High incidence of pandrug-resistant Acinetobacter baumannii isolates collected from patients with ventilator-associated pneumonia in Greece, Italy and Spain as part of the MagicBullet clinical trial

Abstract

ObjectivesTo investigate the molecular epidemiology, antimicrobial susceptibility and carbapenem resistance determinants of Acinetobacter baumannii isolates from respiratory tract samples of patients diagnosed with ventilator-associated pneumonia (VAP) who were enrolled in the MagicBullet clinical trial.Methods A. baumannii isolates were prospectively cultured from respiratory tract samples from 65 patients from 15 hospitals in Greece, Italy and Spain. Susceptibility testing was performed by broth microdilution. Carbapenem resistance determinants were identified by PCR and sequencing. Molecular epidemiology was investigated using rep-PCR (DiversiLab) and international clones (IC) were identified using our in-house database.ResultsOf 65 isolates, all but two isolates (97%) were resistant to imipenem and these were always associated with an acquired carbapenemase, OXA-23 (80%), OXA-40 (4.6%), OXA-58 (1.5%) or OXA-23/58 (1.5%). Resistance to colistin was 47.7%. Twenty-two isolates were XDR, and 20 isolates were pandrug-resistant (PDR). The majority of isolates clustered with IC2 (n = 54) with one major subtype comprising isolates from 12 hospitals in the three countries, which included 19 XDR and 16 PDR isolates.ConclusionsCarbapenem resistance rates were very high in A. baumannii recovered from patients with VAP. Almost half of the isolates were colistin resistant, and 42 (64.6%) isolates were XDR or PDR. Rep-PCR confirmed IC2 is the predominant clonal lineage in Europe and suggests the presence of an epidemic XDR/PDR A. baumannii clone that has spread in Greece, Italy and Spain. These data highlight the difficulty in empirical treatment of patients with A. baumannii VAP in centres with a high prevalence of carbapenem-resistant A. baumannii.

Investigation of carbapenemases and aminoglycoside modifying enzymes of Acinetobacter baumannii isolates recovered from patients admitted to intensive care units in a tertiary-care hospital in Brazil

“…This species is an important agent related to mechanical ventilator-associated pneumonia (VAP), contracted from colonized patients, environmental surfaces, and other unknown sources 8 . In the present study, the respiratory tract was the most important source of CR A. baumannii, which is in accordance with several other countries 9 . The second greatest source of bacteria was catheter tips, which could be indicative of bloodstream infections; or contamination, as previous study reportedy 10 All the CR A. baumannii were positive for bla OXA-51-like and bla OXA-23-like genes, and the detection of bla OXA-51-like confirmed the species identity in all isolates 11 .…”

Evaluation of synergistic effect of tazobactam with meropenem and ciprofloxacin against multi-drug resistant Acinetobacter baumannii isolated from burn patients in Tehran

“…Moreover, Mohammadi et al reported similar results among hospitalized patients with burn infection in 2016 in Iran [32]. Therefore, it is not surprising that Chen et al in 2017 in China, Uwingabiye et al in 2017 in Morocco, and Nowak et al in 2017 in Greece, Italy, and Spain reported similar results in their investigations [33], [34], [35]. The percentage of bla OXA-24-like genes, which encode acquired carbapenemases, was 93.6% in the present study, followed by bla OXA-40-like with 48.9%.…”

In Vitro Activity of Eravacycline in Combination with Colistin Against Carbapenem-Resistant A. baumannii Isolates

“…In accordance with the previous studies, eravacycline MIC values ranged from 0,5-4 mg/L for OXA-23 and OXA-51 producing CRAB strains in our study. Considering the prevalence of OXA-type carbapenemase activity in CRAB strains, eravacycline has been evaluated as a good treatment option (20–22). However, some type of carbapenemase activity, increased expression of the efflux pumps and the presence of tigecycline resistance are associated with increasing MIC values for eravacycline (1, 3).…”