Intensified livestock farming increases antibiotic resistance genotypes and phenotypes in animal feces

Abstract

Animal feces from livestock farming can be a major source of antibiotic resistance to the environment, but a clear gap exists on how the resistance reservoir in feces alters as farming activities intensify. Here, we sampled feces from eight Chinese farms, where yak, sheep, pig, and horse were reared under free-range to intensive conditions, and determined fecal resistance using both genotype and phenotype approaches. Animals reared intensively exhibited increased diversity of antibiotic resistance genes and greater resistance phenotypes in feces, which were cross-correlated. Furthermore, at the metagenome contig level, antibiotic resistance genes were co-located with mobile genetic elements at a higher frequency (27.38%) as farming intensified, with associated resistance phenotypes being less coupled with bacterial phylogeny. Intensified farming also expanded the multidrug resistance preferentially carried on pathogens in fecal microbiomes. Overall, farming intensification can increase antibiotic resistance genotypes and phenotypes in domestic animal feces, with implications for environmental health.

Understanding Anaerobic Co-digestion of Organic Wastes through Meta-Analysis

“…For example, SL often contains high levels of FOG (50% dw) and protein (37% dw), depending on the source (Table S2). Additionally, antibiotic resistance genes (ARGs) are commonly found in AM, , SL, and wastewater due to the extensive use of antibiotics and antiparasitic drugs in animal husbandry. , Therefore, AD of these waste streams, particularly under thermophilic conditions, can mitigate the spread of pathogens and ARGs . However, mono-digestion of SL, particularly under thermophilic conditions, is often inhibited by ammonia and VFAs, posing a challenge to digester stability. , While AM:SL AcoD likely contributes to digestor stability, it did not improve SMY compared with the mono-digestion of AM (ROM = 1.11, p < 0.05, n = 3).…”

“…For example, SL often contains high levels of FOG (50% dw) and protein (37% dw), depending on the source (Table S2). 17 Additionally, antibiotic resistance genes (ARGs) are commonly found in AM, 135,136 SL, 137 and wastewater 138 due to the extensive use of antibiotics and antiparasitic drugs in animal husbandry. 139,140 Therefore, AD of these waste streams, particularly under thermophilic conditions, can mitigate the spread of pathogens 141 and ARGs.…”

Antibiotic Susceptibility Profiles of Bacterial Isolates Recovered from Abscesses in Cattle and Sheep at a Slaughterhouse in Algeria

“…In low- to middle-income countries, the intensification of farming is on the rise, primarily driven by a scarcity of available land and the continuous growth of human populations. This intensified farming demands greater use of antibiotics to combat infectious diseases, subsequently fostering the transfer of antibiotic resistance genes (ARGs) between microbes, resulting in multidrug-resistant bacteria in livestock but also in domestic animals and quick spread of resistant micro-organisms, which have serious consequences on animal health, productivity, and food production that pose both economic and human health problems [ 19 , 20 ]. Livestock animals are at risk of infectious diseases, especially with pyogenic organisms that cause abscesses at various sites of the body, and consequently have an impact on productivity, fertility, and in general to livestock health [ 2 , 21 , 22 ].…”

Evaluation of Surveillance Strategies of Antimicrobial Consumption in Animals

“…After our assessment, we provide a comparative analyses table highlighting the impact, feasibility, and the balance between operational challenges and the potential to inform policy. We continue our analysis to examine and prioritize solutions most amenable to collecting robust data in low- and middle-income countries (LMICs), where there are especially limited surveillance and data about agricultural antimicrobial usage, partnered with an increased risk for AMR due to the increased intensification of farming [ 11 , 18 , 19 ].…”