Serological and molecular analysis of feline vector-borne anaplasmosis and ehrlichiosis using species-specific peptides and PCR

Abstract

BackgroundWith the exception of Bartonella spp. or Cytauxzoon felis, feline vector-borne pathogens (FVBP) have been less frequently studied in North America and are generally under-appreciated as a clinical entity in cats, as compared to dogs or people. This study investigated selected FVBP seroreactivity and PCR prevalence in cats using archived samples.MethodsFeline blood samples submitted to the Vector Borne Diseases Diagnostic Laboratory (VBDDL) at North Carolina State University College of Veterinary Medicine (NCSU-CVM) between 2008 and 2013 were tested using serological assays and PCR. An experimental SNAP® Multi-Analyte Assay (SNAP® M-A) (IDEXX Laboratories, Inc. Westbrook, Maine, USA) was used to screen all sera for antibodies to Anaplasma and Ehrlichia genus peptides and A.phagocytophilum, A.platys, B.burgdorferi, E.canis, E.chaffeensis, and E.ewingii species-specific peptides. PCR assays were used to amplify Anaplasma or Ehrlichia DNA from extracted ethylenediaminetetraacetic acid (EDTA)-anti-coagulated blood samples. Amplicons were sequenced to identify species.ResultsOverall, 7.8 % (56/715) of cats were FVBP seroreactive and 3.2 % (13/406) contained Anaplasma or Ehrlichia DNA. Serologically, B.burgdorferi (5.5 %) was the most prevalent FVBP followed by A.phagocytophilum (1.8 %). Ehrlichia spp. antibodies were found in 0.14 % (12/715) of cats with species-specific seroreactivity to E.canis (n = 5), E.ewingii (n = 2) and E.chaffeensis (n = 1). Of seropositive cats, 16 % (9/56) were exposed to more than one FVBP, all of which were exposed to B.burgdorferi and either A.phagocytophilum (n = 7) or E.ewingii (n = 2). Based upon PCR and DNA sequencing, 4, 3, 3, 2, and 1 cat were infected with A.phagocytophilum, A.platys, E. ewingii, E. chaffeensis and E.canis, respectively.ConclusionsCats are exposed to and can be infected with vector-borne pathogens that commonly infect dogs and humans. To our knowledge, this study provides the first evidence for E.chaffeensis and E.ewingii infection in naturally-exposed cats in North America. Results from this study support the need for regional, serological and molecular FVBP prevalence studies, the need to further optimize serodiagnostic and PCR testing for cats, and the need for prospective studies to better characterize clinicopathological disease manifestations in cats infected with FVBP.

Prevalence study and risk factor analysis of selected bacterial, protozoal and viral, including vector-borne, pathogens in cats from Cyprus

“…There are sporadic reports of this canine pathogen in cats from North America and Brazil [7, 56, 57], and recently A. platys- like strains were identified in cats from Sardinia, Italy [58]. In this study, we report a case of presumptive A. platys infection in a cat from Cyprus based on partial sequencing of 16S rRNA gene.…”

Update on Canine and Feline Blood Donor Screening for Blood‐Borne Pathogens

“…Client‐owned cats with clinical signs of disease have been documented with E. canis , and E. canis ‐like organism DNA in their blood . Studies evaluating for E. canis or E. canis ‐like organisms in healthy cats in the United States have yielded negative results .…”

Prevalence of Vector‐Borne Pathogens in Southern California Dogs With Clinical and Laboratory Abnormalities Consistent With Immune‐Mediated Disease

“…However, the geographic distribution of E. ewingii is expanding, and the organism was recently amplified from a cat in California. 43,44 These 3 Ehrlichia PCRpositive dogs were SNAP Ò 4DX Plus Ò ELISA seronegative for Ehrlichia species, and E. canis IFA negative. Ehrlichia DNA was not PCR-amplified from their acute blood samples, and amplicons were not obtained from the convalescent samples using alternate E. ewingii-specific primers.…”

“…E. ewingii infection is most commonly documented in the southeast and mid‐atlantic regions of the United States. However, the geographic distribution of E. ewingii is expanding, and the organism was recently amplified from a cat in California . These 3 Ehrlichia PCR‐positive dogs were SNAP ® 4DX Plus ® ELISA seronegative for Ehrlichia species, and E. canis IFA negative.…”