Legionellosis, also known as Legionnaires' disease, is caused by a type of bacterium called Legionella. In 1976 many people who attended a convention of the American Legion in Philadelphia, USA suffered from an outbreak of this disease, a type of pneumonia. Legionellosis is a disease of significant medical and public interest.

The bacterium Legionella is found in aquatic habitats where it can survive and multiply in various protozoa. The bacterium is transmissible to humans and pathogenic to humans.

Legionella is used in the laboratory as a model system for the analysis of bacterial survival, acquisition of nutrients and replication inside cells. The genome sequences of four L. pneumophila strains have been published.

Further reading: Legionellosis

Labels: Legionella, Legionellosis, Legionnaires disease

Pasteurella bacteria are Gram-negative bacteria. Some members of the Pasteurellaceae family are important pathogens such as Haemophilus influenzae and others are harmless commensals and live in the gut of humans and other mammals. Information on the biology of these organisms has grown in recent years, due mainly to genetic and molecular studies. The family consists of thirteen genera. Many members of the Pasteurellaceae are used as models of bacterial pathogenesis and host-pathogen-interactions.

Further reading at Pasteurella

Labels: commensal, Haemophilus, pasteurella, Pasteurellaceae, pathogen

Biodegradation refers to the breakdown of substances by living organisms or, more usually, by the enzymes produced by the organisms. Microorganisms in nature breakdown many substances in the course of their normal lives. Different microorganisms are able to breakdown different substances. Variour microorganisms possess the ability to degrade, transform or accumulate a huge range of compounds including hydrocarbons (e.g. oil), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical substances, radionuclides and metals. Many of these substances are considered (by humans) to be pollutants and therefore there has been much interest in harnessing the naturally occurring ability of microorganisms to remove of pollutants from contaminated areas.

In addition, there has been considerable interest in genetically modifying microorganisms to increase their usefulness for this purpose.

Further reading: Microbial Biodegradation: Genomics and Molecular Biology

Labels: biodegradation, bioremediation, contamination, pollutants