Characterization of Giardia duodenalis by polymerase-chain-reaction fingerprinting.
The development of a polymerase chain reaction (PCR) based fingerprinting method for the characterization of Giardia duodenalis isolates is described. The method uses three different PCRs; one is specific for the A ("Polish") major group of G. duodenalis isolates, another is specific for the B ("Belgian") group of isolates; and one amplifies a fragment of the glutamate dehydrogenase gene present in all G. duodenalis isolates. The PCRs perform highly sensitively on DNA from cultured trophozoites. Isolates were further characterized by restriction-fragment-length polymorphism (RFLP) analysis of the PCR products. In this way, representative isolates from the A and B groups could be grouped together into a number of subgroups. The stability of the genotypes with time and the reproducibility of the two methods were tested on cloned and subcloned lines from a number of isolates and proved to be highly satisfactory. The PCR/RFLP method was evaluated on cysts derived from a number of human patients. It is concluded that the PCR fingerprinting method described in this paper provides a reliable characterization method for Giardia isolates and has the potential to be used as a direct method of typing G. duodenalis cysts from feces.
Microbiological Laboratory of Health Protection, National Institute of Public Health and the Environment, Bilthoven, The Netherlands. wieger.homan@rivm.nl
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Homan
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Gilsing
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Bentala
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Limper
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van Knapen
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002648:Child; D002675:Child, Preschool; D003001:Cloning, Molecular; D016172:DNA Fingerprinting / Q000379:methods; D017931:DNA Primers; D016054:DNA, Protozoan / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000469:parasitology; D005872:Giardia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D005873:Giardiasis / Q000175:diagnosis / Q000469:parasitology; D006801:Humans; D007223:Infant; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D015183:Restriction Mapping
D017931:DNA Primers; D016054:DNA, Protozoan