Metagenomics reveals the resistance patterns of electrochemically treated erythromycin fermentation residue.

Erythromycin fermentation residue (EFR) represents a typical hazardous waste produced by the microbial pharmaceutical industry. Although electrolysis is promising for EFR disposal, its microbial threats remain unclear. Herein, metagenomics was coupled with the random forest technique to decipher the antibiotic resistance patterns of electrochemically treated EFR. Results showed that 95.75% of erythromycin could be removed in 2 hr. Electrolysis temporarily influenced EFR microbiota, where the relative abundances of Proteobacteria and Actinobacteria increased, while those of Fusobacteria, Firmicutes, and Bacteroidetes decreased. A total of 505 antibiotic resistance gene (ARG) subtypes encoding resistance to 21 antibiotic types and 150 mobile genetic elements (MGEs), mainly including plasmid (72) and transposase (52) were assembled in EFR. Significant linear regression models were identified among microbial richness, ARG subtypes, and MGE numbers (r2=0.50-0.81, p< 0.001). Physicochemical factors of EFR (Total nitrogen, total organic carbon, protein, and humus) regulated ARG and MGE assembly (%IncMSE value = 5.14-14.85). The core ARG, MGE, and microbe sets (93.08%-99.85%) successfully explained 89.71%-92.92% of total ARG and MGE abundances. Specifically, gene aph(3')-I, transposase tnpA, and Mycolicibacterium were the primary drivers of the resistance dissemination system. This study also proposes efficient resistance mitigation measures, and provides recommendations for future management of antibiotic fermentation residue.

Metagenomic perspectives on antibiotic resistance genes in tap water: The environmental characteristic, potential mobility and health threat.

As an emerging environmental contaminant, antibiotic resistance genes (ARGs) in tap water have attracted great attention. Although studies have provided ARG profiles in tap water, research on their abundance levels, composition characteristics, and potential threat is still insufficient. Here, 9 household tap water samples were collected from the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in China. Additionally, 75 sets of environmental sample data (9 types) were downloaded from the public database. Metagenomics was then performed to explore the differences in the abundance and composition of ARGs. 221 ARG subtypes consisting of 17 types were detected in tap water. Although the ARG abundance in tap water was not significantly different from that found in drinking water plants and reservoirs, their composition varied. In tap water samples, the three most abundant classes of resistance genes were multidrug, fosfomycin and MLS (macrolide-lincosamide-streptogramin) ARGs, and their corresponding subtypes ompR, fosX and macB were also the most abundant ARG subtypes. Regarding the potential mobility, vanS had the highest abundance on plasmids and viruses, but the absence of key genes rendered resistance to vancomycin ineffective. Generally, the majority of ARGs present in tap water were those that have not been assessed and are currently not listed as high-threat level ARG families based on the World Health Organization Guideline. Although the current potential threat to human health posed by ARGs in tap water is limited, with persistent transfer and accumulation, especially in pathogens, the potential danger to human health posed by ARGs should not be ignored.

Metagenomic Profiling of Internationally Sourced Sewage Influents and Effluents Yields Insight into Selecting Targets for Antibiotic Resistance Monitoring.

It has been debated whether wastewater treatment plants (WWTPs) primarily act to attenuate or amplify antibiotic resistance genes (ARGs). However, ARGs are highly diverse with respect to their resistance mechanisms, mobilities, and taxonomic hosts and therefore their behavior in WWTPs should not be expected to be universally conserved. We applied metagenomic sequencing to wastewater influent and effluent samples from 12 international WWTPs to classify the behavior of specific ARGs entering and exiting WWTPs. In total, 1079 different ARGs originating from a variety of bacteria were detected. This included ARGs that could be mapped to assembled scaffolds corresponding to nine human pathogens. While the relative abundance (per 16S rRNA gene) of ARGs decreased during treatment at 11 of the 12 WWTPs sampled and absolute abundance (per mL) decreased at all 12 WWTPs, increases in relative abundance were observed for 40% of the ARGs detected at the 12th WWTP. Also, the relative abundance of mobile genetic elements (MGE) increased during treatment, but the fraction of ARGs known to be transmissible between species decreased, thus demonstrating that increased MGE prevalence may not be generally indicative of an increase in ARGs. A distinct conserved resistome was documented in both influent and effluent across samples, suggesting that well-functioning WWTPs generally attenuate influent antibiotic resistance loads. This work helps inform strategies for wastewater surveillance of antibiotic resistance, highlighting the utility of tracking ARGs as indicators of treatment performance and relative risk reduction.

Mastering granular activated carbon filtration to remove organic micropollutants, antibiotic resistance and metals for municipal wastewater reuse.

GAC filtration of municipal wastewater was optimized and intensified, making its implementation and operation directly after secondary clarification possible and relevant. GAC was first selected based on laboratory tests. Performances on organic micropollutants were linked to the repartition of BET surface between micropores and meso/macropores. At pilot scale, in order to limit the impact of head loss, downflow declogging sequences (DCS) were implemented and upflow filtration tested. 6 to 12 DCS per day led to a 4.7-5.5-fold increase of particles retention capacity between backwashes (cycle duration of 20-120 h), and upflow operations improved head loss evolution profile with only a slight GAC (<15 %) expansion. DCS allows backwash frequency reduction, enabling significant water savings. Both adaptations maintained high organic micropollutants removals compared to a review of 16 GAC studies at pilot or full-scale, results being in the upper range. A specific dose of 2.0-2.5 g GAC/gC was necessary to obtain an average removal of pharmaceuticals and benzotriazole of 80 % at 20 min contact time, which is comparable to PAC and low granulometry GAC. Higher doses are needed for PFAS but >80 % removals are achievable. Particles, TKN, particulate phosphorus and organic matter are well removed by GAC filtration in both configurations. Biological activity is observed through nitrogen transformation in the GAC bed. Heavy metals are greatly removed in GAC filtration, in particular Cd, Cu, Ni and Pb, probably through biosorption onto the biofilm, developed within the GAC bed. For wastewater reuse applications, GAC filtration has an added value through physicochemical quality improvement and fecal contamination indicators removal of 1 log, facilitating the implementation and optimizing the design of a post-disinfection. Antibiotic resistant bacteria and antibiotic resistance genes are also partially retained in GAC filtration. Finally, biological wastewater treatments combined to GAC filtration is a good solution to effectively treat organic micropollutants together with heavy metals and preparing post-disinfection for reuse.

Antibiotic resistant bacteria and antibiotic resistance genes as contaminants of emerging concern: Occurrences, impacts, mitigations and future guidelines.

Antibiotic resistance, driven by the proliferation of antibiotic resistance genes (ARGs) and antibiotic resistance bacteria (ARBs), has emerged as a pressing global health concern. Antimicrobial resistance is exacerbated by the widespread use of antibiotics in agriculture, aquaculture, and human medicine, leading to their accumulation in various environmental compartments such as soil, water, and sediments. The presence of ARGs in the environment, particularly in municipal water, animal husbandry, and hospital environments, poses significant risks to human health, as they can be transferred to potential human pathogens. Current remediation strategies, including the use of pyroligneous acid, coagulants, advanced oxidation, and bioelectrochemical systems, have shown promising results in reducing ARGs and ARBs from soil and water. However, these methods come with their own set of challenges, such as the need for elevated base levels in UV-activated persulfate and the long residence period required for photocatalysts. The future of combating antibiotic resistance lies in the development of standardized monitoring techniques, global collaboration, and the exploration of innovative remediation methods. Emphasis on combination therapies, advanced oxidation processes, and monitoring horizontal gene transfer can pave the way for a comprehensive approach to mitigate the spread of antibiotic resistance in the environment.

Case study on the relationship between transmission of antibiotic resistance genes and microbial community under freeze-thaw cycle on cold-region dairy farm.

Freeze-thaw cycle (FTC) is a naturally occurring phenomenon in high-latitude terrestrial ecosystems, which may exert influence on distribution and evolution of microbial community in the soil. The relationship between transmission of antibiotic resistance genes (ARGs) and microbial community was investigated upon the case study on the soil of cold-region dairy farm under seasonal FTC. The results demonstrated that 37 ARGs underwent decrease in the abundance of blaTEM from 80.4 % for frozen soil to 71.7 % for thawed soil, and that sul2 from 8.8 % for frozen soil to 6.5 % for thawed soil, respectively. Antibiotic deactivation was identified to be closely related to the highest relative abundance of blaTEM, and the spread of sulfonamide resistance genes (SRGs) occurred mainly via target modification. Firmicutes in frozen soil were responsible for dominating the abundance of ARGs by suppressing the native bacteria under starvation effect in cold regions, and then underwent horizontal gene transfer (HGT) among native bacteria through mobile genetic elements (MGEs). The TRB-C (32.6-49.1 %) and tnpA-06 (0.27-7.5 %) were significantly increased in frozen soil, while Int3 (0.67-10.6 %) and tnpA-04 (11.1-19.4 %) were up-regulated in thawed soil. Moreover, the ARGs in frozen soil primarily underwent HGT through MGEs, i.e. TRB-C and tnpA-06, with increased number of Firmicutes serving as carrier. The case study not only demonstrated relationship between transmission of ARGs and microbial community in the soil under practically relevant FTC condition, but also emphasized the importance for formulating better strategies for preventing FTC-induced ARGs in dairy farm in cold regions.

Comparative assessment of microbiome and resistome of influent and effluent of sewage treatment plant and common effluent treatment plant located in Delhi, India using shotgun approach.

Antimicrobial resistance (AMR) is a significant threat that demands surveillance to identify and analyze trends of the emerging antibiotic resistance genes (ARGs) and potential microbial carriers. The influent of the wastewater treatment plants (WWTPs) reflects the microbes derived from the population and effluent being the source of dissemination of potential pathogenic microbes and AMR. The present study aimed to monitor microbial communities and antibiotic resistance genes in WWTPs employing a whole metagenome shotgun sequencing approach. The samples were collected from a sewage treatment plant (STP) and a common effluent treatment plant (CETP) in Delhi, India. The results showed the influent of STP to be rich in Bifidobacterium, Bacteroides, Escherichia, Arcobacter, and Pseudomonas residents of gut microbiota and known to cause diseases in humans and animals; whereas the CETP sample was abundant in Aeromonas, Escherichia, and Shewanella known to be involved in the degradation of different compounds. Interestingly, the effluent samples from both STPs and CETP were rich in microbial diversity, comprising organic and xenobiotic compound degrading and disease-causing bacteria, indicating the effluent being the source of dissemination of concerning bacteria to the environment. The functional profile at both sites displayed similarity with an abundance of housekeeping function genes as analyzed by Clusters of Orthologous Genes (COG), KEGG Orthology (KO), and subsystem databases. Resistome profiling by MEGARes showed the dominance of ARGs corresponding to beta-lactams having relative abundance ranging from 16% to 34% in all the metagenome datasets, followed by tetracycline (8%-16%), aminoglycosides (7%-9%), multi-drug (5%-9%), and rifampin (3%-9%). Also, AMR genes oxa, ant3-DPRIME, and rpoB, which are of clinical importance were predominantly and most prevalently present in all the samples. The presence of AMR in effluents from both types of treatment plants indicates that wastewater from both sources contributes to the spread of pathogenic bacteria and resistance genes, increasing the environmental AMR burden and therefore requires tertiary treatment before discharge. This work will facilitate further research towards the identification of suitable biomarkers for monitoring antibiotic resistance.

Assessing pediatric antibiotic knowledge and practices among community pharmacists in Palestine: implications for antibiotic use and resistance.

BACKGROUND: Antibiotics are widely used in the pediatric population, and their inappropriate use contributes to antibiotic resistance, which is a growing concern in developing countries. Therefore, this national cross-sectional study aimed to assess community pharmacists' knowledge, attitudes and practices regarding appropriate antibiotic use and dosing in pediatric patients and to explore the barriers to such use in Palestine. METHODS: A questionnaire-based survey was conducted among community pharmacists on the West Bank, Palestine, from September 2022 to March 2023. The survey assessed the pharmacists' sociodemographic characteristics; knowledge, practices, and attitudes toward antibiotic use; and understanding of antibiotic dosing. The data were analyzed using descriptive statistics, and the factors affecting pharmacists' knowledge were evaluated. RESULTS: The study included 301 community pharmacists, with an average age of 30.06 years, who were primarily female (75.1%). The majority of the pharmacists (80.1%) correctly believed that antibiotics are effective against bacterial infections. However, 18.3% believed that antibiotics are effective against viruses. While 61.8% knew that antibiotics kill germs, 32.0% were unaware that not all antibiotics require refrigeration. Furthermore, 67.8% were aware that antibiotics do not speed up recovery from diarrhea. Over 99% of the participants recognized that antibiotic resistance developed due to various resistant mechanisms. The majority (78.7%) believed that each infection needed a different antibiotic. Pharmacists demonstrated reasonable knowledge of antibiotic dosing in case scenarios. Knowledge was positively correlated with years of experience (P = 0.001). CONCLUSIONS: This study revealed that community pharmacy professionals have a good understanding of antibiotic usage in pediatric patients. The findings suggest that professional expertise and quality training improve healthcare services. However, the results may not be universally applicable, as identifying knowledge gaps is necessary to help with the development of focused interventions. Therefore, ongoing educational initiatives, awareness campaigns and antibiotic stewardship programs are recommended.

The occurrence of banana Fusarium wilt aggravates antibiotic resistance genes dissemination in soil.

The spread of antibiotic resistance genes (ARGs) and subsequent soil-borne disease outbreaks are major threats to soil health and sustainable crop production. However, the relationship between occurrences of soil-borne diseases and the transmission of soil ARGs remains unclear. Here, soil ARGs, mobile genetic elements and microbial communities from co-located disease suppressive and conducive banana orchards were deciphered using metagenomics and metatranscriptomics approaches. In total, 23 ARG types, with 399 subtypes, were detected using a metagenomics approach, whereas 23 ARG types, with 452 subtypes, were discovered using a metatranscriptomics method. Furthermore, the metagenomics analysis revealed that the ARG total abundance levels were greater in rhizospheres (0.45 ARGs/16S rRNA on average) compared with bulk (0.32 ARGs/16S rRNA on average) soils. Interestingly, metatranscriptomics revealed that the total ARG abundances were greater in disease-conducive (8.85 ARGs/16S rRNA on average) soils than disease suppressive (1.45 ARGs/16S rRNA on average) soils. Mobile genetic elements showed the same trends as ARGs. Network and binning analyses indicated that Mycobacterium, Streptomyces, and Blastomonas are the main potential hosts of ARGs. Furthermore, Bacillus was significantly and negatively correlated with Fusarium (P < 0.05, r = -0.84) and hosts of ARGs (i.e., Mycobacterium, Streptomyces, and Blastomonas). By comparing metagenomic and metatranscriptomic analyses，this study demonstrated that metatranscriptomics may be more sensitive in indicating ARGs activities in soil. Our findings enable the more accurate assessment of the transmission risk of ARGs. The data provide a new perspective for recognizing soil health, in which soil-borne disease outbreaks appear to be associated with ARG spread, whereas beneficial microbe enrichment may mitigate wilt disease and ARG transmission.

Antimicrobial resistance in the Americas: Addressing one of the most pressing health threats

Antimicrobial resistance (AMR) occurs when microorganisms that cause infection (bacteria, parasites, viruses, and fungi) become resistant to the antimicrobial drugs we use to treat them. When this happens, infections last longer, are more severe, and become more contagious. Resistance leads to the ineff ectiveness of antimicrobials, the cornerstone of modern medicine, threatening our ability to treat infections and perform safe, life-saving procedures. AMR is also very costly in economic terms. Much longer hospital stays and expensive drugs are needed to treat AMR infections, leading to higher healthcare costs and higher morbidity and mortality of hospital patients, especially those in intensive care units, oncology, and neonatology.

Tratamiento de las enfermedades infecciosas 2024-2026. Novena edición

Esta guía de Tratamiento de las enfermedades infecciosas 2024-2026 es una referencia útil para guiar la prescripción de antimicrobianos en medicina familiar y comunitaria, así como para orientar a especialistas en formación. La publicación contiene recomendaciones sobre el tratamiento más apropiado de las enfermedades infecciosas, considerando la epidemiología de los microorganismos causales y los patrones de sensibilidad en los países de América Latina y el Caribe, a la vez que se busca contribuir a la contención de la resistencia que surge del uso excesivo o incorrecto de fármacos antimicrobianos. Para la presente edición, se hizo una revisión exhaustiva del tratamiento de la sepsis y el síndrome de sepsis, con hincapié en su detección y tratamiento tempranos para reducir la morbilidad y mortalidad por sepsis. También se han incorporado principios del sistema AWaRe (Acceso, Precaución y Reserva) de la Organización Mundial de la Salud, que proporciona orientación concisa, con base en información comprobada, sobre el tratamiento de las 30 infecciones más comunes de niños y adultos.

Tebuconazole exacerbates co-occurrence and horizontal transfer of antibiotic resistance genes.

As one of the most widely used pesticides in the global fungicide market, tebuconazole has become heavily embedded in soil along with antibiotic resistance genes (ARGs). However, it remains unclear whether the selective pressure produced by tebuconazole affects ARGs and their horizontal transfer. In this experiment, we simulated a tebuconazole-contaminated soil ecosystem and observed changes in the abundance of ARGs and mobile genetic element (MGEs) due to tebuconazole exposure. We also established a plasmid RP4-mediated conjugative transfer system to investigate in depth the impact of tebuconazole on the horizontal transfer of ARGs and its mechanism of action. The results showed that under tebuconazole treatment at concentrations ranging from 0 to 10 mg/L, there was a gradual increase in the frequency of plasmid conjugative transfer, peaking at 10 mg/L which was 7.93 times higher than that of the control group, significantly promoting horizontal transfer of ARGs. Further analysis revealed that the conjugative transfer system under tebuconazole stress exhibited strong ability to form biofilm, and the conjugative transfer frequency ratio of biofilm to planktonic bacteria varied with the growth cycle of biofilm. Additionally, scanning electron microscopy and flow cytometry demonstrated increased cell membrane permeability in both donor and recipient bacteria under tebuconazole stress, accompanied by upregulation of ompA gene expression controlling cell membrane permeability. Furthermore, enzyme activity assays indicated significant increases in CAT, SOD activity, and GSH content in recipient bacteria under tebuconazole stress. Moreover, expression levels of transmembrane transporter gene trfAp as well as genes involved in oxidative stress and SOS response were found to be correlated with the frequency of plasmid conjugative transfer.

Climate change and antibiotic resistance: A scoping review.

This scoping review aimed to investigate the potential association between climate change and the rise of antibiotic resistance while also exploring the elements of climate change that may be involved. A scoping review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews, comprehensively searching scientific literature up to 31 January 2024. Multiple databases were utilized, including MEDLINE, Web of Science and SCOPUS. Various search strategies were employed, and selection criteria were established to include articles relevant to antibiotic resistance and climate change. The review included 30 selected articles published predominantly after 2019. Findings from these studies collectively suggest that rising temperatures associated with climate change can contribute to the proliferation of antibiotic resistance, affecting diverse ecosystems. This phenomenon is observed in soil, glaciers, rivers and clinical settings. Rising temperatures are associated with a rise in the prevalence of antibiotic resistance across various environments, raising concerns for global health. However, these studies provide valuable insights but do not establish a definitive causal link between environmental temperature and antibiotic resistance. The selective pressure exerted by antibiotics and their residues in ecosystems further complicates the issue.

Knowledge, attitude, and practices of pharmacy students in 7 Middle Eastern countries concerning antibiotic resistance: A cross-sectional study.

Addressing antimicrobial resistance (AMR) stands as a major global health challenge threatening humanity. Resolving this issue can be initiated through emphasizing the significance of AMR education among students in health colleges during their undergraduate studies. Hence, the aim of this study is to assess the pharmacy students' knowledge, attitudes, and practices regarding antibiotic resistance in 7 Middle Eastern countries. A cross-sectional study was conducted among undergraduate pharmacy students at universities in Egypt, Jordan, Saudi Arabia, Lebanon, the United Arab Emirates, Qatar, and Kuwait between March 2021 and January 2022. The first section of the questionnaire gathered demographic information. The knowledge section comprised 7 questions. Subsequently, the questionnaire explored participants' attitudes (6 items) and practices (2 items) concerning antibiotic resistance. Mann-Whitney and Kruskal-Wallis tests were used to compare the median knowledge score between different demographic groups. Logistic regression was used to estimate odds ratios, with 95% confidence intervals (CIs) for being more knowledgeable about antibiotic resistance. A 2-sided P < .05 was considered statistically significant. A total of 4265 pharmacy students were involved in this study (Egypt (2249), Jordan (n = 704), Saudi Arabia (n = 531), Lebanon (n = 401), United Araba Emirates (n = 130), Qatar (n = 129), and Kuwait (n = 121)). The median knowledge score for the participating pharmacy students was 5.00 (IQR = 4.00-6.00) out of 7, equals to 71.4% with 4th, and 5th year students and bachelor of pharmacy program students have higher odds of being more knowledgeable about antibiotics resistance compared to other students (P < .05). The majority of the students agreed that antibiotic resistance is increasing, they should be more concerned regarding antibiotic consumption and that government should create more awareness of antibiotic resistance, and that they should have enough knowledge to prevent antibiotic resistance. Around 3 quarters of the students (73.0%) confirmed that they take antibiotic only after getting prescription from their physician and almost half (51.7%) reported that they take antibiotic to manage their fever. The study concluded good educational programs in Middle East pharmacy schools with the need for targeted educational interventions promoting responsible antibiotic stewardship practices among future pharmacists.

Simultaneous removal of ammonia nitrogen, sulfamethoxazole, and antibiotic resistance genes in self-corrosion microelectrolysis-enhanced counter-diffusion biofilm system.

A self-corrosion microelectrolysis (SME)-enhanced membrane-aerated biofilm reactor (eMABR) was developed for the removal of pollutants and reduction of antibiotic resistance genes (ARGs). Fe2+ and Fe3+ formed iron oxides on the biofilm, which enhanced the adsorption and redox process. SME can induce microorganisms to secrete more extracellular proteins and up-regulate the expression of ammonia monooxygenase (AMO) (0.92 log2). AMO exposed extra binding sites (ASP-69) for antibiotics, weakening the competition between NH4+-N and sulfamethoxazole (SMX). The NH4+-N removal efficiency in the S-eMABR (adding SMX and IC) increased by 44.87 % compared to the S-MABR (adding SMX). SME increased the removal performance of SMX by approximately 1.45 times, down-regulated the expressions of sul1 (-1.69 log2) and sul2 (-1.30 log2) genes, and controlled their transfer within the genus. This study provides a novel strategy for synergistic reduction of antibiotics and ARGs, and elucidates the corresponding mechanism based on metatranscriptomic and molecular docking analyses.

Risk level and removal performance of antibiotic resistance genes and bacterial pathogens in static composting with different temperatures.

The effect of different levels of temperature on resistance genes is not clear in mesophilic static composting (<50 °C). This study conducted livestock manure composting with different temperature gradients from 20 to 50 °C, it was found that the reduction rates of risk rank-I antibiotic resistance genes (from 3 % to 66 %), metal resistance genes (from -50 % to 76 %) and bacterial pathogens (from 72 % to 91 %) all increased significantly with increasing temperature from 20 to 50°C. The vulnerability of bacterial communities increased significantly, and the assembly process of bacterial communities changed from deterministic to stochastic with the increase of composting temperature. Higher temperature could accelerate the removal of thermolabile resistance genes hosts or pathogenic hosts carrying mobile genetic elements by directly or indirectly affecting organic acids content. Therefore, for soil safety, the temperature of the manure recycling process should be increased as much as possible.

Sewage sludge fertilization affects microbial community structure and its resistome in agricultural soils.

Global sewage sludge production is rapidly increasing, and its safe disposal is becoming an increasingly serious issue. One of the main methods of municipal sewage sludge management is based on its agricultural use. The wastewater and sewage sludge contain numerous antibiotic resistance genes (ARGs), and its microbiome differs significantly from the soil microbial community. The aim of the study was to assess the changes occurring in the soil microbial community and resistome after the addition of sewage sludge from municipal wastewater treatment plant (WWTP) in central Poland, from which the sludge is used for fertilizing agricultural soils on a regular basis. This study used a high-throughput shotgun metagenomics approach to compare the microbial communities and ARGs present in two soils fertilized with sewage sludge. The two soils represented different land uses and different physicochemical and granulometric properties. Both soils were characterized by a similar taxonomic composition of the bacterial community, despite dissimilarities between soils properties. Five phyla predominated, viz. Planctomycetes, Actinobacteria, Proteobacteria, Chloroflexi and Firmicutes, and they were present in comparable proportions in both soils. Network analysis revealed that the application of sewage sludge resulted in substantial qualitative and quantitative changes in bacterial taxonomic profile, with most abundant phyla being considerably depleted and replaced by Proteobacteria and Spirochaetes. In addition, the ratio of oligotrophic to copiotrophic bacteria substantially decreased in both amended soils. Furthermore, fertilized soils demonstrated greater diversity and richness of ARGs compared to control soils. The increased abundance concerned mainly genes of resistance to antibiotics most commonly used in human and animal medicine. The level of heavy metals in sewage sludge was low and did not exceed the standards permitted in Poland for sludge used in agriculture, and their level in fertilized soils was still inconsiderable.

Sewerage surveillance tracking characteristics of human antibiotic resistance genes in sewer system.

Sewage surveillance is widely applied to track valid human excretion information and identify public health conditions during corona virus disease 2019 (COVID-19) pandemic. This approach can be applied to monitor the antibiotic resistance level in sewers and to assess the risk of spreading antibiotic resistance in municipal wastewater systems. However, there is still little information about human antibiotic resistance occurrence characteristics in sewer system. This study conducted a field trial for whole year to advance understanding on spatial and temporal occurrence of antibiotic resistance genes (ARGs) in gravity sewerage. The spatial distribution of ARGs along the drainage pipe line (from human settlements to wastewater treatement pant (WWTP)) was insignificant, which may be affected by irregular human emission alongside the pipeline. The correlation between ARGs and antibiotics in sewage was insignificant. The temporal distribution showed that the effect of temperature on ARGs abundance was evident, the ARGs abundance in sewage was generally higher during the cold season. Metagenomic analysis revealed that the detected ARGs were mainly distributed in Proteobacteria (47.51 %) and Antinobacteria (20.11 %). Potential hosts of ARGs in sewage were mainly identified as human gut microorganisms, including human pathogenic bacteria, such as Prevotella, Kocuria, and Propionibacterium, etc. This study provides a new insight into the sewerage surveillance tracking characteristics of human ARGs in sewer system, and suggesting that the sewage-carried ARGs surveillance is a promising method for assessment and management of antibiotic resistance level on population size.