scholarly journals Effects of pH and Magnetic Material on Immunomagnetic Separation of Cryptosporidium Oocysts from Concentrated Water Samples

2002 ◽  
Vol 68 (4) ◽  
pp. 2066-2070 ◽  
Author(s):  
Ryan C. Kuhn ◽  
Channah M. Rock ◽  
Kevin H. Oshima

ABSTRACT In this study, we examined the effect that magnetic materials and pH have on the recoveries of Cryptosporidium oocysts by immunomagnetic separation (IMS). We determined that particles that were concentrated on a magnet during bead separation have no influence on oocyst recovery; however, removal of these particles did influence pH values. The optimal pH of the IMS was determined to be 7.0. The numbers of oocysts recovered from deionized water at pH 7.0 were 26.3% higher than those recovered from samples that were not at optimal pH. The results indicate that the buffers in the IMS kit did not adequately maintain an optimum pH in some water samples. By adjusting the pH of concentrated environmental water samples to 7.0, recoveries of oocysts increased by 26.4% compared to recoveries from samples where the pH was not adjusted.

2000 ◽  
Vol 41 (7) ◽  
pp. 197-202 ◽  
Author(s):  
F. Zanelli ◽  
B. Compagnon ◽  
J. C. Joret ◽  
M. R. de Roubin

The utilization of the ChemScan® RDI was tested for different types of water concentrates. Concentrates were prepared by cartridge filtration or flocculation, and analysed either without purification, or after Immunomagnetic separation (IMS) or flotation on percoll-sucrose gradients. Theenumeration of the oocysts was subsequently performed using the ChemScan® RDI Cryptosporidium application. Enumeration by direct microscopic observation of the entire surface of the membrane was carried out as a control, and recoveries were calculated as a ratio between the ChemScan® RDI result and the result obtained with direct microscopic enumeration. The Chemscan enumeration technique proved reliable, with recoveries yielding close to 100% in most cases (average 125%, range from 86 to 467%) for all the concentration/purification techniques tested. The quality of the antibodies was shown to be critical, with antibodies from some suppliers yielding recoveries a low as 10% in some cases. This difficulty could, however, be overcome by the utilization of the antibody provided by Chemunex. These data conclusively prove that laser scanning cytometry, which greatly facilitates the microscopic enumeration of Cryptosporidium oocysts from water samples and decreases the time of observation by four to six times, can be successfully applied to water concentrates prepared from a variety of concentration/purification techniques.


1995 ◽  
Vol 31 (5-6) ◽  
pp. 435-438 ◽  
Author(s):  
R. Kfir ◽  
C. Hilner ◽  
M. du Preez ◽  
B. Bateman

The levels of Giardia cysts and Cryptosporidium oocysts in 650 environmental water samples were investigated. Cysts and oocysts were found in all types of water tested. The presence of Giardia cysts exceeded Cryptosporidium oocysts both in the number per sample and the number of positive samples. Almost 50% of sewage samples studied contained Giardia cysts and 30% contained both Giardia cysts and Cryptosporidium oocysts. Treatment of sewage resulted in a reduction in the percentage of samples containing cysts and/or oocysts (30% of treated effluent samples were positive for Giardia and 25% had both cysts and oocysts). Higher numbers of Giardia cysts were found in surface water samples than in either sewage or treated effluents (55% of surface water samples were positive). However, the number of cysts isolated per surface water sample was lower on average. Most water purification plants showed effective removal of cysts and oocysts. However, 13% of potable water samples contained protozoan parasites, indicating occasional failure of the purification processes and the need for monitoring final treated water.


2000 ◽  
Vol 41 (7) ◽  
pp. 111-117 ◽  
Author(s):  
A. Pezzana ◽  
Ph. Vilaginès ◽  
F. Bordet ◽  
D. Coquard ◽  
B. Sarrette ◽  
...  

The method for concentration of Cryptosporidium oocysts in large drinking water samples using the Envirocheck capsule has been optimized for the detection of low levels of oocysts. Elution from the filter by contact time and vortex agitation gave 68% oocyst recovery. Centrifugation (1,250 g; 30 min; 4°C) improved recovery to 94% without morphological damage of the oocysts. Increasing the ratio of magnetic beads to sample volume in the IMS procedure led to 69% efficiency. In these conditions, the overall recovery of the procedure was 49% as assessed with low oocysts spike doses in 100 litres tap water samples. The methodology described allows the detection of 0.1 oocyst per litre when 100 litres samples are processed.


2017 ◽  
Vol 4 (3) ◽  
pp. 42-47
Author(s):  
Mohammad-Reza Mahmoudi ◽  
Mojgan Bandepour ◽  
Bahram Kazemi ◽  
Asad Mirzaei ◽  
◽  
...  

1998 ◽  
Vol 64 (11) ◽  
pp. 4495-4499 ◽  
Author(s):  
Z. Bukhari ◽  
R. M. McCuin ◽  
C. R. Fricker ◽  
J. L. Clancy

ABSTRACT Immunomagnetic separation (IMS) procedures which specifically capture Cryptosporidium oocysts and have the potential to isolate oocysts from debris have become commercially available. We compared two IMS kits (kit DB [Dynabeads anti-Cryptosporidium; product no. 730.01; Dynal A.S., Oslo, Norway] and kit IC1 [Crypto Scan IMS; product no. R10; Clearwater Diagnostics Company, LLC, Portland, Maine]) and a modification of kit IC1 (kit IC2 [Crypto Scan IMS; product no. R10; Clearwater Diagnostics Company, LLC]) at three turbidity levels (50, 500, and 5,000 nephelometric turbidity units [ntu]) by using water matrices obtained from different geographical locations. In deionized water, kit DB yielded recoveries between 68 and 83%, whereas the recoveries obtained with kits IC1 and IC2 were more variable and ranged from 0.2 to 74.5%. In water matrices with turbidity levels up to 500 ntu, the oocyst recoveries were more variable with kit DB; however, the recoveries were similar to those obtained in deionized water. In contrast, there were notable reductions in oocyst recoveries in the turbid matrices with kits IC1 and IC2, and the highest recovery (8.3%) was obtained with a 50-ntu sample. An examination of the effects of age on oocyst recovery with kit DB revealed that oocysts up to 16 weeks old yielded recoveries similar to the recoveries observed with fresh oocysts. These data indicate that all IMS kits do not perform equally well, and it is important to conduct in-house quality assurance work before a commercially available IMS kit is selected to replace flotation procedures for recovery of Cryptosporidium oocysts.


2002 ◽  
Vol 48 (6) ◽  
pp. 542-549 ◽  
Author(s):  
Ryan C Kuhn ◽  
Kevin H Oshima

An optimized hollow-fiber ultrafiltration system (50 000 MWCO) was developed to concentrate Cryptosporidium oocysts from 10-L samples of environmental water. Seeded experiments were conducted using a number of surface-water samples from the southwestern U.S.A. and source water from four water districts with histories of poor oocyst recovery. Ultrafiltration produced a mean recovery of 47.9% from 19 water samples (55.3% from 39 individual tests). We also compared oocyst recoveries using the hollow-fiber ultrafiltration system with those using the Envirochek filter. In limited comparison tests, the hollow-fiber ultrafiltration system produced recoveries similar to those of the Envirochek filter (hollow fiber, 74.1% (SD = 2.8); Envirochek, 71.9% (SD = 5.2)) in low-turbidity (3.9 NTU) samples and performed better than the Envirochek filter in high-turbidity (159.0 NTU) samples (hollow fiber, 27.5%; Envirochek, 0.4%). These results indicate that hollow-fiber ultrafiltration can efficiently recover oocysts from a wide variety of surface waters and may be a cost-effective alternative for concentrating Cryptosporidium from water, given the reusable nature of the filter.Key words: Cryptosporidium, ultrafiltration, oocyst.


Author(s):  
RIGOBERTO ZETINA LEZAMA ◽  
OSCAR HUGO TOSQUY VALLE ◽  
VALENTÍN A. ESQUEDA ESQUIVEL

Objective: to determine the effect of liquid micronized CaCO3 on soil pH and pineapple vegetative development in acidic soils at Isla, Veracruz. Design/Methodology/Approach: randomized blocks with four replications and four treatments: Non-liming control (T1), 2.0 t ha-1 of dolomite (T2), 10.0 (T3) and 20.0 (T4) L ha-1  of liquid CaCO3. The soil pH was measured, before liming and at 30, 60, 90 and 120 days after sowing, at depths of 0-5, 5-15 and 15-30 cm, and the biomass was determined at the 60, 90 and 120 dds. Analysis of variance and the 5% Fisher test were performed to separate means. Results: up to 90 dds, with dolomite, optimal pH values were reached for pineapple, significantly higher than those of CaCO3 in both doses. At 120 dds, with 20 L ha-1 CaCO3 the pH was higher than 5.0, similar to that of dolomite and higher than those of the low dose of CaCO3 and the control. At the last date, with 20 L ha-1 of CaCO3 1,346 g plant-1 biomass were produced, an amount similar to dolomite and the low dose of CaCO3 and significantly higher than that of the control. Findings/Conclusions: up to 120 dds, with 20 L ha-1 of liquid CaCO3, the optimum pH for pineapple was reached in the three strata, the values were similar to those of dolomite and higher than those of the low dose of CaCO3 and the control. CaCO3 (20 L ha-1) and dolomite (2 t ha-1) produced 33.1 and 20.9% more biomass than the control.


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