Due to bladder sling surgery, my bladder neck is at an extreme angle to the bladder and so I am susceptible to post-coital UTIs. I take macrobid post-coitus (consulted with urologist for this regimen) as prevention, as well as diligent pre-and post hygiene practices, but twice in the last six months I have had UTIs caused by the Serratia marcescens bacteria. Much of our sexual activity is oral. I suspect that transmission is from that vector, as my partner has really foul breath despite frequent brushing. I understand that the S. marcesens bacteria lives subgingivally. Would antibiotic treatment of him help? What other approaches can he take to reduce oral colonization? Thanks.