Ceftazidime-Avibactam plus Aztreonam for the Treatment of Infections by VIM-Type-Producing Gram-Negative Bacteria.

This is a retrospective single-center study of 24 patients who received ceftazidime-avibactam plus aztreonam (CZA/ATM) for the treatment of VIM-type-producing Gram-negative bacillus (GNB) infections. The bacteria isolated were Enterobacterales in 22 patients and Pseudomonas aeruginosa in 2. Sixteen out of 19 isolates showed synergistic activity. Two patients presented clinical failure at day 14, and the 30-day mortality was 17% (4/24). CZA/ATM could be considered an alternative therapy for VIM-type-producing GNB infections.

Ceftolozane/tazobactam for the treatment of XDR Pseudomonas aeruginosa infections.

PURPOSE: The aim of this study was to evaluate the effectiveness of ceftolozane/tazobactam (C/T) for treating extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) infections, and to analyze whether high C/T dosing (2 g ceftolozane and 1 g tazobactam every 8 h) and infection source control have an impact on outcome. METHODS: Retrospective study of all consecutive patients treated with C/T for XDR-PA infection at a tertiary referral hospital (November 2015-July 2017). Main clinical and microbiological variables were analyzed. RESULTS: Thirty-eight patients were included. Median age was 59.5 years and Charlson Comorbidity Index was 3.5. Fourteen (36.8%) patients had respiratory tract infection, six (15.8%) soft tissue, and six (15.8%) urinary tract infection. Twenty-three (60.5%) received high-dose C/T and in 24 (63.2%) C/T was combined with other antibiotics. At completion of treatment, 33 (86.8%) patients showed clinical response. At 90 days of follow-up, 26 (68.4%) achieved clinical cure, and 12 (31.6%) had clinical failure because of persistent infection in one patient, death attributable to the XDR-PA infection in four, and clinical recurrence in seven. All-cause mortality was 5 (13.2%). Lower C/T MIC and adequate infection source control were the only variables significantly associated with clinical cure. CONCLUSIONS: C/T should be considered for treating XDR-PA infections, with infection source control being an important factor to avoid failure and resistance.