scholarly journals Identification of Cryptosporidium spp. Oocysts in United Kingdom Noncarbonated Natural Mineral Waters and Drinking Waters by Using a Modified Nested PCR-Restriction Fragment Length Polymorphism Assay

2003 ◽  
Vol 69 (7) ◽  
pp. 4183-4189 ◽  
Author(s):  
R. A. B. Nichols ◽  
B. M. Campbell ◽  
H. V. Smith
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Water Samples ◽  
Nested Pcr ◽  
Fragment Length Polymorphism ◽  
Mineral Waters ◽  
Natural Mineral ◽  
Drinking Waters ◽  
Restriction Fragment Length

ABSTRACT We describe a nested PCR-restriction fragment length polymorphism (RFLP) method for detecting low densities of Cryptosporidium spp. oocysts in natural mineral waters and drinking waters. Oocysts were recovered from seeded 1-liter volumes of mineral water by filtration through polycarbonate membranes and from drinking waters by filtration, immunomagnetizable separation, and filter entrapment, followed by direct extraction of DNA. The DNA was released from polycarbonate filter-entrapped oocysts by disruption in lysis buffer by using 15 cycles of freeze-thawing (1 min in liquid nitrogen and 1 min at 65°C), followed by proteinase K digestion. Amplicons were readily detected from two to five intact oocysts on ethidium bromide-stained gels. DNA extracted from Cryptosporidium parvum oocysts, C. muris (RN 66), C. baileyi (Belgium strain, LB 19), human-derived C. meleagridis, C. felis (DNA from oocysts isolated from a cat), and C. andersoni was used to demonstrate species identity by PCR-RFLP after simultaneous digestion with the restriction enzymes DraI and VspI. Discrimination between C. andersoni and C. muris isolates was confirmed by a separate, subsequent digestion with DdeI. Of 14 drinking water samples tested, 12 were found to be positive by microscopy, 8 were found to be positive by direct PCR, and 14 were found to be positive by using a nested PCR. The Cryptosporidium species detected in these finished water samples was C. parvum genotype 1. This method consistently and routinely detected >5 oocysts per sample.

Detection of Cryptosporidium in stool sample by PCR-RFLP v1

2021 ◽  
Author(s):  
botchiesenyo not provided
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Length Polymorphism ◽  
Nested Pcr ◽  
Fragment Length Polymorphism ◽  
Mineral Waters ◽  
Natural Mineral ◽  
Cryptosporidium Spp ◽  
Drinking Waters ◽  
Pcr Rflp ◽  
Restriction Fragment Length

Nested PCR-RFLP adapted from Nichols, R.A.B., Campbell, B.M. and Smith, H.V., 2003. Identification of Cryptosporidium spp. oocysts in United Kingdom noncarbonated natural mineral waters and drinking waters by using a modified nested PCR-restriction fragment length polymorphism assay. Applied and environmental microbiology, 69(7), p.4183.

scholarly journals Species-Specific, Nested PCR-Restriction Fragment Length Polymorphism Detection of Single Cryptosporidium parvum Oocysts

2001 ◽  
Vol 67 (6) ◽  
pp. 2665-2668 ◽  
Author(s):  
Gregory D. Sturbaum ◽  
Carrie Reed ◽  
Paul J. Hoover ◽  
B. Helen Jost ◽  
Marilyn M. Marshall ◽  
...  
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Cryptosporidium Parvum ◽  
Restriction Enzyme ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Nested Pcr ◽  
Fragment Length Polymorphism ◽  
Enzyme Digestion ◽  
Restriction Enzyme Digestion ◽  
Restriction Fragment Length

ABSTRACT Concurrent with recent advances seen with Cryptosporidium parvum detection in both treated and untreated water is the need to properly evaluate these advances. A micromanipulation method by which known numbers of C. parvum oocysts, even a single oocyst, can be delivered to a test matrix for detection sensitivity is presented. Using newly developed nested PCR-restriction fragment length polymorphism primers, PCR sensitivity was evaluated with 1, 2, 3, 4, 5, 7, or 10 oocysts. PCR detection rates (50 samples for each number of oocysts) ranged from 38% for single oocysts to 92% for 5 oocysts, while 10 oocysts were needed to achieve 100% detection. The nested PCR conditions amplified products from C. parvum,Cryptosporidium baileyi, and Cryptosporidium serpentis but no other Cryptosporidium sp. or protozoan tested. Restriction enzyme digestion with VspI distinguished between C. parvum genotypes 1 and 2. Restriction enzyme digestion with DraII distinguishedC. parvum from C. baileyi and C. serpentis. Use of known numbers of whole oocysts encompasses the difficulty of liberating DNA from the oocyst and eliminates the standard deviation inherent within a dilution series. To our knowledge this is the first report in which singly isolatedC. parvum oocysts were used to evaluate PCR sensitivity. This achievement illustrates that PCR amplification of a single oocyst is feasible, yet sensitivity remains an issue, thereby illustrating the difficulty of dealing with low oocyst numbers when working with environmental water samples.

scholarly journals Detection and Resolution of Cryptosporidium Species and Species Mixtures by Genus-Specific Nested PCR-Restriction Fragment Length Polymorphism Analysis, Direct Sequencing, and Cloning

2011 ◽  
Vol 77 (12) ◽  
pp. 3998-4007 ◽  
Author(s):  
Norma J. Ruecker ◽  
Rebecca M. Hoffman ◽  
Rachel M. Chalmers ◽  
Norman F. Neumann
Keyword(s):  
Restriction Fragment Length Polymorphism ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Nested Pcr ◽  
Fragment Length Polymorphism ◽  
Rflp Analysis ◽  
Content Type ◽  
Pcr Rflp ◽  
Pcr Products ◽  
Restriction Fragment Length

ABSTRACTMolecular methods incorporating nested PCR-restriction fragment length polymorphism (RFLP) analysis of the 18S rRNA gene ofCryptosporidiumspecies were validated to assess performance based on limit of detection (LoD) and for detecting and resolving mixtures of species and genotypes within a single sample. The 95% LoD was determined for seven species (Cryptosporidium hominis,C. parvum,C. felis,C. meleagridis,C. ubiquitum,C. muris, andC. andersoni) and ranged from 7 to 11 plasmid template copies with overlapping 95% confidence limits. The LoD values for genomic DNA from oocysts on microscope slides were 7 and 10 template copies forC. andersoniandC. parvum, respectively. The repetitive nested PCR-RFLP slide protocol had an LoD of 4 oocysts per slide. When templates of two species were mixed in equal ratios in the nested PCR-RFLP reaction mixture, there was no amplification bias toward one species over another. At high ratios of template mixtures (>1:10), there was a reduction or loss of detection of the less abundant species by RFLP analysis, most likely due to heteroduplex formation in the later cycles of the PCR. Replicate nested PCR was successful at resolving many mixtures ofCryptosporidiumat template concentrations near or below the LoD. The cloning of nested PCR products resulted in 17% of the cloned sequences being recombinants of the two original templates. Limiting-dilution nested PCR followed by the sequencing of PCR products resulted in no sequence anomalies, suggesting that this method is an effective and accurate way to study the species diversity ofCryptosporidium, particularly for environmental water samples, in which mixtures of parasites are common.

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