Acinetobacter calcoaceticus is a nonfermenting, Gram-negative, aerobic coccobacilli,
belonging to the genus of bacteria known as Acinetobacter and to the Moraxellaceae
family. The genus Acinetobacter includes more than 50 species .
Together with the species A. baumannii, A. dijkshoorniae, A. nosocomialis, A. pittii and A. seifertii, A. calcoaceticus forms part of the so-called Acinetobacter-calcoaceticus-A.- baumannii complex (the ACB complex). The species that make up the ACB complex are more closely related than other species of Acinetobacter and are phenotypically very similar .
It is not usually possible to differentiate between the individual species using routine identification programs . In cases where Acinetobacter calcoaceticus is detected, it is not possible to rule out confusion with the clinically most important representative of the ACB complex, A. baumannii .
Acinetobacter calcoaceticus has only rarely been isolated from human clinical specimens (e.g. sputum). Its involvement in clinical infections therefore remains unclear.
The clinical pictures relate to cases of:
A. calcoaceticus is an environmental pathogen found primarily in soil and water. The bacterium has also been detected in wastewater and on human skin, as well as on animals and vegetables .
Relevance of pathogen in transmission in endoscopy
Gastroenterology: Not relevant
Ear, nose, and throat: Not relevant
Urology: Not relevant
Relevance for endoscope surveillance
High concern organism
Resistance to antibiotics
The individual species of the A. calcoaceticus-A. baumannii complex (ACB) are difficult to distinguish from one another based on their phenotypic characteristics. A. calcoaceticus can usually be ruled out when resistance patterns are investigated . Two studies conducted in China have identified clinical isolates with the resistance gene blaNDM-1 on plasmids . This gene enables the production of the New Delhi metallo-betalactamase (NDM-1) enzyme, which inactivates antibiotics of the carbapenem class. The resistance gene can be transferred to other species and contribute to the further spread of antibiotic-resistant strains of bacteria.
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