Efficacy of antimicrobials in preventing resistance in solid organ transplant recipients: A systematic review of clinical trials.

Abstract

<h4>Background</h4>In the absence of effective antimicrobials, transplant surgery is not viable, and antirejection immunosuppressants cannot be administered, as resistant infections compromise the life-saving goal of organ transplantation.<h4>Aim</h4>To evaluate the efficacy of antimicrobials in preventing resistance in solid organ transplant recipients.<h4>Methods</h4>A systematic review was conducted using a search methodology consistent with the preferred reporting items for systematic reviews and meta-analyses. This review included randomized clinical trials that evaluated the efficacy of antimicrobial agents (prophylactic or therapeutic) aimed at preventing antimicrobial resistance. The search strategy involved analyzing multiple databases, including PubMed/MEDLINE, Web of Science, Embase, Scopus, and SciELO, as well as examining gray literature sources on Google Scholar. A comprehensive electronic database search was conducted from the databases' inception until May 2024, with no language restrictions.<h4>Results</h4>After the final phase of the eligibility assessment, this systematic review ultimately included 7 articles. A total of 2318 patients were studied. The most studied microorganisms were cytomegalovirus, although vancomycin-resistant enterococci, <i>Clostridioides difficile</i>, and multidrug-resistant <i>Enterobacterales</i> were also analyzed. The antimicrobials used in the interventions were mainly maribavir, valganciclovir, ganciclovir, and colistin-neomycin. Of concern, all clinical trials showed significant proportions of resistant microorganisms after the interventions, with no statistically significant differences between the groups (mean resistance 13.47% <i>vs</i> 14.39%), except for two studies that demonstrated greater efficacy of maribavir and valganciclovir (mean resistance 22.2% <i>vs</i> 41.1% in the control group; <i>P</i> < 0.05). The total reported deaths in three clinical trials were 75, and there were 24 graft rejections in two studies.<h4>Conclusion</h4>All clinical trials reported significant proportions of antimicrobial-resistant microorganisms following interventions. More high-quality randomized clinical trials are needed to corroborate these results.