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

Abstract

The survival, proliferation, and epidemic spread of Acinetobacter baumannii (A. baumannii) in hospital settings is associated with several characteristics, including resistance to many commercially available antibiotics as well as the expression of multiple virulence mechanisms. This severely limits therapeutic options, with increased mortality and morbidity rates recorded worldwide. The World Health Organisation, thus, recognises A. baumannii as one of the critical pathogens that need to be prioritised for the development of new antibiotics or treatment. The current review will thus provide a brief overview of the antibiotic resistance and virulence mechanisms associated with A. baumannii’s “persist and resist strategy”. Thereafter, the potential of biological control agents including secondary metabolites such as biosurfactants [lipopeptides (surfactin and serrawettin) and glycolipids (rhamnolipid)] as well as predatory bacteria (Bdellovibrio bacteriovorus) and bacteriophages to directly target A. baumannii, will be discussed in terms of their in vitro and in vivo activity. In addition, limitations and corresponding mitigations strategies will be outlined, including curtailing resistance development using combination therapies, product stabilisation, and large-scale (up-scaling) production.

Prevalence of biofilm producing Acinetobacter baumannii clinical isolates: A systematic review and meta-analysis

“…Evidences report revealed that biofilm-producing A.baumannii nosocomial isolates are so common. The survival, proliferation, and epidemic spread of the biofilm-producing A. baumannii in hospital settings, which results in resistance to many commercially available antibiotics and the expression of numerous virulence mechanisms, can be linked to the alarmingly increased prevalence of this organism [1,48]. This is because the biofilm encourages microbial adhesion and long-term survival on biotic and abiotic surfaces, which contributes to chronic and persistent infections, antimicrobial resistance, and strong survival in the hospital environment, particularly from immunocompromised patients in intensive care units [1,2].…”

Evaluation of Potential Factors Influencing the Dissemination of Multidrug-Resistant Klebsiella pneumoniae and Alternative Treatment Strategies

“…Owing to this, efforts are currently being made on research in alternative antimicrobials which complement antibiotic therapy and help combat the further development and spread of resistance in the future [ 96 ]. Accordingly, particular focus has been awarded to biological control strategies due to their low resistant frequencies, environmentally friendly, cost effective, and self-sustaining abilities [ 97 ]. The review further highlights the alternative control strategies including plant extracts and microbially synthesised secondary metabolites such as biosurfactants against antibiotic-resistant K. pneumoniae .…”

Emergence ofAcinetobacter baumanniiInternational Clone 10 predominantly found in the Middle East

“…Acinetobacter baumannii is a Gram-negative bacterium that, over the last four decades, has become one of the most frequently encountered and problematic human opportunistic pathogens, largely due to its antimicrobial resistance profile 1 . As a cause of hospital-acquired infections, A .…”