Parasitol Res (2011) 109:405–409 DOI 10.1007/s00436-011-2268-9
ORIGINAL PAPER
Histopathology of the reproductive system of male sheep experimentally infected with Toxoplasma gondii Welber D. Z. Lopes & Thaís R. Santos & M. C. R. Luvizotto & C. A. M. Sakamoto & G. P. Oliveira & A. J. Costa
Received: 30 June 2010 / Accepted: 19 January 2011 / Published online: 1 February 2011 # Springer-Verlag 2011
Abstract The aim of this study was to investigate the histopathological changes in reproductive system (testicles, epididymis, seminal vesicles, and prostate) of small male ruminants after Toxoplasma gondii infection. Eight sheep were inoculated with T. gondii: group I, four sheep (2.0× 105 P-strain oocysts); group II, four sheep (1.0×106 RHstrain tachyzoites); and group III, two uninfected sheep maintained as control. Infection with T. gondii was confirmed by seroconversion (indirect fluorescent antibody test-IgG) in all the infected animals beginning on postinoculation day (PID) 7. On PID 70, all the animals were euthanized and tissue samples (testicles, epididymis, seminal vesicles, and prostate) were collected and processed for histological analysis. The main changes detected were a focal mononuclear interstitial inflammatory infiltrate in the prostate and seminal vesicles; diffuse testicular degeneration associated with calcification foci and a multifocal mononuclear interstitial inflammatory infiltrate; and a mononuclear interstitial infiltrate and focal necrotic areas of the muscle fibers surrounding the seminal vesicles. The histopathological findings of this work, along with the detection of T. gondii in the examined parenchyma tissues (immunohistochemistry) and the results obtained by other authors examining different tissues, suggest that histological changes diagnosed in the reproductive W. D. Z. Lopes : T. R. Santos (*) : C. A. M. Sakamoto : G. P. Oliveira : A. J. Costa CPPAR-Animal Health Research Center, Faculdade de Ciências Agrárias e Veterinárias, UNESP, Via de acesso prof. Paulo Donatto Castellani, s/n CEP:14884-900 Jaboticabal, São Paulo, Brazil e-mail:
[email protected] M. C. R. Luvizotto Department of Clinic, Surgery and Animal Reproduction, FMVA, UNESP, Araçatuba, SP, Brazil
system of rams infected with T. gondii are strongly suggestive of toxoplasmatic infection.
Introduction Toxoplasma gondii is a protozoan parasite that is distributed thru the world. This parasite can infect a wide range of animal species and has an indirect life cycle with felids as definitive hosts. Ovine toxoplasmosis was first described by Hartley et al. (1954) and Hartley and Marshall (1957), and was thereafter recognized in many other countries. Infection by T. gondii is relatively common in small ruminants (Mainar et al. 1996), causing reproductive problems and economic losses in sheep and goat herds (Buxton et al. 2007). Its prevalence in sheep is generally very high due to the continuous contamination of pastures by T. gondii oocysts (Dubey 2004). Studies conducted using experimental infection are the most suitable to elucidate the clinical, laboratory, pathological, and epidemiological aspects of T. gondii infection, especially with regard to prophylaxis. Some host species are more susceptible to clinical toxoplasmosis than others. Although T. gondii has been isolated from caprine (Dubey and Sharma 1980), ovine (Aganga et al. 1988), swine (Moura et al. 2007), bovine (Scarpelli et al. 2009), and human (De Paepe et al. 1990) semen in several studies, there is practically no risk of venereal transmission (Janitschke and Nürnberger 1975; Dubey and Beattie 1988). However, there is little information on whether toxoplasmosis affects a man's or a male animal's fertility. The majority sheep production systems, in Brazil diverse regions, consist of stud farms, with primarily pasture-fed animals. However, there is no information concerning the effects of T. gondii infection in the male reproductive
406 Table 1 Results of the serological titers (IFAT) of noninoculated (control) and T. gondii oocyst-inoculated (2.0×105) or tachyzoite-inoculated (1.0× 106) animals
− negative serology
Parasitol Res (2011) 109:405–409 Post-inoculation day
Reciprocal serological titers Oocysts
Control
2
9
16
22
7
48
52
61
43
44
−2 7 14 21 28 35 42 49 56
− 32 64 4,096 1,024 1,024 4,096 4,096 4,096
− − 32 1,024 256 256 1,024 4,096 4,096
− 32 64 4,096 256 528 1,024 4,096 4,096
− 32 64 4,096 1,024 1,024 1,024 4,096 4,096
− 32 4,096 1,024 528 528 4,096 4,096 4,096
− 32 256 256 256 256 1,024 528 4,096
− − 256 256 8,192 528 1,024 4,096 4,096
− 16 1,024 1,024 1,024 528 1,024 4,096 4,096
− − − − − − − − −
− − − − − − − − −
63 70
256 256
256 256
256 256
256 256
256 528
528 256
528 1,024
528 256
− −
− −
system of these species. The aim of this study was to investigate histopathological changes in the reproductive system (testicles, epididymis, seminal vesicles, and prostate) of male sheep experimentally infected with T. gondii.
Materials and methods This study was carried out using P (Jamara and Vieira 1991) and RH (Sabin 1941) strains of T. gondii. These strains were maintained at the Animal Health Research Center (Centro de Pesquisas em Sanidade Animal, CPPAR) of the Faculty of Agrarian and Veterinary Sciences (Faculdade de Ciências Agrárias e Veterinárias, FCAV) of São Paulo State University (UNESP). The inocula were obtained by periodic inoculation of brain cysts (P strain) and/ Table 2 Immunohistochemistry of the reproductive system (testes, epididymis, seminal vesicles, and prostate) of uninfected male sheep (controls) and male sheep inoculated with 2.0×105 oocysts or 1.0×106 tachyzoites of T. gondii
Tachyzoites
Number
2 9 16 1,224 Total 7 48 52 1,234 Total 43 44 Total
Group
Oocysts Oocysts Oocysts Oocysts Tachyzoites Tachyzoites Tachyzoites Tachyzoites Control Control
or tachyzoites (RH strain) into albino mice. Toxoplasma gondii oocysts were obtained using a technique similar to that described by Dubey et al. (1972). Eight undefined breeding sheep, 14 months of age and serologically negative (cut-off points
