Copro-diagnosis of Echinococcus granulosus infection in dogs by amplification of a newly identified repeated DNA sequence.
Diagnosis of Echinococcus granulosus infection in dogs by detecting adult worms recovered post mortem or purged from the intestines after treatment with arecoline is not suitable for mass screening. Large-scale diagnosis by detection of copro-antigens is useful but only with relatively high intensity infections, and only by genus. To provide a more sensitive and specific diagnosis, a polymerase chain reaction (PCR) assay was developed, that amplified a target repeated sequence (EgG1 Hae III) newly identified in the genome of the common sheep strain of E. granulosus. This repeated sequence consists of approximately 6,900 copies, arranged in tandem, in groups of 2-6 repeats. The corresponding primers used in the PCR easily detected a single egg with no cross-amplification of DNA from closely related cestodes, including E. multilocularis and Taenia spp. Fecal samples from naturally infected dogs, with 2-10,000 E. granulosus worms at necropsy, were all PCR positive, while E. multilocularis or Taenia spp. positive controls as well as non-endemic controls were all PCR negative. This copro-PCR assay was demonstrated to be 100% specific and also detected all necropsy-positive E. granulosus-infected dogs. It is suggested that this copro-PCR assay has the potential for pre-mortem diagnosis of E. granulosus infection even in areas where E. granulosus and E. multilocularis are co-endemic.
Abbasi
Ibrahim
I
Department of Parasitology, The Kuvin Centre for the Study of Infectious and Tropical Diseases, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Branzburg
Anna
A
Campos-Ponce
Maiza
M
Abdel Hafez
Sami K
SK
Raoul
Francis
F
Craig
Philip S
PS
Hamburger
Joseph
J
D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000032:analysis*; D017931:DNA Primers; D004197:Disease Reservoirs; D004283:Dog Diseases / Q000175:diagnosis* / Q000469:parasitology / Q000635:transmission; D004285:Dogs; D004443:Echinococcosis / Q000175:diagnosis / Q000662:veterinary*; D004446:Echinococcus / Q000235:genetics* / Q000302:isolation & purification; D005243:Feces / Q000469:parasitology; D016678:Genome; D006801:Humans; D008969:Molecular Sequence Data; D010270:Parasite Egg Count; D016133:Polymerase Chain Reaction / Q000592:standards*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
D017931:DNA Primers; D004247:DNA