Akademik Veri Yönetim Sistemi
ENVIRONMENTAL POLLUTION, cilt.396, 2026 (SCI-Expanded, Scopus)
K & imath;z & imath;l & imath;rmak River is the longest in T & uuml;rkiye poses a potential contamination risk due to its use in intensive agriculture and livestock farming. This study characterizes Aeromonas spp. isolated from the K & imath;z & imath;l & imath;rmak River by analyzing their antibiotic and heavy metal resistance profiles, virulence genes, biofilm formation, and genetic relatedness, including whole-genome sequencing of selected isolates. From 78 water samples collected across seven villages, 40 Aeromonas isolates were identified. A. veronii was the predominant species (85%), followed by A. hydrophila and A. eucrenophila. Phenotypic testing showed high carbapenem resistance, with 83% of isolates resistant to ertapenem and 50% to imipenem, and 52.5% of isolates classified as multidrug-resistant. The MAR index of 27 isolates exceeded the 0.2 threshold indicating high-risk contamination sources. Colistin MICs reached 16 mu g/mL, especially in A. hydrophila isolates, and this was supported by the frequent detection of mcr-5 (100%) and mcr-3/7 (90%). Virulence genes act, aerA, and alt were highly prevalent, and biofilm assays revealed that 90% of the isolates exhibited moderate to strong biofilm formation. Heavy metal tolerance was observed, especially to copper, and this was supported by both MIC testing and PCR. Whole-genome sequencing of four selected A. veronii and A. hydrophila isolates revealed diverse resistance genes (including cphA, adeF, and OXA variants), chromosomally encoded virulence factors (T3SS, T4SS, T6SS) and mobile genetic elements. These findings suggest that Aeromonas spp. in the K & imath;z & imath;l & imath;rmak River act as potential transmission routes for clinically relevant virulence traits, antimicrobial and heavy metal resistance, emphasizing the need for enhanced monitoring of aquatic environments impacted by agricultural and livestock-related contamination.