Project description:Incomplete antibiotic removal in pharmaceutical wastewater treatment plants (PWWTPs) could lead to the development and spread of antibiotic-resistant bacteria (ARBs) and genes (ARGs) in the environment, posing a growing public health threat. In this study, two multiantibiotic-resistant bacteria, Ochrobactrum intermedium (N1) and Stenotrophomonas acidaminiphila (N2), were isolated from the sludge of a PWWTP in Guangzhou, China. The N1 strain was highly resistant to ampicillin, cefazolin, chloramphenicol, tetracycline, and norfloxacin, while the N2 strain exhibited high resistance to ampicillin, chloramphenicol, and cefazolin. Whole-genome sequencing revealed that N1 and N2 had genome sizes of 0.52 Mb and 0.37 Mb, respectively, and harbored 33 and 24 ARGs, respectively. The main resistance mechanism in the identified ARGs included efflux pumps, enzymatic degradation, and target bypass, with the N1 strain possessing more multidrug-resistant efflux pumps than the N2 strain (22 vs 12). This also accounts for the broader resistance spectrum of N1 than of N2 in antimicrobial susceptibility tests. Additionally, both genomes contain numerous mobile genetic elements (89 and 21 genes, respectively) and virulence factors (276 and 250 factors, respectively), suggesting their potential for horizontal transfer and pathogenicity. Overall, this research provides insights into the potential risks posed by ARBs in pharmaceutical wastewater and emphasizes the need for further studies on their impact and mitigation strategies.
Project description:Heavy metals have been postulated as significant nitrification inhibitor in wastewater treatment plant. The effect of heavy metals such as Cd2+, Cu2+ and Hg2+ to nitrifying bacterium, Nitrosomonas europaea, was studied in pseudo-steady state batch reactor. Under incubation of Nitrosomonas europaea with 1 ?M CdCl2 for 1 hour, transcripts for 66 of 2460 genes were found at high level, yet transcripts of 50 genes were found at low level. Mercury resistance genes (merACDPT) showed 277-fold up regulation. Keywords: cadmium, stress response, global transcription, mercury resistance genes, merA,
Project description:Antibiotic resistance is exacerbated by the exchange of antibiotic resistance genes (ARGs) between microbes from diverse habitats. Plasmids are important ARGs mobile elements and are spread by horizontal gene transfer (HGT). In this study, we demonstrated the presence of multi-resistant plasmids from inhalable particulate matter (PM) and its effect on gene horizontal transfer. Three transferable multi-resistant plasmids were identified from PM in a hospital, using conjugative mating assays and nanopore sequencing. pTAir-3 contained 26 horizontal transfer elements and 10 ARGs. Importantly pTAir-5 harbored carbapenem resistance gene (blaOXA) which shows homology to plasmids from human and pig commensal bacteria, thus indicating that PM is a media for antibiotic resistant plasmid spread. In addition, 125 μg/mL PM2.5 and PM10 significantly increased the conjugative transfer rate by 110% and 30%, respectively, and augmented reactive oxygen species (ROS) levels. Underlying mechanisms were revealed by identifying the upregulated expressional levels of genes related to ROS, SOS, cell membranes, pilus generation, and transposition via genome-wide RNA sequencing. The study highlights the airborne spread of multi-resistant plasmids and the impact of inhalable PM on the horizontal transfer of antibiotic resistance.
Project description:Metaproteomic analysis of air particulate matter provides information about the properties of bioaerosols in the atmosphere and their influence on climate and public health. In this work, a new method for the extraction and analysis of proteins in airborne particulate matter from quartz microfiber filters was developed. Different protein extraction procedures were tested in order to select the best extraction protocol in terms of protein recovery. The optimized method was tested for extraction of proteins from spores of ubiquitous bacteria species and used for the first time for the metaproteomics characterization of filters from work environment. In particular, ambient aerosol samples were collected in different working environments, i.e. a composting plant, wastewater treatment plant and agricultural holding. One-hundred seventy-nine, 15, 205 and 444 proteins were successfully identified in composting plant, wastewater treatment plant, and agricultural holding, respectively. All identified proteins were mainly originate from fungi, bacteria and plants which is in line with the major categories of primary biological aerosol particles. The paper is the first metaproteomic study applied to bioaereosol samples collected in occupationally relevant environmental sites providing interesting information on the composting, wastewater treatment and feed blending processes. Significance This manuscript describes the metaproteomic analysis of aerosol samples collected in work enviroments. This is a novel use of aereosol samples and is needed as there is no really comprehensive way of analysing aereosol samples from a metaproteomic point of view. This paper could help to advance methods for metaproteomic analysis of bioaersols, specifically by comparing protein extraction protocols and pairing the best performing extraction protocol with a gel-free protein separation procedure applied for the first time for analysis of bioaerosol samples. The obtained data showed as bioaerosol was essentially made of fungi, bacteria and plant proteins, many of which could be associated to possible aerosolisation and could be a major health concern for workers on site and to the populations residing in neighbouring area.
2025-07-14 | PXD012345 | Pride
Project description:Unveiling Antibiotic Resistance Genes in Airborne Particles During a Severe Smog