Diagnosing Catheter-associated Urinary Tract Infection in Critically Ill Patients: Do the Guidelines Help?

Severe infections caused by difficult-to-treat Gram-negative bacteria

PURPOSE OF REVIEW

Antimicrobial resistance (AMR) in Gram-negative bacteria (GNB) poses a significant global health concern, contributing to increased infections, mortality rates, and healthcare costs. This review discusses the main clinical manifestations, therapeutic options, and recent findings in managing antibiotic-resistant GNB, with a focus on difficult-to-treat infections.

RECENT FINDINGS

Difficult-to-treat resistance (DTR) is a novel classification that identifies GNB exhibiting intermediate or resistant phenotypes to first-line agents in the carbapenem, beta-lactam, and fluoroquinolone categories. The main pathogens implicated in severe infections include DTR Enterobacterales, DTR Pseudomonas aeruginosa , and DTR Acinetobacter baumannii. Although the clinical implications of DTR strains are still under investigation, certain studies have linked them to prolonged hospital stays and poor patient outcomes.

SUMMARY

Severe infections caused by DTR-GNB pose a formidable challenge for healthcare providers and represent a growing global health issue. The proper administration and optimization of novel antibiotics at our disposal are of paramount importance for combating bacterial resistance and improving patient prognosis.

Reducing Catheter-Associated Urinary Tract Infections Across a Hospital System Through Urine Culture Stewardship

Objective

To evaluate the effectiveness and safety of an evidence-based urine culture stewardship program in reducing hospital catheter-associated urinary tract infections (CAUTIs) and the rate of CAUTIs across a 3-hospital system.

Patients and Methods

This is a prospective, 2-year quality improvement program conducted from October 1, 2018, to September 30, 2020. An evidence-based urine culture stewardship program was designed, which consisted of the following: criteria for allowing or restricting urine cultures from catheterized patients, a best practice advisory integrated into the ordering system of an electronic medical record, and a systematic provider education and feedback program to ensure compliance. The system-wide rates of CAUTIs (total CAUTIs/catheter days×1000), changes in intercepts, trends, mortality, length of stay, rates of device utilization, and rates of hospital-onset sepsis were compared for 3 years before and 2 years after the launch of the program.

Results

Catheter-associated urinary tract infections progressively decreased after the initiation of the program (B=−0.21, P=.001). When the trends before and after the initiation of the program were compared, there were no statistically significant increases in the ratio of actual to predicted hospital length of stay, intensive care unit length of stay, system-wide mortality, and intensive care unit mortality. Although the rates of hospital-acquired sepsis remained consistent after the implementation of the stewardship program through the first quarter of 2020, the rates showed an increase in the second and third quarters of 2020. However, hospital-onset sepsis events associated with the diagnosis of a urinary tract infection did not increase after the intervention.

Conclusion

Urine culture stewardship is a safe and effective way to reduce CAUTIs among patients in a large multihospital health care system. Patient safety indicators appeared unchanged after the implementation of the program, and ongoing follow-up will improve confidence in the long-term sustainability of this strategy.

Prevalence and genetic lineages of Staphylococcus aureus nasal colonization and urinary tract infection among people living with HIV/AIDS in Nigeria: A systematic review

To provide an empirical insight on Staphylococcus aureus (S. aureus) nasal colonization and urinary tract infection (UTI) among people living with HIV/AIDS (PLWHA) in Nigeria, a quantitative synthesis and systematic review were executed. A comprehensive bibliometric search was conducted for published articles using the keywords 'nasal S. aureus carriage', 'Urinary S. aureus', 'nasal MRSA', 'staphylococci-HIV coinfection', 'urinary MRSA' and 'all states of Nigeria'. Eligible studies and the number of subjects (n) were analysed according to the PRISMA criteria. Out of the 79 examined studies, only 6 (n=1181) and 6 (n= 1350) on nasal and urine samples, respectively, were eligible. The pooled prevalence of nasal carriage and UTI of S. aureus were 29.6% and 6.8%, respectively. However, the pooled nasal MRSA carriage was 13.4%. The pooled prevalence of luk-F/S-PV-carrying S. aureus among nasal samples was 13.0%. Molecular typing from 3 studies showed MRSA-ST8-t064 and MSSA-ST15-t084 as the predominant genetic lineages. The S. aureus isolates from both sample types had the highest (>50%) resistance to penicillin, sulfamethoxazole-trimethoprim, erythromycin, and tetracycline. Multi-drug resistance was not significantly higher among S. aureus isolates from urine than nasal samples (60% versus 40.0% of eligible studies) (p= 0.5271). A moderate and high pooled prevalence of genetically diverse MRSA and luk-F/S-PV-carrying S. aureus were obtained from PLWHA, respectively. These findings emphasize the importance of routine screening for MRSA among PLWHA in Nigeria and other HIV endemic countries.

Bacterial urine profile and optimal urine specimen collection timing in asymptomatic chronically catheterized adults with spinal cord injuries and disorders

BACKGROUND

Adults with spinal cord injuries and disorders (SCI/D) require chronic indwelling catheterization which is associated with an increased risk of catheter-associated (CA) adverse events.

METHODS

We studied urine samples (culture and urinalysis) from 2 cohorts of chronically catheterized males with SCI/D. Cohort 1 included 28 participants; 3 samples per patient were collected (before, after, and 7 days after catheter change). Cohort 2 included 21 participants; 7 samples per patient were collected (before, immediately after, 30 minutes, 1 hour, 1 day, 2 days, and 7 days after catheter change).

RESULTS

A statistically significant decrease in the post catheter change percentage of "significant cultures" was found in both our cohorts (P<.05). Additionally, our second cohort demonstrated a significant decrease in the number of organisms growing at 100.000 cfu/mL (median=-1, mean=-1.5, P=.0006) and in urinalysis bacterial numbers (median=-0.5, mean=-1, P=.006) from pre- to 1-hour post catheter removal.

CONCLUSIONS

Although there appears to be an improvement of organism burden seen after catheter change, this is only temporary, and its significance in chronically catheterized patients is still unknown. Our second cohort demonstrated an optimal time for sample collection at the 1-hour post-catheter change sample, but further research is required for the extrapolation of these findings.

Catheter-Associated Urinary Tract Infections: Current Challenges and Future Prospects

Catheter-associated urinary tract infection (CAUTI) is the most common healthcare-associated infection and cause of secondary bloodstream infections. Despite many advances in diagnosis, prevention and treatment, CAUTI remains a severe healthcare burden, and antibiotic resistance rates are alarmingly high. In this review, current CAUTI management paradigms and challenges are discussed, followed by future prospects as they relate to the diagnosis, prevention, and treatment. Clinical and translational evidence will be evaluated, as will key basic science studies that underlie preventive and therapeutic approaches. Novel diagnostic strategies and treatment decision aids under development will decrease the time to diagnosis and improve antibiotic accuracy and stewardship. These include several classes of biomarkers often coupled with artificial intelligence algorithms, cell-free DNA, and others. New preventive strategies including catheter coatings and materials, vaccination, and bacterial interference are being developed and investigated. The antibiotic pipeline remains insufficient, and new strategies for the identification of new classes of antibiotics, and rational design of small molecule inhibitor alternatives, are under development for CAUTI treatment.