# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 2835 | 0 | 1.0000 | Wastewater used for urban agriculture in West Africa as a reservoir for antibacterial resistance dissemination. State of art metagenomics were used to investigate the microbial population, antibiotic resistance genes and plasmids of medical interest in wastewater used for urban agriculture in Ouagadougou (Burkina Faso). Wastewater samples were collected from three canals near agricultural fields in three neighbourhoods. Assessment of microbial population diversity revealed different microbial patterns among the different samples. Sequencing reads from the wastewaters revealed different functional specializations of microbial communities, with the predominance of carbohydrates and proteins metabolism functions. Eleven pathogen-specific and 56 orthologous virulence factor genes were detected in the wastewater samples. These virulence factors are usually found in human pathogens that cause gastroenteritis and/or diarrhoea. A wide range of antibiotic resistance genes was identified; 81 are transmissible by mobile genetic elements. These included seven different extended spectrum β-lactamase genes encoding synthesis of four enzyme families, including two metallo-β-lactamases (bla(AIM-1) and bla(GES-21)). Ten different incompatibility groups of Enterobacteriaceae plasmid replicons (ColE, FIB, FIC, FII, P, Q, R, U, Y, and A/C), and 30 plasmid replicon types from Gram-positive bacteria. All are implicated in the wide distribution of antibiotic resistance genes. We conclude that wastewater used for urban agriculture in the city represents a high risk for spreading bacteria and antimicrobial resistance among humans and animals. | 2019 | 30253312 |
| 1592 | 1 | 0.9999 | Identification of ESBL-Producing Enterobacterales From Vegetable Plants: Preliminary Findings From a Small Cross-Sectional Study in a Rural Area of Madagascar. Extended-spectrum beta-lactamases (ESBL)-producing enterobacterales are considered a key indicator for antimicrobial resistance (AMR) epidemiological surveillance in animal, human, and environment compartments. In this study, we aim to investigate the presence and genetic diversity of ESBL-producing enterobacterales on vegetable plants. We isolated beta-lactam resistant enterobacterales from several vegetable plants and sequenced their whole genome. Utilising standard genomic and phylogenetic methods, we sought to (i) characterise the resistance genes and plasmid content of the plant-isolated strains, (ii) investigate their genetic structure, and (iii) determine their relationships with strains from other reservoirs. Among the 22 strains collected from vegetable plants, 6 showed resistance to beta-lactam antibiotics, with 5 of them identified as ESBL producers. Our results indicated the presence of multidrug-resistant (MDR) strains containing multiple antibiotic resistance genes (ARGs). Importantly, no host-specific lineages were identified among the plant-isolated ESBL-producing E. coli (ESBL-Ec). Instead, these strains exhibited genetic and epidemiological connections with strains isolated from animals, humans, and the environment, suggesting transfer of ESBL-Ec between plants and other sources in rural Madagascar. These preliminary findings suggest that vegetable plants are contaminated as a result of human activities, posing a potential risk of human and animal exposure to antibiotic-resistant bacteria and genes. | 2025 | 40528688 |
| 2836 | 2 | 0.9999 | Waste water effluent contributes to the dissemination of CTX-M-15 in the natural environment. OBJECTIVES: Multidrug-resistant Enterobacteriaceae pose a significant threat to public health. We aimed to study the impact of sewage treatment effluent on antibiotic resistance reservoirs in a river. METHODS: River sediment samples were taken from downstream and upstream of a waste water treatment plant (WWTP) in 2009 and 2011. Third-generation cephalosporin (3GC)-resistant Enterobacteriaceae were enumerated. PCR-based techniques were used to elucidate mechanisms of resistance, with a new two-step PCR-based assay developed to investigate bla(CTX-M-15) mobilization. Conjugation experiments and incompatibility replicon typing were used to investigate plasmid ecology. RESULTS: We report the first examples of bla(CTX-M-15) in UK river sediment; the prevalence of bla(CTX-M-15) was dramatically increased downstream of the WWTP. Ten novel genetic contexts for this gene were identified, carried in pathogens such as Escherichia coli ST131 as well as indigenous aquatic bacteria such as Aeromonas media. The bla(CTX-M-15) -gene was readily transferable to other Gram-negative bacteria. We also report the first finding of an imipenem-resistant E. coli in a UK river. CONCLUSIONS: The high diversity and host range of novel genetic contexts proves that evolution of novel combinations of resistance genes is occurring at high frequency and has to date been significantly underestimated. We have identified a worrying reservoir of highly resistant enteric bacteria in the environment that poses a threat to human and animal health. | 2014 | 24797064 |
| 2843 | 3 | 0.9999 | High Throughput Screening of Antimicrobial Resistance Genes in Gram-Negative Seafood Bacteria. From a global view of antimicrobial resistance over different sectors, seafood and the marine environment are often considered as potential reservoirs of antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs); however, there are few studies and sparse results on this sector. This study aims to provide new data and insights regarding the content of resistance markers in various seafood samples and sources, and therefore the potential exposure to humans in a global One Health approach. An innovative high throughput qPCR screening was developed and validated in order to simultaneously investigate the presence of 41 ARGs and 33 MGEs including plasmid replicons, integrons, and insertion sequences in Gram-negative bacteria. Analysis of 268 seafood isolates from the bacterial microflora of cod (n = 24), shellfish (n = 66), flat fishes (n = 53), shrimp (n = 10), and horse mackerel (n = 115) show the occurrence of sul-1, ant(3″)-Ia, aph(3')-Ia, strA, strB, dfrA1, qnrA, and bla(CTX-M-9) genes in Pseudomonas spp., Providencia spp., Klebsiella spp., Proteus spp., and Shewanella spp. isolates and the presence of MGEs in all bacterial species investigated. We found that the occurrence of MGE may be associated with the seafood type and the environmental, farming, and harvest conditions. Moreover, even if MGE were detected in half of the seafood isolates investigated, association with ARG was only identified for twelve isolates. The results corroborate the hypothesis that the incidence of antimicrobial-resistant bacteria (ARB) and ARG decreases with increasing distance from potential sources of fecal contamination. This unique and original high throughput micro-array designed for the screening of ARG and MGE in Gram-negative bacteria could be easily implementable for monitoring antimicrobial resistance gene markers in diverse contexts. | 2022 | 35744743 |
| 2837 | 4 | 0.9999 | Molecular evidence of the close relatedness of clinical, gull and wastewater isolates of quinolone-resistant Escherichia coli. Escherichia coli with reduced susceptibility to quinolones isolated from different environmental sources (urban wastewater treatment plants, n=61; hospital effluent, n=10; urban streams, n=9; gulls, n=18; birds of prey, n=17) and from hospitalised patients (n=28) were compared based on multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). The habitats with the most diversified genotypes of quinolone-resistant E. coli, corresponding to the highest genetic diversity (H'), were wastewater and gulls. In addition, genetically distinct populations were observed in clinical samples and birds of prey, suggesting the influence of the habitat or selective pressures on quinolone-resistant E. coli. The close genetic relatedness between isolates of clinical origin and from gulls and wastewater suggests the existence of potential routes of propagation between these sources. The most common sequence types were ST131 and ST10, with ST131 being highly specific to patients, although distributed in all of the other habitats except birds of prey. The prevalence of antimicrobial resistance was significantly higher in isolates from patients and gulls than from other sources (P<0.01), suggesting that the effect of selective pressures met by isolates subjected to strong human impacts. The evidence presented suggests the potential circulation of bacteria between the environmental and clinical compartments, with gulls being a relevant vector of bacteria and resistance genes. | 2015 | 27842875 |
| 5613 | 5 | 0.9998 | Characterizing Antimicrobial Resistance in Clinically Relevant Bacteria Isolated at the Human/Animal/Environment Interface Using Whole-Genome Sequencing in Austria. Antimicrobial resistance (AMR) is a public health issue attributed to the misuse of antibiotics in human and veterinary medicine. Since AMR surveillance requires a One Health approach, we sampled nine interconnected compartments at a hydrological open-air lab (HOAL) in Austria to obtain six bacterial species included in the WHO priority list of antibiotic-resistant bacteria (ARB). Whole genome sequencing-based typing included core genome multilocus sequence typing (cgMLST). Genetic and phenotypic characterization of AMR was performed for all isolates. Eighty-nine clinically-relevant bacteria were obtained from eight compartments including 49 E. coli, 27 E. faecalis, 7 K. pneumoniae and 6 E. faecium. Clusters of isolates from the same species obtained in different sample collection dates were detected. Of the isolates, 29.2% were resistant to at least one antimicrobial. E. coli and E. faecalis isolates from different compartments had acquired antimicrobial resistance genes (ARGs) associated with veterinary drugs such as aminoglycosides and tetracyclines, some of which were carried in conjugative and mobilizable plasmids. Three multidrug resistant (MDR) E. coli isolates were found in samples from field drainage and wastewater. Early detection of ARGs and ARB in natural and farm-related environments can identify hotspots of AMR and help prevent its emergence and dissemination along the food/feed chain. | 2022 | 36232576 |
| 2577 | 6 | 0.9998 | Molecular Detection of bla(TEM) and bla(SHV) Genes in ESBL-Producing Acinetobacter baumannii Isolated from Antarctic Soil. The phenomenon of antimicrobial resistance (AMR) in cold environments, exemplified by the Antarctic, calls into question the assumption that pristine ecosystems lack clinically significant resistance genes. This study examines the molecular basis of AMR in Acinetobacter spp. Isolated from Antarctic soil, focusing on the bla(TEM) and bla(SHV) genes associated with extended-spectrum beta-lactamase (ESBL) production; Soil samples were collected and processed to isolate Antarctic soil bacteria. Molecular detection was then conducted using polymerase chain reaction (PCR) to identify the bacteria species by 16S rRNA/rpoB and 10 different beta-lactamase-producing genes. PCR amplicons were sequenced to confirm gene identity and analyze genetic variability. Acinetobacter baumannii were identified by both microbiological and molecular tests. Notably, both the bla(TEM) and bla(SHV) genes encoding the enzymes responsible for resistance to penicillins and cephalosporins were identified, indicating the presence of resistance determinants in bacteria from extreme cold ecosystems. The nucleotide sequence analysis indicated the presence of conserved ARGs, which suggest stability and the potential for horizontal gene transfer within microbial communities. These findings emphasize that AMR is not confined to human-impacted environments but can emerge and persist in remote, cold habitats, potentially facilitated by natural reservoirs and global microbial dispersal. Understanding the presence and role of AMR in extreme environments provides insights into its global dissemination and supports the development of strategies to mitigate the spread of resistance genes in both environmental and clinical contexts. | 2025 | 40142377 |
| 3311 | 7 | 0.9998 | Appearance of mcr-9, bla(KPC), cfr and other clinically relevant antimicrobial resistance genes in recreation waters and sands from urban beaches, Brazil. The co-occurrence of mcr-like and carbapenemase-encoding genes have been reported mainly in humans and animals, whereas, in the environment, studies are gradually increasing due to the One Health approach. In this study, we investigated antimicrobial resistance genes (ARGs) in water and sand samples from marine environments in Brazil. Total DNA from 56 samples (33 sands and 23 waters) was obtained and 27 different ARGs were detected, highlighting the presence of mcr-9, bla(KPC) and cfr genes. Additionally, the microbiological analysis revealed that sand samples of all analyzed beaches were not recommended for primary use, whereas water samples from most beaches were classified as unsuitable for bathing. The presence of clinically relevant ARGs in urban beaches suggests the presence of antimicrobial-resistant bacteria. Furthermore, to the best of our knowledge, this is the first report of mcr-9 and cfr genes in the environment from Brazil and recreational areas worldwide. | 2021 | 33839570 |
| 1934 | 8 | 0.9998 | Sulfonamide resistance evaluation in five animal species and first report of sul4 in companion animals. Sulfonamides are one of the oldest groups of antibacterial agents with a broad-spectrum, used as first line treatment in bacterial infections. Their widespread use produced a selective pressure on bacteria, as observed by the high incidence of sulfonamides resistance mainly in Gram negative bacteria isolated from animals. In this research, the presence of sulfonamide resistance genes (sul1, sul2, sul3, and sul4) in phenotypically resistant Escherichia coli isolates has been studied. These genes were amplified in isolates recovered from five animal species, with different interactions to humans: cattle, swine, poultry as livestock, and dogs and cats as companion animals. Isolates were collected according to their phenotypic resistance, and the magnetic bead-based Luminex technology was applied to simultaneously detect sul target genes. The frequency of sul genes was highest in swine, among livestock isolates. The sul1 and sul2 were the most frequently sulfonamide resistance genes detected in all phenotypically resistant isolates. Notably, in companion animals, with a closest interaction with human, sul4 gene was detected. To our knowledge, this is the first report of the presence of sul4 gene in E. coli collected from animals, whereas previously the presence of this gene was reported in environmental, municipal wastewater and human clinical isolates. These results highlighted the importance of continuous antimicrobial resistant genes monitoring in animal species, with a special care to companion animals. | 2024 | 39029236 |
| 2734 | 9 | 0.9998 | High Frequency of Antibiotic Resistance Genes (ARGs) in the Lerma River Basin, Mexico. The spread of beta-lactamase-producing bacteria is of great concern and the environment has been found to be a main source of contamination. Herein, it was proposed to determine the frequency of antimicrobial-resistant-Gram-negative bacteria throughout the Lerma River basin using phenotypic and molecular methods. Resistant bacteria were isolated with chromogenic media and antimicrobial susceptibility tests were used to characterize their resistance. ARGs for beta-lactams, aminoglycosides, and quinolones were detected by PCR. Species were identified by Sanger sequencing the 16S rRNA gene and the representative genomes of MDR strains were sequenced by NGS. A high variation in the number of isolates was observed in the 20 sampled sites, while observing a low diversity among the resistant bacteria. Of the 12 identified bacterial groups, C. freundii, E. coli, and S. marcescens were more predominant. A high frequency of resistance to beta-lactams, quinolones, and aminoglycosides was evidenced, where the bla(CTX,)qnrB, qnrS y, and aac(6')lb-cr genes were the most prevalent. C. freundii showed the highest frequency of MDR strains. Whole genome sequencing revealed that S. marcescens and K. pneumoniae showed a high number of shared virulence and antimicrobial resistance genes, while E. coli showed the highest number of unique genes. The contamination of the Lerma River with MDR strains carrying various ARGs should raise awareness among environmental authorities to assess the risks and regulations regarding the optimal hygienic and sanitary conditions for this important river that supports economic activities in the different communities in Mexico. | 2022 | 36360888 |
| 2578 | 10 | 0.9998 | Bacteria tolerant to colistin in coastal marine environment: Detection, microbiome diversity and antibiotic resistance genes' repertoire. The global spread of mobilized colistin resistance (mcr) genes in clinical and natural environments dangerously diminishes the effectiveness of this last-resort antibiotic, becoming an urgent health threat. We used a multidisciplinary approach to detect mcr-1 gene and colistin (CL)-resistant bacteria in seawater from two Croatian public beaches. Illumina-based sequencing of metagenomic 16S rRNA was used to assess the taxonomic, functional, and antibiotic resistance genes (ARGs) profiling of the bacterial community tolerant to CL regarding different culture-based isolation methodologies. Data revealed that the choice of methodology alters the diversity and abundance of taxa accounting for the CL-resistance phenotype. The mcr-1 gene was identified by cloning and sequencing in one sample, representing the first report of mcr-1 gene in Croatia. Culturing of CL-resistant strains revealed their resistance phenotypes and concurrent production of clinically significant β-lactamases, such as CTX-M-15, CTX-M-3 and SHV-12. We also report the first identification of bla(CTX-M-15) gene in Klebsiella huaxiensis and K. michiganensis, as well as the bla(TEM-1+CTX-M-3) in Serratia fonticola. ARGs profiles derived from metagenomic data and predicted by PICRUSt2, showed the highest abundance of genes encoding for multidrug efflux pumps, followed by the transporter genes accounting for the tetracycline, macrolide and phenicol resistance. Our study evidenced the multidrug resistance features of CL-tolerant bacterial communities thriving in surface beach waters. We also showed that combined application of the metagenomic approaches and culture-based techniques enabled successful detection of mcr-1 gene, which could be underreported in natural environment. | 2021 | 34289613 |
| 1933 | 11 | 0.9998 | Antibiotic Resistance Genes Occurrence in Conventional and Antibiotic-Free Poultry Farming, Italy. Antimicrobial resistance is a complex and widespread problem threatening human and animal health. In poultry farms, a wide distribution of resistant bacteria and their relative genes is described worldwide, including in Italy. In this paper, a comparison of resistance gene distribution in litter samples, recovered from four conventional and four antibiotic-free broiler flocks, was performed to highlight any influence of farming systems on the spreading and maintenance of resistance determinants. Conventional PCR tests, targeting the resistance genes related to the most used antibiotics in poultry farming, along with some critically important antibiotics for human medicine, were applied. In conventional farms, n. 10 out of n. 30 investigated genes were present in at least one sample, the most abundant fragments being the tet genes specific for tetracyclines, followed by those for aminoglycosides and chloramphenicol. All conventional samples resulted negative for colistin, carbapenems, and vancomycin resistance genes. A similar trend was observed for antibiotic-free herds, with n. 13 out of n. 30 amplified genes, while a positivity for the mcr-1 gene, specific for colistin, was observed in one antibiotic-free flock. The statistical analysis revealed a significant difference for the tetM gene, which was found more frequently in the antibiotic-free category. The analysis carried out in this study allowed us to obtain new data about the distribution of resistance patterns in the poultry industry in relation to farming types. The PCR test is a quick and non-expensive laboratory tool for the environmental monitoring of resistance determinants identifying potential indicators of AMR dissemination. | 2022 | 36139170 |
| 1938 | 12 | 0.9998 | The Aquatic Ecosystem, a Good Environment for the Horizontal Transfer of Antimicrobial Resistance and Virulence-Associated Factors Among Extended Spectrum β-lactamases Producing E. coli. One of the main public health problems nowadays is the increase of antimicrobial resistance, both in the hospital environment and outside it (animal environment, food and aquatic ecosystems, among others). It is necessary to investigate the virulence-associated factors and the ability of horizontal gene transfer among bacteria for a better understanding of the pathogenicity and the mechanisms of dissemination of resistant bacteria. Therefore, the objective of this work was to detect several virulence factors genes (fimA, papC, papG III, cnf1, hlyA and aer) and to determine the conjugative capacity in a wide collection of extended-spectrum β-lactamases-producing E. coli isolated from different sources (human, food, farms, rivers, and wastewater treatment plants). Regarding virulence genes, fimA, papC, and aer were distributed throughout all the studied environments, papG III was mostly related to clinical strains and wastewater is a route of dissemination for cnf1 and hlyA. Strains isolated from aquatic environments showed an average conjugation frequencies of 1.15 × 10(-1) ± 5 × 10(-1), being significantly higher than those observed in strains isolated from farms and food (p < 0.05), with frequencies of 1.53 × 10(-4) ± 2.85 × 10(-4) and 9.61 × 10(-4) ± 1.96 × 10(-3), respectively. The reported data suggest the importance that the aquatic environment (especially WWTPs) acquires for the exchange of genes and the dispersion of resistance. Therefore, specific surveillance programs of AMR indicators in wastewaters from animal or human origin are needed, in order to apply sanitation measures to reduce the burden of resistant bacteria arriving to risky environments as WWTPs. | 2020 | 32326434 |
| 1929 | 13 | 0.9998 | Research Note: Detection of antibiotic-resistance genes in commercial poultry and turkey flocks from Italy. Antibiotics are routinely used in commercial poultry farms for the treatment of economically important bacterial diseases. Repeated use of antibiotics, usually administered in the feed or drinking water, may also result in the selection of resistant bacteria in animal feces, able to transfer their antimicrobial-resistance genes (ARG), residing on mobile elements, to other microorganisms, including human pathogens. In this study, single and multiplex PCR protocols were performed to detect tetracycline-, lincomycin-, chloramphenicol-, aminoglycoside-, colistin-, vancomycin-, and carbapenem-resistance genes, starting from 38 litter samples collected from 6 poultry and 2 turkey Italian flocks. The ARG were confirmed for all investigated classes of antimicrobials, except for colistin (mcr-1, mcr-2, mcr-3,mcr-4 mcr-5) and carbapenem (IMP, OXA-48, NDM, KPC), while the vanB gene was only detected for vancomycin. The highest positivity was obtained for tetracycline (tet[L], tet[M], tet[K], tetA[P]] and aminoglycoside (aadA2) ARG, confirming the predominant use of these antimicrobials in the veterinary practice and their potential to enhance the resistance patterns also in humans as a consequence of environmental contamination. On the contrary, the dissemination by poultry of ARG for critically important antimicrobials seems to be of minor concern, suggesting a negligible environmental dissemination by these genes in the Italian poultry industry. Finally, the molecular screening performed in this study using a noninvasive sampling method represents a simple and rapid tool for monitoring the ARG patterns at the farm level. | 2021 | 33799114 |
| 1930 | 14 | 0.9998 | Changes in dominant Escherichia coli and antimicrobial resistance after 24 hr in fecal matter. Intestinal bacteria carry antimicrobial resistance (AMR) genes in mobile genetic elements which have the potential to spread to bacteria in other animal hosts including humans. In fecal matter, Escherichia coli can continue to multiply for 48 hr after being excreted, and in certain environments, E. coli survive long periods of time. It is unclear the extent to which AMR in E. coli changes in the environment outside of its host. In this study, we analyzed changes in the population structure, plasmid content, and AMR patterns of 30 E. coli isolates isolated from 6 chickens (cloacal swabs), and 30 E. coli isolates from fecal samples (from the same 6 chickens) after 24 hr of incubation. Clonality of isolates was screened using the fumC gene sequence and confirmed in a subset of isolates (n = 14) by multi-locus sequence typing. Major shifts in the population structure (i.e., sequence types) and antibiotic resistance patterns were observed among the numerically dominant E. coli isolates after 24 hr. Four E. coli clones isolated from the cloaca swabs and the corresponding fecal samples (after 24 hr incubation) showed different antibiotic resistance patterns. Our study reveals that fecal matter in the environment is an intermediate habitat where rapid and striking changes occur in E. coli populations and antibiotic resistance patterns. | 2019 | 29896865 |
| 3319 | 15 | 0.9998 | Extended-spectrum beta-lactamase (ESBL)-positive Enterobacteriaceae in municipal sewage and their emission to the environment. The spread of Gram-negative bacteria with plasmid-borne extended-spectrum beta-lactamases (ESBLs) has become a worldwide problem. Their prevalence is increasing, both in hospitals and in the environment. The aim of this study was to investigate the presence of ESBL-positive Enterobacteriaceae in municipal sewage and their emission to the ambient air and the river receiving effluent from wastewater treatment plant (WWTP). In the group of 455 isolated strains, up to 19.8% (90 isolates) were phenotypic ESBL-producers. They were detected in the 63 (100%) of sewage samples analyzed, 7 (33.3%) of river water and in 10 (23.8%) of air samples collected at the WWTP area. The plasmid-mediated genes encoding beta-lactams resistance were detected in almost 10% out of bacteria of the WWTP's final effluents and in above 32% out of bacteria of air at the WWTP area. It confirms that those genes are released into the environment, which might facilitate further dissemination among environmental bacteria. Moreover, genes encoding antibiotic resistance were shown to be transferrable to an Escherichia coli recipient strain, which indicates a high possibility of horizontal gene transfer among strains of different genera within the sewage and environmental samples. This study demonstrated that despite the treatment, the municipal sewage may be a reservoir of antibiotic-resistant microorganisms and plasmid-mediated antibiotic resistance genes. This may pose a public health risk, which requires future evaluation and control. | 2013 | 23886578 |
| 2573 | 16 | 0.9998 | Molecular Characterization and Prevalence of Antimicrobial-Resistant Escherichia coli Isolates Derived from Clinical Specimens and Environmental Habitats. Antibiotic-resistant bacteria (ARB) are present in wastewaters as their elimination during treatment in wastewater treatment plants (WWTPs) is often impossible. Water plays an important role in the spread of these microorganisms among humans, animals and the environment. This study aimed to assess the antimicrobial resistance patterns, resistance genes and molecular genotypes by means of phylogenetic groups of E. coli isolates in aquatic habitats, including sewage and receiving water bodies, as well as clinical settings in the Boeotia regional district of Greece. The highest resistance rates among both environmental and clinical isolates were observed to be for penicillins, ampicillin and piperacillin. Resistance patterns related to extended spectrum β-lactamases (ESBL) production and ESBL genes were also detected in both environmental and clinical isolates. Phylogenetic group B2 was predominant in clinical settings and the second most frequent among wastewaters, whereas group A was dominant in all environmental isolates. In conclusion, the studied river water and wastewaters may serve as reservoirs of resistant E. coli isolates that pose potential threats to both human and animal health. | 2023 | 37374900 |
| 2753 | 17 | 0.9998 | Extended-spectrum beta-lactamase-producing Escherichia coli and antimicrobial resistance in municipal and hospital wastewaters in Czech Republic: Culture-based and metagenomic approaches. Wastewaters serve as important hot spots for antimicrobial resistance and monitoring can be used to analyse the abundance and diversity of antimicrobial resistance genes at the level of large bacterial and human populations. In this study, whole genome sequencing of beta-lactamase-producing Escherichia coli and metagenomic analysis of whole-community DNA were used to characterize the occurrence of antimicrobial resistance in hospital, municipal and river waters in the city of Brno (Czech Republic). Cefotaxime-resistant E. coli were mainly extended-spectrum beta-lactamase (ESBL) producers (95.6%, n = 158), of which the majority carried bla(CTX-M) (98.7%; n = 151) and were detected in all water samples except the outflow from hospital wastewater treatment plant. A wide phylogenetic diversity was observed among the sequenced E. coli (n = 78) based on the detection of 40 sequence types and single nucleotide polymorphisms (average number 34,666 ± 15,710) between strains. The metagenomic analysis revealed a high occurrence of bacterial genera with potentially pathogenic members, including Pseudomonas, Escherichia, Klebsiella, Aeromonas, Enterobacter and Arcobacter (relative abundance >50%) in untreated hospital and municipal wastewaters and predominance of environmental bacteria in treated and river waters. Genes encoding resistance to aminoglycosides, beta-lactams, quinolones and macrolides were frequently detected, however bla(CTX-M) was not found in this dataset which may be affected by insufficient sequencing depth of the samples. The study pointed out municipal treated wastewater as a possible source of multi-drug resistant E. coli and antimicrobial resistance genes for surface waters. Moreover, the combination of two different approaches provided a more holistic view on antimicrobial resistance in water environments. The culture-based approach facilitated insight into the dynamics of ESBL-producing E. coli and the metagenomics shows abundance and diversity of bacteria and antimicrobial resistance genes vary across water sites. | 2021 | 33232750 |
| 1935 | 18 | 0.9998 | Antibiotic Susceptibility Profile and Tetracycline Resistance Genes Detection in Salmonella spp. Strains Isolated from Animals and Food. Salmonella spp. is among the leading causes of foodborne infections in humans and a large number of animals. Salmonella spp. is a pathogen involved in the dissemination of antimicrobial resistance because it can accumulate antibiotic resistance genes (ARGs). In this study, the antibiotic resistance profile to 15 antibiotics, belonging to six different classes, of 60 strains of Salmonella spp. collected from pets, farm animals, wildlife, and food in Sicily (Italy) was investigated by the Kirby-Bauer method. Given that almost 33.3% of the Salmonella spp. strains were resistant to tetracycline, Real-Time PCR analysis was applied on all the 60 strains to detect the presence of eight selected tet resistance genes. Besides, the presence of the int1 gene, related to the horizontal gene transfer among bacteria, was also investigated in all the strains by Real-Time PCR analysis. Our data showed that 56% of the isolated strains harbored one or more tet resistance genes and that these strains were most frequently isolated from animals living in close contact with humans. Concerning int1, 17 strains (28.3%) harbored this genetic element and eight of these simultaneously contained tet genes. The results of this study highlight the importance of using a molecular approach to detect resistance genetic determinants, whose spread can increase the diffusion of multidrug-resistant strains. Besides, the study of zoonotic bacteria such as Salmonella spp. which significantly contribute to ARGs dissemination should always follow a One Health approach that considers the health of humans, animals, and the environment to be closely related. | 2021 | 34356729 |
| 2571 | 19 | 0.9998 | Multidrug-resistant Enterobacter spp. in wastewater and surface water: Molecular characterization of β-lactam resistance and metal tolerance genes. Among the ESKAPE group pathogens, Enterobacter spp. is an opportunistic Gram-negative bacillus, widely dispersed in the environment, that causes infections. In the present study, samples of hospital wastewater, raw and treated urban wastewater, as well as surface receiving water, were collected to assess the occurrence of multidrug-resistant (MDR) Enterobacter spp. A molecular characterization of β-lactam antibiotic resistance and metal tolerance genes was performed. According to identification by MALDI-TOF MS, 14 isolates were obtained: 7 E. bugandensis, 5 E. kobei, and 2 E. cloacae. The isolates showed resistance mainly to β-lactam antibiotics, including those used to treat infections caused by MDR bacteria. Multiple antibiotic resistance index was calculated for all isolates. It allowed verify whether sampling points showed a high risk due to antibiotic resistant Enterobacter spp., as well as to determine if the isolates have been in environments with a frequent antibiotic use. Twelve isolates showed β-lactam antibiotic resistance gene, being the bla(KPC) widely detected. Regarding metal tolerance, 13 isolates showed at least two genes that encode metal tolerance mechanisms. Overall, metal tolerance mechanisms to silver, copper, mercury, arsenic and tellurium were found. New data on metal tolerance mechanisms dispersion and antibiotic-resistance characterization of the E. bugandensis and E. kobei species were here provided. The occurrence of MDR Enterobacter spp. in analyzed samples draws attention to an urgent need to put control measures into practice. It also evidences waterborne spread of clinically important antibiotic-resistant bacteria recognized as critical priority pathogens. | 2023 | 37356524 |