Experimental infection by Toxoplasma gondii using contaminated semen containing different doses of tachyzoites in sheep

Abstract

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii that affects reproductive performance in small ruminants. Although the T. gondii life cycle is well understood since 1960s, several aspects related to its infection remain unclear. In the present study we hypothesized that sheep inseminated with T. gondii-contaminated semen would develop toxoplasmosis. In order to test that hypothesis, 41 sheep were experimentally infected with semen spiked with the organism. Females were divided in three groups (G1-G3): (a) females in G1 group were inseminated with semen containing 6.5 x 10(4) tachyzoites; (b) females in G2 group with semen containing 4 x 10(7) tachyzoites; and (c) females in G3 group with tachyzoite-free semen (control group). To confirm T. gondii infection via semen, serological tests were performed using indirect immunofluorescence reaction and the detection of parasite DNA in the blood stream using the nested PCR test. While in G1 group only 5/15 (33.3%) of the females presented seroconversion, all sheep in G2 15/15 (100%) seroconverted. The nested PCR test showed that 14/15 (93.3%) of the females in the G1 and 14/15 (93.3%) in the G2 group were positive for T. gondii while in the G3 group all samples were negative. In addition, ultra-sound test evidenced that in sheep presented embryonic reabsorption in animals from the infected groups. In conclusion, insemination using fresh semen experimentally contaminated with different infectant doses of T. gondii tachyzoites was able to infect sheep, leading to the possibility of toxoplasmosis transmission via semen.

Occurrence of Toxoplasma gondii DNA in sheep naturally infected and slaughtered in abattoirs in Pernambuco, Brazil

“…These results demonstrated the sexual transmission of T. gondii among sheep with a consequent vertical transm000ission to the offspring. Moraes et al (2010a and2010b) confirmed venereal transmission of the parasite during insemination with semen that had been experimentally infected with T. gondii and reported reproductive disorders including fetal death, abortion, hydrometra, mucometra, follicular cysts, anestrous and high rates of embryo resorption.…”

“…Since the distribution of T. gondii in tissues from slaughtered animals has already been studied extensively in farm animals, the present study aimed to investigate the presence of this parasite in organs that have not yet been studied, associated with reproductive aspects. The sexual transmission of this parasite was recently proven in association with the experimental infection of sheep (Moraes et al 2010a(Moraes et al , 2010b. This result inspired the performance of the present study, which aimed to detect genomic DNA of T. gondii in the uterus, tubes, ovaries, fetuses and placenta of sheep that were serologically positive and slaughtered in slaughterhouses in the state of Pernambuco, Brazil.…”

Evaluation of Buffalo Bull Semen for Some Venereal Diseases Using PCR

“…This was agreed by Scarpelli et al [10] who revealed the existence of the parasite in semen samples of animals infected with oocysts (GI) and tachyzoites (GII) which suggest the opportunity of sexual transmission of T. gondii in the bovine species. This also was supported by the isolation of T. gondii in the semen of sheep [9], goats [24] and swine [25]. Moreover, the T.…”

“…Vol. 48, No.2 (2017) and placenta of sheep inseminated with infected semen suggesting the potential infection by contaminated semen [9].…”

“…Toxoplasmosis has health and veterinary importance, responsible for abortions and congenital disease in many intermediate host species [6]. T. gondii was isolated from semen samples of experimentally infected goats [7,8] and sheep [9] proposing Preventing of N. caninum in semen is a chief objective of control platforms as it is a contributing agent of abortion allover the world [11]. Neospora caninum is a universal distributed obligate intracellular protozoan.…”