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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #427349
Research Project: Elucidating the Factors that Determine the Ecology of Human Pathogens in Foods

Location: Produce Safety and Microbiology Research

Title: Pangenomics of high-risk international clones in Acinetobacter baumannii identifies distinctive virulence and antimicrobial resistance profiles

Author
item OROZCO-OCHOA, ALMA - Center For Research In Food And Development (CIAD)
item Quinones, Beatriz
item Lee, Bertram
item GONZALEZ-GOMEZ, JEAN - Center For Research In Food And Development (CIAD)
item LIRA-MORALES, JUAN DANIEL - Center For Research In Food And Development (CIAD)
item CASTRO-DEL CAMPO, NOHELIA - Center For Research In Food And Development (CIAD)
item VALDEZ-TORRES, JOSE - Center For Research In Food And Development (CIAD)
item CHAIDEZ-QUIROZ, CRISTÓBAL - Center For Research In Food And Development (CIAD)

Submitted to: Archives of Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2026
Publication Date: 2/2/2026
Citation: Orozco-Ochoa, A.K., Quinones, B., Lee, B.G., Gonzalez-Gomez, J.P., Lira-Morales, J., Castro-del Campo, N., Valdez-Torres, J.B., Chaidez-Quiroz, C. 2026. Pangenomics of high-risk international clones in Acinetobacter baumannii identifies distinctive virulence and antimicrobial resistance profiles. Archives of Microbiology. 208. Article 173. https://doi.org/10.1007/s00203-026-04738-4.
DOI: https://doi.org/10.1007/s00203-026-04738-4

Interpretive Summary: Antimicrobial resistance represents a critical issue to public health and food safety. Acinetobacter baumannii is an opportunistic bacterial pathogen and a leading causative agent of nosocomial human infections worldwide. Previous studies have identified A. baumannii in sources such as water, soil, and air, as well as food. A. baumannii has been prioritized as a diagnostic target due to its ability to evade most antibiotics in clinical settings. Given the increasing prevalence of resistant strains, the present study conducted comparative genomic and phenotypic analyses to characterize high-risk international clones with the ultimate goal of expanding the limited treatment options against this opportunistic pathogen.

Technical Abstract: Acinetobacter baumannii is an emerging and opportunistic bacterial pathogen and is considered a critical threat to global public health due to the extensive antimicrobial resistance. The present study conducted comparative pangenomics on a collection of A. baumannii from distinct geographical locations and clinical sources to further identify the key determinants conferring a virulence potential to this bacterial pathogen. The phylogenomic analyses revealed three distinct evolutionary clades belonging to nine distinct sequence types and associated with the international clones IC2, IC5, IC1, IC7, and non-classified groups. In particular, the A. baumannii isolates from Mexico had significant relatedness to the highly prevalent European IC2, Latin American IC5 and cosmopolitan clones. Resistome studies in the examined A. baumannii strain collection showed that a wide array of markers, consistently detected across all genomes, were conferring resistance to intrinsic and acquired beta-lactamases, aminoglycoside, fluoroquinolones, chloramphenicol, macrolides, tetracyclines, and sulfonamides. Phenotypic studies on antimicrobial susceptibility confirmed multidrug resistance against the examined antibiotics in A. baumannii strains with an enhanced ability in biofilm formation. The characterization of multidrug-resistant A. baumannii clinical clones that are widely prevalent and globally distributed established a foundation for the subsequent development of novel intervention strategies.