scholarly journals Cryptosporidium Oocyst Contamination in Drinking Water: A Case Study in Italy

Author(s):  
Cristina Pignata ◽  
Silvia Bonetta ◽  
Sara Bonetta ◽  
Simone M. Cacciò ◽  
Anna R. Sannella ◽  
...  

The aim of this study was to evaluate the occurrence of Cryptosporidium oocysts in a drinking water treatment plant (DWTP) located in a rural area of northern Italy. Influent and effluent samples were collected at the DWTP over three years (2013–2016). In parallel, tap water samples from a public drinking fountain were collected as well. All samples were analyzed for the presence of Cryptosporidium spp. oocysts by a common method based on an immunomagnetic separation (IMS)/immunofluorescence assay (IFA), complemented by 4,6-diamidino-2-phenylindole (DAPI) staining. A reverse transcriptase-PCR (RT-PCR) protocol was added to evaluate oocyst viability. The results highlighted a high variability of oocyst concentrations across all samples (mean 4.3 ± 5.8/100 L) and a high variability in the percentage of DAPI-positive specimens (mean 48.2% ± 40.3%). Conversely, RT-PCR did not reveal the presence of viable C. parvum and C. hominis oocysts. A nested PCR targeting Cryptosporidium 18S ribosomal DNA, carried out in two water samples, confirmed the presence of a Cryptosporidium genotype associated with wild animals in the river and in tap water. The results obtained underline the vulnerability of the investigated surface water to Cryptosporidium spp. contamination. Although the recovered Cryptosporidium genotype is not a human pathogen, its presence demonstrates the existence of a potential pathogen Cryptosporidium spp. contamination risk. Moreover, these results underline the importance of also considering unconventional (not bacterial) biological contaminations (protozoa) in water resources in rural areas, including those of developed countries.

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
C Pignata ◽  
S i Bonetta ◽  
S a Bonetta ◽  
S M Cacciò ◽  
A R Sannella ◽  
...  

Abstract Over the past decade, several outbreaks of cryptosporidiosis have been reported in many EU countries in association with the consumption of contaminated drinking water, recreational waters, food consumption and contact with animals. The aim of this study was to evaluate the occurrence of Cryptosporidium oocysts in a drinking water treatment plant (DWTP) located in a rural area of northern Italy. Influent and effluent samples at the DWTP, together with tap water samples from a public fountain were collected for three years (2013-2016). All samples were analysed for the presence of Cryptosporidium spp. oocysts by the EPA Method 1623 based on immunomagnetic separation (IMS)/immunofluorescence assay (IFA), complemented by 4,6-diamidino-2-phenylindole (DAPI) staining. The detection has been implemented with a reverse transcriptase-PCR (RT-PCR) protocol to evaluate the oocyst viability. The results highlighted a high variability of oocyst concentrations in all samples (mean 4.3 - 5.8/100 L) and a high percentage variability of the DAPI-positive specimens (mean 48.2% - 40.3%). Conversely, RT-PCR did not reveal the presence of any viable C. parvum and C. hominis oocysts. A nested PCR targeting Cryptosporidium 18S ribosomal DNA was carried out in two water samples to deepen the understanding of the obtained results. This test revealed the presence of a particular Cryptosporidium genotype associated with wild animals in the river and in tap water. Although the recovered Cryptosporidium genotype is not a human pathogen, its presence demonstrates the existence of a potential pathogen Cryptosporidium spp. contamination risk. Moreover, these results underline the importance of considering unconventional (not bacterial) biological contaminations (protozoa) in water resources in rural areas, including those of developed countries. Key messages The supply source and the drinking water treatment plant examined represent a classic example of a system that requires continuous monitoring to guarantee population health. Cryptosporidium oocysts may still be a Public Health problem even in industrialized countries, especially in rural and mountain areas.


Author(s):  
Wenjin Xue ◽  
Christopher W. K. Chow ◽  
John van Leeuwen

Abstract The bacterial regrowth potential (BRP) method was utilised to indirectly measure the assimilable organic carbon (AOC) as an indicator for the assessment of the microbial regrowth potential in drinking water distribution systems. A model using various microbial growth parameters was developed in order to standardise the experimental interpretation for BRP measurement. This study used 82 experimental BRP data sets of water samples collected from the water treatment plant to locations (customer taps) in the distribution system. The data were used to model the BRP process (growth curve) by a data fitting procedure and to obtain a best-fitted equation. Statistical assessments and model validation for evaluating the equation obtained by fitting these 82 sets of data were conducted, and the results show average R2 values were 0.987 for treated water samples (collected at the plant prior to chlorination) and 0.983 for tap water (collected at the customer taps). The F values obtained from the F-test are all exceeded their corresponding F critical values, and the results from the t-test also showed a good outcome. These results indicate this model would be successfully applied in modelling BRP in drinking water supply systems.


2008 ◽  
Vol 6 (2) ◽  
pp. 281-288 ◽  
Author(s):  
Orapin Thapsingkaew ◽  
Vilailuck Kijjanapanich ◽  
Werawan Ruangyuttikarn

The efficiency of ozonation in comparison to chlorination for removal of microcystins and production of trihalomethanes (THMs) in water was investigated. One hundred and ninety water samples of ozone and chlorine treated water were collected at a water treatment plant between August 2004 and March 2005. The level of THMs, total organic carbon and residual chlorine were determined. Protein phosphatase 2A inhibition assay was used to detect microcystins and the presence of microcystins was confirmed by HPLC. The results show that 91.5% of the THM species in treated water was chloroform and 8.5% was bromodichloromethane. The mean THM level± standard error of mean in chlorinated water (CW) (45.1±3.0 μg/L) was higher than the mean of THM level in ozonated water (OW) (18.6±2.2 μg/L). In addition, no OW sample exceeded the first stage U.S. EPA maximum THM contaminant level for drinking water (80 μg/L) and only 8% of these samples exceeded the second stage level (40 μg/L). On the other hand, 3% of CW samples exceeded 80 μg/L and 68% exceeded the 40 μg/L level. The microcystin level in all water samples was below the WHO guideline value (1 μg/L) for drinking water.


2015 ◽  
Vol 3 (3) ◽  
pp. 528-536
Author(s):  
Yehia A. Osman ◽  
Waled M. El-Senousy ◽  
Adel A. El-Morsi ◽  
Mohammed K. Rashed

The fecal bacteria have been taken as the gold standard for water industry. However, the spread of viral gastroenteritis due to drinking water have given a momentum to a recent push by microbiologists to consider viruses as important pollution indicator as fecal bacteria. Therefore, we designed a study to evaluate the efficiency of two types of water purification systems: the traditional water treatment plant and two types compact units. Both systems produced drinking waters free of bacteria, chemical contaminants and mostly viruses free.  However, recent advances in molecular biology techniques, such as RT-PCR have detected Rotaviruses in chlorinated drinking waters resulted from all systems. The frequency of Rotaviruses since October 2010 till September 2012 in Shark El-Mansoura WTP in drinking water samples was 12.5% similar to raw water. While the compact unit at Depo Awam (American design) the frequency of Rotavirus was 16.6% in both raw and drinking water samples.  On the other hand the virus frequency in the raw and drinking water sample in El-Danabik unit (Egyptian design) were 12.5% and 4.16% respectively. Signifying failure of the chlorination process in removing viruses completely.  However, detection of Rotavirus genome in the drinking water samples does not means the presence of its infectivity. The infectious ability of the rotaviruses was confirmed by CC-RT-PCR in all positive samples, where viral RNA was not detected in the collected drinking water samples.  In conclusion RT-PCR and CC-RT-PCR techniques high lightened the need to include viruses as mandatory pollution indicator in water treatment plants. Int J Appl Sci Biotechnol, Vol 3(3): 528-536


2001 ◽  
Vol 43 (12) ◽  
pp. 39-48 ◽  
Author(s):  
L. Gofti-Laroche ◽  
B. Gratacap-Cavallier ◽  
O. Genoulaz ◽  
J. C. Joret ◽  
Ph. Hartemann ◽  
...  

This work assessed the risks associated with the virological quality of tapwater using a molecular analytical tool manageable in a field survey. It combined a daily epidemiological follow-up of digestive morbidity among a panel of volunteers and a microbiological surveillance of drinking water. RT-PCR was used for detection of enterovirus, rotavirus and astrovirus. 712 cases of acute digestive conditions occurred in the 544 volunteers. 38% (9/24) raw water and 23% (10/44) tap water samples were positive for at least one virus marker with 9/10 positive tap water samples complying with bacterial criteria. No statistically significant association was found between the presence of viral markers and observed incidence of digestive morbidity. However, when an outbreak occurred, enterovirus and rotavirus RNA was detected in the corresponding stored tap water samples. Sequencing of the amplified fragments showed that the rotavirus detected was of bovine origin. This work demonstrated that enteric virus markers were common in tapwater of the study communities (characterised by a vulnerable raw water) despite absence of bacterial indicators. Tangential ultrafiltration coupled to RT-PCR allowed a simultaneous and fast detection of the study viruses from environmental samples. This process is a promising tool usable for virological water surveillance, in as much the corresponding know-how is transferred to the field professionals.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Belay Desye ◽  
Biniam Belete ◽  
Zinabu Asfaw Gebrezgi ◽  
Tsegaye Terefe Reda

Introduction. Access to safe drinking water is essential to health, and it is a basic human right. However, drinking water treatment plant efficiency and its water quality are not well investigated in low-income countries including Ethiopia. Methods. A laboratory-based cross-sectional study was conducted among 75 water samples. Data analysis was carried out using SPSS version 22 to generate descriptive statistics, and one-way ANOVA was used to test statistically significant difference. Results. Physicochemical qualities of the water samples from tap water sources were found to be pH (6.88 ± 0.05), turbidity (5.15 ± 0.006 NTU), electrical conductivity (170.6 ± 0.1 μS/cm), residual chlorine (0.19 ± 0.003 mg/L), and fluoride (1.17 ± 0.009 mg/L). The removal efficiency of turbidity, total hardness, and nitrate was found to be 94.4%, 52.3%, and 88.7%, respectively. Removal efficiency of the treatment plant for total coliforms up to 91.6% (15 ± 0.26 CFU/100 mL in tap water) and faecal coliforms up to 99% (1.51 ± 0.03 CFU/100 mL in tap water) was recorded. Parameters of pH, temperature, and faecal coliform were statistically significant different at p < 0.05 in tap water source. The overall efficiency of the treatment plant (68.5%) and the water quality index (76) were recorded. Conclusion. Based on the results, some of the investigated parameters of water quality (turbidity, residual chlorine, total coliform, and faecal coliform) were found to be not within the permissible limits of WHO guideline values for drinking water quality. The water quality index of the water samples was categorized under good water quality. To adequately treat drinking water and improve the treatment plant, adequate preliminary treatments like screening to reduce the incoming organic loading, proper chlorination of the drinking water system, and frequent monitoring and maintenance of the treatment plant system are required.


2011 ◽  
Vol 77 (16) ◽  
pp. 5697-5706 ◽  
Author(s):  
Ivone Vaz-Moreira ◽  
Olga C. Nunes ◽  
Célia M. Manaia

ABSTRACTSphingomonadaceae(n= 86) were isolated from a drinking water treatment plant (n= 6), tap water (n= 55), cup fillers for dental chairs (n= 21), and a water demineralization filter (n= 4). The bacterial isolates were identified based on analysis of the 16S rRNA gene sequence, and intraspecies variation was assessed on the basis ofatpDgene sequence analysis. The isolates were identified as members of the generaSphingomonas(n= 27),Sphingobium(n= 28),Novosphingobium(n= 12),Sphingopyxis(n= 7), andBlastomonas(n= 12). The patterns of susceptibility to five classes of antibiotics were analyzed and compared for the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance prevalence values were observed in members of the generaSphingomonasandSphingobiumand for beta-lactams, ciprofloxacin, and cotrimoxazole. In tap water and in water from dental chairs, antibiotic resistance was more prevalent than in the other samples, mainly due to the predominance of isolates of the generaSphingomonasandSphingobium. These two genera presented distinct patterns of association with antibiotic resistance, suggesting different paths of resistance development. Antibiotic resistance patterns were often related to the species rather than to the site or strain, suggesting the importance of vertical resistance transmission in these bacteria. This is the first study demonstrating that members of the familySphingomonadaceaeare potential reservoirs of antibiotic resistance in drinking water.


2004 ◽  
Vol 70 (6) ◽  
pp. 3632-3636 ◽  
Author(s):  
Hwa Kyung Lee ◽  
Yong Seok Jeong

ABSTRACT The total culturable virus assay (TCVA) and an integrated cell culture-PCR (ICC-PCR) were compared in parallel to evaluate their detection reliability. Source, finished, and tap water samples from three drinking water treatment plant systems were analyzed by TCVA, and every cell culture dish was subsequently examined by reverse transcription (RT) multiplex PCR using enterovirus- and adenovirus-specific primers. Twenty-seven of 180 (15%) inoculated dishes exhibited cytopathic effects (CPE). Virus concentrations for source water ranged from 3.3 to 21.0 most probable numbers of infectious units (MPN) per 100 liters. No finished or tap water samples were positive. On the other hand, 38 (21%) of the dishes were positive in multiplex ICC-PCR. Virus concentrations ranged from 4.5 to 10.2 MPN/100 liters for source water and 0 to 0.9 MPN/100 liters for finished and tap water. In spite of its superior sensitivity, the ICC-PCR assay resulted in lower virus concentration values than the TCVA for two of the source water sites. Retest of the CPE-positive dishes using reovirus-specific RT-PCR revealed that 24 of the 27 (89%) dishes were also positive for reoviruses. These observations suggested that the detection reliability of ICC-PCR is restricted by the primer sets that are integrated in the reaction mixture. The observation of an uneven distribution of PCR-positive culture dishes in a given sample raises an additional caution that simple extrapolation of the ICC-PCR result from the analysis of a limited fraction of collected samples should be avoided to minimize possible over- and underestimation of the amount of virus.


Author(s):  
V.V. Lapenko ◽  
L.N. Bikbulatova ◽  
E.M. Ternikova

Water is very important for humans, as it is a solvent for metabolic products. Moreover, it is necessary for metabolism, biochemical and transport processes. The elemental status in persons depends on the geochemical environment and consumption of bioelements with food and water. The aim of the paper is to conduct a comprehensive assessment of chemical composition of drinking tap water in Khanty-Mansiysk and Salekhard. Materials and Methods. The chemical composition of 100 samples of drinking tap water was analyzed by atomic absorption spectrometry, spectrophotometry and capillary electrophoresis. All in all, there were 50 samples from Khanty-Mansiysk and 50 samples from Salekhard. The results were compared with Sanitary Rules and Norms 2.1.4.1074-01. Results. Drinking tap water in Salekhard contains a significantly higher concentration of iron, which is much above the maximum allowable concentration, if compared to water samples in Khanty-Mansiysk (p=0.03). In the cities under consideration, the water undergoes high-quality reagent-free treatment. However, the deterioration of the water supply networks in Salekhard is 3 times as high as in Khanty-Mansiysk. Calcium and magnesium concentration in water samples from Khanty-Mansiysk is 5.6 and 3.9 times lower than the MAC; in water samples from Salekhard calcium concentration is 6.3 (p=0.008) and magnesium concentration 4.6 (p<0.001) times lower than the MAC. Conclusion. The consumption of ultra-fresh drinking water leads to low intake of bioelements, which are a part of enzymes contributing to the human antioxidant defense and can result in manifestation of cardiovascular diseases. This is especially true for Salekhard with very soft drinking water and high iron concentration, which excess can exhibit prooxidant properties. Keywords: tap water, bioelements, northern region, antioxidants. Вода является важнейшим соединением для человека: необходима в качестве растворителя продуктов метаболизма и протекания обменных, биохимических и транспортных процессов. Элементный статус организма человека зависит от геохимического окружения и поступления биоэлементов с пищей и водой. Цель. Провести комплексную оценку химического состава водопроводной воды городов Ханты-Мансийск и Салехард. Материалы и методы. Методами атомно-абсорбционной спектрометрии, спектрофотометрии и капиллярного электрофореза проанализирован химический состав 100 проб водопроводной воды: по 50 из Ханты-Мансийска и Салехарда. Результаты сравнивали с СанПиН 2.1.4.1074-01. Результаты. В водопроводной воде Салехарда установлена превышающая ПДК и достоверно более высокая концентрация железа сравнительно с водой Ханты-Мансийска (р=0,03). При условии качественной безреагентной водоподготовки в изучаемых городах это обусловлено изношенностью водопроводных сетей в Салехарде, более чем в 3 раза превышающей этот показатель в Ханты-Мансийске. Концентрация кальция и магния в воде Ханты-Мансийска в 5,6 и 3,9 раза ниже ПДК; в воде Салехарда – в 6,3 (р=0,008) и 4,6 (р<0,001) раза ниже ПДК соответственно. Заключение. Употребление ультрапресной питьевой воды на фоне очень малого поступления с водой биоэлементов, входящих в состав ферментов антиоксидантной защиты организма человека, может привести к манифестации кардиоваскулярных заболеваний. Это особенно актуально для г. Салехарда с очень мягкой питьевой водой с повышенным содержанием железа, избыток которого может проявлять прооксидантные свойства. Ключевые слова: водопроводная вода, биоэлементы, северный регион, антиоксиданты.


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