Evaluation of PCR Assay over Culture for the Detection of Acanthamoeba Spp. In Amoebic Keratitis and Amoebic Meningitis/ Meningoencephalitis Patients in India

Authors: Himanshu SB*, Gita S, Anita Panda, Pooja B and Manjari T

Volume 4, Issue 2

Abstract

Aims: Evaluation of PCR assay over culture for the detection of Acanthamoeba spp. in corneal scrapings of suspected amoebic keratitis patients and CSF from suspected amoebic meningitis/ meningoencephalitis patients. Methods and Results: Corneal scrapings and CSF were collected from 183 and 149 patients suspected of having amoebic Keratitis and Acanthamoeba meningitis/ meningoencephalitis (AME) respectively from 2010 to 2015. A part of the specimen (corneal scraping and CSF) was inoculated onto a 2% non-nutrient agar plate overlaid with E. coli. for culture and a second part of the specimen was placed in 500μl PBS buffer (pH 7.4) for molecular diagnosis. Acanthamoeba spp. could be detected in culture from 29(15.84%) cases, by PCR assay from 32(17.48%) cases in suspected amoebic keratitis patients. Likewise out of 149 suspected patients of Acanthamoeba meningitis/ meningoencephalitis 10(06.71%) cases were positive in culture where as 11(07.38%) were positives by PCR assay. Conclusion: PCR assay was found to be more sensitive and specific than culture for detection of Acanthamoeba spp. in corneal scrapings of suspected amoebic Keratitis patients and CSF collected from suspected AME patients. Significance and Impact of Study: PCR assay should be performed along with culture (gold standard) for efficient laboratory diagnosis of Acanthamoeba spp. in patient samples.

Keywords: Acanthamoeba keratitis; Acanthamoeba meningitis/ meningoencephalitis; 18S rDNA PCR; PCR assay of Acanthamoeba spp

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