Samuel L. Hayes

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The effect of UV exposure on Toxoplasma gondii oocysts has not been completely defined for use in water disinfection. This study evaluated UV-irradiated oocysts by three assays: a SCID mouse bioassay, an in vitro T. gondii oocyst plaque (TOP) assay, and a quantitative reverse transcriptase real-time PCR (RT-qPCR) assay. The results from the animal bioassay(More)
When exposed to 254-nm UV, spores of Encephalitozoon intestinalis, Encephalitozoon cuniculi, and Encephalitozoon hellem exhibited 3.2-log reductions in viability at UV fluences of 60, 140, and 190 J/m(2), respectively, and demonstrated UV inactivation kinetics similar to those observed for endospores of DNA repair-defective mutant Bacillus subtilis strains(More)
Transferrin (Tf) plays an important role during immunologic activation by donating iron to activated lymphocytes. Therefore, synthesis by lymphomyeloid cells has been investigated. Mouse macrophages and macrophage cell lines synthesized Tf, with levels being markedly increased by gamma-interferon (gamma-IFN) and, to a lesser extent, by interleukin-1 beta(More)
AIMS The research was initiated to confirm earlier ultraviolet (u.v.) light inactivation studies performed on Giardia cysts using excystation as the viability indicator. Following this, a comparison of in vitro excystation and animal infectivity was performed for assessing cyst viability after exposure to low-pressure u.v. irradiation. METHODS AND RESULTS(More)
AIMS To assess the virulence of Aeromonas spp. using two models, a neonatal mouse assay and a mouse intestinal cell culture. METHODS AND RESULTS After artificial infection with a variety of Aeromonas spp., mRNA extracts from the two models were processed and hydridized to murine microarrays to determine host gene response. Definition of virulence was(More)
An immunocompromised mouse model was used to characterize Aeromonas strains for their ability to cause opportunistic, extraintestinal infections. A total of 34 isolates of Aeromonas (A. hydrophila [n = 12]), A. veronii biotype sobria [n = 7], A. caviae [n = 4], A. enchelia [n = 4], A. allosaccharophila [n = 2], A. salmonicida (n = 4), and A. bestiarum [n =(More)
Recent studies have demonstrated the potential to use Bacillus pumilus endospores as a surrogate for human adenovirus (HAdV) in UV disinfection studies. The use of endospores has been limited by observations of batch-to-batch variation in UV sensitivity. This study reports on a propagation method that utilizes a commercially available medium to produce UV(More)
Homeostasis is known to be absolutely critical to the sustainability of living organisms. At the heart of homeostasis are various feedback loops, which can control and regulate a system to stay in a most favourable stable state upon the influence of various disturbance. While variability has emerged as a key factor in sustainability, too much variability(More)