We　study　stochastic　phenomena　for　a　model　of　bacterial　infection　and　neutrophils　defense.　Sufficient　conditions　of　stochastic　permanence　and　extinction　for　the　random　model　are　discussed.　To　explore　the　effect　of　different　noises　on　the　bacteria　dynamics,　we　estimate　the　confidence　intervals　by　the　Stochastic　Sensitivity　Function　(SSF)　technique.　Numerical　simulations　show　the　dramatic　change　of　bacterial　concentration　induced　by　noises,　that　is,　the　solution　with　initial　value　near　the　positive　deterministic　equilibrium　can　shift　into　the　extinct　zone　due　to　the　effect　of　noises.　(C)　2020　Elsevier　Inc.　All　rights　reserved.