Hematological values associated to the serological and molecular diagnostic in cats suspected of Ehrlichia canisinfection

Abstract

The literature contains several studies on feline ehrlichiosis. However, information about the characteristics of Ehrlichia infection in cats is still scanty. This study evaluated the association between Ehrlichia spp. infection and the hematologic data of 93 cats treated at the Federal University of Mato Grosso Veterinary Hospital in Cuiabá, state of Mato Grosso, Brazil. The presence of or exposure to Ehrlichia spp. infection was evaluated by Polymerase Chain Reaction (PCR) targeting the dsb and 16S rRNA gene of Ehrlichia, and by detection of anti-Ehrlichia canis IgG antibodies in Indirect Fluorescence Assay (IFA), respectively. Eight (8.6%) cats tested positive by PCR and the partial DNA sequence obtained from PCR products was a 100% match to E. canis. Forty-two (45.1%) cats showed antibody reactivity against Ehrlichia spp. Hematological alterations such as low erythrocyte count, thrombocytopenia, lymphopenia and monocytosis were observed in PCR positive cats. Among them, low erythrocyte counts were associated with IgG antibody titers of 40 to 640 and five cats also tested positive by PCR. Furthermore, PCR-positive cats showed a tendency to be lymphopenic. No correlation was found between age and sex, and no ticks were observed in any of the examined cats.Keywords: Ehrlichiosis, feline, hematology, polymerase chain reaction, indirect fluorescence assay, diagnosis. ResumoDiversos estudos sobre erliquiose felina vêm sendo relatados na literatura. No entanto, a caracterização da infecção por Ehrlichia em gatos ainda é escassa. O presente estudo objetivou avaliar a associação entre infecção por Ehrlichia e dados hematológicos em 93 gatos atendidos no Hospital Veterinário da Universidade Federal de Mato Grosso, em Cuiabá, Brasil. A presença de infecção por Ehrlichia spp. foi avaliada pela Reação em Cadeia pela Polimerase (PCR) visando à amplificação dos genes dsb e 16S rRNA de Ehrlichia e por Reação de Imunofluorescência Indireta (RIFI). Oito (8,6%) gatos demonstraram ser positivos pela PCR, sendo suas sequências parciais de DNA 100% idênticas à E. canis. Quarenta e dois gatos (45,1%) apresentaram anticorpos reativos contra Ehrlichia spp. Alterações hematológicas como baixas contagens de eritrócitos, trombocitopenia, linfopenia e monocitose foram observadas em gatos positivos pela PCR. Dentre essas, eritropenia foi associada em gatos com títulos de anticorpos IgG entre 40 e 640, sendo cinco destes positivos pela PCR. Adicionalmente, gatos positivos na PCR apresentaram uma tendência a serem linfopênicos. Não foram observadas associações entre a presença de infecção nos gatos e suas respectivas idades e sexo. Nenhum carrapato foi observado nos gatos examinados.Palavras-chave: Erliquiose, felinos, hematologia, reação em cadeia pela Polimerase, reação de imunofluorescência indireta, diagnóstico.

SEROLOGICAL EVIDENCE OF EXPOSURE TO Ehrlichia canis IN CATS

“…This prevalence is in agreement with the canine ehrlichiosis profile at the locality (20) , indicating that the epidemiological behavior of feline ehrlichiosis is similar to the canine ehrlichiosis in that region, as described in Cuiabá by Braga et al (14) . We found the same association comparing seropositivity in cats (present study) and dogs (20) at matching geographic location.…”

“…No statistical differences were observed when comparing the presence of antibodies in cats according to the county of origin, gender, age, breed, and modus vivendi, similarly to previous reports (14,22) . However, the high frequency of positive adult and stray cats demonstrated in this work should be explained by the higher time of exposure and higher possibility of contact with the vectors, respectively.…”

“…has been described in wild and domestic felids in various regions of the world, through hematoscopy, serology, and molecular techniques, feline ehrlichiosis being caused especially by E. canis (7)(8)(9)(10)(11)(12)(13)(14)(15)(16) . However, most surveys regarding E. canis occur in dogs and the reports about its occurrence in cats still remain scarce (4) .…”

Investigação molecular de Ehrlichia canis, Anaplasma platys, Anaplasma phagocytophilum e Rickettsia spp. em felídeos selvagens cativos

“…Em gatos domésticos, já foi documentada a infecção natural e experimental por Ehrlichia spp. (Almosny 1998, Little 2010, Ebani & Bertelloni 2014, Maia et al 2014) e assume-se que as alterações clínicas e laboratoriais nessa espécie sejam semelhantes às que ocorrem em cães (Almosny 1998, Little 2010, Braga et al 2013. Braga et al (2013) encontraram anemia, trombocitopenia e linfopenia nos gatos positivos na PCR para E. canis.…”

Divergence of the TRP36 protein (gp36) in Ehrlichia canis strains found in Brazil

“…Infection of felines by E. canis has been reported in Brazil since 2009 (Oliveira et al, 2009). Recently, Braga et al (2013) reported the molecular detection of E. canis in domestic cats in a region recognized as endemic for canine ehrlichiosis in Brazil, where at least two different E. canis TRP36 (Cba#1 and CBA#16) genotypes infect dogs .…”