Distinct Resistomes and Microbial Communities of Soils, Wastewater Treatment Plants and Households Suggest Development of Antibiotic Resistances Due to Distinct Environmental Conditions in Each Environment

Abstract

The use of antibiotics in humans and animals results in a release of excess antibiotic residues into the environment through wastewaters and insufficient removal in wastewater treatment plants (WWTP), leading to increasing numbers of bacteria enriched in antibiotic resistance genes (ARG). However, the potential transfer of ARG and their host bacteria between different environments remains largely unexplored. Since many factors need to be fulfilled for a transfer between different environments, we hypothesized that antibiotic resistance (ABR) is less frequently transferred between environments in the same geographical region but rather develops and clusters in each distinct environment, leading to characteristic metagenome patterns in samples of different environments. We sampled agricultural soils, a WWTP and private households and performed metagenomic analyses to evaluate differences and potential overlaps in bacterial communities and resistomes of different environments. Wastewater revealed significantly higher richness of ARG (n = 40) and mobile genetic elements (n = 52) than soil and household samples. Bacterial communities differed between the environments and antibiotic resistance factors clustered distinctly. Overall, only few overlaps of ARG between the environments were observed, leading to the conclusion that ABR predominantly develops in individual environments as caused by environmental filtering for ARG, while a transfer between different environments is less likely.

Design and Validation of Primer Sets for the Detection and Quantification of Antibiotic Resistance Genes in Environmental Samples by Quantitative PCR

“…According to these results, high ARGs’ detection frequencies (ranging from 70 to 100%) were found in the environmental samples using the de novo primer sets and qPCR methodologies proposed in this research, except for the mecA gene. The widespread occurrences and ubiquitous distribution of ARGs for the most used antibiotics (beta-lactams, fluoroquinolones, tetracyclines, macrolides, and sulfonamides) in natural and engineered ecosystems have been identified as a severe public health concern [ 27 ], a fact widely attributed to the subminimum concentrations of antibiotics that reach these ecosystems [ 35 ].

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A Comprehensive View of Microbial Communities in the Laundering Cycle Suggests a Preventive Effect of Soil Bacteria on Malodour Formation

“…Amongst other bacteria associated with humans, staphylococci and Cutibacterium acnes (C. acnes) were especially regularly detected on the towel samples. In contrast, the dominant species in the washing machine were water-borne bacteria such as Pseudomonas aeruginosa (P. aeruginosa) and Stenotrophomonas maltophilia (S. maltophilia) , which have been found in washing machines before [ 43 ]. While these data generally support the idea of a low infection risk associated with domestic laundry, our findings clearly show the presence of pathogens on used textiles, which may pose a risk under certain circumstances.…”

Efeitos da compostagem termofílica industrial na qualidade do lodo de esgoto e na dissipação de resistência antimicrobiana em solos

“…Su et al (2015) atribuíram a alta proporção de Actinobacteriota ao aumento de GRAs em compostos de lodo de esgoto. Logo, a composição da comunidade microbiana influencia diretamente a distribuição de genes de resistência a antimicrobianos (GRAs) e genes de elementos genéticos móveis (EGMs), gerando um resistoma particular entre os solos (Schages et al, 2021).…”