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Background/Objectives: Multiple-drug-resistant (MDR) bacteria are pathogens resistant to three or more antibiotic classes, and infection with these bacteria is associated with increased mortality, morbidity, and hospital management costs. Given the rise in antibiotic resistance, selecting appropriate antimicrobial drugs and avoiding the unnecessary use of new antibiotics are crucial. Due to their nosocomial nature, monitoring and preventing MDR infections are essential. Methods: This study enrolled patients who underwent cardiac surgery from January 2020 to May 2022. The patients included were those 18 years or older who tested positive for MDR intestinal colonization before surgery. Excluded were patients who tested positive after surgery, or were younger than 18, pregnant, or lactating. For each positive patient, the National Surgical Quality Improvement Program (NSQIP) score was calculated. The data collected included age, gender, body mass index (BMI), the type of surgery, the intensive care unit (ICU) length of stay, ICU readmission, mortality, and other infections (pneumonia, bacteremia, or surgical site infection) to establish a control group and postoperative outcome measures. Results: No statistically significant differences were found between the groups regarding the ICU length of stay, new ICU admissions, or mortality. Additionally, there were no differences in the infection rates, such as bacteremia, wound infections, and pneumonia. Conclusions: Preoperative rectal colonization by MDR bacteria does not appear to worsen postoperative outcomes for cardiac surgery patients. These findings suggest that patients with a preoperative MDR-positive rectal sample might undergo cardiac surgery without significantly increased risk. Besides the limitations of this study, pre-surgical antibiotic prophylaxis may not need to be adjusted for patients with preoperative MDR positivity.

Median sternotomy and steel wires for sternal closure are the standard approach for cardiac surgery. An incomplete repair associated with chest wall motion, especially in the presence of predisposing factors, can lead to life-threatening deep sternal wound infection, also known as mediastinitis, in 2-5% of cases. Despite current antibiotic and surgical treatments, mediastinitis is associated with a 10-40% mortality rate and a significant increase in morbidity and hospital stay. High mortality and difficult treatment appear to be due to bacterial biofilm, a self-produced extracellular polymeric product that incorporates host tissue and is responsible for the failure of immune defenses and standard antimicrobial therapies. Nanostructures are an effective strategy to enhance the healing process, as they establish a favorable environment for the neosynthesis of the extracellular matrix, supporting tissue development. Synthetic polymers have been proven to exhibit suitable biodegradable and mechanical properties, and their biofunctionalization to enhance cell attachment and interaction with the extracellular matrix is being widely investigated. The use of antibiotic treatments suspended in poly-D,L-lactide and polyethylene oxide and electrospun into nanofibers, or in sponges, has been shown to inhibit bacterial biofilm production. Additionally, growth factors can be incorporated into 3D bioresorbable scaffolds with the aim of constituting a structural and biological framework to organize and expedite the healing process. Therefore, these combined approaches may change the treatment of mediastinitis in the near future.