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328800.9604Is our winter experience safe? Micropollutant risks for artificial snowing. Artificial snowing is a process that allows ski operators adapt to snow scarcity due to climate change while raising environmental and public health concerns about the role it plays in environmental dissemination of pollutants, but studies addressing this question are still scarce. This study aimed to fill this gap in understanding the role of artificial snowmaking in dissemination of antibiotics, bacterial contaminants, antibiotic resistant bacteria (ARB) and genetic determinants (ARGs) thereof. Technical snow and water used for its production were examined from 11 ski stations located in four river catchments, varying in anthropopressure and the presence/absence of storage reservoirs where water is collected before snowmaking. Culturable E. coli were found in all water intakes with clear reduction/elimination during snowmaking. Fourteen antimicrobial agents were detected using UHPLC/MS/MS. Concentration and prevalence of antimicrobials differed between the catchments; the sites located downstream of long-term stay health centers were most severely contaminated. Two antibiotics of restricted use (vancomycin and linezolid) were detected downstream of hospitals. Antimicrobial resistance of 158 E. coli strains was tested using disk diffusion method. The resistance to penicillins (e.g. ampicillin, amoxicillin/clavulanic acid) was most frequent and in general followed the pattern of antibiotic consumption rather than antibiotic concentration in water. Extended-spectrum beta lactamase (ESBL) genes were detected using PCR tests: 66.46 % (105 out of 158) strains possessed at least one ARG among which blaTEM was most frequent, followed by blaCTX-M and blaSHV. Our study indicates that the major sources of aquatic environment and technical snow contamination with antimicrobial agents are effluents from long-term stay medical centers, while bacterial contamination (including ARB and ARGs) stems from municipal WWTPs, i.e. the main hubs of antimicrobial resistance transfer to the environment. The storage reservoir construction may aid in reducing the transfer rate of pollutants and micropollutants from contaminated water to technical snow.202539970557
524810.9599Antibiotic resistance of heterotrophic bacteria from the sediments of adjoining high Arctic fjords, Svalbard. Antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) are now considered major global threats. The Kongsfjorden and Krossfjorden are the interlinked fjords in the Arctic that are currently experiencing the effects of climate change and receiving input of pollutants from distant and regional sources. The present study focused on understanding the prevalence of antibiotic resistance of retrievable heterotrophic bacteria from the sediments of adjacent Arctic fjords Kongsfjorden and Krossfjorden. A total of 237 bacterial isolates were tested against 16 different antibiotics. The higher resistance observed towards Extended Spectrum β-lactam antibiotic (ESBL) includes ceftazidime (45.56%) followed by trimethoprim (27%) and sulphamethizole (24.05%). The extent of resistance was meagre against tetracycline (2.53%) and gentamycin (2.95%). The 16S rRNA sequencing analysis identified that Proteobacteria (56%) were the dominant antibiotic resistant phyla, followed by Firmicutes (35%), Actinobacteria (8%) and Bacteroidetes. The dominant resistant bacterial isolates are Bacillus cereus (10%), followed by Alcaligenes faecalis (6.47%), Cytobacillus firmus (5.75%) Salinibacterium sp. (5%) and Marinobacter antarcticus (5%). Our study reveals the prevalence of antibiotic resistance showed significant differences in both the inner and outer fjords of Kongsfjorden and Krossfjorden (p < 0.05). This may be the input of antibiotic resistance bacteria released into the fjords from the preserved permafrost due to the melting of glaciers, horizontal gene transfer, and human influence in the Arctic region act as a selection pressure for the development and dissemination of more antibiotic resistant bacteria in Arctic fjords.202438767750
121420.9598Plasmid-mediated quinolone resistance genes in fecal bacteria from rooks commonly wintering throughout Europe. This study concerned the occurrence of fecal bacteria with plasmid-mediated quinolone resistance (PMQR) genes in rooks (Corvus frugilegus, medium-sized corvid birds) wintering in continental Europe during winter 2010/2011. Samples of fresh rook feces were taken by cotton swabs at nine roosting places in eight European countries. Samples were transported to one laboratory and placed in buffered peptone water (BPW). The samples from BPW were enriched and subcultivated onto MacConkey agar (MCA) supplemented with ciprofloxacin (0.06 mg/L) to isolate fluoroquinolone-resistant bacteria. DNA was isolated from smears of bacterial colonies growing on MCA and tested by PCR for PMQR genes aac(6')-Ib, qepA, qnrA, qnrB, qnrC, qnrD, qnrS, and oqxAB. All the PCR products were further analyzed by sequencing. Ciprofloxacin-resistant bacteria were isolated from 37% (392 positive/1,073 examined) of samples. Frequencies of samples with ciprofloxacin-resistant isolates ranged significantly from 3% to 92% in different countries. The qnrS1 gene was found in 154 samples and qnrS2 in 2 samples. The gene aac(6')-Ib-cr was found in 16 samples. Thirteen samples were positive for qnrB genes in variants qnrB6 (one sample), qnrB18 (one), qnrB19 (one), qnrB29 (one), and qnrB49 (new variant) (one). Both the qnrD and oqxAB genes were detected in six samples. The genes qnrA, qnrC, and qepA were not found. Wintering omnivorous rooks in Europe were commonly colonized by bacteria supposedly Enterobacteriaceae with PMQR genes. Rooks may disseminate these epidemiologically important bacteria over long distances and pose a risk for environmental contamination.201222731858
227430.9593Contribution of genetic factors towards cefotaxime and ciprofloxacin resistance development among Extended spectrum beta-lactamase producing-Quinolone resistant pathogenic Enterobacteriaceae. β-lactams and quinolones are widely utilised to treat pathogenic Enterobacterial isolates worldwide. Due to improper use of these antibiotics, both ESBL producing and quinolone resistant (ESBL-QR) pathogenic bacteria have emerged. Nature of contribution of beta-lactamase (bla)/quinolone resistant (QR) genes, efflux pumps (AcrAB-TolC) over-expression and outer membrane proteins (OMPs) /porin loss/reduction and their combinations towards development of this phenotype were explored in this study. Kirby-Bauer disc diffusion method was used for phenotypic characterization of these bacteria and minimum inhibitory concentration of cefotaxime and ciprofloxacin was determined by broth micro dilution assay. Presence of bla, QR, gyrA/B genes was examined by PCR; acrB upregulation by real-time quantitative PCR and porin loss/reduction by SDS-PAGE. Based on antibiogram, phenotypic categorization of 715 non-duplicate clinical isolates was: ESBL(+)QR(+) (n = 265), ESBL(+)QR(-) (n = 6), ESBL(-)QR(+) (n = 346) and ESBL(-)QR(-)(n = 11). Increased OmpF/K35 and OmpC/K36 reduction, acrB up-regulation, prevalence of bla, QR genes and gyrA/B mutation was observed among the groups in following order: ESBL(+)QR(+)> ESBL(-)QR(+)> ESBL(+)QR-> ESBL(-)QR(-). Presence of bla gene alone or combined porin loss and efflux pump upregulation or their combination contributed most for development of a highest level of cefotaxime resistance of ESBL(+)QR(+) isolates. Similarly, combined presence of QR genes, porin loss/reduction, efflux pump upregulation and gyrA/B mutation contributed towards highest ciprofloxacin resistance development of these isolates.202437884102
708240.9592Catchment-scale export of antibiotic resistance genes and bacteria from an agricultural watershed in central Iowa. Antibiotics are administered to livestock in animal feeding operations (AFOs) for the control, prevention, and treatment of disease. Manure from antibiotic treated livestock contains unmetabolized antibiotics that provide selective pressure on bacteria, facilitating the expression of anti-microbial resistance (AMR). Manure application on row crops is an agronomic practice used by growers to meet crop nutrient needs; however, it can be a source of AMR to the soil and water environment. This study in central Iowa aims to directly compare AMR indicators in outlet runoff from two adjacent (221 to 229 ha) manured and non-manured catchments (manure comparison), and among three catchments (600 to 804 ha) with manure influence, no known manure application (control), and urban influences (mixed land use comparison). Monitored AMR indicators included antibiotic resistance genes (ARGs) ermB, ermF (macrolide), tetA, tetM, tetO, tetW (tetracycline), sul1, sul2 (sulfonamide), aadA2 (aminoglycoside), vgaA, and vgaB (pleuromutilin), and tylosin and tetracycline resistant enterococci bacteria. Results of the manure comparison showed significantly higher (p<0.05) tetracycline and tylosin resistant bacteria from the catchment with manure application in 2017, but no differences in 2018, possibly due to changes in antibiotic use resulting from the Veterinary Feed Directive. Moreover, the ARG analysis indicated a larger diversity of ARGs at the manure amended catchment. The mixed land use comparison showed the manure amended catchment had significantly higher (p<0.05) tetracycline resistant bacteria in 2017 and significantly higher tylosin resistant bacteria in 2017 and 2018 than the urban influenced catchment. The urban influenced catchment had significantly higher ermB concentrations in both sampling years, however the manure applied catchment runoff consisted of higher relative abundance of total ARGs. Additionally, both catchments showed higher AMR indicators compared to the control catchment. This study identifies four ARGs that might be specific to AMR as a result of agricultural sources (tetM, tetW, sul1, sul2) and optimal for use in watershed scale monitoring studies for tracking resistance in the environment.202031923233
450650.9591Molecular profiling of multidrug-resistant river water isolates: insights into resistance mechanism and potential inhibitors. Polluted waters are an important reservoir for antibiotic resistance genes and multidrug-resistant bacteria. This report describes the microbial community, antibiotic resistance genes, and the genetic profile of extended spectrum β-lactamase strains isolated from rivers at, Pune, India. ESBL-producing bacteria isolated from diverse river water catchments running through Pune City were characterized for their antibiotic resistance. The microbial community and types of genes which confer antibiotic resistance were identified followed by the isolation of antibiotic-resistant bacteria on selective media and their genome analysis. Four representative isolates were sequenced using next generation sequencing for genomic analysis. They were identified as Pseudomonas aeruginosa, Escherichia coli, and two isolates were Enterobacter cloacae. The genes associated with the multidrug efflux pumps, such as tolC, macA, macB, adeL, and rosB, were detected in the isolates. As MacAB-TolC is an ABC type efflux pump responsible for conferring resistance in bacteria to several antibiotics, potential efflux pump inhibitors were identified by molecular docking. The homology model of their MacB protein with that from Escherichia coli K12 demonstrated structural changes in different motifs of MacB. Molecular docking of reported efflux pump inhibitors revealed the highest binding affinity of compound MC207-110 against MacB. It also details the potential efflux pump inhibitors that can serve as possible drug targets in drug development and discovery.202031236860
708160.9591Seasonal variations in export of antibiotic resistance genes and bacteria in runoff from an agricultural watershed in Iowa. Seasonal variations of antimicrobial resistance (AMR) indicators in runoff water can help improve our understanding of AMR sources and transport within an agricultural watershed. This study aimed to monitor multiple areas throughout the Black Hawk Lake (BHL) watershed (5324 ha) in central Iowa during 2017 and 2018 that consists of both swine and cattle feeding operations as well as known areas with manure application. The measured indicators included plate counts for fecal indicator bacteria (FIB) E. coli, Enterococcus, antibiotic resistant fecal indicator bacteria (ARBs) tylosin resistant Enterococcus, tetracycline resistant Enterococcus, and antibiotic resistance genes (ARGs): ermB, ermF (macrolide), tetA, tetM, tetO, tetW (tetracycline), sul1, sul2 (sulfonamide), aadA2 (aminoglycoside), vgaA, and vgaB (pleuromutilin). Both the plate count and the ARG analyses showed seasonal trends. Plate counts were significantly greater during the growing season, while the ARGs were greater in the pre-planting and post-harvest seasons (Wilcoxon Rank-Sum Test p < 0.05). The ermB gene concentration was significantly correlated (p < 0.05) with E. coli and Enterococcus concentrations in 2017, suggesting a potential use of this ARG as an indicator of environmental AMR and human health risk. Flow rate was not a significant contributor to annual variations in bacteria and AMR indicators. Based on observed seasonal patterns, we concluded that manure application was the likely contributor to elevated ARG indicators observed in the BHL watershed, while the driver of elevated ARB indictors in the growing season can only be speculated. Understanding AMR export patterns in agricultural watersheds provides public health officials knowledge of seasonal periods of higher AMR load to recreational waters.202032806354
106670.9588Biomonitoring marine habitats in reference to antibiotic resistant bacteria and ampicillin resistance determinants from oviductal fluid of the nesting green sea turtle, Chelonia mydas. During the egg-laying process, oviductal fluid was collected using a non-invasive procedure from the cloacal vent of the green turtles. Forty-two independent isolates of antibiotic-resistant bacteria from 11 genera were obtained from 20 turtles during nesting. The dominant isolate was Citrobacter (52.4%), followed by Pseudomonas, Proteus, Enterobacter, Salmonella, Escherichia coli, Shigella, Edwardsiella, Morganella, Providencia and Arcomobacter. Most of the isolates were resistant to ampicillin. Ampicillin-resistant isolates showed variations in their resistance for the following classes of β-lactamases: extended-spectrum β-lactamases (EBSLs), AmpC type β-lactamases C (AmpC), and screen-positive β-lactamase. None of the isolates produced metallo β-lactamase. Some ampicillin-resistant genes were detected by multiplex polymerase chain reaction (PCR) only. Inhibitor based test (IBT) categorized some isolates as AmpC β-lactamase producers. β-Lactamase genes were detected from a few strains. The sequencing of those genes revealed the presence of cephamycinase (CMY) and AmpC β-lactamases. The oviductal fluid was used in this study as a source of bacterial antibiotic-resistant determinants for biomonitoring marine turtles exposed to contaminated effluents. This data can be of value in understanding the decline of this endangered species as a result of exposure to marine pollution which is threatening their survival.201222406312
354580.9588Fecal indicators and antibiotic resistance genes exhibit diurnal trends in the Chattahoochee River: Implications for water quality monitoring. Water bodies that serve as sources of drinking or recreational water are routinely monitored for fecal indicator bacteria (FIB) by state and local agencies. Exceedances of monitoring thresholds set by those agencies signal likely elevated human health risk from exposure, but FIB give little information about the potential source of contamination. To improve our understanding of how within-day variation could impact monitoring data interpretation, we conducted a study at two sites along the Chattahoochee River that varied in their recreational usage and adjacent land-use (natural versus urban), collecting samples every 30 min over one 24-h period. We assayed for three types of microbial indicators: FIB (total coliforms and Escherichia coli); human fecal-associated microbial source tracking (MST) markers (crAssphage and HF183/BacR287); and a suite of clinically relevant antibiotic resistance genes (ARGs; blaCTX-M, blaCMY, MCR, KPC, VIM, NDM) and a gene associated with antibiotic resistance (intl1). Mean levels of FIB and clinically relevant ARGs (blaCMY and KPC) were similar across sites, while MST markers and intI1 occurred at higher mean levels at the natural site. The human-associated MST markers positively correlated with antibiotic resistant-associated genes at both sites, but no consistent associations were detected between culturable FIB and any molecular markers. For all microbial indicators, generalized additive mixed models were used to examine diurnal variability and whether this variability was associated with environmental factors (water temperature, turbidity, pH, and sunlight). We found that FIB peaked during morning and early afternoon hours and were not associated with environmental factors. With the exception of HF183/BacR287 at the urban site, molecular MST markers and intI1 exhibited diurnal variability, and water temperature, pH, and turbidity were significantly associated with this variability. For blaCMY and KPC, diurnal variability was present but was not correlated with environmental factors. These results suggest that differences in land use (natural or urban) both adjacent and upstream may impact overall levels of microbial contamination. Monitoring agencies should consider matching sample collection times with peak levels of target microbial indicators, which would be in the morning or early afternoon for the fecal associated indicators. Measuring multiple microbial indicators can lead to clearer interpretations of human health risk associated with exposure to contaminated water.202236439800
729590.9586Dissemination of antibiotic resistance in receiving environments under a changing climate: A modeling exercise. Antibiotic resistance in rivers has become a global problem, particularly due to the discharge of wastewater treatment plant (WWTP) effluents into these systems. These effluents contain residual antibiotics, antibiotic-resistance genes (ARGs), and antibiotic-resistant bacteria (ARB). While watershed-scale models are commonly used to address other water quality issues, they have not typically been used to address antibiotic resistance. In this study, we present a new model called SWAT-ARB (SWAT- Antibiotic-Resistant Bacteria) that can simulate antibiotic resistance in E. coli at the watershed scale. SWAT-ARB is an adaptation of the widely-used SWAT (Soil and Water Assessment Tool) model, which is a physically-based, watershed-scale hydrological model. We used SWAT-ARB to study the receiving environments of WWTPs in the Adyar River basin in India, Crab Creek in the United States, and the Upper Viskan basin in Sweden. We analyzed the simulations of resistant fractions (the ratio of resistant E. coli concentration to total E. coli concentration) in the streamflow at different flow levels. We also examined the long-term trends of resistant fractions to understand how rising temperatures may impact resistance. We found that in the Adyar and Crab Creek basins, the resistant fractions were largely influenced by temperature rather than flow and wash-off processes, while in the Upper Viskan basin, the resistant fractions were affected by both temperature and flow conditions. In a simulation where we only increased temperatures by 2 °C in the bacteria sub-routine, we found that the Adyar basin showed a decrease in resistant fractions of up to 17 % in dry conditions, while Crab Creek showed increases of 17.5-24.1 % and Upper Viskan showed increases of 4.6-33.5 % across flow classes. Under future climate scenarios (SSP 2-4.5 and SSP 5-8.5), Adyar's resistant fractions decreased by up to 55.5 % as temperatures approached the bacterial growth inhibition threshold, while Crab Creek's resistant fractions increased by up to 175 % as temperatures remained within the optimal 10-20 °C growth range. Our results suggest that the SWAT-ARB model could be further improved by incorporating temperature-dependent parameters into the resistance simulation component.202540743959
5275100.9586Characterization of antibiotic-resistance genes in antibiotic resistance Escherichia coli isolates from a lake. The spread of antibiotic-resistance bacteria and antibiotic-resistance genes (ARGs) has been of concern worldwide. In this study, 114 Escherichia coli isolates were isolated from surface water samples of a lake to identify their susceptibility to antibiotics, including tetracycline (TC), gentamicin (GN), ampicillin (AMP), streptomycin (ST), oxytetracycline (OC), levofloxacin (LEV), nalidixic acid (NA), and sulfamethoxazole/trimethoprim (SFT). Isolates showing resistance to TC, GN, AMP, ST, OC, LEV, NA, and SFT occurred in 50, 76, 68, 71, 55, 32, 82, and 85 % of the total isolates, respectively. Thirty-seven different resistance patterns were identified, and the most abundant resistance profile (28 of 104) was TC/GN/AMP/ST/OC/LEV/NA/SFT. The occurrence of 29 ARGs were detected in their corresponding resistance clones, and 88 % of TC-resistance, 94 % of SFT-resistance, 90 % of AMP-resistance, 78 % of ST-resistance, and 72 % of quinolone-resistance clones can be described by their corresponding ARGs. It should be noted that most of these antibiotic-resistance clones harbored at least two corresponding ARGs, indicating that high frequencies of combined ARGs occurred in these isolates. In addition, 9 new types of DNA sequence of qnr(B) gene were obtained and were clustered into the same group as showed by phylogenetic trees analysis. These results suggest that the development of antibiotic resistance can be ascribed to the high frequency in the recombination of ARGs through horizontal gene transfer.201323846774
3079110.9586Quantification of antibiotic resistance genes (ARGs) in clouds at a mountain site (puy de Dôme, central France). Antibiotic resistance in bacteria is becoming a major sanitary concern worldwide. The extensive use of large quantities of antibiotics to sustain human activity has led to the rapid acquisition and maintenance of antibiotic resistant genes (ARGs) in bacteria and to their spread into the environment. Eventually, these can be disseminated over long distances by atmospheric transport. Here, we assessed the presence of ARGs in clouds as an indicator of long-distance travel potential of antibiotic resistance in the atmosphere. We hypothesized that a variety of ARGs can reach the altitude of clouds mainly located within the free troposphere. Once incorporated in the atmosphere, they are efficiently transported and their respective concentrations should differ depending on the sources and the geographical origin of the air masses. We deployed high-flow rate impingers and collected twelve clouds between September 2019 and October 2021 at the meteorological station of the puy de Dôme summit (1465 m a.s.l., France). Total airborne bacteria concentration was assessed by flow cytometry, and ARGs subtypes of the main families of antibiotic resistance (quinolone, sulfonamide, tetracycline; glycopeptide, aminoglycoside, β-lactamase, macrolide) including one mobile genetic element (transposase) were quantified by qPCR. Our results indicate the presence of 29 different ARGs' subtypes at concentrations ranging from 1.01 × 10(3) to 1.61 × 10(4) copies m(-3) of air. Clear distinctions could be observed between clouds in air masses transported over marine areas (Atlantic Ocean) and clouds influenced by continental surfaces. Specifically, quinolones (mostly qepA) resistance genes were prevalent in marine clouds (54 % of the total ARGs on average), whereas higher contributions of sulfonamide, tetracycline; glycopeptide, β-lactamase and macrolide were found in continental clouds. This study constitutes the first evidence for the presence of microbial ARGs in clouds at concentrations comparable to other natural environments. This highlights the atmosphere as routes for the dissemination of ARGs at large scale.202336587700
5321120.9585Fluoroquinolone (FQ) contamination does not correlate with occurrence of FQ-resistant bacteria in aquatic environments of Vietnam and Thailand. Fluoroquinolone antibiotics (FQs) have been used worldwide for chemotherapy, animal husbandry, and aquaculture, and the occurrence of FQ-resistant (FQs(r)) bacteria in natural environments has been reported. Plasmid-mediated transferable quinolone resistance (PMQR) genes are suspected to originate from the chromosomes of water-dwelling bacteria. However, the occurrence of and the potential reservoir of FQs(r) bacteria and PMQR genes in aquatic environments have not been elucidated. In this study, we detected FQs(r) bacteria and PMQR genes in aquatic environments in Thailand and Vietnam, and measured FQ contamination. Levels of contamination were greater Thailand (avg. 5130, max 46100 ng L(-1)) than in Vietnam (avg. 235, max 1130 ng L(-1)); however, the occurrence of FQs(r) bacteria was higher in Vietnam (~15%) than in Thailand (~7.0%), suggesting that contamination by FQs is not directly linked to the development of FQs(r) bacteria. Diverse taxonomic groups of FQs(r)-bacteria were identified, and one of the PMQR genes, qnrB, was detected from bacteria of environmental origin, not enteric bacteria. This suggests that the environmental bacteria are a potential reservoir of antibiotic resistance determinants even at un-contaminated sites.201121502737
7779130.9585Metagenomic 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.201930833934
1820140.9585Intensive farming as a source of bacterial resistance to antimicrobial agents in sedentary and migratory vultures: Implications for local and transboundary spread. The role of wild birds in the carriage and transmission of human and food animal bacteria with resistant genotypes has repeatedly been highlighted. However, few studies have focussed on the specific exposure sources and places of acquisition and selection for antimicrobial-resistant bacteria in vultures relying on livestock carcasses across large areas and different continents. The occurrence of bacterial resistance to antimicrobial agents was assessed in the faecal microbiota of sedentary Griffon vultures (Gyps fulvus) and trans-Saharan migratory Egyptian vultures (Neophron percnopterus) in central Spain. High rates (generally >50%) of resistant Escherichia coli and other enterobacteria to amoxicillin, cotrimoxazole and tetracycline were found. About 25-30% of samples were colonised by extended-spectrum beta-lactamases (ESBL) producing bacteria, while 5-17% were positive for plasmid mediated quinolone resistance (PMQR) phenotypes, depending on vulture species and age. In total, nine ESBL types were recorded (7 in griffon vultures and 5 in Egyptian vultures), with CTX-M-1 the most prevalent in both species. The most prevalent PMQR was mediated by qnrS genes. We found no clear differences in the occurrence of antimicrobial resistance in adult vultures of each species, or between nestling and adult Egyptian vultures. This supports the hypothesis that antimicrobial resistance is acquired in the European breeding areas of both species. Bacterial resistance can directly be driven by the regular ingestion of multiple active antimicrobials found in medicated livestock carcasses from factory farms, which should be not neglected as a contributor to the emergence of novel resistance clones. The One Health framework should consider the potential transboundary carriage and spread of epidemic resistance from high-income European to low-income African countries via migratory birds.202032758969
1806150.9585Seawater is a reservoir of multi-resistant Escherichia coli, including strains hosting plasmid-mediated quinolones resistance and extended-spectrum beta-lactamases genes. The aim of this study was to examine antibiotic resistance (AR) dissemination in coastal water, considering the contribution of different sources of fecal contamination. Samples were collected in Berlenga, an uninhabited island classified as Natural Reserve and visited by tourists for aquatic recreational activities. To achieve our aim, AR in Escherichia coli isolates from coastal water was compared to AR in isolates from two sources of fecal contamination: human-derived sewage and seagull feces. Isolation of E. coli was done on Chromocult agar. Based on genetic typing 414 strains were established. Distribution of E. coli phylogenetic groups was similar among isolates of all sources. Resistances to streptomycin, tetracycline, cephalothin, and amoxicillin were the most frequent. Higher rates of AR were found among seawater and feces isolates, except for last-line antibiotics used in human medicine. Multi-resistance rates in isolates from sewage and seagull feces (29 and 32%) were lower than in isolates from seawater (39%). Seawater AR profiles were similar to those from seagull feces and differed significantly from sewage AR profiles. Nucleotide sequences matching resistance genes bla TEM, sul1, sul2, tet(A), and tet(B), were present in isolates of all sources. Genes conferring resistance to 3rd generation cephalosporins were detected in seawater (bla CTX-M-1 and bla SHV-12) and seagull feces (bla CMY-2). Plasmid-mediated determinants of resistance to quinolones were found: qnrS1 in all sources and qnrB19 in seawater and seagull feces. Our results show that seawater is a relevant reservoir of AR and that seagulls are an efficient vehicle to spread human-associated bacteria and resistance genes. The E. coli resistome recaptured from Berlenga coastal water was mainly modulated by seagulls-derived fecal pollution. The repertoire of resistance genes covers antibiotics critically important for humans, a potential risk for human health.201425191308
1230160.9585Lentic and effluent water of Delhi-NCR: a reservoir of multidrug-resistant bacteria harbouring blaCTX-M, blaTEM and blaSHV type ESBL genes. Antimicrobial resistance is not restricted to clinics but also spreading fast in the aquatic environment. This study focused on the prevalence and diversity of extended-spectrum β-lactamase (ESBL) genes among bacteria from lentic and effluent water in Delhi-NCR, India. Phenotypic screening of 436 morphologically distinct bacterial isolates collected from diverse sites revealed that 106 (∼24%) isolates were ESBL positive. Antibiotic profiling showed that 42, 60, 78 and 59% ESBL producing isolates collected from Ghazipur slaughterhouse, Lodhi garden pond, Hauz Khas lake and Jasola wastewater treatment plant, respectively, were multidrug-resistant (MDR). The multiple antibiotic resistance (MAR) index varied from 0.20 to 0.32 among selected locations. The prevalence of ESBL gene variants blaSHV, blaTEM and blaCTX-M were found to be 17.64, 35.29 and 64%, respectively. Furthermore, the analysis of obtained gene sequences showed three variants of blaCTX-M (15, 152 and 205) and two variants of blaTEM (TEM-1 and TEM-116) among ESBL producers. The co-existence of 2-3 gene variants was recorded among 48% ESBL positive isolates. New reports from this study include the blaCTX-M gene in Acinetobacter lwoffii, Enterobacter ludwigii, Exiguobacterium mexicanum and Aeromonas caviae. Furthermore, the identification of blaTEM and blaSHV in an environmental isolate of A. caviae is a new report from India.202134371496
2621170.9585Extended Spectrum Beta-Lactamase (ESBL)-producing bacteria isolated from hospital wastewaters, rivers and aquaculture sources in Nigeria. Untreated wastewater is a risk factor for the spread of antibiotic resistance in the environment. However, little is known about the contribution of untreated wastewater to the burden of antibiotic resistance in the Nigerian environment. In this study, a total of 143 ceftazidime-/cefpodoxime-resistant bacteria isolated from untreated wastewater and untreated wastewater-contaminated surface and groundwater in Nigeria were screened for extended-spectrum β-lactamase (ESBL) genes, integrons and integron gene cassettes by PCR. The genetic environment of bla (CTX-M-15) was mapped by PCR and potentially conjugative plasmids were detected among the isolates by degenerate primer MOB typing (DPMT). ESBL production was confirmed in 114 (79.7%) isolates and ESBL genes (bla (SHV), bla (CTX-M-15) and bla (TEM)) were detected in 85 (74.6%) ESBL-producing isolates. bla (CTX-M-15) was associated with ISEcp1 and with orf477 in 12 isolates and with ISEcp1, IS26 and orf477 in six others. To the best of our knowledge, this is the first report of bla (CTX-M-15) in hand-dug wells and borehole serving as sources of drinking water and a first report of the genetic environment of bla (CTX-M-15) in environmental bacteria from Nigeria. The results of this study confirm untreated wastewater as an important medium for the spread of ESBL-producing bacteria within the Nigerian environment. Hence, the widespread practice of discharging untreated wastewater into the aquatic ecosystem in Nigeria is a serious risk to public health.201829139076
1217180.9585Antimicrobial Susceptibility Profiles among Pseudomonas aeruginosa Isolated from Professional SCUBA Divers with Otitis Externa, Swimming Pools and the Ocean at a Diving Operation in South Africa. SCUBA divers are predisposed to otitis externa caused by Pseudomonas aeruginosa, which is becoming increasingly multi-drug resistant (MDR). The present work assessed the antibiotic resistance profiles of P. aeruginosa obtained from SCUBA divers and their environment in Sodwana Bay, South Africa. Bacterial isolates from a total of 137 random water and ear swab samples were identified using biochemical and molecular methods. P. aeruginosa strains were further evaluated for antibiotic susceptibility using the Kirby-Bauer assay. Double disk synergy test (DDST) to confirm metallo-β-lactamase (MBL) production and PCR amplification of specific antibiotic resistance genes was performed. All (100%) 22 P. aeruginosa isolates recovered were resistant to 6 of the β-lactams tested including imipenem but exhibited susceptibility to trimethoprim-sulfamethoxazole. MBL production was observed in 77% of isolates while the most prevalent extended-spectrum β-lactamase (ESBL) genes present included bla(AmpC) (86.9%) followed by bla(TEM) (82.6%). Sulfonamide resistance was largely encoded by sul1 (63.6%) and sul2 (77.3%) genes with a high abundance of class 1 integrons (77.3%) of which 18.2% carried both Intl1 and Intl2. P. aeruginosa found in Sodwana Bay exhibits multi-drug resistance (MDRce) to several pharmaceutically important drugs with the potential to transfer antibiotic resistance to other bacteria if the judicious use of antibiotics for their treatment is not practiced.202235056039
5264190.9585Comparison of Culture- and Quantitative PCR-Based Indicators of Antibiotic Resistance in Wastewater, Recycled Water, and Tap Water. Standardized methods are needed to support monitoring of antibiotic resistance in environmental samples. Culture-based methods target species of human-health relevance, while the direct quantification of antibiotic resistance genes (ARGs) measures the antibiotic resistance potential in the microbial community. This study compared measurements of tetracycline-, sulphonamide-, and cefotaxime-resistant presumptive total and fecal coliforms and presumptive enterococci versus a suite of ARGs quantified by quantitative polymerase chain reaction (qPCR) across waste-, recycled-, tap-, and freshwater. Cross-laboratory comparison of results involved measurements on samples collected and analysed in the US and Portugal. The same DNA extracts analysed in the US and Portugal produced comparable qPCR results (variation <28%), except for bla(OXA-1) gene (0%-57%). Presumptive total and fecal coliforms and cefotaxime-resistant total coliforms strongly correlated with bla(CTX-M) and intI1 (0.725 ≤ R(2) ≤ 0.762; p < 0.0001). Further, presumptive total and fecal coliforms correlated with the Escherichia coli-specific biomarkers, gadAB, and uidA, suggesting that both methods captured fecal-sourced bacteria. The genes encoding resistance to sulphonamides (sul1 and sul2) were the most abundant, followed by genes encoding resistance to tetracyclines (tet(A) and tet(O)) and β-lactams (bla(OXA-1) and(,)bla(CTX-M)), which was in agreement with the culture-based enumerations. The findings can help inform future application of methods being considered for international antibiotic resistance surveillance in the environment.201931671709