LAUSR

Initial correspondence from Drs. Simeone, Lagier and Mokart We would like to congratulate Montravers et al. [1], on their study, which challenged medical dogma and demonstrated that short-duration (8 days) antibiotic regimen in critically ill patients treated for postoperative intraabdominal infections appeared to be safe as compared to extended antibiotic regimen (15 days). One striking message of this study is that the emergence of multidrugresistant (MDR) bacteria is associated with extended antibiotic regimen. In the article [1], the authors provided additional data (Supplementary Table S4) showing rates of combined antibiotic therapy, defined as the use of three or more antibiotics in each group: 35 of 116 (30%) in the 15-day arm versus 54 of 120 (45%) in the 8-day arm. No statistical analysis of these data was provided. However, a Fisher exact test shows that the two groups were significantly different as p = 0.022 with an odds ratio of 0.52 (0.29–0.93). Thus, the two groups were significantly different regarding the use of combined antibiotics therapy. Although clinical evidence is limited, several in vitro studies have underlined the interest in using antibiotic combinations in order to avoid MDR bacteria emergence [2, 3]. Unbalanced use of combined antibiotic therapy seems significant enough to raise some concerns about the observed effect regarding the lower MDR bacteria emergence in the short-duration antibiotic regimen group.