Multiple choice The naturally occuring bacteria in humans and apes is salmonella shigella staphylococcus clostridium Reveal answer Fill a bubble to check yourself B Correct answer Explanation Shigella is a genus of Gram-negative, nonspore forming, rod-shaped bacteria closely related to Escherichia coli and Salmonella. It is only naturally found in humans and apes. During infection, it typically causes dysentery.