Baldwin, Michael
Assistant Professor

Bacteria are a highly successful group of single-cell organisms that have evolved to colonize and grow in many natural environments once considered too extreme for any form of life. Humans are invariably exposed to and colonized by bacterial organisms living within the biosphere, and these interactions can be viewed as beneficial, harmful or benign with regard to human life. Many of the bacteria that live on the external surfaces of humans perform beneficial and sometimes essential functions required for our wellbeing. Bacterial pathogens are those organisms which can cause disease of humans. In addition to those bacteria which are obligate pathogens of humans, bacteria such as Staphylococcus aureus may exist as a commensal organism on the skin and nasal tissues, initiating disease only when normal barriers have been breached. Bacteria are able to produce disease because they possess certain structural, biochemical, or genetic traits (referred to as virulence determinants) that render them pathogenic. The outcome of infection by a bacterial pathogen is dynamic, depending of many factors, such as the route of entry, the virulence of the bacteria, the number of bacteria encountered during the initial exposure, and the immune status of the host.