Vol. 11, Special Issue 7 (2022)

Author(s):
Monika, Gayatri Gujar, Abhishek Gupta, Bhavana Rathore, AK Chouhan and DB Sodha

Abstract:
Many coprological and serological techniques have been described for detection of the parasites with the limitations of sensitivity and specificity. Molecular techniques are being increasingly employed for detection of Cryptosporidium during the last two decades mainly because of the inability to differentiate Cryptosporidium species by conventional microscopy. PCR technology offers an effective alternative to conventional diagnosis of Cryptosporidium for both clinical and environmental samples. We compared microscopic examination by a conventional modified Ziehl-Neelsen (mZN) acid-fast staining procedure with a nested PCR test directed against the 18S SSU rRNA gene as standard reference test for the diagnosis of cryptosporidiosis in bovines. Out of 103 random faecal samples collected from bovines, specific PCR amplification was achieved in 44 samples (42.72%), whereas, only 19 samples (18.45%) turned positive by acid-fast staining. Microscopy therefore exhibited 63.77% sensitivity as compared to PCR. PCR was more sensitive and easier to interpret but required more hands-on time to perform and was more expensive than microscopy. PCR, however, was very adaptable to batch analysis, reducing the costs considerably. An important advantage of the PCR test, its ability to directly differentiate between different Cryptosporidium genotypes, will assist in determining the source of cryptosporidial outbreaks. Sensitivity, specificity, ability to genotype, ease of use, and adaptability to batch testing make PCR a useful tool for future diagnosis and studies on the molecular epidemiology of Cryptosporidium sp. infections. However, conventional modified ZN method provided the required sensitivity and specificity along with nominal cost for diagnosis on per sample basis, and may be considered as a viable diagnostic alternative when PCR is not an option for a particular laboratory setting, especially in developing countries.