Pathogenicity and virulence of Acinetobacter baumannii: Factors contributing to the fitness in healthcare settings and the infected host

ABSTRACT

Acinetobacter baumannii is a common cause of healthcare-associated infections and hospital outbreaks, particularly in intensive care units. Much of the success of A. baumannii relies on its genomic plasticity, which allows rapid adaptation to adversity and stress. The capacity to acquire novel antibiotic resistance determinants and the tolerance to stresses encountered in the hospital environment promote A. baumannii spread among patients and long-term contamination of the healthcare setting. This review explores virulence factors and physiological traits contributing to A. baumannii infection and adaptation to the hospital environment. Several cell-associated and secreted virulence factors involved in A. baumannii biofilm formation, cell adhesion, invasion, and persistence in the host, as well as resistance to xeric stress imposed by the healthcare settings, are illustrated to give reasons for the success of A. baumannii as a hospital pathogen.

KEYWORDS:

• Acinetobacter baumannii
• desiccation
• metals uptake
• secretion systems
• tolerance
• virulence factors

Acknowledgements

We apologize to those colleagues whose work could not be cited in this paper due to space limitations.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data Availability statement

The authors confirm that the data supporting the findings of this study are available within the article or from the corresponding author [R.Z.] upon request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/21505594.2023.2289769

Additional information

Funding

The authors acknowledge funding support from the Italian Ministry of University and Research (MUR), grants PRIN 2017 (no. 2017SFBER to R.Z. and no. 20177J5Y3P to P.V. and F.I.), grant PRIN 2020 (no. 20208LLXEJ to F.I.) and Excellence Departments grant to the Department of Science of the Roma Tre University (art. 1, comma 314-337 Legge 232/2016), from Regione Lazio (grant no. A0375-2020-36558 GAVAP to P.V.) and from the Rome Technopole (PNRR grant M4-C2-Inv). The authors also acknowledge the support of NBFC to Department of Science of the Roma Tre University (MUR PNRR, Missione 4 Componente 2, “Dalla ricerca all’impresa”, Investimento 1.4, Project CN00000033).