Investigation of Neospora caninum, Hammondia sp., and Toxoplasma gondii in tissues from slaughtered beef cattle in Bahia, Brazil

Abstract

Neospora caninum, Hammondia sp., and Toxoplasma gondii are parasites with morphological and genetic similarities. N. caninum and T. gondii are important abortive agents of cattle and sheep, respectively, and may infect numerous animal species. Hammondia sp. is not known to induce disease in animals, but may cause confusion in the identification of closely related coccidia. The aim of this study was to investigate infection rates caused by N. caninum, Hammondia sp., and T. gondii in beef cattle using a nested PCR for Toxoplasmatinae rDNA, followed by sequencing of the PCR products. Antibodies to N. caninum and T. gondii were also investigated in the tested animals. Brains and hearts were obtained from 100 beef cattle in a slaughterhouse in Bahia. Seven samples from brain tested positive for Toxoplasmatinae DNA. No positive reactions were found in heart tissues. After sequencing of the PCR products from all positive tissues, five sequences matched with N. caninum and two matched with T. gondii. Antibodies to N. caninum and T. gondii were found in 20% and 26% of the animals, respectively. The confirmation of N. caninum and the absence of Hammondia heydorni in the tested animals is suggestive that cattle are not efficient intermediate hosts of H. heydorni; however further studies need to be performed using a greater variety of tissues and a higher sample size. The detection of T. gondii DNA in bovine tissues reinforces the potential risk of transmission of this parasite to humans and other animals through the consumption of bovine meat.

Sero-occurrence of anti-Toxoplasma gondii antibodies and vertical transmission in slaughtered beef cows (Bos indicus)

“…Interesting the fact that Garcia et al (1999), Ogawa et al (2005), that worked with animals from northern Paraná state, found 25.8% and 26%, and Santos et al (2010) that studied cattle from Bahia found 26% of serum prevalence of antibodies, which were similar than observed for us in the present study.…”

Screening for Toxoplasma gondii in aborted bovine fetuses in Brazil

“…Despite the presence of T. gondii has been confirmed in beef cattle in Brazil by serological studies (GarCia et al, 1999), PCR and sequencing (sanTos et al, 2010), and isolation by bioassay (maCeDo et al, 2012), the present investigation performed in aborted fetuses with lesions indicative of protozoal infection were negative for T. gondii DNA, in accordance to studies performed in many countries, where the rate of infected bovine fetus with T. gondii was low (Dubey, 1986).…”

Neospora caninum in bovine fetuses of Minas Gerais, Brazil: genetic characteristics of rDNA

“…The gene region ITS-1 has become the target for phylogenetic studies, since this region experiences greatest mutagenic evolutionary pressure and is subject to polymorphism (PAYNE and ELLIS, 1996;AL-QASSAB et al, 2009;AL-QASSAB et al, 2010;SANTOS et al, 2010). Despite these studies, there are still few gene sequences of ITS-1 deposited in GenBank, including those originating from Brazil.…”

“…Phylogenetic investigations on N. caninum contribute towards expanding the knowledge of the characteristics and behavior of samples of the parasite in Brazil (SANTOS et al, 2010). The gene region ITS-1 has become the target for phylogenetic studies, since this region experiences greatest mutagenic evolutionary pressure and is subject to polymorphism (PAYNE and ELLIS, 1996;AL-QASSAB et al, 2009;AL-QASSAB et al, 2010;SANTOS et al, 2010).…”