In Vitro Cultivation of a ZoonoticBabesiasp. Isolated from Eastern Cottontail Rabbits (Sylvilagus floridanus) on Nantucket Island, Massachusetts

Abstract

A Babesia sp. found in eastern cottontail rabbits (Sylvilagus floridanus) on Nantucket Island, Massachusetts, is the same organism that caused human babesiosis in Missouri and Kentucky, on the basis of morphology and identical small-subunit rRNA (SSU rRNA) gene sequences. Continuous cultures of the rabbit parasite were established from infected blood samples collected from two cottontail rabbits livetrapped on Nantucket Island. HL-1 medium or minimal essential medium alpha medium supplemented with 20% human serum best supported in vitro propagation of the parasite in human or cottontail erythrocytes, respectively. Parasite growth was not sustained in domestic-rabbit erythrocytes or in medium supplemented with domestic-rabbit serum. The cultured parasites were morphologically indistinguishable from the Kentucky human isolate. Transmission electron microscopy revealed similar fine structures of the parasite regardless of the host erythrocyte utilized in the cultures. Two continuous lines of the zoonotic Babesia sp. were established and confirmed to share identical SSU rRNA gene sequences with each other and with the Missouri and Kentucky human Babesia isolates.

Serum Antibodies to Whole-Cell and Recombinant Antigens of Borrelia Burgdorferi in Cottontail Rabbits

“…The isolation of a Babesia species from eastern cottontail rabbits ( Sylvilagus floridanus ) in tick-infested areas of Nantucket Island, Massachusetts, USA (Holman et al, 2005), further illustrates the diversity of etiologic agents associated with these hosts. By harboring an array of pathogens, rabbits might be serving as reservoirs of multiple infectious agents.…”

First Case of Human Babesiosis in Korea: Detection and Characterization of a Novel Type of Babesia sp. (KO1) Similar to Ovine Babesia

“…Recently, it has increasingly gained attention as an emerging zoonosis in humans (4,8). Two main species of Babesia parasites, namely, B. microti (socalled small Babesia) and B. divergens (large Babesia, or the genus Babesia sensu stricto) have been known to be involved in human infections in the United States and Europe, respectively (4,6,7). In addition, a newly emerging Babesia species, referred to as WA1 (13,16) and CA1 (11), that causes human babesiosis has been reported and was recently identified as B. duncani sp.…”

In vitro cultivation of Babesia canis canis parasites isolated from dogs in Poland

“…There could be a lot of reasons for their relatively short survival time. Serum and erythrocytes are critical for maintaining the cultivation (Holman et al 1998(Holman et al , 2005Zintl et al 2004). As far as serum is concerned, our studies used commercial canine serum subjected to inactivation; however, the dogs from which the infected blood was taken and which served as erythrocyte donors could not be an optimum source of RBCs, which caused limitations during cultivation, making it impossible to obtain higher parasitemia.…”