Edina Szekeres
Research Scientist II - Taxonomy and Ecology
Biography
Researcher specialising in environmental microbiology, studying the relationships between aquatic microbial communities, emerging contaminants and antibiotic resistance. My work focuses on understanding microbial dynamics in relation to pollution and climate change.
Publications
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article
Contrary Effects Of Increasing Temperatures On The Spread Of Antimicrobial Resistance In River Biofilms |
Bagra Kenyum; Kneis David; Padfield Daniel; Szekeres Edina; Teban-Man Adela; Coman Cristian; Singh Gargi; Berendonk Thomas U.; Kluemper Uli | Msphere, 2024 | |
AbstractRiver microbial communities regularly act as the first barrier of defense against the spread of antimicrobial resistance genes (ARGs) that enter environmental microbiomes through wastewater. However, how the invasion dynamics of wastewater-borne ARGs into river biofilm communities will shift due to climate change with increasing average and peak temperatures remains unknown. Here, we aimed to elucidate the effects of increasing temperatures on the naturally occurring river biofilm resistome, as well as the invasion success of foreign ARGs entering through wastewater. Natural biofilms were grown in a low-anthropogenic impact river and transferred to artificial laboratory recirculation flume systems operated at three different temperatures (20 degrees C, 25 degrees C, and 30 degrees C). After 1 week of temperature acclimatization, significant increases in the abundance of the naturally occurring ARGs in biofilms were detected at higher temperatures. After this acclimatization period, biofilms were exposed to a single pulse of wastewater, and the invasion dynamics of wastewater-borne ARGs were analyzed over 2 weeks. After 1 day, wastewater-borne ARGs were able to invade the biofilms successfully with no observable effect of temperature on their relative abundance. However, thereafter, ARGs were lost at a far increased rate at 30 degrees C, with ARG levels dropping to the initial natural levels after 14 days. Contrary to the lower temperatures, ARGs were either lost at slower rates or even able to establish themselves in biofilms with stable relative abundances above natural levels. Hence, higher temperatures come with contrary effects on river biofilm resistomes: naturally occurring ARGs increase in abundance, while foreign, invading ARGs are lost at elevated speeds.IMPORTANCEInfections with bacteria that gained resistance to antibiotics are taking millions of lives annually, with the death toll predicted to increase. River microbial communities act as a first defense barrier against the spread of antimicrobial resistance genes (ARGs) that enter the environment through wastewater after enrichment in human and animal microbiomes. The global increase in temperature due to climate change might disrupt this barrier effect by altering microbial community structure and functions. We consequently explored how increasing temperatures alter ARG spread in river microbial communities. At higher temperatures, naturally occurring ARGs increased in relative abundance. However, this coincided with a decreased success rate of invading foreign ARGs from wastewater to establish themselves in the communities. Therefore, to predict the effects of climate change on ARG spread in river microbiomes, it is imperative to consider if the river ecosystem and its resistome are dominated by naturally occurring or invading foreign ARGs. Infections with bacteria that gained resistance to antibiotics are taking millions of lives annually, with the death toll predicted to increase. River microbial communities act as a first defense barrier against the spread of antimicrobial resistance genes (ARGs) that enter the environment through wastewater after enrichment in human and animal microbiomes. The global increase in temperature due to climate change might disrupt this barrier effect by altering microbial community structure and functions. We consequently explored how increasing temperatures alter ARG spread in river microbial communities. At higher temperatures, naturally occurring ARGs increased in relative abundance. However, this coincided with a decreased success rate of invading foreign ARGs from wastewater to establish themselves in the communities. Therefore, to predict the effects of climate change on ARG spread in river microbiomes, it is imperative to consider if the river ecosystem and its resistome are dominated by naturally occurring or invading foreign ARGs. |
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article
Environmental Microbiome Diversity And Stability Is A Barrier To Antimicrobial Resistance Gene Accumulation |
Kluemper Uli; Gionchetta Giulia; Catao Elisa; Bellanger Xavier; Dielacher Irina; Elena Alan Xavier; Fang Peiju; Galazka Sonia; Goryluk-Salmonowicz Agata; Kneis David; Okoroafor Uchechi; Radu Elena; Szadziul Mateusz; Szekeres Edina; Teban-Man Adela; Coman Cristian; Kreuzinger Norbert; Popowska Magdalena; Vierheilig Julia; Walsh Fiona; Woegerbauer Markus; Burgmann Helmut; Merlin Christophe; Berendonk Thomas Ulrich | Communications Biology, 2024 | |
AbstractWhen antimicrobial resistant bacteria (ARB) and genes (ARGs) reach novel habitats, they can become part of the habitat's microbiome in the long term if they are able to overcome the habitat's biotic resilience towards immigration. This process should become more difficult with increasing biodiversity, as exploitable niches in a given habitat are reduced for immigrants when more diverse competitors are present. Consequently, microbial diversity could provide a natural barrier towards antimicrobial resistance by reducing the persistence time of immigrating ARB and ARG. To test this hypothesis, a pan-European sampling campaign was performed for structured forest soil and dynamic riverbed environments of low anthropogenic impact. In soils, higher diversity, evenness and richness were significantly negatively correlated with relative abundance of >85% of ARGs. Furthermore, the number of detected ARGs per sample were inversely correlated with diversity. However, no such effects were present in the more dynamic riverbeds. Hence, microbiome diversity can serve as a barrier towards antimicrobial resistance dissemination in stationary, structured environments, where long-term, diversity-based resilience against immigration can evolve. |
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article
Genome-Wide Transcriptional Response To Silver Stress In Extremely Halophilic Archaeon Haloferax Alexandrinus Dsm 27206 T |
Buda Doriana Madalina; Szekeres Edina; Tudoran Lucian Barbu; Esclapez Julia; Banciu Horia Leonard | Bmc Microbiology, 2023 | |
AbstractBackground The extremely halophilic archaeon Haloferax (Hfx.) alexandrinus DSM 27206 T was previously documented for the ability to biosynthesize silver nanoparticles while mechanisms underlying its silver tolerance were overlooked. In the current study, we aimed to assess the transcriptional response of this haloarchaeon to varying concentrations of silver, seeking a comprehensive understanding of the molecular determinants underpinning its heavy metal tolerance.Results The growth curves confirmed the capacity of Hfx. alexandrinus to surmount silver stress, while the SEM-EDS analysis illustrated the presence of silver nanoparticles in cultures exposed to 0.5 mM silver nitrate. The RNA-Seq based transcriptomic analysis of Hfx. alexandrinus cells exposed to 0.1, 0.25, and 0.5 mM silver nitrate revealed the differential expression of multiple sets of genes potentially employed in heavy-metal stress response, genes mostly related to metal transporters, basic metabolism, oxidative stress response and cellular motility. The RT-qPCR analysis of selected transcripts was conducted to verify and validate the generated RNA-Seq data.Conclusions Our results indicated that copA, encoding the copper ATPase, is essential for the survival of Hfx. alexandrinus cells in silver-containing saline media. The silver-exposed cultures underwent several metabolic adjustments that enabled the activation of enzymes involved in the oxidative stress response and impairment of the cellular movement capacity. To our knowledge, this study represents the first comprehensive analysis of gene expression in halophillic archaea facing increased levels of heavy metals. |
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article
Karst Spring Microbiome: Diversity, Core Taxa, And Community Response To Pathogens And Antibiotic Resistance Gene Contamination |
Szekeres Edina; Baricz Andreea; Cristea Adorjan; Levei Erika Andrea; Stupar Zamfira; Brad Traian; Kenesz Marius; Moldovan Oana Teodora; Banciu Horia Leonard | Science Of The Total Environment, 2023 | |
AbstractKarst aquifers are important water resources for drinking water supplies worldwide. Although they are susceptible to anthropogenic contamination due to their high permeability, there is a lack of detailed knowledge on the stable core microbiome and how contamination may affect these communities. In this study, eight karst springs (distributed across three different regions in Romania) were sampled seasonally for one year. The core microbiota was analysed by 16S rRNA gene amplicon sequencing. To identify bacteria carrying antibiotic resistance genes and mobile genetic ele-ments, an innovative method was applied, consisting of high-throughput antibiotic resistance gene quantification per-formed on potential pathogen colonies cultivated on Compact DryTM plates. A taxonomically stable bacterial community consisting of Pseudomonadota, Bacteroidota, and Actinomycetota was revealed. Core analysis reaffirmed these results and revealed primarily freshwater-dwelling, psychrophilic/psychrotolerant species affiliated to Rhodoferax, Flavobacterium, and Pseudomonas genera. Both sequencing and cultivation methods indicated that more than half of the springs were contaminated with faecal bacteria and pathogens. These samples contained high levels of sulfonamide, macrolide, lincosamide and streptogramins B, and trimethoprim resistance genes spread primarily by transposase and insertion sequences. Differential abundance analysis found Synergistota, Mycoplasmatota, and Chlamydiota as suitable candidates for pollution monitoring in karst springs. This is the first study highlighting the ap-plicability of a combined approach based on high-throughput SmartChipTM antibiotic resistance gene quantification and Compact Dry-pathogen cultivation for estimating microbial contaminants in karst springs and other challenging low biomass environments. |
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article
Microbial Water Quality And Health Risk Assessment In Karst Springs From Apuseni Mountains, Romania |
Stupar Zamfira; Levei Erika Andrea; Neag Emilia; Baricz Andreea; Szekeres Edina; Moldovan Oana Teodora | Frontiers In Environmental Science, 2022 | |
AbstractIn Apuseni Mountains (North-Western Romania), many of the inhabitants live in rural communities with limited or no access to the centralized and controlled water supply. This study assesses the microbiological quality of six karst spring waters from Bihor County used by rural communities as drinking water sources. Twenty-four water samples collected in January, April, June, and November 2021 were analyzed for E. coli, total coliforms, intestinal enterococci, Pseudomonas aeruginosa, and heterotrophic plate count at 37 and 22?. Standard microbiological methods based on the membrane filter technique or pour plate method were used for the microbiological characterization of the spring waters. The study revealed that the karst springs from the studied area present microbiological contamination. The microbiological parameters for five out of the six studied spring waters exceeded the maximum limits allowed by the 98/83/EC Directive. Quantitative Microbial Risk Assessment estimated the risk of gastrointestinal illness for both adults and children due to the enteropathogenic E. coli contamination. According to the health risk evaluation model, the risk of infection/day and the risk of infection/year were high, with the maximum values of 0.24 and 1.00, respectively. The probability of illness caused by E. coli contamination of water ranged between 0.09 and 0.35 for five out of six groundwater sources. The local communities using the contaminated springs are exposed to daily and accumulated health threats. Therefore, preventive measures accompanied by continuous monitoring are necessary mainly for those water sources that are critical drinking water sources for the rural communities. |
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article
Molecular Typing Reveals Environmental Dispersion Of Antibiotic-Resistant Enterococci Under Anthropogenic Pressure |
Farkas Anca; Coman Cristian; Szekeres Edina; Teban-Man Adela; Carpa Rahela; Butiuc-Keul Anca | Antibiotics-Basel, 2022 | |
AbstractAs a consequence of global demographic challenges, both the artificial and the natural environment are increasingly impacted by contaminants of emerging concern, such as bacterial pathogens and their antibiotic resistance genes (ARGs). The aim of this study was to determine the extent to which anthropogenic contamination contributes to the spread of antibiotic resistant enterococci in aquatic compartments and to explore genetic relationships among Enterococcus strains. Antimicrobial susceptibility testing (ampicillin, imipenem, norfloxacin, gentamycin, vancomycin, erythromycin, tetracycline, trimethoprim-sulfamethoxazole) of 574 isolates showed different rates of phenotypic resistance in bacteria from wastewaters (91.9-94.4%), hospital effluents (73.9%), surface waters (8.2-55.3%) and groundwater (35.1-59.1%). The level of multidrug resistance reached 44.6% in enterococci from hospital effluents. In all samples, except for hospital sewage, the predominant species were E. faecium and E. faecalis. In addition, E. avium, E. durans, E. gallinarum, E. aquimarinus and E. casseliflavus were identified. Enterococcus faecium strains carried the greatest variety of ARGs (bla(TEM-1), aac(6 ')-Ie-aph(2 ''), aac(6 ')-Im, vanA, vanB, ermB, mefA, tetB, tetC, tetL, tetM, sul1), while E. avium displayed the highest ARG frequency. Molecular typing using the ERIC2 primer revealed substantial genetic heterogeneity, but also clusters of enterococci from different aquatic compartments. Enterococcal migration under anthropogenic pressure leads to the dispersion of clinically relevant strains into the natural environment and water resources. In conclusion, ERIC-PCR fingerprinting in conjunction with ARG profiling is a useful tool for the molecular typing of clinical and environmental Enterococcus species. These results underline the need of safeguarding water quality as a strategy to limit the expansion and progression of the impending antibiotic-resistance crisis. |
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article
Municipal Wastewaters Carry Important Carbapenemase Genes Independent Of Hospital Input And Can Mirror Clinical Resistance Patterns |
Teban-Man Adela; Szekeres Edina; Fang Peiju; Klumper Uli; Hegedus Adriana; Baricz Andreea; Berendonk Thomas Ulrich; Parvu Marcel; Coman Cristian | Microbiology Spectrum, 2022 | |
AbstractThe spatiotemporal variation of several carbapenemase-encoding genes (CRGs) was investigated in the influent and effluent of municipal WWTPs, with or without hospital sewage input. Correlations among gene abundances, bacterial community composition, and wastewater quality parameters were tested to identify possible predictors of CRGs presence. Also, the possible role of wastewaters in mirroring clinical resistance is discussed. The taxonomic groups and gene abundances showed an even distribution among wastewater types, meaning that hospital sewage does not influence the microbial diversity and the CRG pool. The bacterial community was composed mainly of Proteobacteria, Firmicutes, Actinobacteria, Patescibacteria, and Bacteroidetes. Acinetobacter spp. was the most abundant group and had the majority of operational taxonomic units (OTUs) positively correlated with CRGs. This agrees with recent reports on clinical data. The influent samples were dominated by bla(KPC), as opposed to effluent, where bla(IMP) was dominant. Also, bla(IMP) was the most frequent CRG family observed to correlate with bacterial taxa, especially with the Mycobacterium genus in effluent samples. Bacterial load, bla(NDM), bla(KPC), and bla(OXA-48) abundances were positively correlated with BOD5, TSS, HEM, Cr, Cu, and Fe concentrations in wastewaters. When influent gene abundance values were converted into population equivalent (PE) data, the highest copies/1 PE were identified for bla(KPC) and bla(OXA-48), agreeing with previous studies regarding clinical isolates. Both hospital and non-hospital-type samples followed a similar temporal trend of CRG incidence, but with differences among gene groups. Colder seasons favored the presence of bla(NDM), bla(KPC), and bla(OXA-48), whereas warmer temperatures show increased PE values for bla(VIM) and bla(IMP). IMPORTANCE Wastewater-based epidemiology has recently been recognized as a valuable, cost-effective tool for antimicrobial resistance surveillance. It can help gain insights into the characteristics and distribution of antibiotic resistance elements at a local, national, and even global scale. In this study, we investigated the possible use of municipal wastewaters in the surveillance of clinically relevant carbapenemase-encoding genes (CRGs), seen as critical antibiotic resistance determinants. In this matter, our results highlight positive correlations among CRGs, microbial diversity, and wastewater physical and chemical parameters. Identified predictors can provide valuable data regarding the level of raw and treated wastewater contamination with these important antibiotic resistance genes. Also, wastewater-based gene abundances were used for the first time to observe possible spatiotemporal trends of CRGs incidence in the general population. Therefore, possible hot spots of carbapenem resistance could be easily identified at the community level, surpassing the limitations of health care-associated settings. |
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article
Antibiotic Resistance In Pseudomonas Spp. Through The Urban Water Cycle |
Butiuc-Keul Anca; Carpa Rahela; Podar Dorina; Szekeres Edina; Muntean Vasile; Iordache Dumitrana; Farkas Anca | Current Microbiology, 2021 | |
AbstractSelection and dissemination of resistant bacteria and antibiotic resistance genes (ARGs) require a deeper understanding since antibiotics are permanently released to the environment. The objective of this paper was to evaluate the phenotypic resistance of 499 isolates of Pseudomonas spp. from urban water sources, and the prevalence of 20 ARGs within those isolates. Resistance to penicillins, cephalosporins, carbapenems, quinolones, macrolides, and tetracyclines was mainly observed in the hospital effluent, municipal wastewater and river water downstream the city. Resistant strains were frequently identified as P. aeruginosa and P. putida. P. aeruginosa isolates were mostly resistant to cefepime, ceftazidime, imipenem, and gentamycin, while P. putida strains were especially resistant to piperacillin-tazobactam. ARGs such as bla(TEM-1), bla(SHV-1), bla(PER-1), bla(AmpC), bla(VIM-1), PstS, qnrA, qnrB, ermB, tetA, tetB and tetC have been detected. The bla(AmpC) gene was found in P. aeruginosa, while bla(TEM-1) and bla(PER-1) genes were found in P. putida. Class 1 integron integrase gene was found in 6.81% of the Pseudomonas isolates. |
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article
Spatio-Temporal Insights Into Microbiology Of The Freshwater-To-Hypersaline, Oxic-Hypoxic-Euxinic Waters Of Ursu Lake |
Baricz Andreea; Chiriac Cecilia Maria; Andrei Adrian-Stefan; Bulzu Paul-Adrian; Levei Erika Andrea; Cadar Oana; Battes Karina Paula; Cimpean Mirela; Senila Marin; Cristea Adorjan; Muntean Vasile; Alexe Mircea; Coman Cristian; Szekeres Edina Kriszta; Sicora Cosmin Ionel; Ionescu Artur; Blain David; O'Neill William Kenneth; Edwards Jessica; Hallsworth John Edward; Banciu Horia Leonard | Environmental Microbiology, 2021 | |
AbstractUrsu Lake is located in the Middle Miocene salt deposit of Central Romania. It is stratified, and the water column has three distinct water masses: an upper freshwater-to-moderately saline stratum (0-3 m), an intermediate stratum exhibiting a steep halocline (3-3.5 m), and a lower hypersaline stratum (4 m and below) that is euxinic (i.e. anoxic and sulphidic). Recent studies have characterized the lake's microbial taxonomy and given rise to intriguing ecological questions. Here, we explore whether the communities are dynamic or stable in relation to taxonomic composition, geochemistry, biophysics, and ecophysiological functions during the annual cycle. We found: (i) seasonally fluctuating, light-dependent communities in the upper layer (>= 0.987-0.990 water-activity), a stable but phylogenetically diverse population of heterotrophs in the hypersaline stratum (water activities down to 0.762) and a persistent plate of green sulphur bacteria that connects these two (0.958-0.956 water activity) at 3-3.5 to 4 m; (ii) communities that might be involved in carbon- and sulphur-cycling between and within the lake's three main water masses; (iii) uncultured lineages including Acetothermia (OP1), Cloacimonetes (WWE1), Marinimicrobia (SAR406), Omnitrophicaeota (OP3), Parcubacteria (OD1) and other Candidate Phyla Radiation bacteria, and SR1 in the hypersaline stratum (likely involved in the anaerobic steps of carbon- and sulphur-cycling); and (iv) that species richness and habitat stability are associated with high redox-potentials. Ursu Lake has a unique and complex ecology, at the same time exhibiting dynamic fluctuations and stability, and can be used as a modern analogue for ancient euxinic water bodies and comparator system for other stratified hypersaline systems. |
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article
Wastewaters, With Or Without Hospital Contribution, Harbour Mdr, Carbapenemase-Producing, But Not Hypervirulent Klebsiella Pneumoniae |
Teban-Man Adela; Farkas Anca; Baricz Andreea; Hegedus Adriana; Szekeres Edina; Parvu Marcel; Coman Cristian | Antibiotics-Basel, 2021 | |
AbstractCarbapenemase-producing Klebsiella pneumoniae (CPKP) isolated from influent (I) and effluent (E) of two wastewater treatment plants, with (S1) or without (S2) hospital contribution, were investigated. The strains belonged to the Kp1 phylogroup, their highest frequency being observed in S1, followed by S2. The phenotypic and genotypic hypervirulence tests were negative for all the strains tested. At least one carbapenemase gene (CRG), belonging to the blaKPC, blaOXA-48, blaNDM and blaVIM families, was observed in 63% of CPKP, and more than half co-harboured two to four CRGs, in different combinations. Only five CRG variants were observed, regardless of wastewater type: blaKPC-2, blaNDM-1, blaNDM-6, blaVIM-2, and blaOXA-48. Sequence types ST258, ST101 and ST744 were common for both S1 and S2, while ST147, ST525 and ST2502 were found only in S1 and ST418 only in S2. The strains tested were multi-drug resistant (MDR), all being resistant to beta-lactams, cephalosporins, carbapenems, monobactams and fluoroquinolones, followed by various resistance profiles to aminoglycosides, trimethoprim-sulphamethoxazole, tigecycline, chloramphenicol and tetracycline. After principal component analysis, the isolates in S1 and S2 groups did not cluster independently, confirming that the antibiotic susceptibility patterns and gene-type profiles were both similar in the K. pneumoniae investigated, regardless of hospital contribution to the wastewater type. |
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