Studies of experimental infection of the cotton rat, Sigmodon hispidus, with the virulent Sheila Smith (R type) and the avirulent Si 7 (U type) strains of Rickettsia rickettsii were undertaken to evaluate the role of this native wild mammal in the ecology of Rocky Mountain spotted fever. The Sheila Smith strain, which was highly lethal for guinea pigs, was nonpathogenic for cotton rats. Serial ...

The effects of environmental conditions on population trends of plant-parasitic nematodes were studied in experimental plots of five wheatgrasses in the western Utah desert. In a 3-year (1984-86) field study, soil water and temperature affected the population trends of the ectoparasites, Tylenchorhynchus acutoides and Xiphinema americanum, and the migratory endoparasite, Pratylenchus neglectus,...

We evaluate the use of mitochondrial DNA (mtDNA) genetic markers to describe population structure and matrilineal kinship on a microgeographic scale. An analysis of restriction site variation in 134 cotton rats (Sigmodon hispidus) collected from a 3.2 hectare field revealed significant spatial and temporal heterogeneity in frequencies of mtDNA genotypes among nest sites. Inspection of particula...

Poxvirus has been identified morphologically from skin lesions in captive and free-ranging bottlenosed dolphins, Tursiops truncatus and a stranded Atlantic white-sided dolphin, Lagenorhynchus acutus. The lesions, commonly referred to as ring or pinhole lesions, appear as solitary or coalesced circular grey blemishes. Advanced ring lesions may take the form of black punctiform stippled patterns ...

Ochrobactrum anthropi is an emerging pathogen in immunocompromised patients, with the majority of human cases being central venous catheter-related infections. In contrast, O. anthropi-related biliary sepsis is much rare. Herein we report the clinical and microbiological characteristics of O. anthropi-related biliary sepsis in order to increase awareness of the potential role of O. anthropi in ...

Intranasal inoculation of type 5 adenovirus into the cotton rat Sigmodon hispidus produces a pneumonia pathologically similar to that in humans, and it, therefore, provides an excellent animal model to investigate the pathogenesis of this disease. The goal of this study was to test the hypothesis that accumulation of viral structural proteins is responsible for a major portion of the cell-damag...

We report a case of spontaneous bacterial peritonitis from Ochrobactrum anthropi. O. anthropi is recognized as an emerging pathogen in immunocompromised patients. In contrast to most previously described cases, the patient reported here had no indwelling catheter. To our knowledge, no case of O. anthropi spontaneous bacterial peritonitis has been reported in the medical literature until now.