Metagenomic Profiling of Soil Microbiomes and Resistomes in Arid Ecosystems of Kuwait

Background/Objective: This study addresses a significant knowledge gap in the literature concerning antibiotic resistance genes (ARGs) in arid soils by employing metagenomic approaches to characterise their diversity, using Kuwait as a model environment. Methods: Soil samples were collected from two agriculturally managed sites (K1 and K3) and one coastal unmanaged site (K2), representing distinct ecological conditions. Results: Taxonomic profiling revealed notable variation in microbial communities at both the phylum and genus levels. Alpha diversity analyses based on the Chao1 and Shannon indices indicated that agricultural soils exhibited greater microbial richness and diversity than the coastal soil. Beta diversity analysis further demonstrated substantial differences in microbial community composition among the sites. Consistent with previous soil microbiome studies, ARGs such as tetA, aac(3)-Ib, sul1, qep, muxB, mexW, mexB, and macB were detected across the sites. However, the identification of distinct clinically relevant resistance genes, including ugd, blaOXA-18, blaCMY-19, blaMOX-7, blaFOX-7, blaLRA-12, and novA, suggests the influence of site-specific or extreme selective pressures. Conclusions: Several of the detected ARGs appear to be rare or previously unreported in soil environments. Although the sample size is too small to support broad generalisations, the detection of ugd in soil is particularly noteworthy, suggesting that soils may serve as reservoirs of polymyxin resistance, potentially undermining the effectiveness of polymyxin antibiotics.