Pseudomonas aeruginosa is a versatile gram negative bacterium that grows in soil, marshes, and coastal marine habitats, as well as on plant and animal tissues. People with cystic fibrosis, burn victims, individuals with cancer, and persons infected with HIV are particularly at risk of disease resulting from Pseudomonas aeruginosa. Unlike many environmental bacteria, Pseudomonas aeruginosa has a remarkable capacity to cause disease in susceptible hosts. It has the ability to adapt to and thrive in many ecological niches, from water and soil to plant and animal tissues. The bacterium is capable of utilizing a wide range of organic compounds as food sources, thus giving it an exceptional ability to colonize ecological niches where nutrients are limited. Pseudomonas aeruginosa can produce a number of toxic proteins, which not only cause extensive tissue damage, but also interfere with the human immune systems defense mechanisms. These proteins range from potent toxins that enter and kill host cells at or near the site of colonization to degradative enzymes that permanently disrupt the cell membranes and connective tissues in various organs. In people with cystic fibrosis the most serious complication is respiratory tract infection by the ubiquitous bacterium Pseudomonas aeruginosa. CF is one of the most common fatal genetic disorders in the United States, affecting about 30,000 individuals. A comparable number of people in Europe also have CF. It is most prevalent in the Caucasian population, occurring in one of every 3,300 live births. The gene involved in cystic fibrosis was identified in 1989. Located on human chromosome 7, it codes for a protein called the cystic fibrosis transmembrane conductance regulator (CFTR). This protein, normally produced in a number of tissues throughout the body, regulates the movement of salt and water in and out of these cells. The abnormality in the CFTR gene alters the CFTR prot...
