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Proteus mirabilis is an opportunistic pathogen and is responsible for more than 40% of all cases of catheter-associated urinary tract infections (CAUTIs). Healthcare-associated infections have been aggravated by the constant emergence of antibiotic-resistant bacterial strains. Because of this, the use of phages to combat bacterial infections gained renewed interest. In this study, we describe the biological and genomic features of two P. mirabilis phages, named BigMira and MidiMira. These phages belong to the Acadevirus genus (family Autographiviridae). BigMira and MidiMira are highly similar, differing only in four missense mutations in their phage tail fiber. These mutations are sufficient to impact the phages' depolymerase activity. Subsequently, the comparative genomic analysis of ten clinical P. mirabilis strains revealed differences in their antibiotic resistance profiles and lipopolysaccharide locus, with the latter potentially explaining the host range data of the phages. The massive presence of antimicrobial resistance genes, especially in the phages' isolation strain P. mirabilis MCS, highlights the challenges in treating infections caused by multidrug-resistant bacteria. The findings reinforce BigMira and MidiMira phages as candidates for phage therapy purposes.

RESUMEN

BACKGROUND: Microorganisms can migrate from the external environment to the patient's organism through the insertion of catheters. Despite being indispensable medical device, the catheter surface can be colonized by microorganisms and become a starting point for biofilm formation. Therefore, new technologies are being developed in order to modify surfaces to prevent the adhesion and survival of microorganisms. Patents with the use of DMPEI have been filed. OBJECTIVE: In the present work, we coated latex catheter surfaces with 2 mg mL-1 DMPEI in different solvents, evaluated the wettability of the surface and the anti- biofilm activity of the coated catheter against Escherichia coli, Staphylococcus aureus, and Candida albicans. METHODS: We coated the inner and outer catheter surfaces with 2 mg mL-1 of DMPEI solubilized in butanol, dimethylformamide, and cyclohexanone and the surfaces were analyzed visually. Contact angle measurement allowed the analysis of the wettability of the surfaces. The CFU mL-1 count evaluated E. coli, S. aureus, and C. albicans adhesion onto the control and treated surfaces. RESULTS: The contact angle decreased from 50.48º to 46.93º on the inner surface and from 55.83º to 50.91º on the outer surface of latex catheters coated with DMPEI. The catheter coated with DMPEI showed anti-biofilm activity of 83%, 88%, and 93% on the inner surface and 100%, 92%, and 86% on the outer surface for E. coli, S. aureus, and C. albicans, respectively. CONCLUSION: Latex catheter coated with DMPEI efficiently impaired the biofilm formation both on the outer and inner surfaces, showing a potential antimicrobial activity along with a high anti-biofilm activity for medical devices.

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RESUMEN

OBJECTIVE: To evaluate the effectiveness of a hospital-wide initiative to improve patient safety by implementing high-reliability practices as part of a quality improvement (QI) program aimed at reducing all preventable harm. STUDY DESIGN: A hospital wide quasi-experimental time series QI initiative using high-reliability concepts, microsystem-based multidisciplinary teams, and QI science tools to reduce hospital acquired harm was implemented. Extensive error prevention training was provided for all employees. Change concepts were enacted using the Institute for Healthcare Improvement's Model for Improvement. Compliance with change packages was measured. RESULTS: Between 2010 and 2012, the serious safety event rate decreased from 1.15 events to 0.19 event per 10 000 adjusted hospital-days, an 83.3% reduction (P < .001). Preventable harm events decreased by 53%, from a quarterly peak of 150 in the first quarter of 2010 to 71 in the fourth quarter of 2012 (P < .01). Observed hospital mortality decreased from 1.0% to 0.75% (P < .001), although severity-adjusted expected mortality actually increased slightly, and estimated harm-related hospital costs decreased by 22.0%. Hospital-wide safety climate scores increased significantly. CONCLUSION: Substantial reductions in serious safety event rate, preventable harm, hospital mortality, and cost were seen after implementation of our multifaceted approach. Measurable improvements in the safety culture were noted as well.

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