Epididymitis in mice experimentally infected with Trypanosoma equiperdum: a histopathological and immunohistochemical study.

Trypanosoma equiperdum is a causative agent of dourine in equids and is transmitted from stallions to mares by coitus. Dourine-affected stallions develop orchitis and epididymitis, and these lesions are considered to be responsible for the sexual transmission of T. equiperdum during coitus. However, the parasitic site of trypanosomes in the reproductive organs and the mechanisms underlying transmission have not yet been elucidated histopathologically. We examined the reproductive organs of male mice infected with T. equiperdum histopathologically and identified severe epididymitis with sperm granulomas. Many trypanosomes were detected in the epididymal interstitium and a few were seen within tubular lumen. Interstitial inflammatory cells mainly consisted of Iba1-, iNOS- and CD204-positive cells with a few CD3-, FOXP3- or PAX5-positive cells. There was diffuse immunolabelling of tumour necrosis factor-α (TNF-α) within these inflammatory foci. While caspase-3-positive epithelial cells in the epididymis were not observed in control mice, they were detected multifocally in infected mice and were frequently associated with loss of immunolabelling of zonula occludens-1 (ZO-1), a major protein that forms tight junctions between epididymal epithelial cells. Anti-laminin immunofluorescence revealed an indistinct basement membrane of the epididymal duct. These results suggest that trypanosomes in the epididymal interstitium induce the infiltration of TNF-α-secreting macrophages. Secreted TNF-α may impair the tight junctions of the epididymal duct by inducing apoptosis and downregulating ZO-1 expression.

Presence of Toxoplasma gondii tissue cysts in human semen: Toxoplasmosis as a potential sexually transmissible infection.

OBJECTIVES: Toxoplasma gondii is a widely prevalent protozoan parasite in human populations. This parasite is thought to be primarily transmitted through undercooked meat and contamination by cat feces. Here, we seek to determine if Toxoplasma gondii cysts can be found within human semen. METHODS: We used a mixture of histological and immunofluorescence stains to visualize Toxoplasma gondii cysts in thin smears of human semen. Further, we probed for presence of bradyzoite-specific mRNA transcription using in-situ hybridization. RESULTS: We visualized Toxoplasma gondii cysts in ejaculates of immune-competent and latently infected human volunteers. We confirmed the encystment by probing transcription of a bradyzoite-specific gene in these structures. These observations extend previous observations of the parasite in semen of several non-human host species, including rats, dogs, and sheep. CONCLUSIONS: Toxoplasma gondii infection is a clinically significant infection, in view of its high prevalence, its purported role in neuropsychiatric disorders such as schizophrenia, as well as in the more serious form of congenital toxoplasmosis. Our demonstration of intact Toxoplasma gondii cysts in the ejaculate supports the possibility of sexual transmission of the parasite and provides an impetus for further investigations.

Unaffected semen quality parameters in Neospora caninum seropositive Belgian Blue bulls.

Neospora caninum is a protozoan parasite that causes abortion, perinatal mortality, and subfertility in cattle worldwide. Despite the presence of the DNA of the parasite in semen of infected bulls, the effect on semen quality has not been extensively studied. This study aimed to investigate the effect of a natural Neospora caninum infection on fresh and frozen semen quality parameters in Belgian Blue bulls. Two hundred and fourteen bulls were serologically screened with an indirect ELISA-test specific for anti-Neospora caninum antibodies, every two months during one year. In addition to serological screening, semen was collected twice weekly using an artificial vagina. The following semen quality parameters were assessed: ejaculate volume, concentration, total motility of fresh semen samples, as well as morphology, total and progressive motility for frozen/thawed semen samples. Bulls were semen sampled throughout the whole year, but only semen samples of bulls that had six consecutive positive or negative ELISA-test results were included in our dataset (n = 98). Generalized linear and binomial mixed models were used for statistical analysis of each outcome variable. In these models the explanatory variables were defined as: age, barn location, mean Temperature Humidity Index (THI) during sperm production (14-42 days before sampling), maximum daily THI at collection, season of sperm production, season at collection and the Neospora caninum antibody test results. Initially, individual explanatory variables were tested in univariable models for each outcome variable. Akaike information criterion (AIC) values were used to select explanatory variables to build a multivariable model, where the Neospora caninum test result was forced in all models. The present study reveals an overall apparent seroprevalence of Neospora caninum of 9,2% in the study population. No significant associations were detected between natural neosporosis, substantiated by ELISA-antibody levels, and any of our tested outcome variables on fresh and frozen/thawed semen samples. Based on the results of the present study, we conclude that Neospora caninum seropositive bulls do not have lower semen quality parameters compared with seronegative bulls.

Investigation of Tritrichomonas foetus in cryopreserved bovine semen by culture and polymerase chain reaction / Pesquisa por Tritrichomonas foetus em sêmen bovino criopreservado mediante isolamento e reação em cadeia da polimerase

Bovine Trichomoniasis (BT) is an infectious disease caused by Tritrichomonas foetus that can be transmitted either sexually or by fomites. In males, the disease is asymptomatic and permanent. T. foetus has been detected in semen samples where it is able to remain viable even when frozen. The objective of this study was to investigate the presence of T. foetus in 27 samples of commercial frozen bovine semen by culture and Polymerase Chain Reaction (PCR). Samples were thawed in water at 37°C. Part of the samples was inoculated in a test tube containing Diamond's medium and incubated at 35°C. Growth was evaluated every 24 hours via direct examination under a microscope. The other part was placed in an Eppendorf tube and frozen for later molecular analysis. After 10 days of culture, all samples were negative for T. foetus. The Quick-DNA Miniprep Kit (Zymo Research) without proteinase K was used for DNA extraction. The primers used in PCR were TRF3 and TRF4. PCR results were negative for all samples. In conclusion, bovine semen samples were negative for T. foetus in both diagnostic methods, according to the adopted methodology.(AU)

A tricomonose genital bovina (TGB), uma doença infectocontagiosa causada pelo Tritrichomonas foetus, é transmitida por via venérea e fômites contaminados. Em machos a doença é assintomática e permanente. O agente já foi encontrado em amostras de sêmen e é capaz de permanecer viável quando congelado. Este trabalho teve por objetivo investigar a presença de T. foetus em 27 amostras de sêmen bovino comercial congelado, por meio de cultivo e reação em cadeia da polimerase (PCR). As amostras foram descongeladas em água a 37ºC; parte foi inoculada em tubo de ensaio contendo meio Diamond, incubada a 35ºC com consequente avaliação de crescimento e avaliada a cada 24 horas, via exame direto em microscópio, e a outra parte foi diluída em PBS para análise molecular. Após 10 dias de cultivo, todas as amostras foram negativas. Para a detecção molecular foi utilizado o kit Quick-DNA Miniprep (Zymo Research) sem proteinase K para extração do DNA. Os iniciadores utilizados na PCR foram TRF3 e TRF4. O resultado da PCR foi negativo para todas as amostras. Conclui-se que as amostras utilizadas foram realmente negativas para a presença do patógeno em ambos os métodos diagnósticos, o que comprovou a inocuidade do sêmen testado.(AU)

Detection of Toxoplasma gondii infection in semen of rams used for natural mating in commercial sheep farms in Tunisia.

Toxoplasmosis, a parasitic infection, disrupts sexual functions resulting in decline in reproductive and economic performance in sheep. Lacking discernible symptoms, toxoplasmosis is difficult to detect and diagnose in infected animals. Here, to estimate the prevalence of natural infection by Toxoplasma gondii, we used PCR to amplify and detect T. gondii DNA in semen from 92 rams of three breeds from four regions in Tunisia and seroprevalence was determined using a commercial ELISA kit. From the PCR amplifications, 51.09 ±â€¯10.21% of the rams were tested positive for T. gondii with an overall seroprevalence of 39.13 ±â€¯9.97%. Risk factors including ram location and number of accomplished mating seasons significantly (p < .05) affected the sero- and molecular prevalence of T. gondii in semen but, there was a fair concordance between sero- and molecular prevalence (Kappa = 0.33). Sequences of T. gondii from five positive samples were 100% identical (same haplotype). Comparison of these sequences with those archived at the GenBank showed a sequence similarity range between 95 and 100%. The haplotype defining the five Tunisian sequences was similar to the one observed in chicken, cats, European pole cat and humans from Brazil, St Kitts and Nevis, Great Britain and Tunisia, respectively. This indicates its wide geographic distribution and non-species specificity. Our findings suggest a high prevalence of toxoplasmosis in Tunisian matting rams; further studies concerning its venereal transmission capacity are needed prior to recommending a systematic screening of T. gondii DNA in rams' semen used for both natural breeding and artificial insemination.

Case Report: Highlighting Male Genital Schistosomiasis (MGS) in Fishermen from the Southwestern Shoreline of Lake Malawi, Mangochi District.

Urogenital schistosomiasis causes morbidity within the genitalia but is underreported and infrequently examined in men. To draw attention to male genital schistosomiasis (MGS), a longitudinal cohort study was conducted among fishermen along the southwestern shoreline of Lake Malawi. A case series of five participants is presented inclusive of questionnaire interviews, parasitological examinations, ultrasonography, and provision of a standard dose (40 mg/kg) of praziquantel (PZQ) treatment at baseline, 1-, 3-, 6-, and 12-month follow-up time points. Eggs of Schistosoma haematobium were observed in urine or semen across all time points; parasitological diagnostics were bolstered by real-time PCR for Schistosoma DNA in semen and by portable ultrasonography to document putative MGS-associated morbidity. We highlight the importance of developing standard diagnostic tests for MGS and increasing the accessibility of PZQ treatment to men, especially those in at-risk endemic areas.

How can schistosome circulating antigen assays be best applied for diagnosing male genital schistosomiasis (MGS): an appraisal using exemplar MGS cases from a longitudinal cohort study among fishermen on the south shoreline of Lake Malawi.

We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.

Neospora caninum Natural Infection in Tunisian Rams: Serological Study and Molecular Identification of Infection in Semen.

PURPOSE: The aim of this study was to estimate the seroprevalence and molecular prevalence and perform a molecular identification of Neospora caninum in semen of Tunisian rams. METHODS: A total of 92 blood samples were collected from four farms located in four Tunisian governorates (Jendouba, Kairouan, Zaghouan and Ben Arous) and samples were screened with a commercial ELISA kit for N. caninum antibodies. For the same rams, semen samples were collected and tested for the presence of N. caninum ITS1 gene using PCR. Five amplicons were randomly selected for sequencing. A phylogenetic tree was constructed to compare the partial sequences of the ITS1 gene with sequences deposited in GenBank. RESULTS: The seroprevalence of N. caninum infection was 25% (23/92) and PCR revealed that the molecular infection prevalence in semen was 11.95% (11/92). Kappa test showed an average agreement between seroprevalence and parasite prevalence in semen (κ = 0.44). The highest molecular prevalence was for rams that accomplished more than two mating seasons (21.0 ± 12.1%) compared to those performed less than two mating seasons and yearling individuals (4.0 ± 5.5%) (P = 0.01). There were no differences in N. caninum molecular prevalence according to either breed or locality. Comparison of the partial sequences of the ITS1 gene revealed 99-100% similarity with those deposited in GenBank. CONCLUSION: To the best of our knowledge, this is the first detection and molecular identification of N. caninum in semen from rams in North Africa. Our findings indicate that N. caninum infection rate was high in rams.

Reduction of Trypanosoma equiperdum from equine semen by single layer centrifugation.

Trypanosoma equiperdum (T. equiperdum) causes dourine, a venereally transmitted infection in horses. Purification of semen by single layer centrifugation (SLC) has been proven to be successful in reducing venereally transmitted diseases when dealing with other pathogens. The objective of this study was to evaluate the purification of T. equiperdum spiked semen by SLC. Semen was spiked using cryopreserved T. equiperdum stabilates (Dodola strain isolate 943). In total, 6 concentrations, varying from 102 to >5 × 106 trypanosomes, were added to semen samples. Subsequently, SLC was performed following standard procedures. The presence of the parasite in the purified semen was checked by wet smear examination, ITS1 PCR and in vivo inoculation in mice. Before SLC, all spiked semen samples, except the negative controls, were positive on PCR analysis. After SLC, all the pellets were found to be negative for T. equiperdum on microscopic examinations. Examination of the pellet by PCR could also not detect any parasite-DNA in the SLC-pellet of semen spiked with the lower number of parasites (102 to104 trypanosomes). However, in the SLC pellets spiked with 104 - 5 × 104 trypanosomes, only 1 out of the 4 replicates was negative for parasite DNA. All groups spiked with >5 × 104 trypanosomes were found to be positive on PCR. All mice in the positive controls exhibited parasitaemia (5/5). Mice inoculated with SLC-purified semen that was spiked with lower than 5 × 104 trypanosomes, remained free of parasitaemia, similar to the negative controls. However inoculation with SLC-pellets from samples with a higher number of trypanosomes (>5 × 104 - 5 × 106 and > 5 × 106), induced parasitaemia in 2 out of 5 and 3 out of 5 mice, respectively. This study indicates that single layer centrifugation can be used to clear T. equiperdum infected semen but that the success is dependent on the number of parasites.

Tissue (re)distribution of Trypanosoma equiperdum in venereal infected and blood transfused horses.

Dourine, caused by Trypanosoma equiperdum, is a life-threatening venereal disease in equidae. So far, there is no clear evidence on how and when stallions become infectious, nor which tissues are affected by the parasite in diseased animals. Post-infection, after a transient, temporary phase of parasitaemia, the parasite disperses to different tissues in an unknown distribution pattern. This study describes the distribution of the parasite after infection by artificial insemination (AI) or blood transfusion. Mares (N = 4) were artificially inseminated with T. equiperdum spiked semen whereas stallions (N = 4) were infected by blood transfusion. The course of the disease was monitored by parasitological (Woo) and molecular (PCR) tests and clinical signs and haematological parameters were recorded. At 120 days post infection, horses had a full necropsy, histopathology and PCR. A similar pattern of parasitaemia, disease progression and tissue distribution were seen in all horses. Ejaculated semen in the preclinical stage and epididymal semen in the chronic stage of the disease was positive on PCR and caused infection in mice. Cymelarsan® treatment in the chronic stage did not result in a clinico-haematological or histopathological improvement. At necropsy, lesions were observed in the nervous and reproductive system. Histopathological lesions were most severe in the peripheral nerves and associated ganglia, the testicles and genital mucosae with multifocal infiltration of lymphocytes, plasma cells and histocytes. The parasites disseminated to several tissues including the nervous system, testicles and semen. The results indicate that transmission of T. equiperdum is possible through semen even from symptomless stallions post-treatment.

Detection of Trypanosoma vivax DNA in semen from experimentally infected goats.

The present work aimed to investigate the presence of T. vivax DNA in the semen of experimentally infected goats. Twelve male goats native to the Brazilian Northeast, adults, were randomly assigned to two experimental groups: the infected group consisting of six goats infected intravenously with 0.5 mL of blood containing approximately 1.25 × 105 trypomastigotes of T. vivax, and a control group composed of six uninfected goats. After the infection, clinical examinations aiming to evaluate rectal temperature, parasitemia and hematocrit were performed. Semen samples were collected from goats by electroejaculation on the 7th, 14th and 21st days post-infection (dpi). The recombinant DNA-encoding gene encoding the L-like-specific gene for T. vivax. The infection was characterized by increased rectal temperature, high parasitemia and significant reduction of hematocrit values. Results for T. vivax DNA detection using TviCatL-PCR were positive in all semen samples from the infected group collected on 7th, 14th and 21st dpi. The presence of T. vivax DNA in 7th dpi suggests the early invasion of the parasite in the reproductive organs. Also, the finding of T. vivax DNA in all periods analyzed may suggest the continued elimination of the parasite in the semen, which may increase the chances of sexual transmission. Thus, T. vivax DNA is recorded for the first time in the semen of infected goats. Thus, these data are of great importance, since the detection of the T. vivax genetic material in the semen may point to the possibility that the parasite may be transmitted through the sexual pathway.

Evidence for Previously Unidentified Sexual Transmission of Protozoan Parasites.

Knowing the mode of transmission of a disease can affect its control and prevention. Here, we identify 5 protozoan parasites with demonstrated presence in seminal fluid, only 1 of which has been identified as a sexually transmitted disease among humans.

Investigation of Toxoplasma gondii in semen, testicle and epididymis tissues of primo-infected cats (Felis catus).

This study aimed to investigate the presence of Toxoplasma gondii in semen, testicle and epididymis tissues of cats experimentally infected by this coccidium. A total of 12 male felines without a definite breed that were of reproductive age and serologically negative for T. gondii were selected and distributed to the following three experimental groups: GI, inoculated with 600 tissue cysts of the P strain of T. gondii (isolate III); GII, inoculated with 2×105 tachyzoites of the RH strain (isolate I); and GIII, not inoculated (control group). Prior to inoculation (day -7 and 0) and on post inoculation days (PIDs) 7, 14, 21, 28, 42, 56, and 70, all felines were subjected to assessments of anti-T. gondii IgG by indirect immunofluorescence (IIF) and assessments of parasitemia. Collection of semen (electroejaculation) was performed on the specified dates, followed by nested PCR and bioassays in mice to detect T. gondii. On PID 70, all 12 felines were orchiectomized, and the presence of the parasite in the testicles and epididymides was evaluated by nested PCR, murine bioassay, and histopathological and immunohistochemical analyses. All felines inoculated with T. gondii (GI and GII) seroconverted to the toxoplasmic infection after PID 14; on PID 7, seroconversion of three felines (P4, RH2 and RH4) could observed, and all exhibited detectable titers by PID 64. The GII felines exhibited greater serological titers compared with GI felines. The maximum serological titer (IgG) was observed in feline RH3 (titer 1024), while in other experimental felines, a maximum titer of 256 was detected. Parasitemic peaks were diagnosed in all felines of groups I and II from PIDs 7-42. A total of five parasitemic peaks were diagnosed in GI and nine in GII. In none of the experimental time points was the presence of T. gondii diagnosed in seminal samples collected from the felines or in the testicle or epididymis tissues collected from these animals. Thus, sexual transmission in domestic cats does not appear to be a major route of T. gondii infection, possibly demonstrating the tendency of this protozoan to develop a response directed to the formation and excretion of oocysts in the feces of these definite hosts, which act as its main route of perpetuation in the environment.

Toxoplasma gondii transmission by artificial insemination in sheep with experimentally contaminated frozen semen.

Toxoplasma gondii is a parasite considered one of the major causes of reproductive problems in sheep. Furthermore, the presence of the agent in ram semen urges the possibility of sexual transmission in this species. The aim of this study was to evaluate if ram's frozen semen spiked with T. gondii tachyzoites would be able to cause infection in sheep by laparoscopic artificial insemination (AI). Nine ewes tested seronegative to anti-T. gondii antibodies by the modified agglutination test (MAT) were superovulated and inseminated to collect embryos. Animals were divided into two groups: G1 (n = 5), ewes inseminated with semen containing 4 × 107 tachyzoites; and G2 (n = 4), ewes inseminated with tachyzoite-free semen (control group). To confirm infection, ewe's blood samples were collected on days -14, -7, 0, 7, 14, 21, 28, 35, 49 and 57 after AI for analysis by MAT and PCR. Tissue samples of these ewes were also collected for histopathology and immunohistochemistry (IHC). Seven days after AI, all ewes of group G1 had specific antibodies to T. gondii, while those of G2 were negative. Toxoplasma gondii DNA was detected in the blood of one ewe and parasites were observed in tissues of all five animals inseminated with contaminated semen, indicating that semen freezing protocol does not affect T. gondii transmission by artificial insemination in sheep.

Toxoplasma gondii infection in dairy ewes: Vertical transmission and influence on milk production and reproductive performance.

The present study aimed to evaluate the transmission of toxoplasmosis (vertical and venereal) and its influence on milk production and reproductive problems of Lacaune sheep seropositives for Toxoplasma gondii. Males and females were serologically selected using indirect immunofluorescence method in three steps of the study. Step 1: In order to evaluate the influence of toxoplasmosis on milk production, the volume of milk produced by 40 sheep (22 seronegatives and 18 seropositives for T. gondii) was weekly measured throughout the lactation period. There were no significant differences between these two groups; in other words, toxoplasmosis did not affect milk production. Step 2: In order to assess T. gondii venereal transmission, five samples of semen from seropositive rams (n = 5) were tested by endpoint and real time PCR with two days of interval; however, these semen samples were PCR negatives for T. gondii. Step 3: To evaluate reproductive problems, 12 seropositive animals out of a flock of 68 pregnant ewes showed signs of reproductive problems, such as abortion or fetal resorption. T. gondii transplacental transmission was evaluated on blood drawn from newborn lambs (n = 41), and their respective seropositive mothers (n = 30) after single, double or triple births. Serological tests showed that 65.8% of the lambs had antibodies against this protozoan, indicating a high transmission from ewe to fetus during pregnancy. Therefore, it is concluded that toxoplasmosis in sheep may impair reproduction with a high percentage of vertical transmission.

Detection and isolation of Toxoplasma gondii from fresh semen of naturally infected dogs in Southern Brazil.

The aim of this study was to isolate Toxoplasma gondii and determine the viability of the parasite in fresh semen samples of clinically healthy adult dogs naturally infected. Eleven seropositive dogs with T. gondii IgG antibodies from southern Brazil were selected to confirm the presence and viability of T. gondii in fresh semen samples using in vitro isolation in Vero cell culture, polymerase chain reaction (PCR) and sequencing analysis. The presence of viable T. gondii was confirmed by in vitro isolation and PCR in five semen samples. The ITS1 region of the isolated protozoa (TG S4) was amplified and sequenced. The nucleotide sequence obtained was 99% compatible with the T. gondii DNA sequences stored in the GenBank. It has been shown that T. gondii tachyzoites may be isolated in vitro from fresh semen samples of clinically healthy dogs seropositive for T. gondii.

Human parasitic protozoan infection to infertility: a systematic review.

Protozoan parasitic diseases are endemic in many countries worldwide, especially in developing countries, where infertility is a major burden. It has been reported that such infections may cause infertility through impairment in male and female reproductive systems. We searched Medline, PubMed, and Scopus databases and Google scholar to identify the potentially relevant studies on protozoan parasitic infections and their implications in human and animal model infertility. Literature described that some of the protozoan parasites such as Trichomonas vaginalis may cause deformities of the genital tract, cervical neoplasia, and tubal and atypical pelvic inflammations in women and also non-gonoccocal urethritis, asthenozoospermia, and teratozoospermia in men. Toxopalasma gondii could cause endometritis, impaired folliculogenesis, ovarian and uterine atrophy, adrenal hypertrophy, vasculitis, and cessation of estrus cycling in female and also decrease in semen quality, concentration, and motility in male. Trypanosoma cruzi inhibits cell division in embryos and impairs normal implantation and development of placenta. Decrease in gestation rate, infection of hormone-producing glands, parasite invasion of the placenta, and overproduction of inflammatory cytokines in the oviducts and uterine horns are other possible mechanisms induced by Trypanosoma cruzi to infertility. Plasmodium spp. and Trypanosoma brucei spp. cause damage in pituitary gland, hormonal disorders, and decreased semen quality. Entamoeba histolytica infection leads to pelvic pain, salpingitis, tubo-ovarian abscess, and genital ulcers. Cutaneous and visceral leishmaniasis can induce genital lesion, testicular amyloidosis, inflammation of epididymis, prostatitis, and sperm abnormality in human and animals. In addition, some epidemiological studies have reported that rates of protozoan infections in infertile patients are higher than healthy controls. The current review indicates that protozoan parasitic infections may be an important cause of infertility. Given the widespread prevalence of parasitic protozoa diseases worldwide, we suggest further studies to better understanding of relationship between such infections and infertility.

Male infertility: a public health issue caused by sexually transmitted pathogens.

Sexually transmitted diseases (STDs) are caused by several pathogens, including bacteria, viruses and protozoa, and can induce male infertility through multiple pathophysiological mechanisms. Additionally, horizontal transmission of STD pathogens to sexual partners or vertical transmission to fetuses and neonates is possible. Chlamydia trachomatis, Ureaplasma spp., human papillomavirus, hepatitis B and hepatitis C viruses, HIV-1 and human cytomegalovirus have all been detected in semen from symptomatic and asymptomatic men with testicular, accessory gland and urethral infections. These pathogens are associated with poor sperm quality and decreased sperm concentration and motility. However, the effects of these STD agents on semen quality are unclear, as are the effects of herpes simplex virus type 1 and type 2, Neisseria gonorrhoeae, Mycoplasma spp., Treponema pallidum and Trichomonas vaginalis, because few studies have evaluated the influence of these pathogens on male infertility. Chronic or inadequately treated infections seem to be more relevant to infertility than acute infections are, although in many cases the exact aetiological agents remain unknown.

Detection of Toxoplasma gondii DNA in fresh and frozen semen from rams in Brazil.

The aim of this study was to estimate the prevalence of genomic DNA of Toxoplasma gondii in semen samples from commercial rams in artificial insemination centres in Brazil, as well as in fresh semen from rams in the northeast of Brazil. In total, 108 semen samples were obtained from artificial insemination centres, and genomic DNA of T. gondii was detected in 24 of 108 (22.2%). The prevalence of antibodies anti-Toxoplasma gondii among sheep on rural properties was 9.2% (10/109), and 100% of the semen samples of these animals were positive in the PCR for T. gondii DNA. The molecular identity was confirmed through sequencing, which indicated 99.9% similarity with the T. gondii DNA sequences stored in the GenBank. This study reports the first occurrence of T. gondii DNA in the semen of rams, which came from artificial insemination centres in Brazil, as well as the occurrence of T. gondii DNA in the fresh semen of naturally infected rams in the northeast of Brazil.