|
Serial passage refers to the process of growing bacteria or a virus in iterations. For instance, a virus may be grown in one environment, and then part of that virus can be removed and put into a new environment. This process is repeated with as many stages as desired, and then the final product is studied, often in comparison with the original virus. This sort of facilitated transmission is often conducted in a laboratory setting, because it is interesting to observe how the virus or bacterium that is being passed evolves over the course of an experiment. In particular, serial passage can be quite useful in experiments that seek to change the virulence of a virus or other pathogen. One consequence of this is that serial passage is useful in creating vaccines, since scientists can apply serial passage and create a strain of virus that has low virulence.〔''Serial passage.'' Biology online. Retrieved 16 April 2014 from ().〕 ==Mechanism== Serial passage can either be performed in vitro or in vivo. In the in vitro method, a virus or a strain of bacteria will be isolated and allowed to grow for a period of time. After the sample has grown for some time, part of it will be transferred to a new environment and allowed to grow for the same period of time.〔Chapuis É, Pagès S, Emelianoff V, Givaudan A, Ferdy J-B (2011). ''Virulence and Pathogen Multiplication: A Serial Passage Experiment in the Hypervirulent Bacterial Insect-Pathogen Xenorhabdus nematophila''. PLoS ONE 6 (1). doi:()〕〔Somerville, GA, Beres, SB, Fitzgerald, JR, DeLeo, FR, Cole, RL, Hoff, JS, & Musser, JM (2002). ''In Vitro Serial Passage of Staphylococcus aureus: Changes in Physiology, Virulence Factor Production, and agr Nucleotide Sequence.'' Journal of Bacteriology 184 (5): 1430–1437.〕 This process will be repeated as many times as desired. Alternatively, an in vivo experiment can be performed where an animal is infected with a pathogen, and this pathogen allowed time to grow in that host before a sample of it is removed from the host and passed to another host. This process is repeated for a certain number of hosts; this number is determined by the individual experiment. When serial passage is performed either in vitro or in vivo, the virus or bacterium that is being manipulated may evolve by mutating repeatedly. Identifying and studying mutations that occur through serial passage often reveals information about the virus or bacterium being studied. Accordingly, after serial passage has been performed it can be valuable to compare the resulting virus or sample of bacteria to the original, noting any mutations that have occurred and what the collective effect of these mutations is. A variety of significant outcomes are possible. The virulence of the virus may be changed,〔Woo, H. J., & Reifman, J. (2014). ''Quantitative Modeling of Virus Evolutionary Dynamics and Adaptation in Serial Passages Using Empirically Inferred Fitness Landscapes.'' Journal of virology, 88 (2), 1039-1050.〕 for example, or a virus could evolve to become adapted to a different host environment than that in which it is typically found.〔 Notice that relatively few passages are necessary to produce a noticeable change in a virus; for instance, a virus can typically adapt to a new host within ten or so passages.〔 In fact, exactly because serial passage allows for rapid evolution of a virus to its host, it can be used to study the evolution of antibiotic resistance; specifically, for determining what mutations could lead to the development of antibiotic resistance.〔Martínez, J. L., Baquero, F., & Andersson, D. I. (2011). ''Beyond serial passages: new methods for predicting the emergence of resistance to novel antibiotics.'' Current opinion in pharmacology, 11 (5), 439-445.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Serial passage」の詳細全文を読む スポンサード リンク
|