Alternative Approaches in Direct Microscobic Examination of Fresh Fecal Samples

Abstract

Aim of the present study was to identify protozoones which are difficult to define through wet slide in fresh fecal samples by using different fixatives with modified Trichrome stain within five minutes. Two different fixatives prepared for the alternative approach. The slides were fixed by two different fixatives, one of them (fixative-1) was based ethylalcohol, formalin, acetic acid, distilled water and the other one (fixative-2) based ethylalcohol, formalin, citric acid, distilled water included a mordant [divalent or polyvalent metals which make coordination complex with some dyes] consisted copper sulphate pentahydrate (CuSO4 .5H2 O). Slides prepared by the two different fixatives were stained by a different modification of Gomori's trichrome stain that we made. Samples fixed by Schaudinn fixative including mercury chloride were stained by Wheatley modification of Gomori's trichrome stain as a gold standard for control and comparison. We worked with 50 fecal samples which we thought included human intestinal protozoones after the wet slide examination. Comparing the methods, slides prepared with the method including citric acid gave almost similar results with the classical method excluded Entamoeba coli cystes. Slides prepared with the methode including acetic acid gave low performance compared with the classical method especially E.coli cystes and Blastocystis spp., Endolimax nana, Iodamoeba bütschlii, E.hartmanni. Both new fixatives gave superior performance at the slides included Dientamoeba fragilis and approximately shorten the procedure process ten times than the classical method. When the both alternative methods compared in each other, the slides prepared with fixative-2 exposed better performance for the protozoones Blastocystis spp., E.nana, I.bütschlii and E.hartmanni while the fixative-1 displayed minimal superiority for D.fragilis including criterias that we based. The fixative-2 and modified stain methode that we used in our study, makes available the diagnostic phase ten times faster than the classical method in human stool parasitological tests excluding the E.coli cystes at parasitology and microbiolgy laboratories. It seems to be a good option to the classical method for routine usage.