Carbapenem alternatives for treatment of bloodstream infections due to AmpC producing enterobacterales.

INTRODUCTION: Carbapenems (CR) have traditionally been the first line treatment for bacteremia caused by AmpC-producing Enterobacterales. However, CR have a high ecological impact, and carbapenem-resistant strains continue rising. Thus, other treatment alternatives like Piperacillin-Tazobactam (P-T) or Cefepime (CEF) and oral sequential therapy (OST) are being evaluated. METHODS: We conducted a retrospective, single-centre observational study. All adult patients with AmpC-producing Enterobacterales bacteremia were included. The primary endpoint was clinical success defined as a composite of clinical cure, 14-day survival, and no adverse events. We evaluated the evolution of patients in whom OST was performed. RESULTS: Seventy-seven patients were included, 22 patients in the CR group and 55 in the P-T/CEF group (37 patients received CEF and 18 P-T). The mean age of the patients was higher in the P-T/CEF group (71 years in CR group vs. 76 years in P-T/CEF group, p = 0.053). In the multivariate analysis, age ≥ 70 years (OR 0.08, 95% CI [0.007-0.966], p = 0.047) and a Charlson index ≥ 3 (OR 0.16, 95% CI [0.026-0.984], p = 0.048), were associated with a lower clinical success. Treatment with P-T/CEF was associated with higher clinical success (OR 7.75, 95% CI [1.273-47.223], p = 0.026). OST was performed in 47% of patients. This was related with a shorter in-hospital stay (OST 14 days [7-22] vs. non-OST 18 days [13-38], p = 0.005) without difference in recurrence (OST 3% vs. non-OST 5%, p = 0.999). CONCLUSIONS: Targeted treatment with P-T/CEF and OST could be safe and effective treatments for patients with AmpC-producing Enterobacterales bacteremia.

Gastrointestinal colonization by OXA-48-producing Enterobacterales: risk factors for persistent carriage.

Carbapenem-resistant Enterobacterales (CRE) infections are a major health problem. Intestinal colonization is a key factor in developing infection. However, factors associated with persistent colonization by CRE are unknown. The aim of the study was to identify factors associated with persistent CRE gut colonization. This is a retrospective, single-centre, observational study of adult patients with CRE gut colonization between January 2015 and January 2020. Epidemiologic characteristics, comorbidities, infectious events, duration of hospitalization and antimicrobial treatment received in the follow-up period were collected. Colonization was defined as isolation in at least 2 rectal swab culture samples of CRE. Decolonization was defined as 3 negative rectal swab cultures or 2 negative cultures and a negative molecular test. A cohort of 86 patients with CRE gut colonization was selected: 44 patients with spontaneous decolonization (DC) and 42 patients with persistent colonization (PC). The mean follow-up period was 24 months (IQR 14-33) in the DC group vs. 25 months (IQR 16-36) in the PC group (p = 0.478). Patient characteristics were similar between both groups. Colonization by other MDR microorganisms was high (44 patients, 51%) and slightly more common in the PC group (PC 60% vs. DC 43%, p = 0.139). The use of ceftazidime-avibactam was more common among the PC group (PC 33% vs. DC 14%, p = 0.041). We observed a higher percentage of antimicrobial therapy in the previous 30 days (PC 68% vs. DC 57%, p = 0.371) and 90 days (PC 81% vs. DC 82%, p = 0.353) in the PC group. Multivariable analysis showed that patients that have received ceftazidime-avibactam therapy (OR 4.9 95% CI [1.45-16.39], p = 0.010), and those colonized by other MDR microorganisms (OR 2.5, 95% CI [0.96-6.25], p = 0.060) presented a higher risk of PC. Ceftazidime-avibactam use and colonization by other MDR microorganisms might be associated with CRE persistent gut colonization.