Activity of ethanol and daptomycin lock on biofilm generated by an in vitro dynamic model using real subcutaneous injection ports

Treatment of long-term catheter-related bloodstream infections with short-course Daptomycin lock and systemic therapy associated with Taurolidine-lock: A multicenter experience

PURPOSE

Few studies describe the efficacy of antibiotic lock therapy (ALT) in long-term catheter-related bloodstream (CRBSI) infections. We applied local protocols combining Daptomycin (DPT) and Taurolidine ALT, associated with systemic antibiotic treatment (SAT), for conservative management of coagulase-negative Staphylococci (CoNS) CRBSI.

METHODS

Patients admitted for CoNS-associated CRBSI and treated with DPT and Taurolidine as ALT were retrospectively analyzed. Success was defined as catheter retention 30 days after ending treatment. Catheter removal within 30 days was considered as failure.

RESULTS

From April 2018 to September 2021, 22 subjects with CoNS-associated-CRBSI were included (95% with cancer, mean age 64 years, 59% male). Staphylococcus epidermidis was isolated in 82% of cases. Mean duration of DPT was 3.9 and 3 days as ALT and SAT, respectively. SAT also included Rifampin for 3 days. Taurolidine ALT was started on day 4 and was combined with oral SAT, that is, either Linezolid or Tedizolid. Mean duration of Taurolidine was 10.5 days, while total antibiotic treatment lasted 13.5 days. Clinical success and failure rates were 95% and 5%, respectively.

DISCUSSION

Short course DPT as ALT, combined with SAT and Taurolidine ALT, allowed high rates of conservative management of catheters in case of CoNS-associated-CRBSI.

Comparing ethanol lock therapy versus vancomycin lock in a salvation strategy for totally implantable vascular access device infections due to coagulase-negative staphylococci (the ETHALOCK study): a prospective double-blind randomized clinical trial

OBJECTIVES

Little is known about efficacy and safety of ethanol lock therapy (ELT) to treat totally implantable venous access device (TIVAD) infections. The objective of this trial was to evaluate the effectiveness and safety profile of a local treatment with ELT without removal for TIVAD infection due to coagulase-negative staphylococci.

METHODS

We performed a prospective, multicenter, double-blind, randomized clinical trial comparing the efficacy of 40% ELT versus vancomycin lock therapy (VLT) in TIVAD infections due to coagulase-negative staphylococci, complicated or not by bloodstream infection.

RESULTS

Thirty-one patients were assigned to the ELT group and 30 to the VLT arm. Concomitant bacteremia was present in 41 patients (67.2%). Treatment success was 58.1 % (18 of 31) for the ELT arm and 46.7% (14 of 30) for the VLT arm (p = 0.37). The overall treatment success was 52.5% (32). The risk of treatment failure due to uncontrolled infections, superinfections, and mechanical complications did not differ significantly between participants receiving ELT (13 out of 31 [42%]) and those receiving VLT (16 out of 30 [53%]) with a hazard ratio of 0.70 (p = 0.343; 95% CI [0.34-1.46], Cox model). Catheter malfunctions were significantly more frequent in the ELT arm (11 patients versus 2 in the VLT group, p = 0.01).

CONCLUSIONS

We found an overall high rate of treatment failure that did not differ between the ELT arm and the VLT arm. TIVAD removal must be prioritized to prevent complications (uncontrolled infections, superinfections, and catheter malfunctions) except in exceptional situations.

Ethanol Lock for Prevention of CVC-Related Bloodstream Infection in Pediatric Patients: A Systematic Review and Meta-Analysis

Ethanol lock therapy (ELT) can be used in patients with an indwelling central line to assist in the prevention of central venous catheter (CVC)-associated infections. However, its efficacy has not been consistently demonstrated in the pediatric population. The primary objective of this review and meta-analysis was to determine the efficacy and safety of ELT in prevention of central line-associated bloodstream infection (CLABSI) in the pediatric population. A search was conducted with the PubMed, CINAHL, PSCYInfo, Cochrane Library, and Academic Search Premier databases from inception through January 21, 2022. Studies were included if they reported incidence of CVC-related infections with ELT in pediatric patients. Meta-analyses used random-effects models according to the heterogeneity of all included studies. Of 736 studies, 25 met inclusion criteria for review and 10 for inclusion in the meta-analysis. Meta-analysis with pre- and post-ELT treatment showed that use of ELT significantly decreased mean CVC-related infections when compared with pre-treatment with no ELT with a mean difference of -5.79 (95% CI, -9.08 to -2.51; p < 0.001). The number of CVC infections also significantly decreased (OR, 0.42; 95% CI, 0.23-0.75; p = 0.004). Increased risk of thrombosis and increased frequency of catheter breakage, repair, and replacement were noted in several studies. Ethanol lock therapy is effective in preventing infection related to central venous catheter use in pediatric patients. Further study is warranted to determine the optimal protocol for, and incidence of, adverse events related to use of ELT.

Daptomycin as an option for lock therapy: a systematic literature review

Aim: To review preclinical and clinical data relevant to daptomycin lock therapy in catheter-related bloodstream infection (CRBSI). Methods: Systematic review in PubMed, Scopus and clinical trial registries. Results: Preclinical data demonstrate daptomycin lock solution stability and compatibility with heparin, good biofilm penetration, bactericidal activity against biofilm-embedded bacteria, and high efficacy in vitro and in animal catheter infection models. Clinical data remain limited (two case reports and five case series totaling n = 65 CRBSI episodes), albeit promising (successful catheter salvage in about 80% of cases). Conclusion: Despite theoretical advantages of daptomycin, clinical data remain scarce. Comparative studies versus alternative lock solutions are needed, as well as studies to define optimal daptomycin lock regimen (including optimal concentration, dwell time and lock duration).

Factors predicting efficacy of ethanol lock therapy as catheter salvage strategy for pediatric catheter-related infections

AIM

Catheter-related infections are difficult to cure, and failure rates are high. We aimed to evaluate the efficacy and safety of ethanol lock therapy (ELT) as catheter salvage strategy in children with central-line-associated bloodstream infection (CLABSI), and to identify factors associated with treatment failure.

METHODS

Data were collected of all the children who received ELT for treatment of CLABSI during 2013-2018 due to failure of standard therapy or multiple catheter-related infections. Univariate and multivariate analyses of risk-factors for ELT failure were performed. Catheter salvage rates were compared to those achieved using systemic antimicrobials alone in an historical control group.

RESULTS

A total of 123 ELT episodes among 95 patients were analyzed. The majority of patients had underlying hemato-oncological disorders. Approximately half the episodes occurred in patients with implantable ports. Early and late treatment failure rates of ELT were 16% (20/123) and 7% (9/123), respectively. Overall, successful catheter salvage was achieved in 78% (96/123) of episodes, compared to 54% using systemic antimicrobials alone (P < .001), including mycobacterium, candida, and most staphylococcus aureus infections. Adverse events were reported in 9% (11/123) of episodes and were mostly mechanical. Multivariate analysis identified four risk factors for ELT failure: Gram-positive bacteria, elevated C-reactive protein, signs of tunnel infection, and low absolute neutrophil counts.

CONCLUSIONS

Our findings support the use of ELT for catheter salvage in children with CLABSI who failed standard therapy or had multiple catheter-related infections. The identified variables associated with ELT failure may help identify patients who can most benefit from ELT.

In Vitro Approach for Identification of the Most Effective Agents for Antimicrobial Lock Therapy in the Treatment of Intravascular Catheter-Related Infections Caused by Staphylococcus aureus

Infection of intravascular catheters by Staphylococcus aureus is a significant risk factor within the health care setting. To treat these infections and attempt salvage of an intravascular catheter, antimicrobial lock solutions (ALSs) are being increasingly used. However, the most effective ALSs against these biofilm-mediated infections have yet to be determined, and clinical practice varies greatly. The purpose of this study was to evaluate and compare the efficacies of antibiotics and antiseptics in current clinical use against biofilms produced by reference and clinical isolates of S. aureus Static and flow biofilm assays were developed using newly described in vivo-relevant conditions to examine the effect of each agent on S. aureus within the biofilm matrix. The antibiotics daptomycin, tigecycline, and rifampin and the antiseptics ethanol and Taurolock inactivated established S. aureus biofilms, while other commonly used antistaphylococcal antibiotics and antiseptic agents were less effective. These findings were confirmed by live/dead staining of S. aureus biofilms formed and treated within a flow cell model. The results from this study demonstrate the most effective clinically used agents and their concentrations which should be used within an ALS to treat S. aureus-mediated intravascular catheter-related infections.

In vitro efficacy of daptomycin and teicoplanin combined with ethanol, clarithromycin or gentamicin as catheter lock solutions

Background

Despite widespread use, optimum choice of antimicrobial agents, concentrations, combinations and exposure times have not been determined for antibiotic lock technique (ALT). Our objective was to evaluate the efficacy of different antibiotic combinations using an in vitro model of catheter-related infection. Daptomycin (DAP) 5 mg/mL, teicoplanin (TEC) 5 mg/mL, both alone and combined with gentamicin (GM) 2.5 mg/mL, clarythromycin (CLA) 5 mg/mL or ethanol 35 % were evaluated against four clinical strains of methicillin resistant coagulase negative staphylococci. Lock solutions were renewed every 24 h.

Results

After 72 h catheters were reincubated with culture media to investigate bacterial regrowth. All antibiotic combinations resulted in significant reductions (p < 0.05) of Log(10) cfu/mL at 72 h for both organisms compared with controls. DAP resulted in significant reductions of Log(10) for all organism versus TEC (p = 0.001). Only DAP reached the limit of detection at 72 h, however did not prevent regrowth after 24 h of ALT removal. DAP + Ethanol and TEC + ethanol eradicated biofilm at 72 h, but only DAP + ethanol (against all strains) and DAP + CLA (against two strains) prevented regrowth at 24 h after ALT removal.

Conclusions

Based on these data, ALT with DAP + ethanol and DAP + CLA should be explored in clinical trials.

Antimicrobial lock therapy in central-line associated bloodstream infections: a systematic review

PURPOSE

Antimicrobial lock therapy (ALT) seems a promising approach for treatment of central line associated bloodstream infections (CLABSI). The recent introduction of molecules such as daptomycin and tigecycline, alone or in combination with other molecules, improved chances of efficacy of ALT, due to their activity on the bacterial biofilm. Our aim was to review the literature concerning ALT for CLABSI, including data concerning novel molecules.

METHODS

We included case-control studies evaluating two or more molecules as ALT in central venous catheter infections extracted from the Medline database. Among 221 available articles in Pubmed, 54 were selected for their particular interest concerning ALT.

RESULTS

Incidence of CLABSI is high worldwide. Mechanisms of catheter infection include contamination by skin bacteria, hand contamination and hematogenous diffusion. Catheter-infection is associated with biofilm formation, which reduces the efficacy of ALT. The most promising situation for ALT to succeed in salvaging a catheter appears to be coagulase-negative Staphylococcus infection, which is the main causative agent of CLABSI. Daptomycin, Tigecycline, Ethanol and Taurolidine appear as the best options for treating CLABSI; data are mostly available for Daptomycin, which showed, alone or associated with Rifampin, good in vitro potency on biofilm, but few in vivo data exist on efficacy.

CONCLUSIONS

The introduction of novel molecules has increased chances of catheter salvage with ALT in case of CLABSI, but further in vivo studies are needed.

Sanitizing Effect of Ethanol Against Biofilms Formed by Three Gram-Negative Pathogenic Bacteria

Sanitizing effect of ethanol on a Yersinia enterocolitica biofilm was evaluated in terms of biomass removal and bactericidal activity. We found that 40 % ethanol was most effective for biofilm biomass removal; however, no significant difference was observed in bactericidal activity between treatment with 40 and 70 % ethanol. This unexpected low ethanol concentration requirement for biomass removal was confirmed using biofilms of two additional pathogenic bacteria, Aeromonas hydrophila and Xanthomonas oryzae. Although only three pathogenic Gram-negative bacteria were tested and the biofilm in nature was different from the biofilm in this study, the results in this study suggested the possible re-evaluation of the effective sanitizing ethanol concentration 70 %, which is the concentration commonly employed for sanitization, on bacteria in a biofilm.