Effect of Toxoplasma gondii on Ram Sperm Quality after Experimental Infection

Abstract

The aim of this study was to investigate the effect of experimental Toxoplasma gondii infection on ram sperm quality. Five months old, pre-pubertal, rams were divided into four groups (n = 8 per group). Group A was the control group; the remaining animals received per os (p.o.) 5000 oocysts per ram. Group B did not receive treatment post-infection (p.i.). Group C received sulphadimidine (intermuscular injection (i.m.) 33 mg/kg for eight days; every 48 h) two months p.i. and Group D received the same drug twice (24 h p.i. and two months later). Blood samples were collected every 15 days to detect serum immunoglobulin G (IgG). Epididymal sperm samples were analyzed for concentration, kinetics, morphology/viability, functional membrane integrity, DNA integrity, and the presence of parasite DNA. Histopathological examination was performed on the testes. The IgG titres in infected groups raised two weeks p.i. and remained high for four months. Higher values were noticed in viability and functional membrane integrity in positive spermatozoa in the control group compared to other groups, level of significance p < 0.05. Abnormal sperm was higher in groups C and D vs. A and C vs. B (p < 0.05). T. gondii DNA was detected in three sperm samples of the infected rams (12.5%). Histopathology revealed similar findings with little variation among all infected groups, characterized mostly by increased interstitial connective tissue, non-purulent inflammation, and presence of seminiferous tubules with spermatogenic cell depletion, which increased gradually from D to C and B groups. In conclusion Toxoplasmosis in pre-pubertal age negatively affected mature ram sperm quality, while sulphadimidine administration failed to alter this.

A Review of Toxoplasma gondii in Animals in Greece: A FoodBorne Pathogen of Public Health Importance

“…This finding agrees with a recent meta-analysis on sheep T. gondii seroprevalence and associated risk factors [71]. Regarding rams, sexual transmission is possible, and an experimental study demonstrated that T. gondii reduces the quality parameters of sperm (viability, motility, velocity), while sulphadimidine treatment did not revert the sperm cell morphological abnormalities [75]. Concerning age, sheep older than four years had higher seroprevalence than younger sheep, most likely due to increased exposure to T. gondii and not because old sheep are more susceptible [7,43,71,76].…”