Long-term Staphylococcus aureus decolonization in patients on home parenteral nutrition: study protocol for a randomized multicenter trial

Randomized clinical trial: Long-term Staphylococcus aureus decolonization in patients on home parenteral nutrition

BACKGROUND & AIMS

Staphylococcus aureus decolonization has proven successful in prevention of S. aureus infections and is a key strategy to maintain venous access and avoid hospitalization in patients receiving home parenteral nutrition (HPN). We aimed to determine the most effective and safe long-term S. aureus decolonization regimen.

METHODS

A randomized, open-label, multicenter clinical trial was conducted. Adult intestinal failure patients with HPN support and carrying S. aureus were randomly assigned to a 'continuous suppression' (CS) strategy, a repeated chronic topical antibiotic treatment or a 'search and destroy' (SD) strategy, a short and systemic antibiotic treatment. Primary outcome was the proportion of patients in whom S. aureus was totally eradicated during a 1-year period. Secondary outcomes included risk factors for decolonization failure and S. aureus infections, antimicrobial resistance, adverse events, patient compliance and cost-effectivity.

RESULTS

63 participants were included (CS 31; SD 32). The mean 1-year S. aureus decolonization rate was 61% (95% CI 44, 75) for the CS group and 39% (95% CI 25, 56) for the SD group with an OR of 2.38 (95% CI 0.92, 6.11, P = 0.07). More adverse effects occurred in the SD group (P = 0.01). Predictors for eradication failure were a S. aureus positive caregiver and presence of a (gastro)enterostomy.

CONCLUSION

We did not demonstrate an increased efficacy of a short and systemic S. aureus decolonization strategy over a continuous topical suppression treatment. The latter may be the best option for HPN patients as it achieved a higher long-term decolonization rate and was well-tolerated (NCT03173053).

Presence of egc-positive major clones ST 45, 30 and 22 among methicillin-resistant and methicillin-susceptible oral Staphylococcus aureus strains

The oral cavity may comprise a significant reservoir for Staphylococcus aureus but the data on molecular epidemiology and clonal distribution of oral strains are really scarce. This study aimed to evaluate the clonal relatedness in S. aureus isolated from oral cavity and their relationship with carriage of virulence genes, and antimicrobial resistance profiles. A total of 139 oral S. aureus isolates were obtained from 2327 analysed oral samples of dental patients. Antimicrobial susceptibility testing was performed. Isolates were characterized using protein A gene (spa) typing, spa-CC clonal complexes, toxin genes and SCCmec typing for MRSA. High resistance rates for penicillin, tetracycline and gentamicin were detected, respectively 58.3%, 42.4%, and 35.2%. Twelve (8.6%) S. aureus isolates were identified as MRSA. All of MRSA isolates were mecA-positive and mecC-negative. SCCmec IV was the most common type (66.7%), which was typical for community-acquired MRSA (CA-MRSA). Overall, the enterotoxin gene cluster (egc) was the most frequent detected virulence factor (44.9%), both in MSSA and MRSA isolates. Presence of genes encoding for the enterotoxins (sea, seb, sec, seh, sek), exfoliative toxin A (eta), and toxic shock syndrome toxin-1 (tst) was also observed. Strains carrying lukS-PV/lukF-PV genes belonged to SCCmecV- spa type t437. The most prevalent spa types were t091, t015, t084, t002, t571, and t026 among all 57 identified. Spa types, including 3 new ones, grouped in 6 different spa-CC clonal complexes, with four major dominated; CC45, CC30, CC5, and CC15. This study demonstrated that both methicillin-susceptible and methicillin-resistant major European clones of S. aureus could be isolated from the oral cavity of dental patients, with the emergence of PVL-positive CA-MRSA strains. The oral cavity should be considered as a possible source of toxigenic egc-positive S. aureus strains, in terms of potential risk of cross-infection and dissemination to other body sites.

Use of Catheter Lock Solutions in Patients Receiving Home Parenteral Nutrition: A Systematic Review and Individual-Patient Data Meta-Analysis

BACKGROUND

Use of catheter lock solutions (CLSs) as a strategy to prevent catheter-related bloodstream infections (CRBSIs) has been evaluated in recent clinical trials. Our aim was to identify the most effective CLS formulation in patients receiving home parenteral nutrition (HPN).

METHODS

We conducted a systematic review and individual-patient data meta-analysis (IPDMA). Prospective randomized clinical trials in adult HPN patients using CLS were identified from PubMed, EMBASE, Web of Science, CINAHL, Cochrane library, and ClinicalTrials.gov. Primary outcome was the number of CRBSIs per 1000 catheter days for each CLS. Other outcomes included time to CRBSI and identification of patients with a higher risk for CRBSIs.

RESULTS

In total, 1107 studies were screened for eligibility, of which three studies comprising 162 HPN patients and 45,695 catheter days were included in the IPDMA. CRBSI rates were significantly decreased in patients using taurolidine (rate 0.13; 95% confidence interval [CI], 0.05-0.32) when compared with saline (rate 0.74; 95% CI, 0.31-1.74; P = .002) or heparin (rate 2.01; 95% CI, 1.03-3.91; P < .001). The cumulative proportion of CRBSI-free patients using taurolidine, saline, and heparin after 1 year was 88%, 56%, and 14%, respectively. Three risk factors for CRBSIs were identified: type of CLS, intestinal dysmotility as underlying condition, and use of central venous catheters.

CONCLUSIONS

Taurolidine was the most effective CLS formulation in HPN patients for the prevention of CRBSIs. We suggest discussing with patients the benefits and risks when starting taurolidine, especially in patients who are considered to have a higher risk for CRBSIs.

Eradication of Staphylococcus aureus colonization by chronic use of mupirocin in patients on home parenteral nutrition

OBJECTIVES

Although in other groups Staphylococcus aureus eradication has proven to be an effective infection prevention measure, to our knowledge, no such studies have been performed in patients on home parenteral nutrition (HPN). The aim of this study was to investigate the efficacy of chronic nasal mupirocin use on S. aureus eradication and prevention of catheter related infections in patients on HPN.

METHODS

This was a cohort study with data collected from adult patients on HPN who were screened for S. aureus carriage. In case of carriage, the patient was instructed to apply mupirocin nasal ointment monthly. Outcomes were the percentage of successful S. aureus eradication and the effect on the incidence of catheter-related infections and development of mupirocin resistance.

RESULTS

S. aureus nasal carriage was found in 54% of the patients. Eradication was successful in 66% (70 of 106) of patients treated with mupirocin. Overall S. aureus catheter-related infection rates decreased by 50% (P = 0.02). The decrease was mostly due to a drop in central line-associated bloodstream infection (CLABSI) rates (0.26versus 0.1 per 1000 central venous catheter days; P = 0.04). The overall CLABSI rates decreased as well (incidence ratio rate, 0.43; 95% confidence interval. 0.24-0.76; P < 0.01). Low-level mupirocin resistance was observed in four patients.

CONCLUSIONS

Findings from the present study highlighted the potential usefulness of mupirocin ointment prophylaxis to establish S. aureus eradication in patients on HPN. However, awareness for the development of mupirocin resistance is prudent. Further research needs to be carried out to validate these findings.