Purpose-Bacterial adherence to the urinary catheter is an early step in biofilm formation and the pathogenesis of catheter associated urinary tract infection. We studied in vitro the effect of silver or nitrofurazone impregnation of urinary catheters on uropathogen ability to adhere to urinary catheters.Materials and Methods-We studied commercially available nitrofurazone-silicone, silicone only, silver-silicone-hydrogel, silicone-hydrogel, silver-latex-hydrogel and latex-hydrogel catheters. Catheters were incubated in sterile broth for 0, 3, 5, 7 and 10 days, respectively, before inoculation and overnight incubation with Escherichia coli or Enterococcus faecalis.Results-Adherence of E. coli and E. faecalis to nitrofurazone catheters was significantly decreased compared to that of silicone-only catheters when catheters were fresh. The antiadherence effect of nitrofurazone on E. coli decreased with time but was still significant at 5 days. For E. faecalis the effect of nitrofurazone was lost by 3 days of pre-incubation. E. coli adherence was not significantly decreased on silver impregnated catheters compared to that on control catheters of the same base material. Silver was associated with a significant decrease in E. faecalis adherence to latex-hydrogel catheters but not to silicone-hydrogel catheters. The adherence of each species to silicone catheters with hydrogel was significantly lower than that to silicone-only control catheters.Conclusions-Silver impregnation had little effect on bacterial adherence in our model and nitrofurazone impregnation had a significant effect only for the first 5 days. Our results do not support a role for silver urinary catheters to prevent catheter associated urinary tract infection by decreasing bacterial adherence.

CovR, the two-component response regulator of Streptococcus pyogenes (group A streptococcus [GAS]) directly or indirectly represses about 15% of the genome, including genes encoding many virulence factors and itself. Transcriptome analyses also showed that some genes are activated by CovR. We asked whether the regulation by CovR of one of these genes, dppA, the first gene in an operon encoding a dipeptide permease, is direct or indirect. Direct regulation by CovR was suggested by the presence of five CovR consensus binding sequences (CBs) near the putative promoter. In this study, we identified the 5 end of the dppA transcript synthesized in vivo and showed that the start of dppA transcription in vitro is the same. We found that CovR binds specifically to the dppA promoter region (PdppA) in vitro with an affinity similar to that at which it binds to other CovR-regulated promoters. Disruption of any of the five CBs by a substitution of GG for TT inhibited CovR binding to that site in vitro, and binding at two of the CBs appeared cooperative. In vivo, CovR activation of transcription was not affected by individual mutations of any of the four CBs that we could study. This suggests that the binding sites are redundant in vivo. In vitro, CovR did not activate transcription from PdppA in experiments using purified GAS RNA polymerase and either linear or supercoiled DNA template. Therefore, we propose that in vivo, CovR may interfere with the binding of a repressor of PdppA.

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Many health care facilities are navigating their way through the new antimicrobial stewardship standards and guidelines. The purpose of this article is to provide information for health care facilities to improve patient care. New regulations and guidelines surrounding antimicrobial stewardship have prompted facilities to review their process related to antimicrobial stewardship. In setting up a program, there are many factors to consider including involving key personnel, obtaining leadership support, identifying an infectious disease physician to chair or cochair the committee, and meeting agenda, metrics, and educational needs. Antimicrobial stewardship plays a vital role in both our hospital and community setting. Pharmacists are uniquely positioned to improve optimal patient care through rounding, review of patients' chart, and contribute to the improvement of antimicrobial stewardship by working with a multidisciplinary team. These efforts may improve the utilization of antimicrobial agents.