Understanding the Mechanism of Antimicrobial Resistance and Pathogenesis of Salmonella enterica Serovar Typhi

Abstract

Salmonella enterica serovar Typhi (S. Typhi) is a Gram-negative pathogen that causes typhoid fever in humans. Though many serotypes of Salmonella spp. are capable of causing disease in both humans and animals alike, S. Typhi and S. Paratyphi are common in human hosts only. The global burden of typhoid fever is attributable to more than 27 million cases each year and approximately 200,000 deaths worldwide, with many regions such as Africa, South and Southeast Asia being the most affected in the world. The pathogen is able to cause disease in hosts by evading defense systems, adhesion to epithelial cells, and survival in host cells in the presence of several virulence factors, mediated by virulence plasmids and genes clustered in distinct regions known as Salmonella pathogenicity islands (SPIs). These factors, coupled with plasmid-mediated antimicrobial resistance genes, enable the bacterium to become resistant to various broad-spectrum antibiotics used in the treatment of typhoid fever and other infections caused by Salmonella spp. The emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains in many countries of the world has raised great concern over the rise of antibiotic resistance in pathogens such as S. Typhi. In order to identify the key virulence factors involved in S. Typhi pathogenesis and infection, this review delves into various mechanisms of virulence, pathogenicity, and antimicrobial resistance to reinforce efficacious disease management.

Surveys on Pet-Reptile-Associated Multi-Drug-Resistant Salmonella spp. in the Timișoara Metropolitan Region—Western Romania

“…Six percent of human Salmonellosis cases are acquired after interactions with reptiles, and the intimate contact between reptiles and their owners creates favorable conditions for the transfer of zoonotic pathogen infections [1][2][3]. In addition, Salmonella strains discovered from pet reptiles have been linked to antibiotic resistance, one of the most serious health issues of the twenty-first century that may have therapeutic repercussions for reptile owners and breeders [1,[4][5][6].…”

“…Salmonella causes serious illness in people and animals [3,7]. A wide range of Salmonella species are ubiquitous in various environments, harboring the capacity to induce infections in both humans and animals [4,8]. Salmonella can occasionally cause more severe illnesses such as bacteremia (with or without metastatic disease), skin and bone infections, UTIs, meningitis, osteomyelitis, and splenic abscesses [7][8][9][10][11][12][13].…”

“…Therefore, it is imperative that all reptiles maintained as pets be viewed as a potential reservoir for human infection, and one must acknowledge their contribution to the increased risk of therapeutic failure in Salmonellosis cases with possibly fatal outcomes in both human and veterinary medicine [3,4]. Despite the rise in the popularity of snakes and lizards as pets worldwide, the true prevalence of Salmonella in the pet trade is likely under-reported due to the lack of studies examining this topic in depth.…”

Design, pharmacokinetic profiling, and assessment of kinetic and thermodynamic stability of novel anti-Salmonella typhi imidazole analogues

“…In this study, we are aiming at the application of in silico techniques to design highly potent, non-toxic, kinetic and thermodynamically stable novel imidazole-based inhibitors of SipA protease of Salmonella typhi, an effector protein of the bacterium crucial to its virulence and pathogenicity. SipA is type-3 secretion protein that enables the bacterium to survive the harsh conditions of the extracellular milieu of the small intestine of the host, due to factors such as low pH, shear stress due to mucosal secretions or blood and host defense mechanisms and subsequently invade the intestines of its host and gains entry into the tissues where it replicates rapidly and manifest varying degree of virulence (Birhanu et al 2021(Birhanu et al , 2018Khan and Shamim 2022). Despite the enormous antibacterial properties of imidazole-based compounds, no in silico investigation of its antibacterial properties Ameji et al Bulletin of the National Research Centre (2023) 47:6 against Salmonella typhi has been carried out to the best of our knowledge.…”

Effectiveness test of African leaf ethanol extract against Salmonella typhi bacteria

“…These bacteria enter the human body through contaminated food and drink. Salmonella typhi is capable of causing a large number of infections in humans, including typhoid fever (enteric fever), focal systemic infections, septicemia, and gastroenteritis which varies in the form of diarrhea and dysentery [9].…”