New drugs for difficult bugs: management of multidrug-resistant gram-negative infections in solid organ transplant recipients

Current state of antimicrobial stewardship and organ transplantation in Spain

INTRODUCTION

Solid-organ transplantation (SOT) remains the best therapeutic option for end-stage organ disease. Regrettably, SOT recipients are disproportionately affected by nosocomial infections produced by multidrug-resistant (MDR) microorganisms and antimicrobial adverse events. Both have a negative impact on the patient´s outcome.

METHODS

Description of data concerning the antimicrobial stewardship program (ASP) in SOT recipients of the University Hospital "12 de Octubre", and review of other Spanish ASPs.

RESULTS

From May 2017 to December 2021, the ASP issued 2.785 recommendations. Approximately, 4.9% were aimed at improving the antimicrobial treatment administered to SOT recipients. Treatment discontinuation or change to a better therapeutic regimen was recommended in 51.8% and 26.3% of cases, respectively. The acceptance rate of the recommendations was close to 92%. Between June 2015 and March 2016, a quasi-experimental study consisting of a joint ASP and hospital-acquired infection control (HAIC) initiative, which included kidney transplant recipients, reported a significant reduction in the consumption of meropenem, vancomycin and ciprofloxacin, and a reduction in the incidence of global bacterial infections, upper urinary tract infections, and cystitis. Although Spain has several robust regional ASPs (e.g., VINCat and PIRASOA), data specifically concerning SOT patients is lacking.

CONCLUSION

ASP coupled with HAIC programs have proven to be effective in SOT, and should be implemented in centers that perform transplantation. Since data is scarce, Spanish centers which have ASP should report their experience in SOT. Understanding the efficacy and safety of the Spanish ASP´s intervention in the SOT population is essential and deserves further study.

Drug Resistance Reversal Potential of Nanoparticles/Nanocomposites via Antibiotic's Potentiation in Multi Drug Resistant P. aeruginosa

Bacteria employ numerous resistance mechanisms against structurally distinct drugs by the process of multidrug resistance. A study was planned to discover the antibacterial potential of a graphene oxide nanosheet (GO), a graphene oxide-zinc oxide nanocomposite (GO/ZnO), a graphene oxide-chitosan nanocomposite (GO-CS), a zinc oxide decorated graphene oxide-chitosan nanocomposite (GO-CS/ZnO), and zinc oxide nanoparticles (ZnO) alone and in a blend with antibiotics against a PS-2 isolate of Pseudomonas aeruginosa. These nanocomposites reduced the MIC of tetracycline (TET) from 16 folds to 64 folds against a multidrug-resistant clinical isolate. Efflux pumps were interfered, as evident by an ethidium bromide synergy study with nanocomposites, as well as inhibiting biofilm synthesis. These nanoparticles/nanocomposites also decreased the mutant prevention concentration (MPC) of TET. To the best of our knowledge, this is the first report on nanomaterials as a synergistic agent via inhibition of efflux and biofilm synthesis.

Management of Multidrug Resistant Infections in Lung Transplant Recipients with Cystic Fibrosis

Cystic fibrosis (CF) is an inherited multisystem disease characterised by bronchiectasis and chronic respiratory infections which eventually cause end stage lung disease. Lung transplantation (LTx) is a well-established treatment option for patients with CF-associated lung disease, improving survival and quality of life. Navigating recurrent infections in the setting of LTx is often difficult, where immune suppression must be balanced against the constant threat of infection. Sepsis/infections are one of the major contributors to post-LTx mortality and multiresistant organisms (eg, Burkholderia cepacia complex, Mycobacterium abscessus complex, Scedosporium spp. and Lomentospora spp.) pose a significant threat to survival. This review will summarize current and novel therapies to assist with the management of multiresistant bacterial, mycobacterial, viral and fungal infections which threaten the CF LTx cohort.