A needleless connector and methods for preventing microbial ingress in medical device connections are disclosed. Various examples provide a needleless connector including a male luer having a recessed distal tip surface containing a water-soluble antimicrobial composition. Further examples include a trap for retaining antimicrobial composition. As the needleless connector is inserted into a female connector, a tapered surface distal edge acts to push microorganisms, while the distal tip surface is configured to leave microorganisms undisturbed. After insertion of the needleless connector, microorganisms present on the female luer surface are biased to reside in the recess region. The recess, trap, and antimicrobial composition are configured to facilitate a long-lasting supply of antimicrobial solution within the fluid-filled recess, at the same time confining the antimicrobial solution inside the recess. This produces a high concentration of antimicrobial solution for an extended time, killing microbes, stopping microbial ingress, and preventing infections in patients.
