Removal efficiency of antibiotic residues, antibiotic resistant bacteria, and genes across parallel secondary settling tank and membrane bioreactor treatment trains in a water reclamation plant.

Antimicrobial resistance is recognized as a potent threat to human health. Wastewater treatment facilities are viewed as hotspots for the spread of antimicrobial resistance. This study provides comprehensive data on the occurrences of 3 different antibiotic resistant opportunistic pathogens (with resistance to up to 5 antibiotics), 13 antibiotic resistant genes and intI1, and 22 different antimicrobial residues in a large water reclamation plant (176 million gallons per day) that runs a conventional Modified Ludzack-Ettinger (MLE) reactor followed by a secondary settling tank (SST) and membrane bioreactor (MBR) in parallel. All the antibiotic resistant bacteria and most of the antibiotic resistance genes were present in the raw influent, ranging from 2.5 × 102-3.7 × 106 CFU/mL and 1.2× 10-1-6.5 × 1010 GCN/mL, respectively. MBR outperformed the SST system in terms of ARB removal as the ARB targets were largely undetected in MBR effluent, with log removals ranging from 2.7 to 6.8, while SST only had log removals ranging from 0.27 to 4.6. Most of the ARG concentrations were found to have significantly higher in SST effluent than MBR permeate, and MBR had significantly higher removal efficiency for most targets (p < 0.05) except for sul1, sul2, blaOXA48, intI1 and 16S rRNA genes (p > 0.05). As for the antibiotic residues (AR), there was no significant removal from the start to the end of the treatment process, although MBR had higher removal efficiencies for azithromycin, chloramphenicol, erythromycin, erythromycin-H2O, lincomycin, sulfamethoxazole and triclosan, compared to the SST system. In conclusion, MBR outperformed SST in terms of ARB and ARGs removal. However low removal efficiencies of most AR targets were apparent.

A 10-year experience with anastomotic leaks in upper gastrointestinal surgery-Retrospective cohort study.

BACKGROUND: Anastomotic leak (AL) in upper gastrointestinal (UGI) surgery continues to be a diagnostic challenge. We seek to identify clinical parameters that predict AL and examine the effectiveness of investigations in evaluating AL following UGI surgeries. METHODS: 592 patients underwent UGI surgeries with an anastomosis between January 2011 and January 2021. Data on patient characteristics, surgery, postoperative investigations and outcomes were prospectively collected and analysed. RESULTS: The overall occurrence of AL was 6.4 %. Tachycardia >120 BPM (OR 6.959, 95 % CI 1.856-26.100, p = 0.004) and leukocyte count >19 × 109/L (OR 3.327, 95 % CI 1.009-10.967, p = 0.048) were independent predictors of AL. On multivariate analysis, patients whose anastomosis was deemed high risk and had pre-emptive investigation done postoperatively to exclude a leak were less likely to require intervention and were more likely to be managed conservatively (66.7 % vs 14.3 %, p = 0.025). Methylene blue test, oral contrast study and Computed Tomography scan with intravenous and oral contrast had 50.0 %, 20.0 % and 9.1 % false negative results, while esophagogastroduodenoscopy had none. There was no misdiagnosed AL when more than 1 investigation (n = 15, 39.5 %) were performed. CONCLUSION: Our study demonstrates that the presence of a triad including desaturation, tachycardia and leucocytosis predicts for AL following UGI surgery and for confirmation of a leak, evaluation with 2 or more investigation is needed. A practice of evaluating high risk anastomosis prior to commencement of feeding decreased the need for surgical intervention and improves success of conservative treatment.

Assessing the additional health burden of antibiotic resistant Enterobacteriaceae in surface waters through an integrated QMRA and DALY approach.

Antibiotic resistant Enterobacteriaceae pose a significant threat to public health. However, limited studies have evaluated the health risks associated with exposure to antibiotic-resistant bacteria (ARB), especially in natural environments. While quantitative microbial risk assessment (QMRA) assesses microbial risks in terms of the probability of infection, it does not account for the severity of health outcomes. In this study, a QMRA-DALY model was developed to integrate QMRA with health burden (disability-adjusted life years (DALY)) from infections caused by ARB. The model considers uncertainties in probability of infection and health burden assessment using Monte Carlo simulations. The study collected antimicrobial resistance (AMR) surveillance data from surface waters with different land uses. Results revealed water bodies with agricultural land use to be the main AMR hotspots, with the highest additional health burden observed in infections caused by meropenem-resistant E. coli (∆DALY = 0.0105 DALY/event) compared to antibiotic-susceptible E. coli. The estimated ∆DALY for antibiotic-resistant K. pneumoniae was lower than for antibiotic-resistant E. coli (highest ∆DALY = 0.00048 DALY/event). The study highlights the need for better evaluation of AMR associated health burden, and effective measures to mitigate the risks associated with antibiotic-resistant bacteria in natural environments.

Arabidopsis TRB proteins function in H3K4me3 demethylation by recruiting JMJ14.

Arabidopsis telomeric repeat binding factors (TRBs) can bind telomeric DNA sequences to protect telomeres from degradation. TRBs can also recruit Polycomb Repressive Complex 2 (PRC2) to deposit tri-methylation of H3 lysine 27 (H3K27me3) over certain target loci. Here, we demonstrate that TRBs also associate and colocalize with JUMONJI14 (JMJ14) and trigger H3K4me3 demethylation at some loci. The trb1/2/3 triple mutant and the jmj14-1 mutant show an increased level of H3K4me3 over TRB and JMJ14 binding sites, resulting in up-regulation of their target genes. Furthermore, tethering TRBs to the promoter region of genes with an artificial zinc finger (TRB-ZF) successfully triggers target gene silencing, as well as H3K27me3 deposition, and H3K4me3 removal. Interestingly, JMJ14 is predominantly recruited to ZF off-target sites with low levels of H3K4me3, which is accompanied with TRB-ZFs triggered H3K4me3 removal at these loci. These results suggest that TRB proteins coordinate PRC2 and JMJ14 activities to repress target genes via H3K27me3 deposition and H3K4me3 removal.

Quaternary ammonium compounds of emerging concern: Classification, occurrence, fate, toxicity and antimicrobial resistance.

Amplified hygiene and precautionary measures are of utmost importance to control the spread of COVID-19 and future infection; however, these changes in practice are projected to trigger a rise in the purchase, utilisation and hence, discharge of many disinfectants into the environment. While alcohol-based, hydrogen peroxide-based, and chlorine-based compounds have been used widely, quaternary ammonium compounds (QACs) based disinfectants are of significant concern due to their overuse during this pandemic. This review presents the classification of disinfectants and their mechanism of action, focusing on QACs. Most importantly, the occurrence, fate, toxicity and antimicrobial resistance due to QACs are covered in this paper. Here we collated evidence from multiple studies and found rising trends of concern, including an increase in the mass load of QACs at a wastewater treatment plant (WWTP) by 331% compared to before the COVID-19 pandemic, as well as an increases in the concentration of 62% in residential dust, resulting in high concentrations of QACs in human blood and breast milk and suggesting that these could be potential sources of persistent QACs in infants. In addition to increased toxicity to human and aquatic life, increased use of QACs and accelerated use of antibiotics and antimicrobials during the COVID-19 pandemic could multiply the threat to antimicrobial resistance.

SAMBA: A Multicolor Digital Melting PCR Platform for Rapid Microbiome Profiling.

During the past decade, breakthroughs in sequencing technology have provided the basis for studies of the myriad ways in which microbial communities in and on the human body influence human health and disease. In almost every medical specialty, there is now a growing interest in accurate and quantitative profiling of the microbiota for use in diagnostic and therapeutic applications. However, the current next-generation sequencing approach for microbiome profiling is costly, requires laborious library preparation, and is challenging to scale up for routine diagnostics. Split, Amplify, and Melt analysis of BActeria-community (SAMBA), a novel multicolor digital melting polymerase chain reaction platform with unprecedented multiplexing capability is presented, and the capability to distinguish and quantify 16 bacteria species in mixtures is demonstrated. Subsequently, SAMBA is applied to measure the compositions of bacteria in the gut microbiome to identify microbial dysbiosis related to colorectal cancer. This rapid, low cost, and high-throughput approach will enable the implementation of microbiome diagnostics in clinical laboratories and routine medical practice.

Population-based variations of a core resistome revealed by urban sewage metagenome surveillance.

Sewage-based surveillance is widely employed to understand the occurrence and distribution of antimicrobial resistance (AMR) in urban community. However, there are limited studies which investigated the sewage of different sources within community. The present study used metagenomics to decipher the AMR profiles in five sources: local residence's source, animal source, migrant workers' source, clinical source , and urban wastewater treatment plant influent. A core resistome of ARGs was found across all samples, accounting for 81.4%-93.3% of the abundance of total resistome with only 17.3% diversity, irrespective of the sewage sources. Clinically relevant ARGs were identified in the core resistome across all wastewater sources. This included genes conferring resistance to beta-lactams as biomarkers of hospital sewage. The pet center wastewater showed a high abundance of genes encoding resistance to tetracycline, which is a commonly used veterinary antibiotic. The resistome profile of sewage from the migrant workers' dormitories showed a slight variation to that of the local residential population, suggesting possible differences in the human gut resistome of the foreign/migrant population, with biomarkers of genes encoding resistance to fosfomycin, fosmidomycin, kasugamycin, MLS, and polymyxin. The co-localization of ARGs and plasmid, MGEs and integrative and conjugative elements (ICEs) could explain variations in the core resistome, presumably a result of high antibiotic selection pressure. Further analysis showed a specific host-associated resistance pattern, in which core hosts mediated the core resistome profile. The core BMRGs were also co-localized with MGEs/ICEs and carried by core potential bacterial hosts. Local healthy population carried the lowest ARG load (copy number discharged by each person per day) but contributed the highest ARG burden (copy number discharged by the population). This study elucidates population-based variations of a core resistome, and further provides important insights into source tracking and management of AMR in urban environments.

A new modelling framework for assessing the relative burden of antimicrobial resistance in aquatic environments.

The infections caused by antibiotic resistant bacteria (ARB) can lead to higher medical costs, prolonged hospital stays, and increased mortality compared to bacteria that are susceptible to antibiotics. Challenges exist in quantifying the potential risk/burden associated with antimicrobial resistance (AMR) as there is a lack of dose-response models available for pathogens which are resistant to antibiotics, in addition to the fact that very little is known regarding the health risks posed by antibiotic resistant genes (ARG). In this paper, we proposed a new modelling framework to evaluate the relative burden of AMR in natural aquatic environments. With this framework, an AMR burden score for each sample was calculated based on burden coefficients assigned for each ARB and ARG, as well as weighted burdens for the separate ARBs and ARGs components. The method developed in this study was applied to assess the relative burden of AMR in local aquatic environments with different land uses at different seasons. The collected filed data were used to verify the applicability of the proposed relative burden assessment method. Through the established method, the spatial and temporal hotspots of AMR were identified, which could provide useful information to agencies for better control and management of AMR emergence in natural aquatic environments.

Development of a Probiotics Practice E-Reference Database for Health Care Professionals.

PURPOSE: Currently available references provide evidence on the efficacy of probiotics strains but exclude product-specific information, making it challenging for health care professionals (HCPs) to provide consumers with suitable recommendations on probiotics. An online probiotics e-reference database was developed to assist HCPs in delivering evidence-based recommendations on probiotics to consumers. The usability and applicability of the database in health care practice were evaluated. METHODS: Information on the efficacy of probiotics and probiotic products was collated using a PubMed literature search, and from local pharmacies and online supplement stores. A web database was compiled using various programming scripts and uploaded onto a web server. The database was beta-tested using an online self-administered questionnaire for community-based pharmacists, and responses were analyzed using descriptive statistics. FINDINGS: The database comprised 584 clinical study excerpts, 449 probiotic products, and 1879 unique product-study links. Users can search for suitable probiotics based on their indication profile or for a specific probiotic product. Information provided includes the probiotic constituents, dosage regimen, and indications of the product, with supporting clinical evidence. Overall, all participants of the beta-test indicated that they were satisfied with the database and were willing to use it again (both, 13 participants [100%]). In addition, all participants indicated that they found the database intuitive to use and smooth functioning, without inconsistencies (both, 13 [100%]). The majority also indicated that they found the information provided to be clear, comprehensive, and useful in health care practice (12 [92.3%] each). IMPLICATIONS: The probiotics e-reference database is an integrated resource that is user-friendly, and provides HCPs with ready access to clear and comprehensive information on probiotic products and clinical studies, so that HCPs can provide consumers with relevant and evidence-based recommendations on probiotics.

Magnetic fields modulate metabolism and gut microbiome in correlation with Pgc-1α expression: Follow-up to an in vitro magnetic mitohormetic study.

Exercise modulates metabolism and the gut microbiome. Brief exposure to low mT-range pulsing electromagnetic fields (PEMFs) was previously shown to accentuate in vitro myogenesis and mitochondriogenesis by activating a calcium-mitochondrial axis upstream of PGC-1α transcriptional upregulation, recapitulating a genetic response implicated in exercise-induced metabolic adaptations. We compared the effects of analogous PEMF exposure (1.5 mT, 10 min/week), with and without exercise, on systemic metabolism and gut microbiome in four groups of mice: (a) no intervention; (b) PEMF treatment; (c) exercise; (d) exercise and PEMF treatment. The combination of PEMFs and exercise for 6 weeks enhanced running performance and upregulated muscular and adipose Pgc-1α transcript levels, whereas exercise alone was incapable of elevating Pgc-1α levels. The gut microbiome Firmicutes/Bacteroidetes ratio decreased with exercise and PEMF exposure, alone or in combination, which has been associated in published studies with an increase in lean body mass. After 2 months, brief PEMF treatment alone increased Pgc-1α and mitohormetic gene expression and after >4 months PEMF treatment alone enhanced oxidative muscle expression, fatty acid oxidation, and reduced insulin levels. Hence, short-term PEMF treatment was sufficient to instigate PGC-1α-associated transcriptional cascades governing systemic mitohormetic adaptations, whereas longer-term PEMF treatment was capable of inducing related metabolic adaptations independently of exercise.

Draft Genome Sequences of a Ceftazidime-Resistant Acinetobacter baumannii Donor and a Conjugal Escherichia coli Recipient with Acquired Resistance.

A ceftazidime-resistant Acinetobacter baumannii strain was isolated from hospital wastewater and used as the donor in a filter mating experiment with an Escherichia coli strain as the recipient. Recipient, donor, and transconjugant were sequenced, and both donor and transconjugant were found to harbor highly similar plasmid sequences, suggesting that plasmid transfer had occurred.

Metagenomic and Resistome Analysis of a Full-Scale Municipal Wastewater Treatment Plant in Singapore Containing Membrane Bioreactors.

Reclaimed water provides a water supply alternative to address problems of scarcity in urbanized cities with high living densities and limited natural water resources. In this study, wastewater metagenomes from 6 stages of a wastewater treatment plant (WWTP) integrating conventional and membrane bioreactor (MBR) treatment were evaluated for diversity of antibiotic resistance genes (ARGs) and bacteria, and relative abundance of class 1 integron integrases (intl1). ARGs confering resistance to 12 classes of antibiotics (ARG types) persisted through the treatment stages, which included genes that confer resistance to aminoglycoside [aadA, aph(6)-I, aph(3')-I, aac(6')-I, aac(6')-II, ant(2″)-I], beta-lactams [class A, class C, class D beta-lactamases (bla OXA)], chloramphenicol (acetyltransferase, exporters, floR, cmIA), fosmidomycin (rosAB), macrolide-lincosamide-streptogramin (macAB, ereA, ermFB), multidrug resistance (subunits of transporters), polymyxin (arnA), quinolone (qnrS), rifamycin (arr), sulfonamide (sul1, sul2), and tetracycline (tetM, tetG, tetE, tet36, tet39, tetR, tet43, tetQ, tetX). Although the ARG subtypes in sludge and MBR effluents reduced in diversity relative to the influent, clinically relevant beta lactamases (i.e., bla KPC, bla OXA) were detected, casting light on other potential point sources of ARG dissemination within the wastewater treatment process. To gain a deeper insight into the types of bacteria that may survive the MBR removal process, genome bins were recovered from metagenomic data of MBR effluents. A total of 101 close to complete draft genomes were assembled and annotated to reveal a variety of bacteria bearing metal resistance genes and ARGs in the MBR effluent. Three bins in particular were affiliated to Mycobacterium smegmatis, Acinetobacter Iwoffii, and Flavobacterium psychrophila, and carried aquired ARGs aac(2')-Ib, bla OXA-278, and tet36 respectively. In terms of indicator organisms, cumulative log removal values (LRV) of Escherichia coli, Enterococci, and P. aeruginosa from influent to conventional treated effluent was lower (0-2.4), compared to MBR effluent (5.3-7.4). We conclude that MBR is an effective treatment method for reducing fecal indicators and ARGs; however, incomplete removal of P. aeruginosa in MBR treated effluents (<8 MPN/100 mL) and the presence of ARGs and intl1 underscores the need to establish if further treatment should be applied prior to reuse.

Genomics and metagenomics of colorectal cancer.

Colorectal cancer (CRC) is a common cancer globally. It is a complex disease influenced by genetic and environmental factors. Early studies on familial cases have identified major genes involved in CRC, such as proto-oncogenes KRAS, PIK3CA and BRAF, and tumour-suppressor genes APC and TP53. These genes have provided valuable insight into the molecular pathogenesis of CRC, and some have made ways to clinical utility to help diagnose cancer syndromes, prognosticate oncological outcomes and predict treatment responses. While these genetic factors are important, recent studies have suggested contribution of microorganisms to colorectal carcinogenesis. Observational studies, animal experiments and translational works have identified several microorganisms as potential carcinogenic bacteria, such as Fusobacterium nucleatum and Peptostreptococcus anaerobius. With the advent of sequencing technology and bioinformatics, more genomic and metagenomic factors are being uncovered as important players in CRC carcinogenesis. This article aims to review recent genomic and metagenomic discoveries relating to CRC.

Draft Genome Sequences of Four Multidrug-Resistant Pseudomonas aeruginosa Isolates from Hospital Wastewater in Singapore.

Four multidrug-resistant Pseudomonas aeruginosa isolates were cultured from intensive care unit wastewater. All isolates exhibited resistance to carbapenem and extended-spectrum beta-lactam antibiotics. Genome characterization revealed the presence of beta-lactamase resistance genes (bla PAO and bla OXA), and three out of the four isolates carried the bla NDM-1 gene encoding resistance against carbapenems.

Microbial water quality and the detection of multidrug resistant E. coli and antibiotic resistance genes in aquaculture sites of Singapore.

Poor microbial water quality jeopardizes the health and safety of food produced by aquaculture farms. Three fish farms and transect sites in Singapore were assessed for microbial water quality and antimicrobial resistance determinants. Of the 33 multidrug resistant E. coli isolated from surface waters of the Johor Straits, 81.8% were ESBL producers. The relative abundance of sul1, qnrA and intI1 genes were higher in sediments than surface waters. Among the surface water samples, higher concentrations (10-1-101) of beta-lactamases (blaSHV, blaOXA, blaCTX-M) were detected in the transect sites. This study highlights a potential antimicrobial resistance transmission chain from environmental waters, to animal carriers and humans.

Removal of antibiotic residues, antibiotic resistant bacteria and antibiotic resistance genes in municipal wastewater by membrane bioreactor systems.

Antibiotic residues, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are considered new classes of water contaminants due to their potential adverse effects on aquatic ecosystems and human health. This paper provides comprehensive data on the occurrences of 19 antibiotics, bacteria resistant to 10 antibiotics, and 15 ARGs in raw influent and different treatment stages of conventional activated sludge (CAS) and membrane bioreactor (MBR) systems. Seventeen out of the 19 target antibiotics were detected in raw influent with concentrations of up to ten micrograms per liter. Concentrations of antibiotics measured in the secondary effluent were much lower compared to those in the raw influent. Among the antibiotics, amoxicillin, azithromycin, ciprofloxacin, chloramphenicol, meropenem, minocycline, oxytetracycline, sulfamethazine and vancomycin had highest removal by CAS or MBR systems with median removal efficiency (RE) > 70%, while trimethoprim and lincomycin were recalcitrant in the CAS system with median RE <50%. Similarly, the target ARB and ARGs were omnipresent in the raw influent samples with average concentrations as high as 2.6 × 106 CFU/mL and 2.0 × 107 gene copies/mL, respectively. The concentrations of ARB in secondary effluent of the CAS system declined relative to the raw influent (i.e. lower than raw influent by 2-3 orders of magnitude) and no ARB were detected in the MF permeate of the MBR system. For ARGs, their concentrations in secondary effluent/MF permeate ranged from below method quantification limit (

Occurrence and characteristics of extended-spectrum ß-lactamase- and carbapenemase- producing bacteria from hospital effluents in Singapore.

One of the most important resistance mechanisms in Gram-negative bacteria today is the production of enzymes causing resistance to cephalosporin and carbapenem antibiotics. The spread of extended-spectrum ß-lactamases (ESBL)- and carbapenemase- producing Gram-negative bacteria is an emerging global public health problem. The aim of the present study was to (i) assess the prevalence of carbapenem-resistant bacteria (CRB) and ESBL-producing strains in sewage effluents from two major hospitals in Singapore, (ii) characterize the isolated strains and (iii) identify some of the ESBL and carbapenemase genes responsible for the resistance. CHROMagar ESBL and KPC plates were used to rapidly screen for ESBL-producing bacteria and those expressing reduced susceptibility to carbapenems, respectively. The abundance of ESBL-producers and CRB in hospital wastewater ranged between 103 and 106CFU/mL. Out of the 66 isolates picked from ESBL and KPC plates, 95%, 82%, 82% and 76% were resistant to ceftriaxone, ceftazidime (3rd generation cephalosporin family), ertapenem and meropenem (carbapenem family), respectively. Among the resistant isolates, the most predominant taxa identified were Pseudomonas spp. (28.2%), Klebsiella spp. (28.2%), Enterobacter spp. (18.3%) and Citrobacter spp. (11.3%). PCR and sequencing analysis showed that the predominant ß-lactamase genes were blaSHV (41.1%) followed by blaNDM-1 (35.6%), blaCTX (35.6%) and blaKPC (28.8%). The results of this study show a high prevalence of bacteria resistant to modern extended-spectrum cephalosporins and carbapenems and the presence of ESBL- and carbapenemase producers in hospital effluents. These findings support the need to improve management of hospital wastewater in order to minimize the spread of antimicrobial resistant microorganisms from this source.

Corrigendum: Characterization of Metagenomes in Urban Aquatic Compartments Reveals High Prevalence of Clinically Relevant Antibiotic Resistance Genes in Wastewaters.

[This corrects the article on p. 2200 in vol. 8, PMID: 29201017.].

Occurrence of Vibrio species, beta-lactam resistant Vibrio species, and indicator bacteria in ballast and port waters of a tropical harbor.

Ballast water discharges are potential sources for the spread of invasive and pathogenic aquatic organisms. Ballast waters from six ships docked in the Port of Singapore were tested to determine if indictor organisms fell within proposed standards for ballast water discharge according to regulation D-2 of the Ballast Water Management Convention (BWMC) guidelines. Vibrio species were cultured on media supplemented with beta-lactam antibiotics to determine the presence of antibiotic resistant Vibrio species in the ballast waters of these vessels. Indicator organisms were quantified using culture media Colilert-18 and Enterolert in ballast waters of six ships docked in a tropical harbor, with uptake from different geographical locations. Of the six ships, one had ballast water originating from the Persian Gulf, another from the East China Sea, and four from the South China Sea. Two of the six ships which carried ballast waters from the East China Sea and the South China Sea did not meet the D-2 stipulated requirements of the Ballast Water Management Convention for indicator organisms with Enterococci values more than three times higher than the acceptable limit of <100CFU/100mL. Using the most-probable-number-PCR (MPN-PCR) method for Vibrio species detection, non-toxigenic species of V. cholerae (2 MPN/100mL), Vibrio vulnificus (>110 MPN/100mL), and Vibrio parahaemolyticus (2 to >110 MPN/100mL) were detected in at least one of six ballast water samples. Using thiosulfate-citrate-bile salts-sucrose agar (TCBS) supplemented with beta-lactam antibiotics (meropenem, ceftazidime), 11 different Vibrio species, exhibiting resistance to beta-lactam antibiotics were isolated; with Vibrio campbellii (44%) and Vibrio alginolyticus (15%) the most detected antibiotic resistant Vibrio species. A practical approach of prioritized screening of high-risk vessels should be conducted to ensure that the water quality meets D-2 standards prior to discharge.

Characterization of Metagenomes in Urban Aquatic Compartments Reveals High Prevalence of Clinically Relevant Antibiotic Resistance Genes in Wastewaters.

The dissemination of antimicrobial resistance (AMR) is an escalating problem and a threat to public health. Comparative metagenomics was used to investigate the occurrence of antibiotic resistant genes (ARGs) in wastewater and urban surface water environments in Singapore. Hospital and municipal wastewater (n = 6) were found to have higher diversity and average abundance of ARGs (303 ARG subtypes, 197,816 x/Gb) compared to treated wastewater effluent (n = 2, 58 ARG subtypes, 2,692 x/Gb) and surface water (n = 5, 35 subtypes, 7,985 x/Gb). A cluster analysis showed that the taxonomic composition of wastewaters was highly similar and had a bacterial community composition enriched in gut bacteria (Bacteroides, Faecalibacterium, Bifidobacterium, Blautia, Roseburia, Ruminococcus), the Enterobacteriaceae group (Klebsiella, Aeromonas, Enterobacter) and opportunistic pathogens (Prevotella, Comamonas, Neisseria). Wastewater, treated effluents and surface waters had a shared resistome of 21 ARGs encoding multidrug resistant efflux pumps or resistance to aminoglycoside, macrolide-lincosamide-streptogramins (MLS), quinolones, sulfonamide, and tetracycline resistance which suggests that these genes are wide spread across different environments. Wastewater had a distinctively higher average abundance of clinically relevant, class A beta-lactamase resistant genes (i.e., blaKPC, blaCTX-M, blaSHV, blaTEM). The wastewaters from clinical isolation wards, in particular, had a exceedingly high levels of blaKPC-2 genes (142,200 x/Gb), encoding for carbapenem resistance. Assembled scaffolds (16 and 30 kbp) from isolation ward wastewater samples indicated this gene was located on a Tn3-based transposon (Tn4401), a mobilization element found in Klebsiella pneumonia plasmids. In the longer scaffold, transposable elements were flanked by a toxin-antitoxin (TA) system and other metal resistant genes that likely increase the persistence, fitness and propagation of the plasmid in the bacterial host under conditions of stress. A few bacterial species (Enterobacter cloacae, Klebsiella pneumoniae, Citrobacter freundii, Pseudomonas aeruginosa) that were cultured from the isolation ward wastewaters on CHROMagar media harbored the blaKPC-2 gene. This suggests that hospital wastewaters derived from clinical specialty wards are hotspots for the spread of AMR. Assembled scaffolds of other mobile genetic elements such as IncQ and IncF plasmids bearing quinolone resistance genes (qnrS1, qnrS2) and the class A beta-lactamase gene (blaTEM-1) were recovered in wastewater samples which may aid the transfer of AMR.