Thállitha Samih Wischral Jayme Vieira

Serosurvey of tick-borne pathogens in dogs from urban and rural areas from Parana State, Brazil

Considering the zoonotic potential of tick-borne disease (TBD) agents and the fact that dogs may act as sentinels for human infection, the aim of the present study was to determine the seroprevalence of TBD agents and risk factors for exposure in two different canine populations from Parana State, Southern Brazil. A total of 138 dog serum samples from urban (UA) (n=68) and rural (RA) (n=70) areas were tested with commercial ELISA rapid test for Anaplasma phagocytophilum, Ehrlichia canis and Borrelia burgdorferi antibodies and indirect immunofluorescence assay (IFAT) for Babesia vogeli. An overall of 92∕138 (66.7%) dogs, being 62∕68 (91.2%) from UA and 30∕70 (42.9%) from RA, were seropositive for at least one TBD agent. From the total number of dogs, sixty-two were positive for E. canis (44.9%), 19 (13.8%) for A. phagocytophilum, and 64 (46.4%) for B. vogeli. Anti-B. burgdorferi antibodies were not detected. Dogs from UA showed a higher percentage of tick infestation (p = 0.0135) and were highly associated with seropositivity to E. canis (p = 0.000005), A. phagocytophilum (p = 0.0001), and B. vogeli (p = 0.0012). In summary, the findings indicate that dogs from urban areas present higher potential risk exposure to TBD pathogens than those from rural areas.

Serological survey of Ehrlichia species in dogs, horses and humans: zoonotic scenery in a rural settlement from southern Brazil.

SUMMARY The aims of this study were to determine the seroprevalence of Ehrlichia spp. and risk factors for exposure in a restricted population of dogs, horses, and humans highly exposed to tick bites in a Brazilian rural settlement using a commercial ELISA rapid test and two indirect immunofluorescent assays (IFA) with E. canis and E. chaffeensis crude antigens. Serum samples from 132 dogs, 16 horses and 100 humans were used. Fifty-six out of 132 (42.4%) dogs were seropositive for E. canis. Dogs > one year were more likely to be seropositive for E. canis than dogs ≤ one year (p = 0.0051). Ten/16 (62.5%) and 8/16 (50%) horses were seropositive by the commercial ELISA and IFA, respectively. Five out of 100 (5%) humans were seropositive for E. canis and E. chaffeensis. Rhipicephalus sanguineus (n = 291, 97.98%) on dogs and Amblyomma cajennense (n = 25, 96.15%) on horses were the most common ticks found. In conclusion, anti-Ehrlichia spp. antibodies were found in horses; however, the lack of a molecular characterization precludes any conclusion regarding the agent involved. Additionally, the higher seroprevalence of E. canis in dogs and the evidence of anti-Ehrlichia spp. antibodies in humans suggest that human cases of ehrlichiosis in Brazil might be caused by E. canis, or other closely related species.

Seroepidemiological survey of Theileria equi and Babesia caballi in horses from a rural and from urban areas of Paraná State, southern Brazil

The objective of this study was to evaluate the seroepidemiological data of Babesia caballi and Theileria equi in horses from a rural settlement and carthorses from urban areas of Paraná State, southern Brazil. A total of 198 horses, including 32 from the rural settlement and 166 carthorses from Colombo (n=48), Pinhais (n=76), Londrina (n=24), and Curitiba city (n=18) was sampled and tested using a commercial competitive inhibition ELISA (cELISA) test. Out of the 198 horses, 193 (97.5%) were seropositive for at least one piroplasm species. Antibodies to T. equi were detected in 155/198 horses (78.3%), antibodies to B. caballi were detected in 137/198 horses (69.2%), and antibodies to both were detected in 99/198 (50.0%) horses. Horses living in the rural settlement and Colombo were more likely to be seropositive to T. equi than those in Curitiba (p<0.05). Horses older than 5 years were more likely to be seropositive for T. equi than those younger than 5 years (p<0.05). No significant association was found between gender or the presence of ticks and seropositivity to T. equi (p>0.05). In conclusion, the high seroprevalences to B. caballi and T. equi observed in this study emphasize that active surveillance programs are critical for monitoring animal health status, particularly because carthorses may act as urban disseminators of these piroplasms.

Use of a Mycoplasma suis-PCR protocol for screening a population of captive peccaries (Tayassu tajacu and Tayassu pecari)

Mycoplasma suis is a hemotropic bacteria of red blood cells and the causative agent of swine eperythrozoonosis. Diagnosis of infection may be reached by direct examination of blood smears; however, the use of polymerase chain reaction (PCR) of the 16S RNA gene of M. suis improves the sensitivity and specificity of detection. The aim of this study was to screen peccaries (Tayassu tajacu and T. pecari) for M. suis infection using a specific conventional PCR. A total of 28 blood samples from captive collared and white-lipped peccaries were collected, DNA extracted and a specific M. suis PCR assay performed. All samples were negatives by both blood smear examination and PCR testing. To verify the presence of amplifiable DNA, PCR for beta-actin gene was performed in all samples. This study was part of an active surveillance program, which is crucial for monitoring animal health status, particularly in wildlife species.

Serosurvey of anti-Toxoplasma gondii antibodies in sport horses from Paraiba state, Northeastern Brazil

Although the infection by Toxoplasma gondii in horses is usually asymptomatic, it may be characterized by the presence of tissue cysts and maintenance of detectable antibody titers. The aim of this study was to detect anti-T.gondii antibodies and to determine risk factors associated in sport horses from Paraíba State, northeastern Brazil. A total of 138 apparently healthy sport horses of different age and gender were sampled. Anti-Toxoplasma gondii antibodies were detected in 16/138 (11.6%; 95% CI: 6.77–18.14%) horses by indirect immunofluorescence antibody assay (IFA). A significant association was found between the water source and seropositivity to T. gondii (p<0.05). The present study highlights the importance of providing good quality water to the animals.

Potentially Same Novel Ehrlichia Species in Horses in Nicaragua and Brazil

To the Editor: In our previously published report, we found that blood samples from 4 naturally infected horses in Nicaragua were PCR positive for the 16S rDNA, sodB, and groEL genes of an Ehrlichia species (1). Similarly, Vieira and colleagues reported a potentially novel Ehrlichia sp. infecting horses in South America, with a high seroprevalence in carthorses; 1 horse blood sample was PCR positive for Ehrlichia 16S rDNA and dsb genes (2). Because these 2 studies sequenced different 16S rDNA regions, the Ehrlichia sp. found in Nicaragua could not be established as the same one infecting horses in Brazil. We retrieved an Ehrlichia PCR-positive horse blood sample (2) from Brazil and performed partial PCR and sequencing of the 16S rDNA, sodb, and groEL genes (1). Phylogenetic analysis of the sequences (3–5) demonstrated a close relationship between the Ehrlichia spp. found in Brazil and Nicaragua, with posterior probability values of 100% for all 3 gene fragments (online Technical Appendix Figure 1, https://wwwnc.cdc.gov/EID/article/24/5/172076-Techapp1.pdf). The 16S rDNA were 100% identical (181 bp/181 bp; GenBank accession no. KJ434178), sodb 99% identical (561 bp/567 bp; GenBank accession nos. MG385129, KJ434180), and groEL 99% identical (579 bp/584 bp; GenBank accession nos. MG385128, KJ434179). When we compared translated amino acid sequences of the Ehrlichia spp. from Brazil and Nicaragua, we observed high percent age identities with the groEL (100%) and sodB (97.8%) alignments (online Technical Appendix Figure 2). Furthermore, when compared with E. ruminantium, the most closely related Ehrlichia sp. on the basis of phylogenetic analyses, percent age identities from the groEL (94.8%) and sodB (78.8%) alignments were lower for both Ehrlichia spp. These findings suggest that the novel Ehrlichia spp. found infecting horses in Nicaragua and Brazil are potentially the same species. Future studies are needed to determine cell culture practices, characterize potential clinical signs of infection, and establish the main vector of this novel equine Ehrlichia species.

Molecular screening for hemotropic mycoplasmas in captive Barbary sheep (Ammotragus lervia) in southern Brazil

Aim: This study is part of an active surveillance program for monitoring animal health status in endangered species, and was conducted to screen captive Barbary sheep (Ammotragus lervia) for hemoplasma infection. Materials and Methods: A total of 12 blood samples were collected, DNA extracted and further tested by a pan-hemoplasma polymerase chain reaction protocol. Results: Animals were clinically healthy and not infested by ectoparasites. Although housekeeping gene DNA was successfully amplified, all the Barbary sheep samples tested negative for Mycoplasma sp. Conclusion: Notwithstanding the negative results, molecular pathogen surveys on Barbary sheep and other exotic wild mammals may provide insights regarding infection of endangered species caused by captivity stress in association with exposure to new pathogens worldwide.