Description: Phages, or bacteriophages, are viruses that specifically infect bacteria. These microorganisms are extremely diverse and are found in almost every ecosystem where bacteria exist, from soil to the human gut. Phages have a simple structure, primarily composed of genetic material (DNA or RNA) surrounded by a protein capsid. Their life cycle can be lytic, where the phage replicates inside the bacterium until it bursts, releasing new phages, or lysogenic, where the phage’s genetic material integrates into the bacterium’s DNA and replicates along with it. This ability to infect and reproduce within bacteria makes them valuable tools in scientific research and biotechnological applications. Additionally, their specificity for bacteria makes them a potential alternative to antibiotics in treating bacterial infections, especially in the context of increasing resistance to these drugs.
History: Phages were discovered in 1915 by bacteriologist Frederick Twort and independently by microbiologist Félix d’Hérelle in 1917. D’Hérelle was the first to demonstrate that phages could be used to treat bacterial infections, leading to initial interest in their therapeutic use. However, with the advent of antibiotics in the 1940s, interest in phages waned in the West. In recent decades, there has been a resurgence in phage research, driven by growing concerns about antibiotic resistance and the search for new therapies.
Uses: Phages are used in various applications, including phage therapy to treat bacterial infections, biocontrol of pathogens in agriculture, and as tools in genetic engineering and molecular biology. They are also being explored for the detection of pathogenic bacteria and in food preservation.
Examples: A notable example of phage therapy is the use of a phage cocktail to treat infections caused by methicillin-resistant Staphylococcus aureus (MRSA) in patients. Another example is the use of phages in the food industry to control contamination by Listeria monocytogenes in meat products.
