Molecular detection of Anaplasma platys, Anaplasma phagocytophilum and Wolbachia sp. but not Ehrlichia canis in Croatian dogs

Abstract

The bacteria Anaplasma platys, Anaplasma phagocytophilum and Ehrlichia canis are tick-borne agents that cause canine vector-borne disease. The prevalence of these pathogens in South Eastern Europe is unknown with the exception of an isolated case of A. platys detected in a dog imported into Germany from Croatia. To gain a better insight into their presence and prevalence, PCR-based screening for these bacterial pathogens was performed on domesticated dogs from different regions of Croatia. Blood samples from 1080 apparently healthy dogs from coastal and continental parts of Croatia as well as tissue samples collected from 63 deceased dogs with a history of anaemia and thrombocytopenia were collected for molecular screening by an Anaplasmataceae-specific 16S rRNA conventional PCR. Positive samples were confirmed using a second Anaplasmataceae-specific PCR assay with the PCR product sequenced for the purpose of bacterial species identification. All sequenced isolates were georeferenced and a kernel intensity estimator was used to identify clusters of greater case intensity. 42/1080 (3.8%; CI 2.7-5.0) of the healthy dogs were PCR positive for bacteria in the Anaplasmataceae. Sequencing of the 16S rRNA gene amplified from these positive samples revealed the presence of A. platys in 2.5% (CI 1.6-3.4%, 27 dogs), A. phagocytophilum in 0.3% (CI 0-0.6%, 3 dogs) and a Wolbachia endosymbiont in 1.1% (CI 0.4-1.6%, 12 dogs) of dogs screened in this study. Necropsied dogs were free from infection. Notably, no evidence of E. canis infection was found in any animal. This survey represents a rare molecular study of Anaplasmataceae in dogs in South Eastern Europe, confirming the presence of A. platys and A. phagocytophilum but not E. canis. The absence of E. canis was surprising given it has been described in all other Mediterranean countries surveyed and raises questions over the regional vector capacity of the Rhipicephalus sanguineus tick.

Dirofilaria repens microfilaremia in humans: Case description and literature review

“…Partial sequences amplified from microfilaria from blood and adult parasites were identical to a Wolbachia sp. endosymbiont of D. repens previously detected in blood from Croatian dogs [ 29 ].…”

Molecular Detection of Ehrlichia canis in the Pet-Dog Population in R. N. Macedonia

“…However, some studies report a rather low prevalence of E. canis (Malaysia -2%, Myanmar -0.75%, etc. ), or even fail to detect the presence of E. canis in the studied dog population (Croatia) [10,29,30]. The established differences in the prevalence of E. canis in different studies are mainly infl uenced by the wide variety of approaches used for the study design.…”

Entomopathogenic Fungi and Bacteria in a Veterinary Perspective

“…On the other hand, an investigation conducted on blood collected from dogs in Haiti found approximately 22% of dogs PCR-positive for Wolbachia [208]. Furthermore, Wolbachia was detected in blood specimens of dogs and was determined from the filarial nematode Dirofilaria repens [209]. Wolbachia has also been detected in the blood of cats and it is supposed to be related to the heartworm Dirofilaria immitis, which harbors this endosymbiont [210].…”