrow in the distribution system and household plumbing. Once within household plumbing, MAC adhere to surfaces and form biofilms, thus preventing their washout. The thermal tolerance of MAC leads to growth in water heating systems. Stagnation does not reduce MAC numbers, as MAC can grow at low oxygen levels. MAC present challenges to current water monitoring approaches as their numbers do not correlate with E. coli, fecal coliforms or heterotrophic plate count bacteria.

The assessment of biofilm community composition on plumbing materials in filtered and unfiltered water distribution systems

2003 ◽  
Vol 3 (1-2) ◽  
pp. 187-191
Author(s):  
M.M. Critchley ◽  
N.J. Cromar ◽  
H.J. Fallowfield
Keyword(s):  
Drinking Water ◽  
Fatty Acid ◽  
Community Composition ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Polymer Materials ◽  
Fatty Acid Profiles ◽  
Water Supplies ◽  
Drinking Water Distribution Systems

Biofilms have been extensively characterised within drinking water distribution systems. However, the significance of materials on biofilm species diversity is not established. This study investigated the community composition of biofilms on plumbing materials receiving filtered and unfiltered water supplies. Biofilms were extracted from polybutylene, polyethylene, cross-linked polyethylene, unplasticised polyvinyl chloride and copper tubes in sampling rigs receiving Murray-Onkaparinga water before or after filtration. Biofilms were extracted and analysed for fatty acid composition using the FAME™ methodology. There were differences in the fatty acid profiles of biofilms and the respective water supplies, indicating differences in the attached and planktonic communities. The results also showed significant differences in the fatty acid profiles of biofilms on the polymer materials compared to copper, suggesting variations in biofilm populations on the different materials. The potential for materials to select for microbial populations has significant implications for the ecology of drinking water biofilms.

scholarly journals Identification of Aminoglycoside Resistance Genes From Bacteria Isolated From Selected Municipal Drinking Water Distribution Systems in Southwestern Nigeria

2020 ◽  
Vol 41 (S1) ◽  
pp. s255-s255
Author(s):  
Ayodele T. Adesoji ◽  
Adeniyi A. Ogunjobi
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Southwestern Nigeria ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

Background: Multidrug-resistant bacteria can lead to treatment failure, resulting in infectious diseases being transferred through nonpotable water. Aminoglycosides are an important class of antibiotics that are abused in Nigeria. Few studies have investigated aminoglycoside-modifying genes (AMGs) that are likely responsible for resistance in Nigeria bacteria isolates. Therefore, we aimed to characterize AMGs from isolates in drinking water distribution systems (DWDS) in southwestern Nigeria. Methods: Multidrug-resistant bacteria (n = 181) that had been previously characterized by 16S rDNA sequencing and that were positive for resistance to at least 1 aminoglycoside antibiotic were selected from 6 treated and untreated water distribution systems. Strains were PCR genotyped for 3 AMGs: aph(3)c, ant(3)b and aph(6)-1dd. Results: Of 181 MDR bacteria tested, 69 (38.12%) were positive for at least 1 of the AMGs. The most common was ant(3)c (27.6%), followed by aph(3")c (18.23%). Both aph(3)c and ant(3")b were found in 7.73% of tested isolates, ant(3)b was most commonly found in Alcaligenes spp (50%). Furthermore, aph(3")c was most commonly detected in Proteus spp (50%). Other genera positive for AMGs included Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter, and Serratia. Conclusions: High occurrence of ant(3)c and aph(3)c among these bacteria call for urgent attention among public health workers because these genes can be easily disseminated to consumers if present on mobile genetic elements like plasmids, integrons, and transposons.Funding: NoneDisclosures: None

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