Antimicrobial Resistance Diversity Suggestive of Distinct Salmonella Typhimurium Sources or Selective Pressures in Food-Production Animals

Abstract

Salmonella enterica subsp. enterica serovar Typhimurium is a common cause of enterocolitis in humans globally, with multidrug resistant (MDR) strains posing an enhanced threat. S. Typhimurium is also a pathogen in food-production animals, and these populations can act as reservoirs of the bacterium. Therefore, surveillance and control measures within food-production animal populations are of importance both to animal and human health and have the potential to be enhanced though improved understanding of the epidemiology of S. Typhimurium within and between food-production animal populations. Here, data from Scotland and national surveillance England and Wales data for isolates from cattle ( n = 1115), chickens ( n = 248) and pigs ( n = 2174) collected between 2003 and 2014 were analyzed. Ecological diversity analyses and rarefaction curves were used to compare the diversity of observed antimicrobial resistance (AMR) profiles between the host species, and within host species populations. Higher AMR profile diversity was observed in isolates from pigs compared to chickens across diversity measures and isolates from cattle for three of four diversity measures. Variation in AMR profile diversity between production sectors was noted, with higher AMR diversity of isolates from broiler compared to layer chickens, breeder compared to rearer and finisher pigs and beef compared to dairy cattle. Findings indicate variation in AMR profile diversity both within and between food-production animal host species. These observations suggest alternate sources of AMR bacteria and/or variation in selective evolutionary pressures within and between food-production animal host species populations.

Market Chickens as a Source of Antibiotic-Resistant Escherichia coli in a Peri-Urban Community in Lima, Peru

“…Many reports have identified high levels of AMR in food animals and retail meats in the United States ( Davis et al, 2018 ; Liu et al, 2018 ), China ( Liu et al, 2017 ; Wu et al, 2018 ; He et al, 2019 ), and Europe ( Gelbíčová et al, 2019 ; Mellor et al, 2019 ). Other studies have assessed ARG dissemination between isolates of human, animal, and environmental origin in LMICs ( Nadimpalli et al, 2019 ; Subbiah et al, 2020 ).…”

Investigation of a Salmonellosis Outbreak Caused by Multidrug Resistant Salmonella Typhimurium in China

“…In addition, outbreak strains also showed resistance to NAL. These five antibiotics were the most common antibiotics for which S. Typhimurium exhibited resistance, especially in China Liang et al, 2018;Khan et al, 2019;Mellor et al, 2019). NAL belongs to the first generation of quinolone antibiotics, and many intestinal infecting bacteria have developed resistance to it.…”

“…In recent years, the antibiotic resistance rate of S. Typhimurium has been increasing, making it a global issue of increasing concern that might result in more severe health outcomes (Parisi et al, 2018;Jiu et al, 2020). Some studies have shown that the proportion of multidrug resistant bacteria in S. Typhimurium is very high and the most frequently observed antibiotic resistance patterns are the ASSuT (ampicillin, streptomycin, sulfonamides, and tetracycline) and ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) tetra-and penta-resistant patterns, respectively (Thung et al, 2016;Mellor et al, 2019;Wang et al, 2019). Multidrug resistant S. Typhimurium has brought difficulties to clinical treatment resulting in increased morbidity and mortality.…”

Plasmid-borne colistin resistance gene mcr-1 in a multidrug resistant Salmonella enterica serovar Typhimurium isolate from an infant with acute diarrhea in China

“…Whereafter, the variety of antibiotic resistance patterns have been reported. For example, the ASSuT tetra-(ampicillin, streptomycin, sulfonamides, and tetracycline) and ACSSuT (ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline) penta-resistant patterns are the most commonly reported (Mellor et al, 2019;Thung et al, 2016;Wang et al, 2019). Salmonella 4, [5],12:i:-, a monophasic variant of Salmonella Typhimurium, progressively became an emerging multidrug resistant clade carrying plasmid-mediated resistance genes (Elnekave et al, 2018;Mourao et al, 2014) and the sequence types mostly are ST19 and ST34 (Elnekave et al, 2018;Pernille Gymoese et al, 2017;Sun et al, 2020).…”