Dust like particles in my camera lens

I am new to photography and i have found some dust like particles inside of my lens ( i think this is a fungus infection , correct me if i am wrong ).

  1. Is this okey to use this way ?
  2. Will it infect other lens and camera body If i keep this with my others ?
  3. What are precuations that i have to take to stop from further growing?
    Cam :nikon d5600
    Lens in the picture: nikon 70-300mm

Thanks in advance
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