Polluted wetlands contain multidrug-resistance plasmids encoding CTX-M-type extended-spectrum β-lactamases.

While most detailed analyses of antibiotic resistance plasmids focus on those found in clinical isolates, less is known about the vast environmental reservoir of mobile genetic elements and the resistance and virulence factors they encode. We selectively isolated three strains of cefotaxime-resistant Escherichia coli from a wastewater-impacted coastal wetland. The cefotaxime-resistant phenotype was transmissible to a lab strain of E.

An evolutionarily conserved program of B-cell development and activation in zebrafish.

Teleost fish are among the most ancient vertebrates possessing an adaptive immune system with B and T lymphocytes that produce memory responses to pathogens. Most bony fish, however, have only 2 types of B lymphocytes, in contrast to the 4 types available to mammals. To better understand the evolution of adaptive immunity, we generated transgenic zebrafish in which the major immunoglobulin M (IgM(+)) B-cell subset expresses green fluorescence protein (GFP) (IgM1:eGFP).

Generation of mice deficient for macrophage galactose- and N-acetylgalactosamine-specific lectin: limited role in lymphoid and erythroid homeostasis and evidence for multiple lectins.

Macrophage receptors function in pattern recognition for the induction of innate immunity, in cellular communication to mediate the regulation of adaptive immune responses, and in the clearance of some glycosylated cells or glycoproteins from the circulation. They also function in homeostasis by initiating the engulfment of apoptotic cells. Evidence has suggested that macrophage receptors function to recognize cells that are destined for programmed cell death but not yet overtly apoptotic.