01 Set Tigecycline, an ecological choice? Retrospective cohort study of colonization or infection risk with Carbapenems-Resistant Klebsiella pneumoniae or Clostridium difficile following antibiotic treatment of intra-abdominal infection

Renato Pascale

The aim of the study was to evaluate the impact of tigecycline (TGC) versus meropenem (MPM) on the development of Clostridium difficile associated diarrhoea (CDAD) and to establish the rate of new colonization with carbapenem-resistant Klebsiella pneumoniae (CR-KP) in intra-adominal infection (IAI) treatment. It is a retrospective, single-center, cohort study. 168 patients with IAI treated with TGC were compared with 168 patients with MPM. Overall the median age was 60 (46-73). Significant differences among TGC and MPM groups were observed for hospital acquisition of IAI (61% vs 71% p=0.03), previous surgery (65 vs 51, p=0.02) admission in ICU (50 vs 40% p=0.06). All-cause in-hospital mortality was similar among the two groups (9% vs 11%, p=0.59). A microbiological diagnosis was obtained in 176 (51%). In 51/176 (29%) a polimicrobial infection was diagnosed. Gram-negative bacilli were found in 128/176 (72%). Of these drug susceptible, fluoroquinolone-resistant and ESBL-Enterobacteriaceae accounted for 27%,7% and 15% of cases, respectively; Among 336 patients, 30 patients (9%) acquired CR-KP bowel colonization with no statistically differences found between the two groups (p=0.44). As regards CDAD, 34 (10%) patients experienced at least one episode of unformed stool of which 11 (3%) tested positive for C.difficile, only 1 patient (1%) in TGC group and 10 (6%) in MPM group (p=0.006). In our study tigecycline is shown effective in preventing overgrowth and toxin production by C.difficile but not for colonization with CR-KP.