10248
Ehrlichia chaffeensis is an obligatory intracellular bacterium that infects monocytes and macrophages and is the etiologic agent of human ehrlichiosis in the United States .
 macrophages, monocytes
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 macrophages, monocytes