scholarly journals Field scale quantification of microbial transport from bovine faeces under simulated rainfall events

2006 ◽  
Vol 5 (1) ◽  
pp. 83-95 ◽  
Author(s):  
Christobel M. Ferguson ◽  
Cheryl M. Davies ◽  
Christine Kaucner ◽  
Nicholas J. Ashbolt ◽  
Martin Krogh ◽  
...  
Keyword(s):  
Cryptosporidium Oocyst ◽  
Experimental Treatment ◽  
Bare Soil ◽  
Simulated Rainfall ◽  
Rainfall Events ◽  
E Coli ◽  
Artificial Rainfall ◽  
Cryptosporidium Oocysts ◽  
Cryptosporidium Parvum Oocysts ◽  
Experimental Soil

The dispersion and transport of Cryptosporidium parvum oocysts, Escherichia coli and PRD1 bacteriophage seeded into artificial bovine faecal pats was studied during simulated rainfall events. Experimental soil plots were divided in two, one sub-plot with bare soil and the other with natural vegetation. Simulated rainfall events of 55 mm.h-1 for 30 min were then applied to the soil plots. Each experimental treatment was performed in duplicate and consisted of three sequential artificial rainfall events (‘Runs’): a control run (no faecal pats); a fresh faecal pat run (fresh faecal pats); and an aged faecal pat run (one week aged faecal pats). Transportation efficiency increased with decreasing size of the microorganism studied; Cryptosporidium oocysts were the least mobile followed by E. coli and then PRD1 phage. Rainfall events mobilised 0.5 to 0.9% of the Cryptosporidium oocysts, 1.3‒1.4% of E. coli bacteria, and 0.03‒0.6% of PRD1 bacteriophages from the fresh faecal pats and transported them a distance of 10 m across the bare soil sub-plots. Subsequent rainfall events applied to aged faecal pats only mobilised 0.01‒0.06% of the original Cryptosporidium oocyst load, between 0.04 and 15% of the E. coli load and 0.0006‒0.06% of PRD1 bacteriophages, respectively.

scholarly journals Dispersion and Transport of Cryptosporidium Oocysts from Fecal Pats under Simulated Rainfall Events

2004 ◽  
Vol 70 (2) ◽  
pp. 1151-1159 ◽  
Author(s):  
Cheryl M. Davies ◽  
Christobel M. Ferguson ◽  
Christine Kaucner ◽  
Martin Krogh ◽  
Nanda Altavilla ◽  
...  
Keyword(s):  
Surface Soil ◽  
Bare Soil ◽  
Vegetation Coverage ◽  
Rainfall Runoff ◽  
Rainfall Events ◽  
Runoff Volume ◽  
Artificial Rainfall ◽  
Cryptosporidium Oocysts ◽  
Loam Soil ◽  
Intact Soil

ABSTRACT The dispersion and initial transport of Cryptosporidium oocysts from fecal pats were investigated during artificial rainfall events on intact soil blocks (1,500 by 900 by 300 mm). Rainfall events of 55 mm h−1 for 30 min and 25 mm h−1 for 180 min were applied to soil plots with artificial fecal pats seeded with approximately 107 oocysts. The soil plots were divided in two, with one side devoid of vegetation and the other left with natural vegetation cover. Each combination of event intensity and duration, vegetation status, and degree of slope (5° and 10°) was evaluated twice. Generally, a fivefold increase (P < 0.05) in runoff volume was generated on bare soil compared to vegetated soil, and significantly more infiltration, although highly variable, occurred through the vegetated soil blocks (P < 0.05). Runoff volume, event conditions (intensity and duration), vegetation status, degree of slope, and their interactions significantly affected the load of oocysts in the runoff. Surface runoff transported from 100.2 oocysts from vegetated loam soil (25-mm h−1, 180-min event on 10° slope) to up to 104.5 oocysts from unvegetated soil (55-mm h−1, 30-min event on 10° slope) over a 1-m distance. Surface soil samples downhill of the fecal pat contained significantly higher concentrations of oocysts on devegetated blocks than on vegetated blocks. Based on these results, there is a need to account for surface soil vegetation coverage as well as slope and rainfall runoff in future assessments of Cryptosporidium transport and when managing pathogen loads from stock grazing near streams within drinking water watersheds.

Microwave Inactivation of Cyclospora cayetanensis Sporulation and Viability of Cryptosporidium parvum Oocysts

2006 ◽  
Vol 69 (8) ◽  
pp. 1957-1960 ◽  
Author(s):  
YNES R. ORTEGA ◽  
JYEYIN LIAO
Keyword(s):  
Cryptosporidium Parvum ◽  
Propidium Iodide ◽  
Cryptosporidium Oocyst ◽  
Cooking Time ◽  
Cyclospora Cayetanensis ◽  
The Third ◽  
Infectivity Assay ◽  
Cryptosporidium Oocysts ◽  
Cryptosporidium Parvum Oocysts ◽  
Cooking Times

The efficacy of microwave heating on the viability of Cryptosporidium parvum oocysts and on the sporulation of Cyclospora cayetanensis oocysts for various periods of cooking times (0, 10, 15, 20, 30, and 45 s) at 100% power was determined. Cyclospora oocysts were stored in 2.5% dichromate at 23°C for 2 weeks, and sporulation rates were then determined. The 4′,6-diamidino-2-phenylindole and propidium iodide vital stain and the neonate animal infectivity assay determined Cryptosporidium oocyst viability. Cryptosporidium oocysts could be completely inactivated with as little as 20 s of cooking time, whereas Cyclospora sporulation was observed up to 45 s. Two of the examined microwave ovens were more effective at reducing sporulation and viability than the third one. Because of the variability of temperature achieved by the various ovens, cooking time was not an accurate parameter for parasite inactivation. Cryptosporidium oocysts could be inactivated only when temperatures of 80°C or higher were reached in the microwave ovens.

scholarly journals Removal of bacteria, protozoa and viruses through a multiple-barrier household water disinfection system

2013 ◽  
Vol 12 (1) ◽  
pp. 94-104 ◽  
Author(s):  
A. C. Espinosa-García ◽  
C. Díaz-Ávalos ◽  
R. Solano-Ortiz ◽  
M. A. Tapia-Palacios ◽  
N. Vázquez-Salvador ◽  
...  
Keyword(s):  
Mexico City ◽  
Cryptosporidium Oocyst ◽  
Water Disinfection ◽  
Giardia Cyst ◽  
E Coli ◽  
Water Characteristics ◽  
Removal Capacity ◽  
Household Water ◽  
Cryptosporidium Oocysts ◽  
Barrier Device

Municipal water disinfection systems in some areas are not always able to meet water consumer needs, such as ensuring distributed water quality, because household water management can be a contributing factor in water re-contamination. This fact is related to the storage options that are common in places where water is scarce or is distributed over limited time periods. The aim of this study is to assess the removal capacity of a multiple-barrier water disinfection device for protozoa, bacteria, and viruses. Water samples were taken from households in Mexico City and spiked with a known amount of protozoa (Giardia cyst, Cryptosporidium oocyst), bacteria (Escherichia coli), and viruses (rotavirus, adenovirus, F-specific ribonucleic acid (FRNA) coliphage). Each inoculated sample was processed through a multiple-barrier device. The efficiency of the multiple-barrier device to remove E. coli was close to 100%, and more than 87% of Cryptosporidium oocysts and more than 98% of Giardia cysts were removed. Close to 100% of coliphages were removed, 99.6% of the adenovirus was removed, and the rotavirus was almost totally removed. An effect of site by zone was detected; this observation is important because the water characteristics could indicate the efficiency of the multiple-barrier disinfection device.

scholarly journals Removal of model viruses, E. coli and Cryptosporidium oocysts from surface water by zirconium and chitosan coagulants

2017 ◽  
Vol 15 (5) ◽  
pp. 695-705 ◽  
Author(s):  
Ekaterina Christensen ◽  
Vegard Nilsen ◽  
Tor Håkonsen ◽  
Arve Heistad ◽  
Christophe Gantzer ◽  
...  
Keyword(s):  
Surface Water ◽  
Salmonella Typhimurium ◽  
Potable Water ◽  
Water Production ◽  
E Coli ◽  
Cryptosporidium Oocysts ◽  
Cryptosporidium Parvum Oocysts ◽  
Filter Bed ◽  
First Time ◽  
Polyaluminium Chloride

The present work evaluates the effect of contact filtration, preceded by coagulation with zirconium (Zr) and chitosan coagulants, on model microorganisms and waterborne pathogens. River water intended for potable water production was spiked with MS2 and Salmonella Typhimurium 28B bacteriophages, Escherichia coli, and Cryptosporidium parvum oocysts prior to coagulation. The hygienic performance demonstrated by Zr comprised 3.0–4.0 log10 removal of viruses and 5.0–6.0 log10 removal of E. coli and C. parvum oocysts. Treatment with chitosan resulted in a removal of 2.5–3.0 log10 of viruses and parasites, and 4.5–5.0 log10 of bacteria. A reference coagulant, polyaluminium chloride (PACl), gave a 2.5–3.0 log10 removal of viruses and 4.5 log10 of E. coli. These results indicate that both Zr and chitosan enable adequate removal of microorganisms from surface water. The present study also attempts to assess removal rates of the selected microorganisms with regard to their size and surface properties. The isoelectric point of the Salmonella Typhimurium 28B bacteriophage is reported for the first time. The retention of the selected microorganisms in the filter bed appeared to have some correlation with their size, but the effect of the charge remained unclear.

Hygienic risk assessment by monitoring pathogens in municipal sewage

2002 ◽  
Vol 2 (3) ◽  
pp. 23-28 ◽  
Author(s):  
C.-H. von Bonsdorff ◽  
L. Maunula ◽  
R.M. Niemi ◽  
R. Rimhanen-Finne ◽  
M.-L. Hänninen ◽  
...  
Keyword(s):  
Enteric Viruses ◽  
Detection Methods ◽  
Municipal Sewage ◽  
Small Community ◽  
E Coli ◽  
Cryptosporidium Oocysts ◽  
High Concentrations ◽  
One Year ◽  
Enteric Protozoa ◽  
Day Care Centre

The purpose of this study was to monitor the levels of human enteric viruses and enteric protozoa and to relate their presence to the microbes used as hygienic quality indicators in domestic sewage from a small community in Finland during a period of one year. Genome-based sensitive detection methods for the pathogens selected (astro- and Norwalk-like viruses, Giardia and Cryptosporidium) have become available only recently and thus no earlier data was available. The effluent sewage is delivered into a river that serves as raw water for a larger town and the pathogens therefore constitute a health risk. The results showed that all the monitored pathogens could be detected, and that enteric viruses were present at considerable concentrations in sewage. High concentrations of astrovirus in raw sewage were observed during a diarrhea epidemic in the local day-care centre. The presence of viruses did not correlate with the monitored bacterial indicators of faecal contamination (coliforms, E. coli and enterococci) or with bacteriophages (somatic coliphages, F-specific RNA phages and B. fragilis phages). Giardia cysts and Cryptosporidium oocysts were detected from one sample (1/10) each.

scholarly journals Use of Oxidative Stress Responses to Determine the Efficacy of Inactivation Treatments on Cryptosporidium Oocysts

2021 ◽  
Vol 9 (7) ◽  
pp. 1463
Author(s):  
Tamirat Tefera Temesgen ◽  
Kristoffer Relling Tysnes ◽  
Lucy Jane Robertson
Keyword(s):  
Oxidative Stress ◽  
Stress Responses ◽  
Target Genes ◽  
Cryptosporidium Oocyst ◽  
Drinking Water Treatment ◽  
Proof Of Concept ◽  
Environmental Matrices ◽  
Oocyst Wall ◽  
Novel Approach ◽  
Cryptosporidium Oocysts

Cryptosporidium oocysts are known for being very robust, and their prolonged survival in the environment has resulted in outbreaks of cryptosporidiosis associated with the consumption of contaminated water or food. Although inactivation methods used for drinking water treatment, such as UV irradiation, can inactivate Cryptosporidium oocysts, they are not necessarily suitable for use with other environmental matrices, such as food. In order to identify alternative ways to inactivate Cryptosporidium oocysts, improved methods for viability assessment are needed. Here we describe a proof of concept for a novel approach for determining how effective inactivation treatments are at killing pathogens, such as the parasite Cryptosporidium. RNA sequencing was used to identify potential up-regulated target genes induced by oxidative stress, and a reverse transcription quantitative PCR (RT-qPCR) protocol was developed to assess their up-regulation following exposure to different induction treatments. Accordingly, RT-qPCR protocols targeting thioredoxin and Cryptosporidium oocyst wall protein 7 (COWP7) genes were evaluated on mixtures of viable and inactivated oocysts, and on oocysts subjected to various potential inactivation treatments such as freezing and chlorination. The results from the present proof-of-concept experiments indicate that this could be a useful tool in efforts towards assessing potential technologies for inactivating Cryptosporidium in different environmental matrices. Furthermore, this approach could also be used for similar investigations with other pathogens.

scholarly journals Effect of tillage, slope, and rainfall on soil surface microtopography quantified by geostatistical and fractal indices during sheet erosion

2020 ◽  
Vol 12 (1) ◽  
pp. 232-241
Author(s):  
Na Ta ◽  
Chutian Zhang ◽  
Hongru Ding ◽  
Qingfeng Zhang
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Soil Surface ◽  
Rainfall Events ◽  
Tillage Practices ◽  
Surface Microtopography ◽  
Artificial Rainfall ◽  
Soil Surface Roughness ◽  
The Difference ◽  
Sheet Erosion

AbstractTillage and slope will influence soil surface roughness that changes during rainfall events. This study tests this effect under controlled conditions quantified by geostatistical and fractal indices. When four commonly adopted tillage practices, namely, artificial backhoe (AB), artificial digging (AD), contour tillage (CT), and linear slope (CK), were prepared on soil surfaces at 2 × 1 × 0.5 m soil pans at 5°, 10°, or 20° slope gradients, artificial rainfall with an intensity of 60 or 90 mm h−1 was applied to it. Measurements of the difference in elevation points of the surface profiles were taken before rainfall and after rainfall events for sheet erosion. Tillage practices had a relationship with fractal indices that the surface treated with CT exhibited the biggest fractal dimension D value, followed by the surfaces AD, AB, and CK. Surfaces under a stronger rainfall tended to have a greater D value. Tillage treatments affected anisotropy differently and the surface CT had the strongest effect on anisotropy, followed by the surfaces AD, AB, and CK. A steeper surface would have less effect on anisotropy. Since the surface CT had the strongest effect on spatial variability or the weakest spatial autocorrelation, it had the smallest effect on runoff and sediment yield. Therefore, tillage CT could make a better tillage practice of conserving water and soil. Simultaneously, changes in semivariogram and fractal parameters for surface roughness were examined and evaluated. Fractal parameter – crossover length l – is more sensitive than fractal dimension D to rainfall action to describe vertical differences in soil surface roughness evolution.

scholarly journals Erosion and Subsequent Transport State of Escherichia coli from Cowpats

2005 ◽  
Vol 71 (6) ◽  
pp. 2875-2879 ◽  
Author(s):  
Richard William Muirhead ◽  
Robert Peter Collins ◽  
Philip James Bremer
Keyword(s):  
Escherichia Coli ◽  
Surface Waters ◽  
Overland Flow ◽  
Single Cells ◽  
Rainfall Event ◽  
Buffer Strips ◽  
Simulated Rainfall ◽  
E Coli ◽  
Unattached Fraction ◽  
Over Time

ABSTRACT Processes by which fecal bacteria enter overland flow and their transportation state to surface waters are poorly understood, making the effectiveness of measures designed to intercept this pathway, such as vegetated buffer strips, difficult to predict. Freshly made and aged (up to 30 days) cowpats were exposed to simulated rainfall, and samples of the cowpat material and runoff were collected. Escherichia coli in the runoff samples were separated into attached (to particles) and unattached fractions, and the unattached fraction was analyzed to determine if the cells were clumped. Within cowpats, E. coli grew for 6 to 14 days, rather than following a typical logarithmic die-off curve. E. coli numbers in the runoff correlated with numbers inside the cowpat. Most of the E. coli organisms eroded from the cowpats were transported as single cells, and only a small percentage (about 8%) attached to particles. The erosion of E. coli from cowpats and the state in which the cells were transported did not vary with time within a single rainfall event or over time as the cowpats aged and dried out. These findings indicate that cowpats can remain a significant source of E. coli in overland flow for more than 30 days. As well, most of the E. coli organisms eroded from cowpats will occur as readily transportable single cells.

Determination of the Recovery Efficiency of Cryptosporidium Oocysts and Giardia Cysts from Seeded Bivalve Mollusks

2013 ◽  
Vol 76 (1) ◽  
pp. 93-98 ◽  
Author(s):  
FRANCISKA M. SCHETS ◽  
HAROLD H. J. L. van den BERG ◽  
ANA MARIA de RODA HUSMAN
Keyword(s):  
Quantitative Assessment ◽  
Intestinal Parasites ◽  
Cryptosporidium Oocyst ◽  
Immunomagnetic Separation ◽  
Giardia Cyst ◽  
Bivalve Mollusks ◽  
Recovery Efficiency ◽  
Risk Of Infection ◽  
Cryptosporidium Oocysts

The intestinal parasites Cryptosporidium and Giardia are transmitted by water and food and cause human gastroenteritis. Filter-feeding bivalve mollusks, such as oysters and mussels, filter large volumes of water and thus concentrate such pathogens, which makes these bivalves potential vectors of disease. To assess the risk of infection from consumption of contaminated bivalves, parasite numbers and parasite recovery data are required. A modified immunomagnetic separation (IMS) procedure was used to determine Cryptosporidium oocyst and Giardia cyst numbers in individually homogenized oysters (Crassostrea gigas) and mussels (Mytilus edulis). About 12% of the commercial bivalves were positive, with low (oo)cyst numbers per specimen. The recovery efficiency of the IMS procedure was systematically evaluated. Experiments included seeding of homogenized bivalves and whole animals with 100 to 1,000 (oo)cysts. Both seeding procedures yielded highly variable recovery rates. Median Cryptosporidium recoveries were 7.9 to 21% in oysters and 62% in mussels. Median Giardia recoveries were 10 to 25% in oysters and 110% in mussels. Giardia recovery was significantly higher than Cryptosporidium recovery. (Oo)cysts were less efficiently recovered from seeded whole animals than from seeded homogenates, with median Cryptosporidium recoveries of 5.3% in oysters and 45% in mussels and median Giardia recoveries of 4.0% in oysters and 82% in mussels. Both bivalve homogenate seeding and whole animal seeding yielded higher (oo)cyst recovery in mussels than in oysters, likely because of the presence of less shellfish tissue in IMS when analyzing the smaller mussels compared with the larger oysters, resulting in more efficient (oo)cyst extraction. The data generated in this study may be used in the quantitative assessment of the risk of infection with Cryptosporidium or Giardia associated with the consumption of raw bivalve mollusks. This information may be used for making risk management decisions.

Cryptosporidium oocyst shedding in buffalo calves in Haryana: A case study

2018 ◽  
Author(s):  
Krutanjali Swain ◽  
Abhilash Routray ◽  
Saraswat Sahoo and Subha Ganguly
Keyword(s):  
Cryptosporidium Oocyst ◽  
Buffalo Calves ◽  
Concentration Technique ◽  
Cryptosporidium Oocysts ◽  
Oil Immersion ◽  
Neonatal Diarrhoea ◽  
Conventional Microscopy ◽  
Animal Sciences ◽  
Acid Fast Staining

Bovine cryptosporidiosisis primarily associated with neonatal diarrhoea with higher morbidity than mortality in young calves till they attain immunological maturity. The present investigation relates to a report on the shedding of Cryptosporidium oocyst in two buffalo calves of buffalo farm, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar from 1st days up to 3 month of age at 15 days interval using simple conventional microscopy. By using formol-ether concentration technique followed by modified Ziehl-Neelsen (ZN) acid fast staining, Cryptosporidium oocysts were concentrated and identified. The Cryptosporidium oocysts appeared as reddish pink coloured bodies against a bluish/greenish coloured background at oil immersion using ZN staining kit. The maximum oocyst shedding was observed (2.3 oocyst / field) during 16 to 30 days of age. The oocyst shedding gradually decreased with increase in age afterwards clearly indicating the disease of young buffalo calves.

Sign in / Sign up

Export Citation Format

Share Document