11 results on '"Popa, Laura Ioana"'
Search Results
2. Shiga Toxin-Producing Escherichia coli Strains from Romania: A Whole Genome-Based Description.
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Usein, Codruța-Romanița, Oprea, Mihaela, Dinu, Sorin, Popa, Laura-Ioana, Cristea, Daniela, Militaru, Cornelia-Mădălina, Ghiță, Andreea, Costin, Mariana, Popa, Ionela-Loredana, Croitoru, Anca, Bologa, Cristina, and Rusu, Lavinia-Cipriana
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WHOLE genome sequencing ,ESCHERICHIA coli ,SEQUENCE analysis ,INTESTINES ,PEDIATRICS - Abstract
The zoonotic Shiga toxin-producing Escherichia coli (STEC) group is unanimously regarded as exceptionally hazardous for humans. This study aimed to provide a genomic perspective on the STEC recovered sporadically from humans and have a foundation of internationally comparable data. Fifty clinical STEC isolates, representing the culture-confirmed infections reported by the STEC Reference Laboratory between 2016 and 2023, were subjected to whole-genome sequencing (WGS) analysis and sequences were interpreted using both commercial and public free bioinformatics tools. The WGS analysis revealed a genetically diverse population of STEC dominated by non-O157 serogroups commonly reported in human STEC infections in the European Union. The O26:H11 strains of ST21 lineage played a major role in the clinical disease resulting in hospitalisation and cases of paediatric HUS in Romania surpassing the O157:H7 strains. The latter were all clade 7 and mostly ST1804. Notably, among the Romanian isolates was a stx2a-harbouring cryptic clade I strain associated with a HUS case, stx2f- and stx2e-positive strains, and hybrid strains displaying a mixture of intestinal and extraintestinal virulence genes were found. As a clearer picture emerges of the STEC strains responsible for infections in Romania, further surveillance efforts are needed to uncover their prevalence, sources, and reservoirs. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Subtypes, resistance and virulence platforms in extended-drug resistant Acinetobacter baumannii Romanian isolates
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Gheorghe, Irina, Barbu, Ilda Czobor, Surleac, Marius, Sârbu, Ionela, Popa, Laura Ioana, Paraschiv, Simona, Feng, Yu, Lazăr, Veronica, Chifiriuc, Mariana Carmen, Oţelea, Dan, and Zhiyong, Zong
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- 2021
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4. Network analytics for drug repurposing in COVID-19.
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Siminea, Nicoleta, Popescu, Victor, Martin, Jose Angel Sanchez, Florea, Daniela, Gavril, Georgiana, Gheorghe, Ana-Maria, Iţcuş, Corina, Kanhaiya, Krishna, Pacioglu, Octavian, Popa, Laura Ioana, Trandafir, Romica, Tusa, Maria Iris, Sidoroff, Manuela, Păun, Mihaela, Czeizler, Eugen, Păun, Andrei, and Petre, Ion
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DRUG repositioning ,COVID-19 ,DRUG target ,PROTEIN-protein interactions ,SARS-CoV-2 - Abstract
To better understand the potential of drug repurposing in COVID-19, we analyzed control strategies over essential host factors for SARS-CoV-2 infection. We constructed comprehensive directed protein–protein interaction (PPI) networks integrating the top-ranked host factors, the drug target proteins and directed PPI data. We analyzed the networks to identify drug targets and combinations thereof that offer efficient control over the host factors. We validated our findings against clinical studies data and bioinformatics studies. Our method offers a new insight into the molecular details of the disease and into potentially new therapy targets for it. Our approach for drug repurposing is significant beyond COVID-19 and may be applied also to other diseases. [ABSTRACT FROM AUTHOR]
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- 2022
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5. Phenotypic and genotypic virulence features of staphylococcal strains isolated from difficult-to-treat skin and soft tissue infections.
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Preda, Mădălina, Mihai, Mara Mădălina, Popa, Laura Ioana, Dițu, Lia-Mara, Holban, Alina Maria, Manolescu, Loredana Sabina Cornelia, Popa, Gabriela-Loredana, Muntean, Andrei-Alexandru, Gheorghe, Irina, Chifiriuc, Carmen Mariana, and Popa, Mircea-Ioan
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SOFT tissue infections ,STAPHYLOCOCCAL diseases ,QUALITY of life ,GENTIAN violet ,GENES - Abstract
Chronic infections represent an important burden on the healthcare system and have a significant impact on the patients' quality of life. While Staphylococcus spp. are commensal bacteria, they can become pathogenic, leading to various types of infections. In this study we aimed to characterize the virulence profiles of staphylococcal strains involved in difficult-to-treat skin and soft tissue infections, from both phenotypic and genotypic points of view. Phenotypic ability of the strains to secrete soluble virulence factors was assessed by a culturing dependent assay and their capacity to develop biofilms on inert substrate was screened by an adapted crystal violet microtiter method. We also tested the presence of several virulence genes by PCR. Most of the studied strains were isolated from purulent secretions of acne lesions and frequently secreted two or three soluble virulence factors. Most frequently secreted soluble virulence factors were caseinase (89%), lipase (71%) and lecithinase (67%). Almost half of the strains produced a well-represented biofilm. The molecular characterization showed the presence of the genes cna, hlg, clfA, and clfB. Staphylococcal strains that produce difficult-to-treat skin and soft tissue infections seem to be characterized by an enhanced ability to produce different soluble virulence factors and to develop biofilms in vitro. Further studies need to be developed in other Staphylococcus spp. infections in order to confirm this hypothesis. [ABSTRACT FROM AUTHOR]
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- 2021
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6. Multidrug Resistant Klebsiella pneumoniae ST101 Clone Survival Chain From Inpatients to Hospital Effluent After Chlorine Treatment.
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Popa, Laura Ioana, Gheorghe, Irina, Barbu, Ilda Czobor, Surleac, Marius, Paraschiv, Simona, Măruţescu, Luminiţa, Popa, Marcela, Pîrcălăbioru, Graţiela Grădişteanu, Talapan, Daniela, Niţă, Mihai, Streinu-Cercel, Anca, Streinu-Cercel, Adrian, Oţelea, Dan, and Chifiriuc, Mariana Carmen
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KLEBSIELLA pneumoniae ,SEWAGE ,WATER pollution ,SURFACE contamination ,CHLORINE ,INTRA-abdominal infections - Abstract
In this paper we describe the transmission of a multi-drug resistant Klebsiella pneumoniae ST101 clone from hospital to wastewater and its persistence after chlorine treatment. Water samples from influents and effluents of the sewage tank of an infectious diseases hospital and clinical strains collected from the intra-hospital infections, during a period of 10 days prior to wastewater sampling were analyzed. Antibiotic resistant K. pneumoniae strains from wastewaters were recovered on selective media. Based on antibiotic susceptibility profiles and PCR analyses of antibiotic resistance (AR) genetic background, as well as whole-genome sequencing (Illumina MiSeq) and subsequent bioinformatic analyses, 11 ST101 K. pneumoniae strains isolated from hospital wastewater influent, wastewater effluent and clinical sector were identified as clonally related. The SNP and core genome analyses pointed out that five strains were found to be closely related (with ≤18 SNPs and identical cgMLST profile). The strains belonging to this clone harbored multiple acquired AR genes [ bla
CTX–M– 15 , blaOXA– 48 , blaOXA– 1 , blaSHV– 106 , blaTEM– 150 , aac(3)-IIa , aac(6′)-Ib-cr , oqx A10, oqx B17, fos A, cat B3, dfr A14, tet (D)] and chromosomal mutations involved in AR (Δ mgrB , Δ ompK35 , amino acid substitutions in GyrA Ser83Tyr, Asp87Asn, ParC Ser80Tyr). Twenty-nine virulence genes involved in iron acquisition, biofilm and pili formation, adherence, and the type six secretion system – T6SS-III were identified. Our study proves the transmission of MDR K. pneumoniae from hospital to the hospital effluent and its persistence after the chlorine treatment, raising the risk of surface water contamination and further dissemination to different components of the trophic chain, including humans. [ABSTRACT FROM AUTHOR]- Published
- 2021
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7. Targeting Plasmids to Limit Acquisition and Transmission of Antimicrobial Resistance.
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Vrancianu, Corneliu Ovidiu, Popa, Laura Ioana, Bleotu, Coralia, and Chifiriuc, Mariana Carmen
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DRUG resistance in microorganisms ,PLASMIDS ,MOBILE genetic elements ,HORIZONTAL gene transfer ,MULTIDRUG resistance in bacteria ,BACTERIAL chromosomes - Abstract
Antimicrobial resistance (AMR) is a significant global threat to both public health and the environment. The emergence and expansion of AMR is sustained by the enormous diversity and mobility of antimicrobial resistance genes (ARGs). Different mechanisms of horizontal gene transfer (HGT), including conjugation, transduction, and transformation, have facilitated the accumulation and dissemination of ARGs in Gram-negative and Gram-positive bacteria. This has resulted in the development of multidrug resistance in some bacteria. The most clinically significant ARGs are usually located on different mobile genetic elements (MGEs) that can move intracellularly (between the bacterial chromosome and plasmids) or intercellularly (within the same species or between different species or genera). Resistance plasmids play a central role both in HGT and as support elements for other MGEs, in which ARGs are assembled by transposition and recombination mechanisms. Considering the crucial role of MGEs in the acquisition and transmission of ARGs, a potential strategy to control AMR is to eliminate MGEs. This review discusses current progress on the development of chemical and biological approaches for the elimination of ARG carriers. [ABSTRACT FROM AUTHOR]
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- 2020
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8. Whole genome sequencing snapshot of multi-drug resistant Klebsiella pneumoniae strains from hospitals and receiving wastewater treatment plants in Southern Romania.
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Surleac, Marius, Czobor Barbu, Ilda, Paraschiv, Simona, Popa, Laura Ioana, Gheorghe, Irina, Marutescu, Luminita, Popa, Marcela, Sarbu, Ionela, Talapan, Daniela, Nita, Mihai, Iancu, Alina Viorica, Arbune, Manuela, Manole, Alina, Nicolescu, Serban, Sandulescu, Oana, Streinu-Cercel, Adrian, Otelea, Dan, and Chifiriuc, Mariana Carmen
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SEWAGE disposal plants ,CARBAPENEMS ,KLEBSIELLA pneumoniae ,NUCLEOTIDE sequencing ,PHARMACOGENOMICS ,DRUG resistance in bacteria ,MULTIDRUG resistance - Abstract
We report on the genomic characterization of 47 multi-drug resistant, carbapenem resistant and ESBL-producing K. pneumoniae isolates from the influent (I) and effluent (E) of three wastewater treatment plants (WWTPs) and from Romanian hospital units which are discharging the wastewater in the sampled WWTPs. The K. pneumoniae whole genome sequences were analyzed for antibiotic resistance genes (ARGs), virulence genes and sequence types (STs) in order to compare their distribution in C, I and E samples. Both clinical and environmental samples harbored prevalent and widely distributed ESBL genes, i.e. bla
SHV , blaOXA , blaTEM and blaCTX M . The most prevalent carbapenemase genes were blaNDM-1 , blaOXA-48 and blaKPC-2 . They were found in all types of isolates, while blaOXA-162 , a rare blaOXA-48 variant, was found exclusively in water samples. A higher diversity of carbapenemases genes was seen in wastewater isolates. The aminoglycoside modifying enzymes (AME) genes found in all types of samples were aac(6'), ant(2'')Ia, aph(3'), aaD, aac(3) and aph(6). Quinolone resistance gene qnrS1 and the multi-drug resistance oqxA/B pump gene were found in all samples, while qnrD and qnrB were associated to aquatic isolates. The antiseptics resistance gene qacEdelta1 was found in all samples, while qacE was detected exclusively in the clinical ones. Trimethroprim-sulfamethoxazole (dfrA, sul1 and sul2), tetracyclines (tetA and tetD) and fosfomycin (fosA6, known to be located on a transpozon) resistance genes were found in all samples, while for choramphenicol and macrolides some ARGs were detected in all samples (catA1 and catB3 / mphA), while other (catA2, cmIA5 and aac(6')Ib / mphE and msrE) only in wastewater samples. The rifampin resistance genes arr2 and 3 (both carried by class I integrons) were detected only in water samples. The highly prevalent ARGs preferentially associating with aquatic versus clinical samples could ascribe potential markers for the aquatic (blaSHV-145 , qacEdelta1, sul1, aadA1, aadA2) and clinical (blaOXA-1 , blaSHV-106 ,blaTEM-150 , aac(3)Iia, dfrA14, oqxA10; oqxB17,catB3, tetD) reservoirs of AR. Moreover, some ARGs (oqxA10; blaSHV-145 ; blaSHV-100 , aac(6')Il, aph(3')VI, armA, arr2, cmlA5, blaCMY-4 , mphE, msrE, oqxB13, blaOXA-10 ) showing decreased prevalence in influent versus effluent wastewater samples could be used as markers for the efficiency of the WWTPs in eliminating AR bacteria and ARGs. The highest number of virulence genes (75) was recorded for the I samples, while for E and C samples it was reduced to half. The most prevalent belong to three functional groups: adherence (fim genes), iron acquisition (ent, fep, fyu, irp and ybt genes) and the secretion system (omp genes). However, none of the genes associated with hypervirulent K. pneumoniae have been found. A total of 14 STs were identified. The most prevalent clones were ST101, ST219 in clinical samples and ST258, ST395 in aquatic isolates. These STs were also the most frequently associated with integrons. ST45 and ST485 were exclusively associated with I samples, ST11, ST35, ST364 with E and ST1564 with C samples. The less frequent ST17 and ST307 aquatic isolates harbored blaOXA-162 , which was co-expressed in our strains with blaCTX-M-15 and blaOXA-1 . [ABSTRACT FROM AUTHOR]- Published
- 2020
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9. Snapshot of Phylogenetic Groups, Virulence, and Resistance Markers in Escherichia coli Uropathogenic Strains Isolated from Outpatients with Urinary Tract Infections in Bucharest, Romania.
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Cristea, Violeta Corina, Gheorghe, Irina, Czobor Barbu, Ilda, Popa, Laura Ioana, Ispas, Bogdan, Grigore, Georgiana Alexandra, Bucatariu, Irina, Popa, Gabriela Loredana, Angelescu, Maria-Cristina, Velican, Alexandra, Marutescu, Luminita, Popa, Marcela, Chifiriuc, Mariana Carmen, and Popa, Ioan Mircea
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BIOMARKERS ,CIPROFLOXACIN ,DRUG resistance in microorganisms ,ESCHERICHIA coli ,MASS spectrometry ,PHYLOGENY ,POLYMERASE chain reaction ,SEX distribution ,TETRACYCLINE ,TUMOR necrosis factors ,URINARY tract infections ,MICROBIAL virulence ,CEFAZOLIN ,AMPICILLIN - Abstract
Background. Urinary tract infections (UTIs) caused by Uropathogenic Escherichia coli (UPEC) are among the most common infections worldwide, including Romania. To the best of our knowledge, this is the first study performed on a significant number of community-acquired (CA) UPEC strains isolated from Romanian outpatients, aiming to evaluate and establish potential correlations among the phylogenetic groups (PG), resistance profiles, and the virulence factors (VF) genes of the CA-UPEC isolates. Materials/Methods. The present study was performed on a total of 787 UPEC nonrepetitive isolates consecutively isolated during one month from outpatients with CA-UTIs, visiting one of the biggest laboratories in Bucharest, Romania, receiving patients from all over the country. The strains identification was performed by MALDI TOF and the susceptibility patterns were tested using Microscan according to CLSI guidelines. PCR assays were performed to detect the presence of different VFs (fimH gene encoding for type 1 fimbriae, afaBC for A fimbriae, sfaDE for S fimbriae, KpsMTII for capsule, hlyA for haemolysin A, hlyD for haemolysin D, and cnf-1 for tumor necrosis factor), the phylogenetic groups (PG) A, B1, B2, and D, and the extended spectrum beta-lactamases (ESBLs) genes. Results. The 787 CA-UPEC strains were isolated predominantly from female patients (90.95%) of >30 years (~74%). The resistance rates were 47.52% for ampicillin, 41.16% for tetracycline, 24.39% for cotrimoxazole, 19.18% for amoxicillin-clavulanic acid, 15.50% for cefazolin, 14.99% for ciprofloxacin, and 14.86% for levofloxacin; 35.19% of the investigated strains were MDR and 9.03% ESBL producers (from which 42.25% were positive for blaCTX-M, 38.02% for blaTEM, and 19.71% for blaSHV). FimH was the most frequent virulence gene (93.90%) followed by hlyD (44.34%); afaBC (38.24%); KpsMTII (32.65%); sfaDE (23.88%); hlyA (12.45%); and cnf-1 (7.75%). The distribution of the analyzed UPEC strains in phylogenetic groups was different for non-MDR and MDR strains. Overall, 35% of the strains belonged to the phylogenetic group B2 (harboring the yjaA gene); 27% to group B1 (confirmed by the presence of the TspE4C2 fragment); 16% to group D; and 22% to group A. The CA-UPEC strains included in PG B1 and PG B2 proved to be the most virulent ones, the number of strains carrying multiple VFs (>3) being significantly larger as compared to strains belonging to PG A and PG D) (p<0,0001). The presence of one or two ESBL genes was significantly associated (p =0.0024) with PGs A and D. Conclusions. Our findings showed that the community UPEC strains circulating in Bucharest, Romania, belong predominantly to group B2 and >90% harbored the fimH gene. High MDR resistance rates were observed, as well as extended VF profiles, highlighting the importance of this type of studies for improving the epidemiological surveillance and the therapeutic or prophylactic management of the respective infections, in the context of antibiotic resistance emergence. [ABSTRACT FROM AUTHOR]
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- 2019
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10. MOBILE GENETIC ELEMENTS INVOLVED IN THE HORIZONTAL TRANSFER OF ANTIBIOTIC RESISTANCE GENES.
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Popa, Laura Ioana, Barbu, Ilda Czobor, and Chifiriuc, Mariana Carmen
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MOBILE genetic elements , *DRUG resistance in bacteria , *HORIZONTAL gene transfer , *MULTIDRUG resistance , *BACTERIAL cells - Abstract
Introduction: Antibiotics are one of the greatest discoveries of the 20th century, but this came with the great responsibility of maintaining their efficacy. Antibiotic resistance (AR) was noticed as early as the first years of the antibiotic era, the matter becoming increasingly worrying nowadays when one of the biggest threats to the global health system is the perspective of a post-antibiotic era. AR is spreading alarmingly due to the transfer of antibiotic resistance genes (ARGs) through horizontal gene transfer, especially under the selective pressure exhibited by the extensive or faulty use of antibiotics. Objectives: In this review, we discuss the mobile genetic elements (MGE) involved in horizontal gene transfer of ARGs and highlight their key role contribution to the dynamics of antibiotic resistance. Methods: A literature survey of the papers indexed in PubMed has been performed, using as key words antibiotic resistance + horizontal gene transfer, antibiotic resistance + mobile genetic elements, horizontal gene transfer + mobile genetic elements. Results: In the presence of antibiotics, MGEs have an increased likelihood to be maintained in the bacterial cells, acquire new ARGs and replicate, leading to a complex resistome and the emergence of multidrug resistance (MDR) phenotypes. Conclusions: Horizontal gene transfer of antibiotic resistance genes is far from being fully understood and majorly affects the global health system. MGEs play a decisive role in the emergence of antibiotic resistance, therefore, the mobile genetic elements must be thoroughly studied and regarded as potential targets for new antibiotic compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2018
11. Bacteriocins in the Era of Antibiotic Resistance: Rising to the Challenge.
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Gradisteanu Pircalabioru, Gratiela, Popa, Laura Ioana, Marutescu, Luminita, Gheorghe, Irina, Popa, Marcela, Czobor Barbu, Ilda, Cristescu, Rodica, Chifiriuc, Mariana-Carmen, and Espuelas Millán, María Socorro
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DRUG resistance in bacteria , *PEPTIDE antibiotics , *ANTIMICROBIAL peptides , *BACTERIOCINS , *ANTIBIOTICS , *FOOD industry , *CAUSES of death , *CELL membranes - Abstract
Decades of antibiotic misuse in clinical settings, animal feed, and within the food industry have led to a concerning rise in antibiotic-resistant bacteria. Every year, antimicrobial-resistant infections cause 700,000 deaths, with 10 million casualties expected by 2050, if this trend continues. Hence, innovative solutions are imperative to curb antibiotic resistance. Bacteria produce a potent arsenal of drugs with remarkable diversity that are all distinct from those of current antibiotics. Bacteriocins are potent small antimicrobial peptides synthetized by certain bacteria that may be appointed as alternatives to traditional antibiotics. These molecules are strategically employed by commensals, mostly Firmicutes, to colonize and persist in the human gut. Bacteriocins form channels in the target cell membrane, leading to leakage of low-molecular-weight, causing the disruption of the proton motive force. The objective of this review was to list and discuss the potential of bacteriocins as antimicrobial therapeutics for infections produced mainly by resistant pathogens. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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