<unk>  injecting its genome into bacterial cell An electron micrograph of bacteriophages attached to a bacterial cell. These viruses are the size and shape of coliphage T1.<unk> , viral<unk> , or<unk> therapy is the therapeutic use of bacteriophages for the treatment of pathogenic bacterial infections. This therapeutic approach emerged at the beginning of the 20th century but was progressively replaced by the use of antibiotics in most parts of the world after the second world war. Bacteriophages, known as<unk> s, are a form of virus that attach to bacterial cells, and inject their genome into the cell. The viral genome effectively replaces the bacterial genome, halting the bacterial infection. The bacterial cell causing the infection is unable to reproduce, and instead produces additional<unk> s.<unk> s are very selective in the strains of bacteria they are effective against. Advantages include reduced side-effects and reduced risk of the bacterium developing resistance since bacteriophages are much more specific than antibiotics. They are typically harmless not only to the host organism but also to other beneficial bacteria, such as the gut microbiota, reducing the chances of opportunistic infections. They have a high therapeutic index, that is,<unk>  would be expected to give rise to few side effects, even at higher-than-therapeutic levels. Because<unk> s replicate in vivo (in cells of living organism), a smaller effective dose can be used. Disadvantages include the difficulty of finding an effective<unk>  for a particular infection: a<unk>  will kill a bacterium only if it matches the specific strain. However, virulent<unk> s can be isolated much more easily than other compounds and natural products. Consequently,<unk>  mixtures ("cocktails") are sometimes used to improve the chances of success. Alternatively, samples taken from recovering patients sometimes contain appropriate<unk> s that can be grown to cure other patients infected with the same strain. Ongoing challenges include the need to increase<unk>  collections from reference<unk>  banks, the development of efficient<unk>  screening methods for the fast identification of the therapeutic<unk> (s), the establishment of efficient<unk>  strategies to tackle infectious biofilms, the validation of feasible<unk>  production protocols that assure quality and safety of<unk>  preparations, and the guarantee of stability of<unk>  preparations during manufacturing, storage and transport.<unk> s tend to be more successful than antibiotics where there is a biofilm covered by a polysaccharide layer, which antibiotics typically cannot penetrate. However, the interactions between<unk> s and biofilms can be complex, with<unk> s developing symbiotic as well as predatory relationships with biofilms.<unk> s are currently being used therapeutically to treat bacterial infections that do not respond to conventional antibiotics, particularly in Russia and Georgia. There is also a<unk>  unit in Wrocław, Poland, established in 2005, which continues several decades long research of the Institute of Immunology and Experimental Therapy of the Polish Academy of Sciences, the only such centre in a European Union country.<unk> s are the subject of renewed clinical attention in western countries, such as the United States. In 2019, the United States Food and Drug Administration approved the first US clinical trial for intravenous<unk> .<unk>  has many potential applications in human medicine as well as dentistry, veterinary science, and agriculture. If the target host of a<unk>  treatment is not an animal, the term "biocontrol" (as in<unk> -mediated biocontrol of bacteria) is usually employed, rather than<unk> ".
Phage therapy
Music therapy
Aquatic therapy
Ultraviolet light therapy
Dance therapy
Virotherapy
Goeckerman therapy
Metaphor therapy