Neglected Drivers of Antibiotic Resistance: Survival of Extended-Spectrum -Lactamase-Producing Pathogenic Escherichia coli from Livestock Waste through Dormancy and Release of Transformable Extracellular Antibiotic Resistance Genes under Heat Treatment

Extended-spectrum & beta;-lactamase(ESBL)-producing Enterobacteriaceae has caused aglobal pandemic with high prevalence in livestock andpoultry, which could disseminate into the environment and humans.To curb this risk, heat-based harmless treatment of livestock wastewas carried out. However, some risks of the bacterial persistencehave not been thoroughly assessed. This study demonstrated that antibiotic-resistantbacteria (ARB) could survive at 55 & DEG;C through dormancy, and simultaneouslytransformable extracellular antibiotic resistance genes (eARGs) wouldbe released. The ESBL-producing pathogenic Escherichiacoli CM1 from chicken manure could enter a dormantstate at 55 & DEG;C and reactivate at 37 & DEG;C. Dormant CM1 hadstronger & beta;-lactam resistance, which was associated with highexpression of & beta;-lactamase genes and low expression of outermembrane porin genes. Resuscitated CM1 maintained its virulence expressionand multidrug resistance and even had stronger cephalosporin resistance,which might be due to the ultra-low expression of the porin genes.Besides, heat at 55 & DEG;C promoted the release of eARGs, some ofwhich possessed a certain nuclease stability and heat persistence,and even maintained their transformability to an Acinetobacterbaylyi strain. Therefore, dormant multidrug-resistantpathogens from livestock waste will still pose a direct health riskto humans, while the resuscitation of dormant ARB and the transformationof released eARGs will jointly promote the proliferation of ARGs andthe spread of antibiotic resistance. Minimalresearch exists on bacterial dormancy in antibiotic-resistantbacteria. This study reports the dormancy strategy of multidrug-resistantbacteria from livestock waste that contributes to the risk of antibioticresistance.