Environmental and physiological factors influencing the survival of resistant Salmonella under infection-related gut conditions

SUMMARYThe human gastrointestinal tract is a dynamic and complex ecosystem that plays a pivotal role in maintaining host health and regulating microbial homeostasis. This environment significantly impacts the survival and evolution of antimicrobial-resistant organisms. Various innate factors, including pH, temperature, osmotic stress, oxygen levels, host secretions, immune response, bile salts, and nutrient gradients, influence microbial behavior, interspecies interactions, and the spread of resistance genes to ensure successful colonization. The potential of the bacteria to avoid or overcome the antimicrobial defenses of the host is one of the most crucial phases in establishing an infection. The behavior of the bacteria in the presence of host physiological parameters and antibiotics will aid in unraveling the survival strategies and mechanisms of resistance in light of the alarming rise in multidrug-resistant gut pathogens and the absence of a licensed vaccine for non-typhoidal Salmonella infections. Uncovering key genetic interactions between the host gut environment and bacterial virulence traits, as well as resistance patterns, is critical in identifying new targets for drugs, target-specific treatment, and new drug or vaccine development, thereby improving treatment options for chronic and recurring infections by Salmonella. This review explores the interplay between gut environmental conditions and the persistence, acquisition, and horizontal transfer of drug resistance traits in Salmonella.