Serum In Vivo and In Vitro Activity of Single Dose of Ertapenem in Surgical Obese Patients for Prevention of SSIs

Background Despite progress made in the control of postoperative infections, the incidence of surgical site infections (SSIs) is still high. An improper perioperative antibiotic use can expose patients to the risk of resistant microorganisms, and, in surgical obese patients, the drug dosage and infusion time are critical points. The aim of our study was to evaluate the effectiveness of ertapenem in the prophylaxis of SSIs in obese patients undergoing general or bariatric surgery. Methods A total of 63 obese patients, candidates for several surgical interventions, were enrolled and divided into two groups. Patients received antibiotic prophylaxis before surgery: the case group received venous infusion of ertapenem; the control group received standard prophylaxis. Serum samples were tested for antimicrobial activity against Gram-positive and Gram-negative bacteria. Results After single-dose ertapenem in obese patients, we registered in vitro activity of sera against the growth of nonextended beta lactamase (ESBL)-producing Escherichia coli, Proteus mirabilis, Citrobacter freundii, Enterobacter cloacae, and non-ESBL-producing Klebsiella pneumoniae. Moreover, methicillin-sensitive Staphylococcus aureus and Streptococcus viridans were also inhibited. We found in vivo efficacy according to clinical monitoring: at the weekly and monthly follow-ups, one patient in the case group and six patients in the control group presented superficial incisional SSIs. Conclusions These preliminary results are suggestive of the efficacy of ertapenem in perioperative prophylaxis of SSIs in obese patients; however, they need to be confirmed by further investigations and more defined trials.