Acinetobacter baumannii as a causative agent of health care associated infections

Acinetobacter baumannii is an opportunistic pathogen that seriously affects sick patients, causing Health Care Associated Infections (HCAI) such as pneumonia associated with mechanical ventilation, urinary tract infections and bacteremia, in recent years this bacterium has become a health problem worldwide, its isolation from infections present in hospitalized patients has been increasing, and it also has various mechanisms of resistance to antibiotics. The present documentary research aims to describe the mechanisms of pathogenicity and resistance to antibiotics used by Acinetobacter baumannii as a causal agent of HCAI. To carry out this work, a literature search was carried out in databases such as: Scielo, PubMed, NCBI, and Elsevier. The pathogenicity mechanisms that allow it to colonize and develop infections in hospitalized patients are: porins, biofilms, pili, lipopolysaccharides, phospholipases, outer membrane vesicles and the production of siderophores. It has enzymatic resistance mechanisms such as beta-lactamases and non-enzymatic mechanisms such as porin modification, efflux pumps, and modifications in DNA gyrase. There are extrinsic factors that favor the development of HCAI, such as the immunological and health condition of the patient, as well as the association with medical equipment. Studies carried out between the years 2005 to 2018 reveal that A. baumannii is one of the main causative agents of pneumonia associated with mechanical ventilation in patients admitted to the Intensive care unit.