Relationship between virulence and antimicrobial resistance in Acinetobacter baumannii
Acinetobacter baumannii is often isolated in nosocomial infections, currently it is been related with severe community-acquired infections. The ability to colonize diverse habitats as well as its versatile metabolism make A. baumanni a troublesome pathogen. In the last years there is been an increase of nosocomial infections due to A. baumannii, such as sepsis, pneumonia and meningitis. This infections appears as outbreaks, dominated by multidrug-resistance epidemics clones generating an increase in morbidity and mortality rates. Most affected wards are Intensive Care Units, where massive antibiotics use might select new multidrug-resistant strains. Due A. baumannii has emerged as serious problem in Europe, United States and Latin America including Colombia, to find out the pathogenesis mechanisms and antibiotics resistance as factors that contribute to this health problem is necessary.
Both, the acquisition of virulence factors and antibiotics resistance determinants explain the pathogenic capacity of this bacteria; particulary the presence of pathogenicity Islands (PAIs) , which contain genes that confer multidrug-resistant and are directly responsible to carry genes involve in pathogenic mechanism as: iron upatke system, biofilm formation on abiotic surfaces, Outer membrane protein 38 production (OMP 38) and the Type Four Secretion System, which has been decribed as responsible for the pathogenesis of this microorganism. This paper reviews the current situation of the nosocomials infections caused by A. baumannii, the main mechanisms of drugs resistance and their association with pathogenicity. Understanding of the elements involved in the pathogenesis of A. baumannii will enable to establish mechanisms to control its dissemination.
