Neurisvan Ramos Guerra

Frequency of Toxoplasma gondii antibodies in bovines in the state of Pernambuco, Brazil

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii that affects homeothermic animals, including humans. Felines are considered the definitive host of this parasite, while other animals act as intermediate hosts. The purpose of this study was to assess the frequency of anti-T. gondii IgG antibodies in bovines in the state of Pernambuco, Brazil. Serum samples (n = 427) from animals in 13 municipalities of the coastal forest/plantation region of the state were analyzed using the immunofluorescent antibody test (IFAT). The overall results revealed a prevalence rate of 16.63% (27/427). High percentages of positivity were found among animals aged 25 to 36 months (28.57%; 30/42) and in males (22.22%; 2/9). The present findings suggest that bovine toxoplasmosis is endemic in the area under study.

Detecção de anticorpos IgG anti-Trypanosoma vivax em bovinos através do teste de Imunofluorescência indireta

Trypanosoma vivax infects a wide range of wild and domestic ungulates, causing important losses for the livestock industry. The aim of the present study was to assess the detection of IgG antibodies against T. vivax in cattle from the state of Pernambuco, Brazil. Therefore, we analyzed 2.053 blood serum samples from cattle herds of municipalities in Pernambuco, what was made by Immunofluorescence Assay. The overall seroprevalence of IgG antibodies against T. vivax in cattle was 13.93% (286/2053). The frequencies, by region, varied from 11.90% to 15.99%. Thus, the data obtained allowed to characterize the state of Pernambuco as an area of enzootic instability for T. vivax. The frequency herein reported (i.e., 13.93%) indicates that Pernambuco is an endemic area for T. vivax, this parasite being spread throughout the state.

Evidência molecular da transmissão vertical precoce de Leishmania (Leishmania) infantum em um cão

Visceral leishmaniasis (VL) is caused by the protozoon Leishmania infantum. Transmission of this parasite to hosts occurs mainly through the bite of infected sand flies. However, alternative infection routes have been hypothesized, especially in areas where the biological vector is absent. The exact time of infection and whether in utero transmission occurs have still not been fully elucidated. This report demonstrates molecular evidence of vertical transmission of L. infantum from a pregnant dog to the embryo. Samples (e.g. vulva, vagina, cervix, uterine body, uterine horn and ovaries) from a female naturally infected by L. infantum and from her embryo were molecularly analyzed by means of qPCR and cPCR followed by DNA sequencing. The gestational age was estimated to be 23±1 day. Through qPCR, the presence of L. infantum DNA was detected in all the samples analyzed (n=7), including the embryo, conversely through cPCR, only four samples (vagina, cervix, uterine body and embryo) were positive. This study demonstrated that transmission of L. infantum from a pregnant dog to the embryo might occur in the early days of pregnancy. In conclusion, this is the first report showing L. infantum infecting a canine embryo.

Development and assessment of a latex agglutination test based on recombinant MSP5 to detect antibodies against Anaplasma marginale in cattle

The recombinant protein MSP5 has been established as an important antigen for serological diagnosis of Anaplasma marginale by enzyme-linked immunosorbent assay (ELISA). However, due to the high cost of specialized equipment, this technique is not accessible to all laboratories, especially in developing countries in areas where the disease is endemic. The present study describes the standardization of a latex agglutination test (LAT) to detect antibodies against A. marginale based on recombinant MSP5. Compared with indirect enzyme-linked immunosorbent assay (iELISA), the relative sensitivity and specificity of the LAT were 95.21% and 91.86% respectively, with an almost perfect agreement between tests (kappa index = 0.863). These results can be considered important for the serological diagnosis of A. marginale, as they indicate that the test represents a rapid and low cost alternative to ELISA.

Molecular and serological investigation of infectious diseases in captive and free-range crab-eating fox (Cerdocyon thous – Linnaeus, 1776) from northeastern Brazil

The aim of this study was to detect DNA and antibodies anti-Leishmania spp., Neospora caninum and Toxoplasma gondii in captive and free-range crab-eating fox (Cerdocyon thous) from northeastern Brazil. Twenty-five crab-eating foxes from different states of northeastern Brazil were sampled by this study. Blood samples were collected by cephalic or jugular vein punctures. The whole blood was submitted to PCR, and the sera samples to the serological analysis as follows: MAT for T. gondii, NAT for N. caninum, and ELISA for L. chagasi. The frequence of antibodies anti-T. gondii was 50% and 29.41% for free-range and captive wild canids, respectively. The frequence of antibodies anti-N. caninum observed by this study was 62.50% and 23.52% for free-range and captive wild canids, respectively. The frequence of antibodies anti-L. chagasi was 4.0% for captive wild canids. Co-infections cases were identified as follows: one captive wild canid seropositive for T. gondii and L. chagasi and two free-range animals seropositive for T. gondii and N. caninum. All PCR assays performed were negative for the pathogens analyzed. This study describes the presence of antibodies anti-T. gondii, N. caninum e L. chagasi in wild canids from northeastern Brazil and highlights the necessity of further studies on infectious diseases in free-range and captive wild canids.

LEISHMANIA SPP. IN DIDELPHIS SPP. FROM NORTHEASTERN BRAZIL

Abstract The synanthropic behavior of marsupials of the genus Didelphis in endemic areas of leishmaniasis suggests that these animals may play an important role in the epidemiology of this infection. The aim of the present study was to detect Leishmania spp. DNA in Didelphis albiventris (white-eared opossum) and Didelphis aurita (big-eared opossum) living in forested and peridomestic areas of northeastern Brazil. Blood samples were collected from 25 animals (23 D. albiventris and 2 D. aurita) by cardiac puncture and then analyzed via PCR. Leishmania (Viannia) braziliensis DNA complex was detected in 4 (16%) of the 25 samples, whereas no samples scored positive for Leishmania (Leishmania) donovani complex. Our data suggest that D. albiventris participates in the wild enzootic cycle of the L. (V.) braziliensis complex. Therefore, humans living in this area are at risk of infection, because Didelphis species are in constant movement between wild and urban environments.