Dan Otelea

Dr. Dan Otelea

Molecular Diagnostics Laboratory, National Institute for Infectious Diseases, Bucharest, Romania

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 January 2013 in Retrovirology
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AAAna Abecasis
Ana Abecasis
AWannemarie M.J. wensing
annemarie M.J. wensing
Dimitrios ParaskevisDimitrios Paraskevis
Dimitrios Paraskevis
JVJurgen Vercauteren
Jurgen Vercauteren
KTKristof Theys
Kristof Theys
AVAnne-Mieke Vandamme
Anne-Mieke Vandamme
Understanding HIV-1 subtype distribution and epidemiology can assist preventive measures and clinical decisions. Sequence variation may affect antiviral drug resistance development, disease progression, evolutionary rates and transmission routes.

30 January 2020 in PLOS ONE
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MSMarius Surleac
Marius Surleac
IBIlda Czobor Barbu
Ilda Czobor Barbu
SPSimona Paraschiv
Simona Paraschiv
LPLaura Ioana Popa
Laura Ioana Popa
IGIrina Gheorghe
Irina Gheorghe
MCMariana Carmen Chifiriuc
Mariana Carmen Chifiriuc
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. blaSHV, 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.

21 July 2014 in BMC Infectious Diseases
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DFDineke Frentz
Dineke Frentz
DVDavid Van De Vijver
David Van De Vijver
AAAna Abecasis
Ana Abecasis
JAJan Albert
Jan Albert
OHOsamah Hamouda
Osamah Hamouda
CBCharles AB Boucher
Charles AB Boucher
One out of ten newly diagnosed patients in Europe was infected with a virus carrying a drug resistant mutation. We analysed the patterns over time for transmitted drug resistance mutations (TDRM) using data from the European Spread program.

3 April 2013 in Retrovirology
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DFDineke Frentz
Dineke Frentz
AWannemarie M.J. wensing
annemarie M.J. wensing
JAJan Albert
Jan Albert
Dimitrios ParaskevisDimitrios Paraskevis
Dimitrios Paraskevis
AAAna Abecasis
Ana Abecasis
SPSpread Programme
Spread Programme
Background: International travel plays a role in the spread of HIV-1 across Europe. It is, however, not known whether international travel is more important for spread of the epidemic as compared to endogenous infections within single countries. In this study, phylogenetic associations among HIV of newly diagnosed patients were determined across Europe. Results: Data came from the SPREAD programme which collects samples of newly diagnosed patients that are representative for national HIV epidemics. 4260 pol sequences from 25 European countries and Israel collected in 2002–2007 were included. We identified 457 clusters including 1330 persons (31.2% of all patients). The cluster size ranged between 2 and 28. A number of 987 patients (74.2%) were part of a cluster that consisted only of patients originating from the same country. In addition, 135 patients (10.2%) were in a cluster including only individuals from neighboring countries. Finally, 208 patients (15.6%) clustered with individuals from countries without a common border. Clustering with patients from the same country was less prevalent in patients being infected with B subtype (P-value <0.0001), in men who have sex with men (P-value <0.0001), and in recently infected patients (P-value =0.045). Conclusions: Our findings indicate that the transmission of HIV-1 in Europe is predominantly occurring between patients from the same country. This could have implications for HIV-1 transmission prevention programmes. Because infections through travelling between countries is not frequently observed it is important to have good surveillance of the national HIV-1 epidemics.

1 May 2015 in AIDS Research and Human Retroviruses
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Closed access
INIulia Niculescu
Iulia Niculescu
SPSimona Paraschiv
Simona Paraschiv
Dimitrios ParaskevisDimitrios Paraskevis
Dimitrios Paraskevis
AAAdrian Abagiu
Adrian Abagiu
IBIonelia Batan
Ionelia Batan
DODan Otelea
Dan Otelea
Since 2011, Romania has faced an HIV outbreak among injecting drug users (IDUs). Our aim was to identify and describe clinical and epidemiological patterns of this outbreak. A cross-sectional study enrolled 138 IDUs diagnosed with HIV infection between 2011 and 2013 with 58 sexually infected individuals included as the control group. The IDUs had a long history of heroin abuse (10 years) and a recent history of new psychostimulant injection (3–4 years). Classical epidemiological data and molecular techniques were used to describe the transmission dynamics. A high prevalence of hepatitis C virus (HCV) coinfection was noted (98.6%) compared to the control group (10.3%) ( p <0.001). IDUs had initially been infected with HCV. HIV infection was more recent, linked to starting injecting stimulants. HIV subtype analysis showed a predominance of the local F1 strain in both IDUs and sexually infected patients; in IDUs it also identified 28 CRF14_BG recombinants and six unique recombinant forms (URFs) between F1 and CRF14_BG. A few patients from both risk groups were infected with subtype B. Among IDUs, CRF14_BG was associated with a lower CD4 cell count and more advanced stages of disease, which correlated with CXCR4 tropism. Phylogenetic analysis revealed the spread of HIV through three major IDU clusters of recent date. Among IDUs with CRF14_BG, some reported travel abroad (Spain, Greece). By identifying clusters of IDUs with related viruses, molecular epidemiologic methods provide valuable information on patterns of HIV transmission that can be useful in planning appropriate harm reduction interventions.

24 June 2021 in Scientific Reports
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IGIrina Gheorghe
Irina Gheorghe
IBIlda Czobor Barbu
Ilda Czobor Barbu
MSMarius Surleac
Marius Surleac
IAIonela Avram
Ionela Avram
LPLaura Ioana Popa
Laura Ioana Popa
ZZZhiyong Zong
Zhiyong Zong
Acinetobacter baumannii has emerged worldwide as a dominant pathogen in a broad range of severe infections, raising an acute need for efficient antibacterials. This is the first report on the resistome and virulome of 33 extended drug-resistant and carbapenem-resistant A. baumannii (XDR CRAB) strains isolated from hospitalized and ambulatory patients in Bucharest, Romania. A total of 33 isolates were collected and analyzed using phenotypic antibiotic susceptibility and conjugation assays, PCR, whole-genome sequencing (WGS), pulsed-field gel electrophoresis (PFGE) and MultiLocus Sequence Typing (MLST). All isolates were extensively drug-resistant (XDR), being susceptible only to colistin. The carbapenem resistance was attributed by PCR mainly to blaOXA-24 and blaOXA-23 genes. PFGE followed by MLST analysis demonstrated the presence of nine pulsotypes and six sequence types. WGS of seven XDR CRAB isolates from healthcare-associated infections demonstrated the high diversity of resistance genes repertoire, as well as of mobile genetic elements, carrying ARGs for aminoglycosides, sulphonamides and macrolides. Our data will facilitate the understanding of resistance, virulence and transmission features of XDR AB isolates from Romanian patients and might be able to contribute to the implementation of appropriate infection control measures and to develop new molecules with innovative mechanisms of action, able to fight effectively against these bugs, for limiting the spread and decreasing the infection rate and mortality.