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Full-Text Articles in Medicine and Health Sciences
Further Characterization Of A Complement-Sensitive Mutant Of A Virulent Avian Escherichia Coli Isolate, Theodore J. Kottom, Lisa K. Nolan, Michael Robinson, John Brown, Tom Gustad, Shelley M. Horne, Catherine W. Giddings
Further Characterization Of A Complement-Sensitive Mutant Of A Virulent Avian Escherichia Coli Isolate, Theodore J. Kottom, Lisa K. Nolan, Michael Robinson, John Brown, Tom Gustad, Shelley M. Horne, Catherine W. Giddings
Lisa K. Nolan
An attempt was made to characterize the mechanism of complement resistance operating in a virulent avian Escherichia coli isolate. Using flow cytometry to detect antibody to C3, we found that there was significantly more antibody bound to a complement-sensitive mutant of this wild type than to the parent organism, suggesting that more C3 subunits were bound to the wild type. Neither the wild type nor the mutant degraded C3. Further, the mutant was phagocytosed to a significantly greater degree than the wild type by cultured phagocytes in the presence of C5-deficient serum. These data suggest that the wild type is …
A Highly Adherent Phenotype Associated With Virulent Bvg+-Phase Swine Isolates Of Bordetella Bronchiseptica Grown Under Modulating Conditions, Karen B. Register, Mark R. Ackermann
A Highly Adherent Phenotype Associated With Virulent Bvg+-Phase Swine Isolates Of Bordetella Bronchiseptica Grown Under Modulating Conditions, Karen B. Register, Mark R. Ackermann
Mark R. Ackermann
The ability of Bvg(-)-phase and Bvg(+)-phase Bordetella bronchiseptica swine isolates, grown under modulating or nonmodulating conditions, to adhere to swine ciliated nasal epithelial cells was determined. When virulent strains were cultivated at 37 degrees C in the Bvg+ phase, numerous adherent bacteria (approximately eight per cell, depending on the strain used) were observed. However, when such strains were grown under modulating conditions (23 degrees C), a significant increase in the level of attachment was seen, suggesting that B. bronchiseptica produces a Bvg-repressed adhesin under these conditions. bvg mutant strains, including an isogenic bvgS mutant, adhered minimally. Western blots indicated that …
Effects Of Pasteurella Multocida Toxin On Porcine Bone Marrow Cell Differentiation Into Osteoclasts And Osteoblasts, S. M. Gwaltney, R. J. S. Galvin, K. B. Register, R. B. Rimler, Mark R. Ackermann
Effects Of Pasteurella Multocida Toxin On Porcine Bone Marrow Cell Differentiation Into Osteoclasts And Osteoblasts, S. M. Gwaltney, R. J. S. Galvin, K. B. Register, R. B. Rimler, Mark R. Ackermann
Mark R. Ackermann
The effect of Pasteurella multocida toxin (PMT) on porcine osteoclast and osteoblast differentiation was studied using in vitro cell culture systems. When grown in the presence of Vitamin D3, isolated porcine bone marrow cells formed multinucleated cells with features characteristic of osteoclasts. Exposure of bone marrow cells to Vitamin D3 and PMT during growth resulted in formation of increased numbers and earlier appearance of osteoclasts compared to controls. Ultrafiltered medium from PMT-treated cells likewise increased osteoclast numbers, suggesting that a soluble mediator may be involved in the action of PMT. When cell cultures were treated with fluorescein-labeled PMT, fluorescence was …
Decreased Intracellular Survival Of An Fkpa Mutant Of Salmonella Typhimurium Copenhagen, Shelley M. Horne, Theodore J. Kottom, Lisa K. Nolan, Kevin D. Young
Decreased Intracellular Survival Of An Fkpa Mutant Of Salmonella Typhimurium Copenhagen, Shelley M. Horne, Theodore J. Kottom, Lisa K. Nolan, Kevin D. Young
Lisa K. Nolan
The fkpA gene of Salmonella typhimurium encodes a protein similar to the macrophage infectivity potentiator (Mip) proteins of Legionella pneumophila and Chlamydia trachomatis. Because Mip proteins enhance the ability of these intracellular pathogens to survive within macrophages and epithelial cells, we tested whether the product of the fkpA gene would have the same effect on the intracellular growth of a virulent strain of S. typhimurium. By a series of P22 transductions, the fkpA gene of S. typhimurium Copenhagen was replaced with the inactive fkpA1::omega-Cm gene from Escherichia coli, creating the mutant S. typhimurium KY32H1. The Copenhagen and KY32H1 strains were …
A Porcine Model For The Evaluation Of Virulence Of Bordetella Bronchiseptica, Mark R. Ackermann, K. B. Register, C. Gentry-Weeks, S. M. Gwaltney, T. Magyar
A Porcine Model For The Evaluation Of Virulence Of Bordetella Bronchiseptica, Mark R. Ackermann, K. B. Register, C. Gentry-Weeks, S. M. Gwaltney, T. Magyar
Mark R. Ackermann
Studies of virulence factors of Bordetella bronchiseptica require a suitable system. Such a system was devised in colostrum-deprived, caesarean-derived pigs, aged 7 d. In two different experiments, pigs (n=11) were inoculated intranasally with 106 colony-forming units of the virulent strain 4609. In the same way, further pigs (n=11) were inoculated with a strain (B133) of unknown virulence. No significant differences between 4609 and B133 colonization were seen. However, colonization of the turbinates was significantly higher than that of the trachea, lung and tonsil, and a significantly higher degree of colonization was present at 11 d post-inoculation (PI) than at 15 …