2 results for Alagappan, A

  • Development of a Two-Color Fluorescence In Situ Hybridization Technique for Species-Level Identification of Human-Infectious Cryptosporidium spp.

    Alagappan, A; Bergquist, Peter; Ferrari, BC (2009-09-15)

    Journal article
    The University of Auckland Library

    A two-color fluorescence in situ hybridization assay that allows for the simultaneous identification of Cryptosporidium parvum and C. hominis was developed. The assay is a simple, rapid, and cost-effective tool for the detection of the major Cryptosporidium species of concern to public health.

    View record details
  • Development of fluorescent in situ hybridisation for Cryptosporidium detection reveals zoonotic and anthroponotic transmission of sporadic cryptosporidiosis in Sydney

    Alagappan, A; Tujula, NA; Power, M; Ferguson, CM; Bergquist, Peter; Ferrari, BC (2008-12)

    Journal article
    The University of Auckland Library

    Cryptosporidium, is the most common non-viral cause of diarrhea worldwide. Of the 5 described species that contribute to the majority of human infections, C. parvum is of major interest due to its zoonotic potential. A species-specific fluorescence in situ hybridisation probe was designed to the variable region in the small subunit of the 18S rRNA of C. parvum and labeled with Cy3. Probe specificity was validated against a panel of 7 other Cryptosporidium spp. before it was applied to 33 human faecal samples positive for cryptosporidiosis which were obtained during the period from 2006–2007. Results were compared to PCR-RFLP targeting the 18S rDNA. FISH results revealed that 19 of the 33 isolates analysed were identified as C. parvum. Correlation of PCR-RFLP and FISH was statistically significant (P < 0.05), resulting in a calculated correlation coefficient of 0.994. In this study, species identification by FISH and PCR-RFLP provided preliminary evidence to support both anthroponotic and zoonotic transmission of sporadic cases of cryptosporidiosis in the Sydney basin. In conclusion, FISH using a C. parvum-specific probe provided an alternative tool for accurate identification of zoonotic Cryptosporidium which will be applied in the future to both epidemiological and outbreak investigations.

    View record details