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Previous work has shown that deletion of the copper - dependent regulator Cuf1 results in decreased virulence and dissemination in brain infection , suggesting that copper acquisition is important to the persistence of this pathogen .
 Chemical: copper; Chemical: copper
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: copper; Chemical: copper