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Biomedical subjects

B R Norment

Publications and source records attributed to B R Norment.

At least 19 recordsLinked to original sources
PubMed1985

Rickettsia-like organisms in ticks and antibodies to spotted fever-group rickettsiae in mammals from northern Mississippi.

Studies were conducted from April through August during 1974 and 1975 on 30 randomly selected trapping sites in Wall Doxey State Park, Holly Springs National Forest, and 1.6 km south of the park in Marshall County, Mississippi to provide information on the occurrence of ticks involved in the maintenance and transmission of spotted fever-group rickettsiae in nature. Of 365 animals (14 species) collected, 186 (51%) were parasitized by 4,169 ticks. Species of ticks collected included: Dermacentor variabilis; Amblyomma americanum; Rhipicephalus sanguineus; Haemaphysalis leporispalustris; and Ixodes texanus. Of 2,105 ticks examined, 116 (5.5%) were positive for rickettsia-like organisms.

Agglutination Tests↗
PubMed1984

Susceptibility and reservoir potential of the dog to spotted fever-group rickettsiae.

This study was initiated to determine the degree of susceptibility of dogs to virulent and nonvirulent spotted fever-group rickettsiae and to evaluate dogs as sources of infection for ticks. Dogs were exposed either by inoculation (syringe) or by infective tick bite to the following rickettsial serotypes: (1) Rickettsia rickettsii (Wachsmuth and Sawtooth female 2 strains), (2) R montana (M/5-6 B strain), and (3) R rhipicephali (3-7-female 6 strain). Results indicated that dogs inoculated with 1,000 or 10,000 egg infective doses of virulent R rickettsii developed a rickettsemia that was detectable as early as 4 days after inoculation to as late as 10 days. Conversely, none of the dogs inoculated with R montana (M/5-6 B) or R rhipicephali (3-7-female 6) or exposed to ticks infected with these strains developed detectable rickettsemia, fever, or other observable clinical signs. None of the 394 ticks that fed on rickettsemic dogs (R rickettsii) infected by inoculation became infected, and only 3 of 348 ticks (0.9% infection rate) were infected after feeding on dogs which had been infected by tick bite. All ticks fed on dogs exposed to R rhipicephali and R montana were shown to be free of rickettsiae. The largest concentrations of plaque-forming units (PFU) in Vero cell culture from undiluted whole blood were found on day 6 and on day 7 in dogs that were inoculated with 10,000 and 1,000 R rickettsii, respectively, of the Sawtooth female 2 strain. The highest rickettsial concentration observed for the dog infected by tick feeding was on day 9.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗