An overview of Acinetobacter baumannii pathogenesis: Motility, adherence and biofilm formation

Genomic Diversity of Bacteriophages Infecting the Genus Acinetobacter

“…Due to an ability to persist for long periods in the environment and to develop resistance to multiple antibiotic classes, including broad spectrum beta-lactams such as third generation cephalosporins and carbapenems, fluoroquinolones, Viruses 2022, 14, 181 2 of 25 aminoglycosides, tigecycline, and colistin, extensively drug-resistant and even pan-drug resistant strains are emerging in clinical settings worldwide [4,5]. Infections caused by A. baumannii are more common in intensive care units and surgical wards, manifesting as ventilator-associated pneumonia or bacteraemia but also as soft-tissue injury and urinary tract and gastrointestinal infections [6,7].…”

Biological Control of Acinetobacter baumannii: In Vitro and In Vivo Activity, Limitations, and Combination Therapies

“…Through the implementation of numerous surface and extracellular-associated structures, A. baumannii is also able to form biofilms, which has been characterised as a major virulence factor contributing to the bacterium’s pathogenicity [ 6 , 50 ]. Biofilm formation has also been associated with increased pathogenicity, with Khalil et al [ 51 ] reporting on an increased killing rate (50 to 90%), observed in a larva ( G. mellonella ) model, by strong biofilm-forming A. baumannii strains in comparison to moderate and weak biofilm-forming strains.…”

“…Two Bap-like proteins (BLP: BLP1 and BLP2) have also been identified in different A. baumannii strains, facilitating both adherence and biofilm formation on bronchial epithelial (A549) cells [ 53 ] ( Figure 1 ). Moreover, extracellular polymeric substances form part of A. baumannii biofilms and are composed of poly-β-(1-6)-N-acetylglucosamine and extracellular DNA, providing structural support and intracellular connectors, which allows for biofilm formation under diverse environmental conditions [ 6 ]. Biofilm formation and maintenance have also been associated with intracellular communication, mediated by 3′,5′-cyclic diguanylic acid and quorum sensing, which is facilitated by AtaI autoinducer synthase and the AbaR cognate receptor [ 50 ] ( Figure 1 ).…”

“…Moreover, the extensive resistome of A. baumannii hampers the efficacy of mono-therapeutic options, and while antibiotic combination therapies have been shown to exhibit in vitro and in vivo activity against various antibiotic-resistant strains, clinical trials have not provided sufficient data to confirm that combination therapies are superior for the treatment of A. baumannii infections [ 5 ]. In addition, A. baumannii ’s virulome, including cellular envelope factors, outer membrane proteins, secretion systems, phospholipases, as well as biofilm formation, allows it to persist under unfavourable environmental conditions for extended time periods, enhancing the colonisation and subsequent infection of susceptible hosts [ 6 ].…”

Role of some proteins in resistance of clinical Acinetobacter baumannii isolates to imipenem

“…The emergence of A.baumannii astonished the world as one of the many pathogens and its unique ability to acquire genes that are resistant to a number of treatments, enabling it to cause mutations in the resistance. In Iraq, the bacteria entered through the wounded and burns of soldiers in 2003 because it is extensive in patients whose immunity is reduced, That's why it was called Iraq's bacteria ( Mea et al,2021). Acinetobacter baumannii is considered a tool that threatens global health, and this was announced and confirmed by the American Infectious Diseases Association, the World Health Organization, and the Center for Disease Control and Prevention (CDC), where it was found that it has resistance to many treatments, which enables it to this danger (Rello et al, 2018).One of the ESKAPE pathogens that causes lung infections, pneumonia, and urinary tract infections is Acinetobacter baumannii.…”