Comparison of staining and concentration techniques for detection of Cryptosporidium oocysts in cattle faecal specimens

Modified Ziehl Neelsen (MZN), Safranin-Methylene Blue (S-MB), Methylene Blue-Eosin (MB-E), Nigrosin, Carbol Fuchsin and Indirect Fluorescent Antibody (IFA) techniques were compared for detection of Cryptosporidium spp. oocysts in cattle faecal specimens. Of the six techniques. S-MB and IFA techniques were found to be the most efficient. Oocysts stained with S-MB were easily recognized as vivid orange round bodies. The IFA technique offered the advantage of a very readily identifiable apple green fluorescence which provided a definite diagnosis. Comparison of Sheather's sugar flotation, Zinc sulphate (ZnSO4) flotation and Formalin-Ethyl Acetate (FEA) sedimentation techniques revealed that Sheather's sugar flotation technique was the most efficient of the three for concentration of Cryptosporidium spp. oocysts from cattle faecal specimens. Of the negative faecal samples, 12% were found to be positive by Sheather's sugar flotation technique followed by S-MB stain whereas only 7% by ZnSO4 flotation and 6% by FEA sedimentation.