A Pilot Study on Prevention of Catheter-Related Urinary Tract Infections with Fluoroquinolones

Biofilm-Producing Bacteria and Risk Factors (Gender and Duration of Catheterization) Characterized as Catheter-Associated Biofilm Formation

Background

A catheter-associated urinary tract infection (CA-UTI) is preceded by biofilm formation, which is related to several risk factors such as gender, age, diabetic status, duration of catheterization, bacteriuria before catheterization, virulence gene factor, and antibiotic usage.

Aims

This study aims to identify the microbial composition of catheter samples, including its corresponding comparison with urine samples, to determine the most important risk factors of biofilm formation and characterize the virulence gene factors that correlate with biofilm formation.

Methods

A longitudinal cross-sectional study was conducted on 109 catheterized patients from September 2017 to January 2018. The risk factors were obtained from the patients' medical records. All catheter and urine samples were cultured after removal, followed by biomass quantification. Isolate identification and antimicrobial susceptibility testing were performed using the Vitex2 system. Biofilm-producing bacteria were identified by the Congo Red Agar (CRA) method. A PCR test characterized the virulence genes of dominant bacteria (E. coli). All data were collected and processed for statistical analysis.

Results

Out of 109 catheterized patients, 78% of the catheters were culture positive, which was higher than those of the urine samples (37.62%). The most common species isolated from the catheter cultures were Escherichia coli (28.1%), Candida sp. (17.8%), Klebsiella pneumoniae (15.9%), and Enterococcus faecalis (13.1%). E. coli (83.3%) and E. faecalis (78.6%) were the main isolates with a positive CRA. A statistical analysis showed that gender and duration prior to catheterization were associated with an increased risk of biofilm formation (p < 0.05).

Conclusion

E. coli and E. faecalis were the most common biofilm-producing bacteria isolated from the urinary catheter. Gender and duration are two risk factors associated with biofilm formation, therefore determining the risk of CAUTI. The presence of PapC as a virulence gene encoding pili correlates with the biofilm formation. Biofilm-producing bacteria, female gender, duration of catheterization (more than five days), and PapC gene presence have strong correlation with the biofilm formation. To prevent CAUTI, patients with risk factors should be monitored by urinalysis tests to detect earlier the risk of biofilm formation.

Discontinuation of peri-operative gentamicin use for indwelling urinary catheter manipulation in orthopaedic surgery

BACKGROUND

Gentamicin has historically been used prior to insertion and removal of indwelling urinary catheters (IDCs) around elective joint replacement surgery to prevent infection; however, this indication is not recognized in the Australian Therapeutic Guidelines: Antibiotic and the paradigm for safe use of gentamicin has shifted.

METHODS

The antimicrobial stewardship team of a 500 bed tertiary regional hospital performed a retrospective clinical study of gentamicin IDC prophylaxis around total hip and knee arthroplasties. Results were presented to the orthopaedic surgeons. A literature review identified no guidelines to support gentamicin prophylaxis and only a very low risk of bacteraemia associated with IDC insertion/removal in patients with established bacteriuria. Consensus was reached with the surgeons to discontinue this practice. Subsequent prospective data collection was commenced to determine effectiveness, with weekly feedback to the Department Head of Orthopaedics.

RESULTS

Data from 137 operations pre-intervention (6 months) were compared with 205 operations post-intervention (12 months). The median patient age was 72 years in both groups. Following the intervention, reductions in gentamicin use were demonstrated for IDC insertion (59/137 (42%) to 4/205 (2%), P < 0.01) and removal (39/137 (28%) to 6/205 (3%), P < 0.01). No gentamicin use was observed during the final 40 weeks of the post-intervention period. There were no significant differences between the groups for pre-operative bacteriuria, surgical site infections or acute kidney injury.

CONCLUSION

A collaborative approach using quality improvement methodology can lead to an evidence-based reappraisal of established practice. Regular rolling audits and timely feedback were useful in sustaining change.

Enhancing the Enrichment of Pharmacophore-Based Target Prediction for the Polypharmacological Profiles of Drugs

PharmMapper is a web server for drug target identification by reversed pharmacophore matching the query compound against an annotated pharmacophore model database, which provides a computational polypharmacology prediction approach for drug repurposing and side effect risk evaluation. But due to the inherent nondiscriminative feature of the simple fit scores used for prediction results ranking, the signal/noise ratio of the prediction results is high, posing a challenge for predictive reliability. In this paper, we improved the predictive accuracy of PharmMapper by generating a ligand-target pairwise fit score matrix from profiling all the annotated pharmacophore models against corresponding ligands in the original complex structures that were used to extract these pharmacophore models. The matrix reflects the noise baseline of fit score distribution of the background database, thus enabling estimation of the probability of finding a given target randomly with the calculated ligand-pharmacophore fit score. Two retrospective tests were performed which confirmed that the probability-based ranking score outperformed the simple fit score in terms of identification of both known drug targets and adverse drug reaction related off-targets.

Antibiotic prophylaxis for short-term catheter bladder drainage in adults

BACKGROUND

Urinary tract infections account for about 40% of hospital-acquired (nosocomial) infections, and about 80% of urinary tract infections acquired in hospital are associated with urinary catheters.

OBJECTIVES

To determine if certain antibiotic prophylaxes are better than others in terms of prevention of urinary tract infections, complications, quality of life and cost-effectiveness in short-term catheterisation in adults.

SEARCH METHODS

We searched the Cochrane Incontinence Group Specialised Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and MEDLINE in Process, and handsearching of journals and conference proceedings (searched 31st October 2012). Additionally, we examined all reference lists of identified trials.

SELECTION CRITERIA

All randomised and quasi-randomised trials comparing antibiotic prophylaxis for short-term (up to and including 14 days) catheterisation in adults.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by all review authors and compared. Disagreements were resolved by discussion. Data were processed as described in the Cochrane Handbook for Systemtic Reviews of Interventions. Where data had not been fully reported, clarification was sought directly from the authors of the trial.

MAIN RESULTS

Six parallel-group randomised controlled trials with 789 participants met the inclusion criteria. All six trials compared antibiotic prophylaxis versus no prophylaxis. Studies presented a low to unclear risk of bias with similar interventions and measured outcomes.The primary outcome of bacteriuria was less common in the prophylaxis group amongst surgical patients with asymptomatic bacteriuria (I(2) = 0; risk ratio (RR) 0.20; 95% confidence interval (CI) 0.13 to 0.31) . Two non-surgical studies could not be combined in a meta-analysis due to heterogeneity and only one showed significantly fewer cases of bacteriuria (RR 0.19; 95% CI 0.09 to 0.37).Two trials of surgical patients with asymptomatic bacteriuria only (255 participants) compared one type of antibiotic prophylaxis with another and neither study showed a significant difference in cases of bacteriuria.One study (78 participants) compared antibiotic prophylaxis in patients at catheterisation only versus antibiotic prophylaxis throughout catheterisation period with asymptomatic bacteriuria. Antibiotics at catheterisation only, resulted in significantly fewer cases of bacteriuria than giving prophylaxis throughout the catheterisation period (RR 0.29 95% CI 0.09 to 0.91).Secondary data of pyuria were provided by two surgical studies (255 participants). When studies were pooled, pyuria occurred in significantly fewer cases in the prophylactic antibiotic group (RR 0.23, 95% CI 0.13 to 0.42). The number of gram-negative isolates in patients' urine just before catheter removal in one study (RR 0.05, 95% CI 0.00 to 0.79) and six weeks after hospital discharge (RR 0.36, 95% CI 0.23 to 0.56) were significantly lower. There were no events in the treatment group before catheter removal. When pooled data from two studies showed significantly reduced febrile morbidity in those receiving antibiotic prophylaxis (RR 0.53 95% CI 0.31 to 0.89).Although all studies assessed micro-organisms isolated from the urine specimens the data were too heterogenous to pool in a meta-analysis and have been provided in a narrative form. Further secondary data such as economic analysis, length of stay and quality of life were not covered in detail.

AUTHORS' CONCLUSIONS

The limited evidence indicated that receiving prophylactic antibiotics reduced the rate of bacteriuria and other signs of infection, such as pyuria, febrile morbidity and gram-negative isolates in patients' urine, in surgical patients who undergo bladder drainage for at least 24 hours postoperatively. There was also limited evidence that prophylactic antibiotics reduced bacteriuria in non-surgical patients.