Data_Sheet_1_Biosolids as a Source of Antibiotic Resistance Plasmids for Commensal and Pathogenic Bacteria.PDF

Antibiotic resistance (AR) is a threat to modern medicine, and plasmids are driving the global spread of AR by horizontal gene transfer across microbiomes and environments. Determining the mobile resistome responsible for this spread of AR among environments is essential in our efforts to attenuate the current crisis. Biosolids are a wastewater treatment plant (WWTP) byproduct used globally as fertilizer in agriculture. Here, we investigated the mobile resistome of biosolids that are used as fertilizer. This was done by capturing resistance plasmids that can transfer to human pathogens and commensal bacteria. We used a higher-throughput version of the exogenous plasmid isolation approach by mixing several ESKAPE pathogens and a commensal Escherichia coli with biosolids and screening for newly acquired resistance to about 10 antibiotics in these strains. Six unique resistance plasmids transferred to Salmonella typhimurium, Klebsiella aerogenes, and E. coli. All the plasmids were self-transferable and carried 3–6 antibiotic resistance genes (ARG) conferring resistance to 2–4 antibiotic classes. These plasmids-borne resistance genes were further embedded in genetic elements promoting intracellular recombination (i.e., transposons or class 1 integrons). The plasmids belonged to the broad-host-range plasmid (BHR) groups IncP-1 or PromA. Several of them were persistent in their new hosts when grown in the absence of antibiotics, suggesting that the newly acquired drug resistance traits would be sustained over time. This study highlights the role of BHRs in the spread of ARG between environmental bacteria and human pathogens and commensals, where they may persist. The work further emphasizes biosolids as potential vehicles of highly mobile plasmid-borne antibiotic resistance genes.

抗生素耐药性（AR）对现代医学构成威胁，质粒通过在微生物群落和环境之间的水平基因转移，推动着全球范围内AR的传播。确定负责这种AR在环境间传播的可移动耐药组（resistome）对于缓解当前危机至关重要。生物固体是废水处理厂（WWTP）的副产品，全球范围内被用作农业肥料。在此，我们研究了用作肥料的生物固体中的可移动耐药组。通过捕获可转移至人类病原体和共生细菌的耐药质粒，我们实现了这一目标。我们使用了一种更高通量的外源质粒分离方法，该方法通过将几种ESKAPE病原体和一种共生的大肠杆菌与生物固体混合，并对这些菌株中约10种抗生素的新获得耐药性进行筛选。六种独特的耐药质粒转移到了鼠伤寒沙门氏菌、产气克雷伯菌和大肠杆菌中。所有质粒都具有自转移性，并携带3-6个抗生素耐药基因（ARG），赋予其对2-4种抗生素类别的耐药性。这些携带的耐药基因被进一步嵌入到促进细胞内重组的遗传元件（即转座子或第1类整合子）中。这些质粒属于广宿主范围质粒（BHR）组IncP-1或PromA。其中一些在无抗生素生长条件下在其新宿主中持续存在，这表明新获得的药物耐药性状将在长时间内得以维持。本研究突出了BHR在环境细菌与人类病原体和共生细菌之间耐药基因（ARG）传播中的作用，其中它们可能持续存在。这项工作进一步强调了生物固体作为高度可移动质粒携带的抗生素耐药基因的潜在载体。