Acinetobacter baumannii

View Large Image Figure ViewerDownload Hi-res image Download (PPT)KEY FACTS:Isolation of extensively resistant and pan-drug-resistant strains ranked as 'high priority' by the WHO (global priority list of antibiotic-resistant bacteria to guide research, discovery and development of new antibiotics, 2017) and the CDC (antibiotic resistance threats in the USA, 2019).Belongs to the 'ESKAPE' group of most problematic nosocomial pathogens.Resistant to desiccation, disinfectant, oxidative stress, and complement-mediated killing.First described as a fast-growing extracellular bacterium; several strains show a potential for intracellular growth in eukaryotic cells.High genetic diversity; rapidly evolving bacteria, with some isolates competent for natural transformation.Lipooligosaccharide instead of classical lipopolysaccharide, with 14 variants identified so far.At least 128 polysaccharide capsule types identified so far.Presence of several secretion systems (SSs): T1SS, T2SS, and T6SS, but absence of T3SS and T4SS usually found in Gram-negative pathogens.Phenotypic heterogeneity by 'phase variation' within clonal populations, with virulent opaque and capsulated (VIR-O) and avirulent translucent and less capsulated (AV-T) types identified.DISEASE FACTS:Nosocomial, community-acquired, and opportunistic infections.Broad infection sites [skin and soft tissue, urinary tract, digestive and respiratory tracts, blood, central nervous system (meningitis), etc.].Can thrive in hospital settings, with a peculiar virulence based on a ‘persist and resist’ strategy.Infection routes and factors favoring infections: colonization of mechanical devices such as catheters and ventilation equipment, open wounds, major trauma or burns, prolonged hospital stays, and immunocompromisation.Therapeutic dead end because of last-resort antibiotic resistance.TAXONOMY AND CLASSIFICATION:KINGDOM: BacteriaPHYLUM: ProteobacteriaCLASS: GammaproteobacteriaORDER: PseudomonadalesFAMILY: MoraxellaceaeGENUS: AcinetobacterSPECIES: Acinetobacter baumanniiDeclaration of interestsNo interests were declared. KEY FACTS:Isolation of extensively resistant and pan-drug-resistant strains ranked as 'high priority' by the WHO (global priority list of antibiotic-resistant bacteria to guide research, discovery and development of new antibiotics, 2017) and the CDC (antibiotic resistance threats in the USA, 2019).Belongs to the 'ESKAPE' group of most problematic nosocomial pathogens.Resistant to desiccation, disinfectant, oxidative stress, and complement-mediated killing.First described as a fast-growing extracellular bacterium; several strains show a potential for intracellular growth in eukaryotic cells.High genetic diversity; rapidly evolving bacteria, with some isolates competent for natural transformation.Lipooligosaccharide instead of classical lipopolysaccharide, with 14 variants identified so far.At least 128 polysaccharide capsule types identified so far.Presence of several secretion systems (SSs): T1SS, T2SS, and T6SS, but absence of T3SS and T4SS usually found in Gram-negative pathogens.Phenotypic heterogeneity by 'phase variation' within clonal populations, with virulent opaque and capsulated (VIR-O) and avirulent translucent and less capsulated (AV-T) types identified. Isolation of extensively resistant and pan-drug-resistant strains ranked as 'high priority' by the WHO (global priority list of antibiotic-resistant bacteria to guide research, discovery and development of new antibiotics, 2017) and the CDC (antibiotic resistance threats in the USA, 2019). Belongs to the 'ESKAPE' group of most problematic nosocomial pathogens. Resistant to desiccation, disinfectant, oxidative stress, and complement-mediated killing. First described as a fast-growing extracellular bacterium; several strains show a potential for intracellular growth in eukaryotic cells. High genetic diversity; rapidly evolving bacteria, with some isolates competent for natural transformation. Lipooligosaccharide instead of classical lipopolysaccharide, with 14 variants identified so far. At least 128 polysaccharide capsule types identified so far. Presence of several secretion systems (SSs): T1SS, T2SS, and T6SS, but absence of T3SS and T4SS usually found in Gram-negative pathogens. Phenotypic heterogeneity by 'phase variation' within clonal populations, with virulent opaque and capsulated (VIR-O) and avirulent translucent and less capsulated (AV-T) types identified. DISEASE FACTS:Nosocomial, community-acquired, and opportunistic infections.Broad infection sites [skin and soft tissue, urinary tract, digestive and respiratory tracts, blood, central nervous system (meningitis), etc.].Can thrive in hospital settings, with a peculiar virulence based on a ‘persist and resist’ strategy.Infection routes and factors favoring infections: colonization of mechanical devices such as catheters and ventilation equipment, open wounds, major trauma or burns, prolonged hospital stays, and immunocompromisation.Therapeutic dead end because of last-resort antibiotic resistance. Nosocomial, community-acquired, and opportunistic infections. Broad infection sites [skin and soft tissue, urinary tract, digestive and respiratory tracts, blood, central nervous system (meningitis), etc.]. Can thrive in hospital settings, with a peculiar virulence based on a ‘persist and resist’ strategy. Infection routes and factors favoring infections: colonization of mechanical devices such as catheters and ventilation equipment, open wounds, major trauma or burns, prolonged hospital stays, and immunocompromisation. Therapeutic dead end because of last-resort antibiotic resistance. TAXONOMY AND CLASSIFICATION:KINGDOM: BacteriaPHYLUM: ProteobacteriaCLASS: GammaproteobacteriaORDER: PseudomonadalesFAMILY: MoraxellaceaeGENUS: AcinetobacterSPECIES: Acinetobacter baumannii KINGDOM: Bacteria PHYLUM: Proteobacteria CLASS: Gammaproteobacteria ORDER: Pseudomonadales FAMILY: Moraxellaceae GENUS: Acinetobacter SPECIES: Acinetobacter baumannii Declaration of interestsNo interests were declared. No interests were declared.