Reservoir Competence of the Rice Rat (Rodentia: Cricetidae) for Borrelia burgdorferi

Abstract

The reservoir competence of the rice rat, Oryzomys palustris, for Borrelia burgdorferi is described. Infected Ixodes scapularis Say (I. dammini, Spielman, Clifford, Piesman & Corwin) nymphs were used to infect animals. Borrelia infection was diagnosed by xenodiagnostic feeding of noninfected I. scapularis larvae and by reisolation of the spirochetes from blood and other tissues. Rice rats acquired B. burgdorferi and maintained spirochete infection for 5-9 wk. B. burgdorferi were cultured from samples of skin and urinary bladders from all animals killed on day 21 (three rats), 35 (three rats), or 56 (three rats) after infection. The spirochetes were also detected in blood samples obtained 1 and 2 wk after exposure. Spirochetes that persisted for 5 wk in rice rats did not lose their infectivity for golden Syrian hamsters. The prepatent period for infecting xenodiagnostic ticks was 1 wk. Overall, 75.6% of I. scapularis larvae (n = 694) that fed on infected rice rats acquired B. burgdorferi. Prevalence of infection reached 83% in ticks that fed on tick-exposed animals during the 2nd-4th wk, 68% during the 5th wk, and 17.4% during the 9th wk. The duration of rice rat infectivity for ticks exceeded 2 mo. I. scapularis nymphs infected as larvae on rice rats transmitted B. burgdorferi. Taken together, these studies confirm the reservoir competence of the rice rat for B. burgdorferi.

Longitudinal study of infection with Borrelia burgdorferi in a population of Peromyscus leucopus at a Lyme disease-enzootic site in Maryland.

“…White-footed mice, in comparison with meadow voles and chipmunks 15 and skunks and raccoons, 16 are generally recognized in these areas as the most important reservoir hosts of the organism. In other areas of the United States in which B. burgdorferi is enzootic, other mammals and reptiles have been demonstrated to be competent reservoir hosts 12,[18][19][20] and may play an equally prominent role.Field studies have implicated I. scapularis as the vector of indirect transmission of the spirochete to mice and other reservoir hosts. 21 The rates of direct horizontal and vertical transmission of B. burgdorferi in the maintenance of the spirochete in a population of white-footed mice are unknown, but the rate of vertical transmission may be extremely low based on laboratory studies.…”

“…White-footed mice, in comparison with meadow voles and chipmunks 15 and skunks and raccoons, 16 are generally recognized in these areas as the most important reservoir hosts of the organism. In other areas of the United States in which B. burgdorferi is enzootic, other mammals and reptiles have been demonstrated to be competent reservoir hosts 12,[18][19][20] and may play an equally prominent role.…”

Socio-ecology of the marsh rice rat (Oryzomys palustris) and the spatio-temporal distribution of Bayou virus in coastal Texas

“…Its major roles and low functional redundancy in this trophic web (Chabreck, 1988) are highlighted by efficient extraction and recycling of marsh resources (Wolfe, 1982). Reservoir competence in O. palustris also has been demonstrated for multiple parasites of commu-nity assemblage importance (Morlan, 1951;Barnard et al, 1971;Levin et al, 1995). Lastly but not exhaustively, its long-distance, frequent dispersal behaviours (Esher et al, 1978) provide a flexible adaptation to survive periodic storm surges (Abuzeineh et al, 2007), minimise competition and inbreeding depression (Loxterman et al, 1998), and produce founder and rescue populations in nearby island systems (Forys and Dueser, 1993).…”

Characterization of Lyme Disease Spirochetes Isolated From Ticks and Vertebrates in North Carolina

“…Three strains of B. burgdorferi previously isolated from I. scapularis ticks, were used as positive controls. These included, the ATCC type strain 35210 (or B31), a clone of JD1 (C2) and a Valhalla isolate (AN 1.2) (Valhalla, New York, USA) (Levin et al, 1995). The Valhalla isolate was reisolated after passage in a Carolina anole (Anolis carolinensis).…”

“…Standard methods for inducing B. burgdorferi infection by needle inoculation (Piesman, 1993) and reisolation of spirochetes from urinary bladder (Levin et al, 1995) and ear tissue (Piesman, 1993) were used throughout this study. Intradermal inoculations (Gern et al, 1993) of culture derived spirochetes of several isolates (C0235, C0064, C0219, and JD1) were given to white mice (Mus musculus, outbred ICR strain) and marsh rice rats (Oryzomys palustris, pathogen-free outbred colony at the Naval Dental Research Laboratory, Great Lakes, Illinois, USA).…”