α-Defensin 1-3 induce agglutination at concentrations lower than its MIC, and its combinatorial effects in concert with other AMPs against pyelonephritis and pyelonephritis multi-drug–resistant strains demonstrate that AMPs are not required in high concentrations that may have deleterious effects such as host cytotoxicity or pathologic inflammatory cascade induction while being efficacious in killing microbes. Here, ADSL is linked to pyelonephritis.