- Indwelling Urinary Catheter Model of Proteus mirabilis Infection. [Journal Article]
- MMMethods Mol Biol 2019; 2021:187-200
- Uncomplicated urinary tract infections, especially those caused by Escherichia coli, have historically been widely studied. However, complicated urinary tract infections are presenting ever increasin…
Uncomplicated urinary tract infections, especially those caused by Escherichia coli, have historically been widely studied. However, complicated urinary tract infections are presenting ever increasing healthcare challenges, particularly with Proteus mirabilis. P. mirabilis is often found on indwelling urinary catheters causing monomicrobial and polymicrobial catheter-associated urinary tract infection (CAUTI). Widespread antibiotic resistance, combined with the ability of P. mirabilis to form urinary calculi during infection, warrants further investigation of this pathogen and its host interaction in an infection model that more closely mimics the presence of an indwelling urinary catheter. Here, we describe the methods necessary to establish a murine model of P. mirabilis CAUTI.
- Evaluation of the potential of colicins to prevent extraluminal contamination of urinary catheters by Escherichia coli. [Journal Article]
- IJInt J Antimicrob Agents 2019 Jul 05
- The feasibility of using colicins to create an antimicrobial lubricant to prevent extraluminal catheter contamination during urinary catheter insertion was assessed. Levels of resistance of uropathog…
The feasibility of using colicins to create an antimicrobial lubricant to prevent extraluminal catheter contamination during urinary catheter insertion was assessed. Levels of resistance of uropathogenic Escherichia coli to antibiotics and colicins were compared and it was revealed that antibiotics and colicins possess similar frequencies of resistance to a single drug, while colicins exhibit significantly lower levels of multi-drug resistance (22%) than antibiotics (42%). Colicins and antibiotics showed complementary inhibitory activity, with each targeting different subsets of pathogenic isolates. The collateral impact of these two antimicrobials on genera that are members of the fecal/vaginal/urinary microbiome was assessed, with colicins showing significantly less collateral damage than antibiotics. Using a novel colicin, SR4, we determined MICs for a panel of 30 uropathogenic isolates and showed that SR4 achieved the same antimicrobial efficacy as gentamicin using 20-30% less drug. Finally, we created a SR4-impregnated catheter lubricant and demonstrated its ability to prevent extraluminal urinary catheter contamination in vitro. These data argue that a colicin-impregnated lubricant may provide a viable prophylactic option for preventing catheter-associated urinary tract infections.
- Design of an Antifungal Surface Embedding Liposomal Amphotericin B Through a Mussel Adhesive-Inspired Coating Strategy. [Journal Article]
- FCFront Chem 2019; 7:431
- Microbial colonization of urinary catheters remains a serious problem for medicine as it often leads to biofilm formation and infection. Among the approaches reported to deal with this problem, surfa…
Microbial colonization of urinary catheters remains a serious problem for medicine as it often leads to biofilm formation and infection. Among the approaches reported to deal with this problem, surfaces functionalization to render them with antimicrobial characteristics, comprises the most promising one. Most of these strategies, however, are designed to target bacterial biofilms, while fungal biofilms are much less taken into account. In real-life settings, fungi will be inevitably found in consortium with bacteria, especially in the field of biomaterials. The development of antifungal coating strategies to be combined with antibacterial approaches will be pivotal for the fight of biomaterial-associated infections. The main goal of the present study was, therefore, to engineer an effective strategy for the immobilization of liposomal amphotericin B (LAmB) on polydimethylsiloxane (PDMS) surfaces to prevent Candida albicans colonization. Immobilization was performed using a two-step mussel-inspired coating strategy, in which PDMS is first immersed in dopamine solution. Its polymerization results in the deposition of a thin adherent film, called polydopamine (pDA), which allowed the incorporation of LAmB, afterwards. Different concentrations of LAmB were screened in order to obtain a contact-killing surface with no release of LAmB. Surface characterization confirmed the polymerization of dopamine and further functionalization with LAmB yielded surfaces with less roughness and more hydrophilic features. The proposed coating strategy rendered the surfaces of PDMS with the ability to prevent the attachment of C. albicans and kill the adherent cells, without toxicity toward mammalian cells. Overall results showed that LAmB immobilization on a surface retained its antifungal activity and reduced toxicity, holding therefore a great potential to be applied for the design of urinary catheters. Since the sessile communities commonly found associated to these devices exhibit a polymicrobial nature, the next challenge will be to co-immobilize LAmB with antibacterial agents to prevent the establishment of catheter-associated urinary tract infections (CAUTI).
- Long-term use of noble metal alloy coated urinary catheters reduces recurrent CAUTI and decreases proinflammatory markers. [Journal Article]
- TATher Adv Urol 2019 Jan-Dec; 11:1756287219854915
- CONCLUSIONS: Long-term use of a NMA-coated catheter was associated with cessation of frequent CAUTIs. The catheter was experienced as comfortable and inflammatory markers were reduced with time. The coating was stable, with no significant metal release into urine and is therefore safe for patient use.
- Problematic Risk Adjustment in National Healthcare Safety Network Measures. [Journal Article]
- AJAm J Med Qual 2019 Jun 27; :1062860619859073
- This article reviews the risk-adjustment models underpinning the National Healthcare Safety Network (NHSN) standardized infection ratios. After first describing the models, the authors focus on hospi…
This article reviews the risk-adjustment models underpinning the National Healthcare Safety Network (NHSN) standardized infection ratios. After first describing the models, the authors focus on hospital intensive care unit (ICU) designation as a variable employed across the various risk models. The risk-adjusted frequency with which ICU services are reported in Medicare fee-for-service claims data was compared as a proxy for determining whether reporting of ICU days is similar across hospitals. Extreme variation was found in the reporting of ICU utilization among admissions for congestive heart failure, ranging from 25% in the lowest admission hospital quartile to 95% in the highest. The across-hospital variation in reported ICU utilization was found to be unrelated to patient severity. Given that such extreme variation appears in a designation of ICU versus non-ICU utilization, the NHSN risk-adjustment models' dependence on nursing unit designation should be a cause for concern.
- Urinary tract colonization is enhanced by a plasmid that regulates uropathogenic Acinetobacter baumannii chromosomal genes. [Journal Article]
- NCNat Commun 2019 06 24; 10(1):2763
- Multidrug resistant (MDR) Acinetobacter baumannii poses a growing threat to global health. Research on Acinetobacter pathogenesis has primarily focused on pneumonia and bloodstream infections, even t…
Multidrug resistant (MDR) Acinetobacter baumannii poses a growing threat to global health. Research on Acinetobacter pathogenesis has primarily focused on pneumonia and bloodstream infections, even though one in five A. baumannii strains are isolated from urinary sites. In this study, we highlight the role of A. baumannii as a uropathogen. We develop the first A. baumannii catheter-associated urinary tract infection (CAUTI) murine model using UPAB1, a recent MDR urinary isolate. UPAB1 carries the plasmid pAB5, a member of the family of large conjugative plasmids that represses the type VI secretion system (T6SS) in multiple Acinetobacter strains. pAB5 confers niche specificity, as its carriage improves UPAB1 survival in a CAUTI model and decreases virulence in a pneumonia model. Comparative proteomic and transcriptomic analyses show that pAB5 regulates the expression of multiple chromosomally-encoded virulence factors besides T6SS. Our results demonstrate that plasmids can impact bacterial infections by controlling the expression of chromosomal genes.
- The case for a population standardized infection ratio (SIR): A metric that marries the device SIR to the standardized utilization ratio (SUR). [Journal Article]
- ICInfect Control Hosp Epidemiol 2019 Jun 24; :1-4
- CONCLUSIONS: Population SIR accounts for predicted device utilization; thus, it is an attractive metric with which to address overall risk of infection or harm to a patient population. It also reduces the risk of selection bias that may impact the device SIR with interventions to reduce device use.
- Preventing Catheter-Associated Urinary Tract Infection: A Multipronged Collaborative Approach. [Journal Article]
- JNJ Nurs Care Qual 2019 Jun 18
- CONCLUSIONS: Implementation of a standardized bundle of practices aimed at reducing CAUTIs resulted in decreased CAUTI rates. Organizations can use the design and implementation approach to reduce and minimize CAUTI rates, which can positively impact cost, care experience, and outcomes.
- Healthcare-associated urinary tract infections with onset post hospital discharge. [Journal Article]
- ICInfect Control Hosp Epidemiol 2019; 40(8):863-871
- CONCLUSIONS: HA-CO UTI may be common within 30 days following hospital discharge. These data suggest that surveillance efforts may need to be expanded to capture the full burden to patients and better inform antibiotic prescribing decisions for patients with a history of hospitalization.
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- Reaching the End of the Line: Urinary Tract Infections. [Journal Article]
- MSMicrobiol Spectr 2019; 7(3)
- Urinary tract infections (UTIs) cause a substantial health care burden. UTIs (i) are most often caused by uropathogenic Escherichia coli (UPEC), (ii) primarily affect otherwise healthy females (50% o…
Urinary tract infections (UTIs) cause a substantial health care burden. UTIs (i) are most often caused by uropathogenic Escherichia coli (UPEC), (ii) primarily affect otherwise healthy females (50% of women will have a UTI), (iii) are associated with significant morbidity and economic impact, (iv) can become chronic, and (v) are highly recurrent. A history of UTI is a significant risk factor for a recurrent UTI (rUTI). In otherwise healthy women, an acute UTI leads to a 25 to 50% chance of rUTI within months of the initial infection. Interestingly, rUTIs are commonly caused by the same strain of E. coli that led to the initial infection, arguing that there exist host-associated reservoirs, like the gastrointestinal tract and underlying bladder tissue, that can seed rUTIs. Additionally, catheter-associated UTIs (CAUTI), caused by Enterococcus and Staphylococcus as well as UPEC, represent a major health care concern. The host's response of depositing fibrinogen at the site of infection has been found to be critical to establishing CAUTI. The Drug Resistance Index, an evaluation of antibiotic resistance, indicates that UTIs have become increasingly difficult to treat since the mid-2000s. Thus, UTIs are a "canary in the coal mine," warning of the possibility of a return to the preantibiotic era, where some common infections are untreatable with available antibiotics. Numerous alternative strategies for both the prevention and treatment of UTIs are being pursued, with a focus on the development of vaccines and small-molecule inhibitors targeting virulence factors, in the hopes of reducing the burden of urogenital tract infections in an antibiotic-sparing manner.