The document lists bacterial pathogens grouped into three stages. Stage 1 lists 12 bacterial pathogens including Chlamydia pneumoniae which causes pneumonia, Francisella tularensis which causes tularemia, and Clostridium botulinum which causes botulism. Stage 2 rearranges the list, and Stage 3 further rearranges the list and highlights Chlamydia pneumoniae, Klebsiella pneumoniae, and Mycoplasma pneumoniae as causing pneumonia.