Redescription of Hepatozoon felis (Apicomplexa: Hepatozoidae) based on phylogenetic analysis, tissue and blood form morphology, and possible transplacental transmission

Abstract

BackgroundA Hepatozoon parasite was initially reported from a cat in India in 1908 and named Leucocytozoon felis domestici. Although domestic feline hepatozoonosis has since been recorded from Europe, Africa, Asia and America, its description, classification and pathogenesis have remained vague and the distinction between different species of Hepatozoon infecting domestic and wild carnivores has been unclear. The aim of this study was to carry out a survey on domestic feline hepatozoonosis and characterize it morphologically and genetically.MethodsHepatozoon sp. DNA was amplified by PCR from the blood of 55 of 152 (36%) surveyed cats in Israel and from all blood samples of an additional 19 cats detected as parasitemic by microscopy during routine hematologic examinations. Hepatozoon sp. forms were also characterized from tissues of naturally infected cats.ResultsDNA sequencing determined that all cats were infected with Hepatozoon felis except for two infected by Hepatozoon canis. A significant association (p = 0.00001) was found between outdoor access and H. felis infection. H. felis meronts containing merozoites were characterized morphologically from skeletal muscles, myocardium and lungs of H. felis PCR-positive cat tissues and development from early to mature meront was described. Distinctly-shaped gamonts were observed and measured from the blood of these H. felis infected cats. Two fetuses from H. felis PCR-positive queens were positive by PCR from fetal tissue including the lung and amniotic fluid, suggesting possible transplacental transmission. Genetic analysis indicated that H. felis DNA sequences from Israeli cats clustered together with the H. felis Spain 1 and Spain 2 sequences. These cat H. felis sequences clustered separately from the feline H. canis sequences, which grouped with Israeli and foreign dog H. canis sequences. H. felis clustered distinctly from Hepatozoon spp. of other mammals. Feline hepatozoonosis caused by H. felis is mostly sub-clinical as a high proportion of the population is infected with no apparent overt clinical manifestations.ConclusionsThis study aimed to integrate new histopathologic, hematologic, clinical, epidemiological and genetic findings on feline hepatozoonosis and promote the understanding of this infection. The results indicate that feline infection is primarily caused by a morphologically and genetically distinct species, H. felis, which has predilection to infecting muscular tissues, and is highly prevalent in the cat population studied. The lack of previous comprehensively integrated data merits the redescription of this parasite elucidating its parasitological characteristics.

Molecular detection of Hepatozoon spp. and Cytauxzoon sp. in domestic and stray cats from Madrid, Spain

“…The sequencing of the PCR products amplified from the cat samples in this study showed that both H. felis and H. canis can infect cats in Spain, although H. felis is by far more common, with only one cat infected with H. canis . A similar higher ratio of H. felis versus H. canis infection in domestic cats was also found in a study from Israel where only two cats out of 55 Hepatozoon -spp.-positive cats were detected with H. canis infection and 53 cats out of a total of 153 tested were positive for H. felis [13]. The Hepatozoon infection prevalences described in previous Spanish studies varied from 0.6% in one study [17], 4% in cats from the Barcelona area [19] and 16% in a cat colony from Barcelona [18], compared to the prevalence in our study of 1.6%.…”

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

“…The exact vectors and routes of transmission of feline hepatozoonoses are not known [27], but vectorial transmission likely plays a key role as for other species of Hepatozoon in different vertebrate species such as dogs [31]. The results of the present study demonstrate the utility of the novel Hepatozoon spp.…”

Prevalence and diversity of Babesia, Hepatozoon, Ehrlichia, and Bartonella in wild and domestic carnivores from Zambia, Africa

“…Based on the gene target used in the current study, several Hepatozoon sequences were detected, but some samples were very similar to H. canis and H. felis. A recent PCR study on wild felids and canids in India detected H. felis only in felids (lions, tigers, and leopards) and H. canis only in canids (domestic dogs and Indian wild dogs) (Pawar et al 2012); however, these parasites are not considered to be specific to the suborders of the Carnivora and H. canis and H. felis have been reported in both canids and felids (Rubini et al 2006;Jittapalapong et al 2006;Baneth et al 2013). Similarly, in the current study, H. canis-like sequences were detected in felids (lions) and hyena and H. felis-like sequences were detected in hyenas.…”