The evolution of carbapenem resistance determinants and major epidemiological lineages among carbapenem‐resistant Acinetobacter baumannii isolates in Germany, 2010‐2019

• Published in: International journal of antimicrobial agents 2022-11, Vol.60 (5-6), p.106689-106689, Article 106689
• Main Authors: Wohlfarth, Esther, Kresken, Michael, Higgins, Paul G, Stefanik, Danuta, Wille, Julia, Hafner, Dieter, Körber-Irrgang, Barbara, Seifert, Harald
• Format: Article
• Language: English
• Subjects: Acinetobacter baumannii - genetics; Acinetobacter baumannii - isolation & purification; Acinetobacter Infections - drug therapy; Acinetobacter Infections - epidemiology; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Bacterial Proteins - genetics; beta-Lactamases - genetics; Carbapenemase; Carbapenems - pharmacology; Carbapenems - therapeutic use; Drug Resistance, Microbial - genetics; Humans; Imipenem - pharmacology; International clone; Microbial Sensitivity Tests; Multilocus Sequence Typing; OXA-23; Surveillance
• ISSN: 0924-8579; 1872-7913
• DOI: 10.1016/j.ijantimicag.2022.106689

•302 Acinetobacter baumannii isolates collected during four multicentre studies conducted in 2010, 2013, 2016 and 2019.•58 isolates were resistant to carbapenems and to most other tested antibiotics, except colistin.•IC2 was the most common clonal lineage in carbapenem-resistant isolates, with blaOXA-23-like the most prevalent class D β-lactamase gene.•Acquired carbapenem resistance determinants identified in clonal lineages IC4, IC7 and IC9.•Carbapenem resistance seems to have decreased in Germany, from 33.3% in 2013 to 13.8% in 2016 and 12.3% in 2019. The aim of this study was to investigate and compare the molecular epidemiology and carbapenem resistance determinants in clinical Acinetobacter baumannii isolates collected during four multicentre surveillance studies conducted by the Paul-Ehrlich-Society for Infection Therapy. Isolates were collected prospectively from hospital in-patients at 17 medical centres in Germany over four periods of three- to six-months starting in October of each of 2010, 2013, 2016 and 2019. Species identification was performed by MALDI-TOF, gyrB multiplex polymerase chain reaction (PCR), and detection of the intrinsic blaOXA-51-like gene. Minimum inhibitory concentrations were determined by broth microdilution. The prevalence of carbapenemase-encoding genes was investigated by OXA-multiplex PCR and whole-genome sequencing. Molecular epidemiology was examined by rep-PCR and core-genome multi-locus sequence typing. A total of 302 A. baumannii isolates were collected. Resistance to imipenem and/or meropenem was detected in 58 isolates (19.2%) from 14 centres. The proportion of carbapenem-resistant isolates increased from 21.3% in 2010 to 33.3% in 2013, and then decreased to 13.8% in 2016 and 12.3% in 2019. Forty-six of these isolates were associated with the international clonal lineage IC2 and five with IC1. The most prevalent carbapenemase gene detected was blaOXA-23-like (n=51). Further carbapenem-resistance determinants were blaOXA-40-like (n=1), blaOXA-58-like (n=3) and blaNDM-1 (n=2). In one isolate, ISAba1 was detected upstream of blaOXA-51-like. In conclusion, IC2 was the most prevalent clonal lineage detected in this study. Interestingly, in Germany, carbapenem resistance seems to have decreased in A. baumannii between 2013 and 2019.