Acinetobacter dijkshoorniae is a bacterial species within the genus Acinetobacter, belonging to the Acinetobacter calcoaceticus–baumannii (ACB) complex. The species was formally described in 2017 following polyphasic taxonomic analysis that combined phenotypic characteristics, multilocus sequence typing, and whole‑genome sequencing to differentiate it from closely related members of the complex, such as A. baumannii, A. pittii, and A. nosocomialis.
Taxonomy
- Domain: Bacteria
- Phylum: Proteobacteria
- Class: Gammaproteobacteria
- Order: Pseudomonadales
- Family: Moraxellaceae
- Genus: Acinetobacter
- Species: Acinetobacter dijkshoorniae
Key characteristics
- Gram‑negative, non‑motile, aerobic rods.
- Non‑fermentative metabolism; oxidase‑negative and catalase‑positive.
- Typically grows on standard laboratory media at 30–37 °C.
Clinical relevance
Acinetobacter dijkshoorniae has been isolated from human clinical specimens, including respiratory secretions, wound exudates, and blood cultures. Isolates are often associated with healthcare‑associated infections, particularly in intensive‑care settings. Like other members of the ACB complex, strains may exhibit multidrug resistance, including resistance to β‑lactam antibiotics and, in some cases, carbapenems, mediated by acquired β‑lactamase genes (e.g., OXA‑type enzymes). Accurate identification of A. dijkshoorniae generally requires molecular methods such as sequencing of housekeeping genes (e.g., rpoB, gyrB) or whole‑genome analysis, as conventional biochemical panels may not reliably distinguish it from other ACB complex species.
Epidemiology
Reports of A. dijkshoorniae are less frequent than for A. baumannii, reflecting both its more recent recognition as a distinct species and the challenges of precise identification. Surveillance data indicate that it is part of the diverse Acinetobacter population contributing to nosocomial infection burdens, particularly in regions with high antimicrobial‑use pressure.
Research and diagnostics
The delineation of A. dijkshoorniae underscores the importance of advanced taxonomic tools in clinical microbiology. Its genome has been sequenced, providing a basis for comparative studies on virulence factors, resistance determinants, and phylogenetic relationships within the ACB complex. Continued monitoring of its prevalence and resistance patterns is essential for informing infection‑control strategies and antimicrobial stewardship programs.
