Infection with a Proposed New Subspecies ofBabesia canis,Babesia canissubsp.presentii, in Domestic Cats

Abstract

Parasitemia with a large Babesia species was identified in two domestic cats from Israel. One cat, also coinfected with feline immunodeficiency virus and "Candidatus Mycoplasma haemominutum," had profound icterus and anemia which resolved after therapy, whereas a second cat was an asymptomatic carrier. Amplification and sequencing of the 18S rRNA gene, followed by phylogenetic analyses, indicated that infection was caused by Babesia canis. However, the sequences of the internal transcribed and 5.8S rRNA regions of the ribosomal operon used for subspeciation of B. canis were markedly different from the recognized subspecies of B. canis, which include B. canis vogeli, B. canis canis, and B. canis rossi. Based on phylogenetic comparisons of the 18S rRNA gene, 5.8S, and internal transcribed spacer sequences of the isolates from the cats and on the smaller sizes of the merozoite and trophozoite stages of this parasite, which distinguish it from the subspecies of B. canis present in dogs, we propose to identify the novel feline genotype of B. canis described in the present study as a new subspecies, B. canis subsp. presentii.Babesia species are tick-borne intraerythrocytic apicomplexan parasites found in a variety of domestic and wild animals and in humans. Babesiosis in domestic cats has primarily been reported in South Africa, where infection is mainly due to Babesia felis, a small Babesia that causes anemia and icterus (24,28). In addition, Babesia cati was reported from a cat (Felis catus) in India (23) and sporadic cases of infection in domestic cats by unidentified Babesia parasites have been reported in France, Germany, Thailand, and Zimbabwe (3,16,22,29). Reports of Babesia in wild felids include Babesia herpailuri from a jaguarundi (Herpailurus yaguarundi) (7), Babesia pantherae from a leopard (Panthera pardus) (8), Babesia leo from lions (Panthera leo) (24), and a unidentified piroplasm in cheetahs (Acinonyx jubatus) (1). Cytauxzoon felis is a piroplasm that is phylogenetically related to Theileria and Babesia and infects the bobcat (Lynx rufus) (11) and domestic cats (34). In a recent study from Spain and Portugal, a partial DNA sequence from the small subunit RNA gene identified as Babesia canis canis was amplified from the blood of three cats in which parasites were not visualized by microscopy (6). This has provided initial molecular evidence for infection by Babesia canis in cats.Babesia infections in domestic dogs are caused by large piroplasms described as B. canis and by smaller parasites that are mostly grouped under the species Babesia gibsoni. Three subspecies of B. canis have been recognized based on differences in the pathological and clinical syndromes caused by each subspecies, antigenic properties, transmission by different vector ticks, and genetic characterization (5,13,27,36). B. canis rossi described in South Africa is transmitted by the tick Haemaphysalis leachi and causes a severe and often fatal hemolytic disease in dogs (25). B. canis vogeli is found in the Middle East, North Africa, ...

A PCR method targeting internal transcribed spacers: the simultaneous detection of Babesia bigemina and Babesia bovis in cattle

“…Because internal transcribed spacers (ITSs) have great variability in both nucleotide and length, ITS sequences were used for discriminating different geographic isolates of piroplasmids, identifying new species, and differentiating between piroplasm species and subspecies (Holman et al 2003, Baneth et al 2004, Conrad et al 2006, Aktas et al 2007, Liu et al 2008.…”

Epidemiological Survey of Tick-Borne Protozoal Infection in Iriomote Cats and Tsushima Leopard Cats in Japan

“…As a screening PCR, nested PCR was performed to amplify a partial 18S rRNA sequence derived from Hepatozoon, Babesia and/or Theileria species using the primers F1 (5′-AGT CAT ATG CTT GTC TTA-3′) and R1 (5′-CCA TCA TTC CAA TTA CAA-3′) for the first round, and then F2 (5′-GAA ACT GCG AAT GGC TCA TTA-3′) and R2 (5′-CGG TAG GCC AAT ACC CTA CCG TC-3′) [3,6]. These primer sets are universal and recognize 18S rRNA genes from Hepatozoon spp., Babesia spp.…”

Serological evidence for Babesia canis infection of horses and an endemic focus of B. caballi in Hungary

“…This means that phenotypic (antigenic) differences between these two piroplasms allow species-specific diagnosis despite existing concomitant infections. On the other hand, B. canis and B. caballi are genetically closely related (Baneth et al, 2004), and the degree of polymorphism between B. caballi and B. canis isolates is similar to that between the three subspecies of B. canis (Zahler et al, 1998); therefore, cross-infection of their hosts is not unlikely. The tick species most frequently found on horses and the vector of B. caballi in Hungary is D. marginatus (Babos, 1965) which can transmit B. canis (Pavlovic et al, 2002).…”