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

BACKGROUND 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. AIM To evaluate the efficacy of antimicrobials in preventing resistance in solid organ transplant recipients. METHODS 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. RESULTS 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, Clostridioides difficile , and multidrug-resistant Enterobacterales 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% vs 14.39%), except for two studies that demonstrated greater efficacy of maribavir and valganciclovir (mean resistance 22.2% vs 41.1% in the control group; P < 0.05). The total reported deaths in three clinical trials were 75, and there were 24 graft rejections in two studies. CONCLUSION All clinical trials reported significant proportions of antimicrobial-resistant microorganisms following interventions. More high-quality randomized clinical trials are needed to corroborate these results.