Abortion outbreak in a sheep flock caused by Toxoplasma gondii clonal type III.

Toxoplasma gondii is a major cause of reproductive losses in small ruminants in several countries. We describe here an outbreak of T. gondii-associated abortion in sheep in Southern Brazil. The flock was comprised of 55 adult sheep, and late-term abortions and stillbirths were detected in 15/36 (41.66%) gestating ewes. Serum samples collected from 45 sheep were tested for T. gondii through indirect immunofluorescence assay; IgM and IgG positive results were detected in 44.44% (20/45) and 86.67% (39/45) of the cases, respectively. Four fetuses and two placentas were pathologically evaluated. Gross changes were restricted to fetal membranes and were characterized by multifocal white areas in the cotyledons. Microscopically, these areas corresponded to necrotic foci affecting the chorionic epithelium accompanied by rare cysts of T. gondii. The main histological change in fetal tissues consisted of well-demarked and sparsely distributed necrotic foci in the central nervous system. Tissue samples from all four fetuses and one placenta had positive PCR results for T. gondii. Restriction fragment length polymorphism (RFLP) genotyping using ten markers (SAG1, 5'-3'SAG2, alt.SAG2, SGA3, BTUB, GRA6, c22-8, c29-2, L358, and PK1) was carried out on one sample, and results were consistent with T. gondii clonal type III (ToxoDB-PCR-RFLP genotype #2, TgCpBr4).

Gastrointestinal helminths in dogs: occurrence, risk factors, and multiple antiparasitic drug resistance.

Helminth infections are detrimental to the overall health of dogs; therefore, this study aimed to identify antiparasitic-resistant helminths and evaluate the infection rate and risk factors for parasitism in canines. For this purpose, a parasitological evaluation of 38 randomly selected animals was performed, followed by the evaluation of the anthelminthic efficacy of three drugs: pyrantel pamoate with praziquantel (Canex Composto®), fenbendazole (Fenzol Pet®), and milbemycin oxime with praziquantel (Milbemax C®). Among the evaluated animals, 22/38 (57.89%) tested negative and 16/38 (42.71%) tested positive for Ancylostoma caninum infection. Evaluation of the efficacy of antiparasitic drugs showed that 12/16 (75%) dogs were infected with helminths that were susceptible to pyrantel pamoate with praziquantel. Among those for which pyrantel pamoate with praziquantel was not effective, 3/4 (75%) were susceptible to fenbendazole, while the remaining case resistant to both pyrantel pamoate with praziquantel and fenbendazole was sensitive to milbemycin oxime with praziquantel (100%). The odds ratio of infection in dogs inhabiting environments containing soil or grass was 6.67 times higher than that in dogs inhabiting impermeable environments. Mixed-breed dogs (SRD) were 6.54 times more likely to be infected compared to purebred dogs. A. caninum resistant to pyrantel pamoate with praziquantel (4/16, 25%) and fenbendazole (1/4, 25%) were detected. The results of this study demonstrated the importance of coproparasitological monitoring by professionals before and after treatments to assess antiparasitic drug effectiveness, ensure animal health and welfare, and minimize animal exposure to risk factors.

Molecular detection of Toxoplasma gondii in placentas of women who received therapy during gestation in a toxoplasmosis outbreak.

Toxoplasmosis is a disease caused by T. gondii, a protozoa which affects humans and animals and is widely distributed worldwide. In humans, there is great concern due to the serious consequences that can occur in the infection of pregnant women and the newborn. The early diagnosis of gestational toxoplasmosis is important for treatment to be carried out in order to prevent vertical transmission or reduce damage. The diagnosis can be made through the detection of antibodies in pregnant women or neonates and PCR of amniotic fluid. Previous studies have also reported PCR of the placenta as a good diagnostic test. Our study evaluated the detection of T. gondii DNA in placenta samples from parturients seen at the University Hospital of Santa Maria, Southern Brazil and treated during the pregnancy. We performed PCR in forty samples and five were positive, representing 12.5%. When correlating the treatment time and the detection of DNA in the placentas, no significant result was found. The prevalence of positive samples was lower than in other studies in the literature. The data reaffirm the importance of carrying out the analysis of the placenta.

Isolation and molecular characterization of Toxoplasma gondii from placental tissues of pregnant women who received toxoplasmosis treatment during an outbreak in southern Brazil.

Toxoplasma gondii is a protozoan that has great genetic diversity and is prevalent worldwide. In 2018, an outbreak of toxoplasmosis occurred in Santa Maria, Brazil, which was considered the largest outbreak ever described in the world. This paper describes the isolation and molecular characterization of Toxoplasma gondii from the placenta of two pregnant women with acute toxoplasmosis who had live births and were receiving treatment for toxoplasmosis during the outbreak. For this, placental tissue samples from two patients underwent isolation by mice bioassay, conventional PCR and genotyping using PCR-RFLP with twelve markers. Both samples were positive in isolation in mice. The isolate was lethal to mice, suggesting high virulence. In addition, the samples were positive in conventional PCR and isolates submitted to PCR-RFLP genotyping presented an atypical genotype, which had never been described before. This research contributes to the elucidation of this great outbreak in Brazil.

In vitro and in vivo acaricidal activity evaluation of organo-modified siloxanes in populations of Rhipicephalus microplus.

Infestations of Rhipicephalus microplus cause significant damage to cattle breeding and their control is primarily based on chemical products. There are extensive reports of efficacy losses of acaricid products over time, as well as resistance of the parasites to them, thereby making it necessary to search for new alternatives. The present work aimed to determine the in vitro and in vivo acaricidal activity of organo-modified siloxanes with and without piperonyl butoxide (PBO) in southern Brazil. For the in vitro test, engorged females of R. microplus were collected and submitted to the immersion test. The formulation containing organo-modified siloxanes was tested at 4 different concentrations: 0.6, 1.0, 2.5, and 5.0%. The lowest dilutions (0.6, 1.0, and 2.5%) were also tested with the inclusion of 10% PBO. The in vivo test was performed by applying 2.5% organo-modified siloxanes, and the addition of 10% PBO was applied by spraying. The results showed high acaricidal activity (100%) in vitro in the concentration of 5% on non-associated forms, and in combinations of concentrations of 0.6, 1.0, 2.5% with PBO. The in vivo results also increased the efficacy with the association of PBO. In view of the current multi-resistance scenario of the R. microplus tick to the different commercially available acaricidal products, this study investigated the use of this product in association with PBO as an alternative to R. microplus control and found positive results. To the authors' knowledge, this is the first study to use organo-modified siloxanes against ticks.

Parasites in dairy cattle farms in southern Brazil / Los parásitos en las granjas de ganado lechero en el sur de Brasil

ABSTRACT Objective. The aim of this study was to investigate the relation among type and size of the farms related to the management of production and especially the presence and control of parasites. Materials and methods. To accomplish the above, 65 farms were used: 56 of semi-extensive system (cows in pastures), classified as low density farms (n=15, up to 15/cows), medium density farms (n=20; between 16-30/cows) and large density farms (n=21; over 31/cows). It was also included nine farms freestall system (n=9; confinement, over 70 cows) as part of the study population. Results. In the farms visited for the study can be noticed that the farms that had the higher level of technological improvement in managements practice were properties in high level (3) and freestall (4). In most of the farms there were observed the presence of ticks and flies, regardless of density of farms. Feces samples collected from 650 cows (n=10/farm), and analyzed using McMaster showed that 191 cows were positive for parasites. The presence of antibodies in bulk milk tank occurred in 36 (55.38%; CI95% 42-67) to Neospora caninum of the studied farms. Conclusions. We also conclude that N. caninum is present in cattle herds in Western Santa Catarina, and may be linked to reproductive problems in cows.

RESUMEN Objetivo. El objetivo de este estudio fue investigar la relación entre el tipo y el tamaño de las fincas relacionadas con la gestión de la producción, y especialmente, la presencia y el control de los parásitos. Materiales y métodos. Para lograr lo anterior, se utilizaron 65 granjas: 56 de semi-extensivo sistema (vacas en los pastos), clasificado como granjas de baja densidad (n=15, hasta 15/vacas), las granjas de densidad media (n=20; entre 16-30/vacas) y granjas grandes densidad (n=21; más de 31/vacas). También se incluyeron nueve del sistema de granjas freestall (n=9; confinamiento, más de 70 vacas) como parte de la población de estudio. Resultados. En las granjas visitadas se pudó notar que tenían el mayor nivel de mejora tecnológica en la práctica de gestiones eran propiedades en alto nivel (3) y estabulación libre (4). En la mayoría de las granjas no se observó la presencia de garrapatas y moscas, independientemente de la densidad de las explotaciones. Muestras de heces recogidas de 650 vacas (n = 10/granja), y analizados usando McMaster mostró que 191 vacas fueron positivas para parásitos. La presencia de anticuerpos en tanque de leche a granel se produjo en 36 (55.38%; IC95% 42-67) por Neospora caninum de las fincas estudiadas. Conclusiones. Se concluye que N. caninum está presente en los rebaños de ganado en el oeste de Santa Catarina, y puede estar vinculado a problemas reproductivos en vacas.