Evaluation of four commercial antibodies

Hoffman, Rebecca M.; Chauret, Christian; Standridge, Jon H.; Peterson, Linda R.

doi:10.1002/j.1551-8833.1999.tb08698.x

Cited by 14 publications

(7 citation statements)

References 19 publications

(18 reference statements)

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“…A higher recovery rate occurred in samples treated by the RM method than by the ADM technique, which was also corroborated in the control-trial ( Table 1). The detected cysts and oocysts are in conformity with standard fluorescence detection criteria 9 . In many of them the Cryptosporidium suture could be observed and exhibited bright green fluorescence.…”

Section: Resultssupporting

confidence: 66%

Occurrence of Cryptosporidium oocysts and Giardia cysts in raw water from the Atibaia river, Campinas, Brazil

Franco

Rocha-Eberhardt

Neto

2001

Rev. Inst. Med. trop. S. Paulo

105

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SUMMARYCryptosporidium parvum and Giardia duodenalis are waterborne parasites that have caused several outbreaks of gastrointestinal disease associated with drinking water. Due to the lack of studies about the occurrence of these protozoa in water in the Southeast of Brazil, an investigation was conducted to verify the presence of cysts and oocysts in superficial raw water of the Atibaia River. The water samples were submitted to membrane filtration (3.0 mm) and elution was processed by (1) scraping and rinsing of membrane (RM method) and (2) acetone-dissolution (ADM method). Microbiologic and chemical parameters were analyzed. Aliquots of the pellets were examined by immunofluorescence (Merifluor, Meridian Diagnostics, Cincinnati, Ohio). All water samples were positive for Cryptosporidium and Giardia, in spite of the high turbidity. Higher recovery rates occurred in samples treated by the RM method than by the ADM technique. The goal for future work is the assessment of viability of cysts and oocysts to determine the public health significance of this finding.

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Section: Resultssupporting

confidence: 66%

Occurrence of Cryptosporidium oocysts and Giardia cysts in raw water from the Atibaia river, Campinas, Brazil

Franco

Rocha-Eberhardt

Neto

2001

Rev. Inst. Med. trop. S. Paulo

105

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“…These samples were analyzed by the same procedures described above. The detected cysts and oocysts in all samples are in conformity with standard fluorescence detection criteria 15 .…”

Section: Methodssupporting

confidence: 73%

Occurrence of Giardia cysts and Cryptosporidium oocysts in activated sludge samples in Campinas, SP, Brazil

Santos

Bonatti

Neto

et al. 2004

Rev. Inst. Med. trop. S. Paulo

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Giardia and Cryptosporidium have caused several outbreaks of gastroenteritis in humans associated with drinking water. Contaminated sewage effluents are recognized as a potential source of waterborne protozoa. Due to the lack of studies about the occurrence of these parasites in sewage samples in Brazil, we compared the efficiency of two procedures for concentrating cysts and oocysts in activated sludge samples of one sewage treatment plant. For this, the samples were submitted to i) concentration by the ether clarification procedure (ECP) and to ii) purification by sucrose flotation method (SFM) and aliquots of the pellets were examined by immunofluorescence. Giardia cysts were present in all samples (100.0%; n = 8) when using ECP and kit 1 reagents, while kit 2 resulted in six positive samples (85.7%; n = 7). As for SFM, cysts were detected in 75.0% and 100.0% of these samples (for kit 1 and 2, respectively). Regarding Cryptosporidium, two samples (25.0%; kit 1 and 28.5% for kit 2) were detected positive by using ECP, while for SFM, only one sample (examined by kit 1) was positive (12.5%). The results of the control trial revealed Giardia and Cryptosporidium recovery efficiency rates for ECP of 54.5% and 9.6%, while SFM was 10.5% and 3.2%, respectively. Considering the high concentration detected, a previous evaluation of the activated sludge before its application in agriculture is recommended and with some improvement, ECP would be an appropriate simple technique for protozoa detection in sewage samples.

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“…From this point on, the authors tested each new lot of reagents used for these experiments before using them for sample analyses or precision and recovery experiments. Lot-to-lot variation of commercially available Cryptosporidium oocyst antibodies has been documented (Hoffman et al, 1999). Users of method 1622 should be aware that inconsistent lot-to-lot variations in the quality and amounts of antibodies compromise the accuracy of analytical results.…”

Section: Discussionmentioning

confidence: 99%

“…A further limitation of the method is that it relies on Cryptosporidium oocyst surface epitopes that react with antibodies used for both IMS and staining. When oocysts are exposed to high concentrations of chlorine, environmental stresses, or stresses from method processing (Hoffman et al, 1999), the conformation of the epitope antigens are known to change, making the oocysts either more or less reactive with the antibodies. In a case in which antibodies used for IMS and staining react less than optimally, oocysts could go undetected, causing false-negative results.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of USEPA Method 1622 for detection of Cryptosporidium oocysts in stream waters

Simmons¹,

Sobsey²,

Schaefer³

et al. 2001

Journal AWWA

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To improve surveillance for Cryptosporidium oocysts in water, the US Environmental Protection Agency developed method 1622, which consists of filtration, concentration, immunomagnetic separation, fluorescent antibody and 4, 6-diamidino-2-phenylindole (DAPI) counter-staining, and microscopic evaluation. Two filters were compared for analysis of 11 stream water samples collected throughout the United States. Replicate 10-L stream water samples (unspiked and spiked with 100-250 oocysts) were tested to evaluate matrix effects.Oocyst recoveries from the stream water samples averaged 22% (standard deviation [SD] = ±17%) with a membrane disk and 12% (SD = ±6%) with a capsule filter. Oocyst recoveries from reagent water precision and recovery samples averaged 39% (SD = ±13%) with a membrane disk and 47% (SD = ±19%) with a capsule filter. These results demonstrate that Cryptosporidium oocysts can be recovered from stream waters using method 1622, but recoveries are lower than those from reagent-grade water. This research also evaluated concentrations of indicator bacteria in the stream water samples. Because few samples were oocyst-positive, relationships between detections of oocysts and concentrations of indicator organisms could not be determined.

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Evaluation of four commercial antibodies

Cited by 14 publications

References 19 publications

Occurrence of Cryptosporidium oocysts and Giardia cysts in raw water from the Atibaia river, Campinas, Brazil

Occurrence of Cryptosporidium oocysts and Giardia cysts in raw water from the Atibaia river, Campinas, Brazil

Occurrence of Giardia cysts and Cryptosporidium oocysts in activated sludge samples in Campinas, SP, Brazil

Evaluation of USEPA Method 1622 for detection of Cryptosporidium oocysts in stream waters

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