The road less travelled: exploring the genomic characteristics and antimicrobial resistance potential of Acinetobacter baumannii from the indigenous Orang Asli community in Peninsular Malaysia

Acinetobacter baumannii is widely recognized as a multidrug-resistant pathogen, but with most public genome datasets biased toward hospital-derived isolates. Little is known about A. baumannii isolates from healthy individuals from the community. This study analysed genome sequences from nine A. baumannii isolates obtained from the upper respiratory tract of the indigenous Orang Asli in their rural community in Peninsular Malaysia. Genomic analysis revealed genetic diversity, including three new Pasteur sequence types (STs) and six novel Oxford STs. One isolate, A. baumannii 19064, belonged to Global Clone 8 (GC8), a lineage linked to clinical infections. Core genome phylogeny showed these community isolates interspersed with clinical isolates from a nearby hospital, indicating potential pathogenicity under suitable conditions. All isolates carried intrinsic blaOXA-51-like carbapenemase and blaADC cephalosporinase genes but remained susceptible to meropenem. Two isolates, A. baumannii 19053 and 19062, were tetracycline-resistant but minocycline-susceptible, and harboured the tet(39)-tetR gene pair within a mobile pdif module on distinct Rep_3-type plasmids. Only one isolate, A. baumannii 19055, is plasmid-free; the rest mainly harboured cryptic plasmids, often containing identifiable pdif modules. These findings highlight the clinical relevance of A. baumannii strains residing in healthy individuals, particularly in isolated communities that are seldom accessible to public health. Despite their remote origins, these isolates possess virulence factors and resistance genes similar to those in hospital settings. This underscores the importance of genomic surveillance of commensal pathogens, and taking this road which is less travelled can offer insights into broader epidemiological trends and guide future public health strategies.