Acinetobacter baumannii NCIMB8209: a rare environmental strain displaying extensive insertion sequence-mediated genome remodeling resulting in the loss of exposed cell structures and defensive mechanisms
Acinetobacter baumannii represents nowadays an important nosocomial pathogen of poorly defined reservoirs outside the clinical setting. Here, we con ducted whole-genome sequencing analysis of the Acinetobacter sp. NCIMB8209 col lection strain, isolated in 1943 from the aerobic degradation (retting)...
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| Autores principales: | , , , , , , |
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| Formato: | publishedVersion |
| Lenguaje: | Inglés |
| Publicado: |
American Society for Microbiology
2021
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| Materias: | |
| Acceso en línea: | http://hdl.handle.net/2133/20524 http://hdl.handle.net/2133/20524 |
| Aporte de: |
| Sumario: | Acinetobacter baumannii represents nowadays an important nosocomial
pathogen of poorly defined reservoirs outside the clinical setting. Here, we con ducted whole-genome sequencing analysis of the Acinetobacter sp. NCIMB8209 col lection strain, isolated in 1943 from the aerobic degradation (retting) of desert gu ayule shrubs. Strain NCIMB8209 contained a 3.75-Mb chromosome and a plasmid of
134 kb. Phylogenetic analysis based on core genes indicated NCIMB8209 affiliation
to A. baumannii, a result supported by the identification of a chromosomal blaOXA 51-like gene. Seven genomic islands lacking antimicrobial resistance determinants, 5
regions encompassing phage-related genes, and notably, 93 insertion sequences (IS)
were found in this genome. NCIMB8209 harbors most genes linked to persistence
and virulence described in contemporary A. baumannii clinical strains, but many of
the genes encoding components of surface structures are interrupted by IS. More over, defense genetic islands against biological aggressors such as type 6 secretion
systems or CRISPR-cas are absent from this genome. These findings correlate with a
low capacity of NCIMB8209 to form biofilm and pellicle, low motility on semisolid
medium, and low virulence toward Galleria mellonella and Caenorhabditis elegans.
Searching for catabolic genes and concomitant metabolic assays revealed the ability
of NCIMB8209 to grow on a wide range of substances produced by plants, including
aromatic acids and defense compounds against external aggressors. All the above
features strongly suggest that NCIMB8209 has evolved specific adaptive features to
a particular environmental niche. Moreover, they also revealed that the remarkable
genetic plasticity identified in contemporary A. baumannii clinical strains represents
an intrinsic characteristic of the species. |
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