Abstract

BOUVET, Beatriz Reina; PAVESI, Adriana Beatriz; PAPARELLA, Cecilia Vicenta  and  OMBRELLA, Adriana María. Identification of human spermatozoids in samples contaminated with yeast. CienciaUAT [online]. 2017, vol.12, n.1, pp.23-35. ISSN 2007-7858.

Sexual violence is a global problem, and represents a serious felony which is often difficult to impute due to the absence of witnesses. The evaluation of semen samples sent to the laboratory, for the detection of spermatozoa is of great importance to find the aggressor. However the evidence is not simple due to the presence of other organisms and sperm lability. The objective of the present study was to identify human spermatozoa in samples contaminated with yeast. Different techniques and microscopic resources were applied and 46 samples of fresh semen were selected. They were divided into two groups: G1 normo or oligozoos-perms (n = 28) and G2 azoosperms (n = 18). Each sample was diluted 1:1 with physiological solution and 0.05 mL of yeast suspension Candida albicans was added. As controls, pure sperm (CE) and pure yeast (CL) were processed. The samples were analyzed with optical microscopy (MO), phase contrast (CF), polarized light (LP) and fluorescent microscope (MF) with different staining techniques. Papanicolaou dye showed greater efficiency than bright hematoxylin-green dye (P < 0.01) to identify spermatozoa with an optical microscope. The presence of refringent elements showed a higher correlation with the presence of spermatozoa (LP: r = 0.966; P < 0.001), that the presence of birrefringent elements (LP: r = 0.737; P < 0.001) and fluorescent elements (MF: r = 0.487, P < 0.05). Confocal microscopy with Evans blue calco-fluor white stain and acridine orange allowed the identification of yeast contamination. The use of microscopic techniques aided by staining techniques confirms the presence of whole or fragmented spermatozoa in semen samples contaminated with yeasts.

Keywords : spermatozoa; yeast; semen; forensic medicine; microscopic techniques.