The dimethyl sulfoxide (DMSO) reductase from Escherichia coli, DmsABC (EcDmsABC), is an S- and N-oxide reductase with a proposed role in anaerobic respiration with DMSO, a compound minimally present in the mammalian body. Interestingly, DmsABC complexes in Actinobacillus pleuropneumoniae and Haemophilus influenzae are highly similar to the E. coli one, and the enzymes appear to support bacterial virulence. Additionally, in H. influenzae, the expression of dmsA was induced following HOCl exposure, and here we revealed that HOCl exposure causes upregulation of a number of molybdenum-containing enzymes in uropathogenic E. coli (UPEC), including dmsA. This suggests that EcDmsABC may have a role in host-pathogen interactions, in which case it should convert S- and N-oxides that, unlike DMSO, occur naturally in the human body. Our preliminary assays showed that the DmsABC from a WT UPEC strain efficiently reduced nicotinamide N-oxide and pyrimidine N-oxide. These S- and N-oxides can form upon exposure to oxidative-inducing compounds including HOCl, which the human immune cells can produce. A ∆dmsA strain constructed in UPEC strain EC958 was unable to grow on the glycerol-DMSO minimal medium where anaerobic respiration is required, but in enzyme assays, approximately 20% of WT DMSO reductase activity was still present. The EC958 ∆dmsA strain also showed reduced growth rates (approximately 85% of WT) under low oxygen tensions in the M9 minimal salt medium. Interestingly, resistance to HOCl was increased by 10 times in the EC958 ∆dmsA strain, while resistance to paraquat and hydrogen peroxide, which the immune cells can also produce, was identical to the WT strain. The loss of DmsABC in the EC958 ∆dmsA strain did not affect adherence to or invasion of the T24 human bladder cell line. In summary, the HOCl-linked induction of EcDmsABC supports a role in E. coli host interactions, however, additional phenotypes may be masked by functional redundancy as E. coli genomes encode a related, HOCl-inducible enzyme complex, YnfEFGH, with a proposed role in selenate reduction.