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  1. Article ; Online: Comparison of an automated DNA extraction and 16S rDNA real time PCR/sequencing diagnostic method using optimized reagents with culture during a 15-month study using specimens from sterile body sites.

    Egli, Konrad / Risch, Martin / Risch, Lorenz / Bodmer, Thomas

    BMC microbiology

    2022  Volume 22, Issue 1, Page(s) 119

    Abstract: Background: 16S rDNA-PCR for the identification of a bacterial species is an established method. However, the DNA extraction reagents as well as the PCR reagents may contain residual bacterial DNA, which consequently generates false-positive PCR results. ...

    Abstract Background: 16S rDNA-PCR for the identification of a bacterial species is an established method. However, the DNA extraction reagents as well as the PCR reagents may contain residual bacterial DNA, which consequently generates false-positive PCR results. Additionally, previously used methods are frequently time-consuming. Here, we describe the results obtained with a new technology that uses DNA-free reagents for automated DNA extraction and subsequent real time PCR using sterile clinical specimens.
    Results: In total, we compared 803 clinical specimens using real time PCR and culturing. The clinical specimens were mainly of orthopedic origin received at our diagnostic laboratory. In 595 (74.1%) samples, the results were concordant negative, and in 102 (12.7%) the results were concordant positive. A total of 170 (21.2%) clinical specimens were PCR-positive, of which 62 (36.5% from PCR positive, 7.7% in total) gave an additional benefit to the patient since only the PCR result was positive. Many of these 62 positive specimens were strongly positive based on crossingpoint values (54% < Cp 30), and these 62 positive clinical specimens were diagnosed as medically relevant as well. Thirty-eight (4.2%) clinical specimens were culture-positive (25 of them were only enrichment culture positive) but PCR-negative, mainly for S. epidermidis, S. aureus and C. acnes. The turnaround times for negative specimens were 4 hours (automated DNA extraction and real time PCR) and 1 working day for positive specimens (including Sanger sequencing). Melting-curve analysis of SYBR Green-PCR enables the differentiation of specific and unspecific PCR products. Using Ripseq, even mixed infections of 2 bacterial species could be resolved.
    Conclusions: For endocarditis cases, the added benefit of PCR is obvious. The crucial innovations of the technology enable timely reporting of explicit reliable results for adequate treatment of patients. Clinical specimens with truly PCR-positive but culture-negative results represent an additional benefit for patients. Very few results at the detection limit still have to be critically examined.
    MeSH term(s) Bacteria/genetics ; DNA, Bacterial/analysis ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Humans ; Indicators and Reagents ; Real-Time Polymerase Chain Reaction ; Staphylococcus aureus/genetics
    Chemical Substances DNA, Bacterial ; DNA, Ribosomal ; Indicators and Reagents
    Language English
    Publishing date 2022-05-02
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2041505-9
    ISSN 1471-2180 ; 1471-2180
    ISSN (online) 1471-2180
    ISSN 1471-2180
    DOI 10.1186/s12866-022-02542-w
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Zeitnaher und spezifischer Erregernachweis. Akute infektiöse Diarrhö: Diagnostik 2.0

    Bodmer, Thomas

    Hausarzt-Praxis

    2016  Volume 11, Issue 12, Page(s) 40

    Language German
    Document type Article
    ZDB-ID 2229849-6
    ISSN 1661-6197
    Database Current Contents Medicine

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  3. Article: SARS-CoV-2 Nucleocapsid Protein Mutations Found in Switzerland Disrupt N-Gene Amplification in Commonly Used Multiplex RT-PCR Assay.

    Hilti, Dominique / Wehrli, Faina / Roditscheff, Anna / Risch, Martin / Risch, Lorenz / Egli, Adrian / Bodmer, Thomas / Wohlwend, Nadia

    Pathogens (Basel, Switzerland)

    2023  Volume 12, Issue 12

    Abstract: At the end of 2021, we observed an increase in N-gene target failures (NGTF) with the TaqPathTM COVID-19 CE-IVD RT-PCR Kit from Thermo Fisher Scientific (TaqPath). We subsequently used whole-genome sequencing (Oxford Nanopore Technology) to identify ... ...

    Abstract At the end of 2021, we observed an increase in N-gene target failures (NGTF) with the TaqPathTM COVID-19 CE-IVD RT-PCR Kit from Thermo Fisher Scientific (TaqPath). We subsequently used whole-genome sequencing (Oxford Nanopore Technology) to identify potential issues with N-gene PCR efficacy. Among 168,101 positive samples with a cycle threshold (CT) value <30 from August 2021 to May 2022, 194 specimens without N-gene amplification by PCR were identified (0.12%). Most NGTF samples originated from a wave of infection attributable to the Delta variant (B.1.617.2) and its sublineages. Sequencing revealed the nucleotide substitution G28922T (A217S) in 151 samples (88.8%). The substitution G215C, a hallmark mutation for Delta lineages, was concurrently present in all of these samples. Ten samples (5.9%) carried the deletion 28,913-28,918 (del214/215), eight samples (4.7%) the deletion 28,913-28,915 (del214) and one sample (0.6%) the deletion 28,892-28,930 (del207-219). Samples showing intact N-gene amplification by PCR lacked these specific mutations, but delayed-type amplification (i.e., partial or pNGTF) was attributable to the exclusive presence of A217S. As the N gene is a common target in many RT-PCR methods for SARS-CoV-2, an in-depth analysis of single-target failures using a combination with viral whole genome sequencing may allow for the identification of diagnostic flaws and eventual new variants.
    Language English
    Publishing date 2023-11-24
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2695572-6
    ISSN 2076-0817
    ISSN 2076-0817
    DOI 10.3390/pathogens12121383
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: S-Gene Target Failure as an Effective Tool for Tracking the Emergence of Dominant SARS-CoV-2 Variants in Switzerland and Liechtenstein, Including Alpha, Delta, and Omicron BA.1, BA.2, and BA.4/BA.5.

    Hilti, Dominique / Wehrli, Faina / Berchtold, Sabine / Bigler, Susanna / Bodmer, Thomas / Seth-Smith, Helena M B / Roloff, Tim / Kohler, Philipp / Kahlert, Christian R / Kaiser, Laurent / Egli, Adrian / Risch, Lorenz / Risch, Martin / Wohlwend, Nadia

    Microorganisms

    2024  Volume 12, Issue 2

    Abstract: During the SARS-CoV-2 pandemic, the Dr. Risch medical group employed the multiplex ... ...

    Abstract During the SARS-CoV-2 pandemic, the Dr. Risch medical group employed the multiplex TaqPath
    Language English
    Publishing date 2024-02-03
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2720891-6
    ISSN 2076-2607
    ISSN 2076-2607
    DOI 10.3390/microorganisms12020321
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Molecular characterization of a ceftriaxone-resistant Neisseria gonorrhoeae strain found in Switzerland: a case report.

    Egli, Konrad / Roditscheff, Anna / Flückiger, Ursula / Risch, Martin / Risch, Lorenz / Bodmer, Thomas

    Annals of clinical microbiology and antimicrobials

    2021  Volume 20, Issue 1, Page(s) 52

    Abstract: Background: The resistance of Neisseria gonorrhoeae to ceftriaxone is unusual in Switzerland. The underlying genotype responsible for resistance is suspected to be novel. Generally, resistance in Neisseria gonorrhoeae (Ng) involves a comprehensive set ... ...

    Abstract Background: The resistance of Neisseria gonorrhoeae to ceftriaxone is unusual in Switzerland. The underlying genotype responsible for resistance is suspected to be novel. Generally, resistance in Neisseria gonorrhoeae (Ng) involves a comprehensive set of genes with many different mutations leading to resistance to different β-lactams and fluoroquinolones.
    Case presentation: A patient had a positive result from specific PCR for Ng. We routinely culture all clinical specimens with a positive NG-PCR. In this particular case, we isolated a strain with resistance to ceftriaxone in Switzerland. A total of seven different genes (penA, ponA, porinB, mtr, gyrA, parC, 23S rRNA gene) in this strain were partially sequenced for comparison with phenotypic susceptibility testing. Interestingly, two different mutations in the porinB gene were observed, and data on this gene are limited. Information on the identified allele type of the penA gene is very limited as well. Three different mutations of parC and gyrA that correlate with ciprofloxacin resistance were found. The combination of ceftriaxone and ciprofloxacin resistance makes an appropriate treatment difficult to obtain due to multidrug resistance.
    Conclusion: The combined results for all genes show the appearance of new mutations in central Europe either due to worldwide spread or the emergence of new genetic combinations of mutations.
    MeSH term(s) Adult ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics ; Ceftriaxone/pharmacology ; Ciprofloxacin/pharmacology ; DNA, Bacterial/genetics ; Gonorrhea/diagnosis ; Gonorrhea/drug therapy ; Gonorrhea/microbiology ; Humans ; Male ; Microbial Sensitivity Tests ; Neisseria gonorrhoeae/drug effects ; Neisseria gonorrhoeae/genetics ; Neisseria gonorrhoeae/isolation & purification ; Phenotype ; Polymerase Chain Reaction ; Switzerland
    Chemical Substances Anti-Bacterial Agents ; Bacterial Proteins ; DNA, Bacterial ; Ciprofloxacin (5E8K9I0O4U) ; Ceftriaxone (75J73V1629)
    Language English
    Publishing date 2021-08-06
    Publishing country England
    Document type Case Reports ; Journal Article
    ZDB-ID 2097873-X
    ISSN 1476-0711 ; 1476-0711
    ISSN (online) 1476-0711
    ISSN 1476-0711
    DOI 10.1186/s12941-021-00456-5
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Exploring the Global Spread of Klebsiella grimontii Isolates Possessing

    Campos-Madueno, Edgar I / Moser, Aline I / Risch, Martin / Bodmer, Thomas / Endimiani, Andrea

    Antimicrobial agents and chemotherapy

    2021  Volume 65, Issue 9, Page(s) e0072421

    Abstract: The spread of plasmid-mediated carbapenemases within Klebsiella oxytoca is well-documented. In contrast, data concerning the closely related species Klebsiella grimontii are scarce. In fact, despite the recent report of the ... ...

    Abstract The spread of plasmid-mediated carbapenemases within Klebsiella oxytoca is well-documented. In contrast, data concerning the closely related species Klebsiella grimontii are scarce. In fact, despite the recent report of the first
    MeSH term(s) Animals ; Anti-Bacterial Agents/pharmacology ; Anti-Bacterial Agents/therapeutic use ; Bacterial Proteins/genetics ; Enterobacter ; Klebsiella/genetics ; Microbial Sensitivity Tests ; Plasmids/genetics ; Retrospective Studies ; beta-Lactamases/genetics
    Chemical Substances Anti-Bacterial Agents ; Bacterial Proteins ; beta-Lactamases (EC 3.5.2.6)
    Language English
    Publishing date 2021-08-17
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 217602-6
    ISSN 1098-6596 ; 0066-4804
    ISSN (online) 1098-6596
    ISSN 0066-4804
    DOI 10.1128/AAC.00724-21
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: First report of a bla

    Campos-Madueno, Edgar I / Sigrist, Thomas / Flückiger, Ursula M / Risch, Lorenz / Bodmer, Thomas / Endimiani, Andrea

    Journal of global antimicrobial resistance

    2021  Volume 25, Page(s) 310–314

    Abstract: Objectives: Klebsiella michiganensis is an emerging pathogen. Like Klebsiella pneumoniae, this species is able to acquire antibiotic resistance genes (ARGs) via mobile genetic elements. In this context, K. michiganensis isolates producing carbapenemases ...

    Abstract Objectives: Klebsiella michiganensis is an emerging pathogen. Like Klebsiella pneumoniae, this species is able to acquire antibiotic resistance genes (ARGs) via mobile genetic elements. In this context, K. michiganensis isolates producing carbapenemases of KPC, NDM, IMP and OXA-48-like types have already been reported. Here we characterised a strain (BD-50-Km) isolated from a rectal swab of a Turkish patient hospitalised in Switzerland.
    Methods: Species identification was initially performed using MALDI-TOF/MS. Antimicrobial susceptibility testing was done by the microdilution method. Whole-genome sequencing (WGS) was performed with both Illumina and Nanopore platforms and was used to confirm species identification, to characterise plasmids and to perform core-genome analyses.
    Results: BD-50-Km was initially identified as Klebsiella oxytoca and showed reduced susceptibility to imipenem. However, WGS indicated that the isolate was actually K. michiganensis. BD-50-Km carried the bla
    Conclusion: This is the first report of a bla
    MeSH term(s) Humans ; Klebsiella/genetics ; Microbial Sensitivity Tests ; Switzerland ; beta-Lactamases/genetics
    Chemical Substances beta-Lactamases (EC 3.5.2.6)
    Language English
    Publishing date 2021-05-04
    Publishing country Netherlands
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2710046-7
    ISSN 2213-7173 ; 2213-7165
    ISSN (online) 2213-7173
    ISSN 2213-7165
    DOI 10.1016/j.jgar.2021.03.027
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Characterisation of a new bla

    Campos-Madueno, Edgar I / Gmuer, Christian / Risch, Martin / Bodmer, Thomas / Endimiani, Andrea

    Journal of global antimicrobial resistance

    2021  Volume 24, Page(s) 325–327

    MeSH term(s) Enterobacter ; Plasmids/genetics
    Language English
    Publishing date 2021-02-08
    Publishing country Netherlands
    Document type Letter ; Research Support, Non-U.S. Gov't
    ZDB-ID 2710046-7
    ISSN 2213-7173 ; 2213-7165
    ISSN (online) 2213-7173
    ISSN 2213-7165
    DOI 10.1016/j.jgar.2021.01.017
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Erratum to 'Carbapenemase-producing Klebsiella pneumoniae strains in Switzerland: human and non-human settings may share high-risk clones' [Journal of Global Antimicrobial Resistance 28 (2022) 206-215].

    Campos-Madueno, Edgar I / Moser, Aline I / Jost, Géraldine / Maffioli, Carola / Bodmer, Thomas / Perreten, Vincent / Endimiani, Andrea

    Journal of global antimicrobial resistance

    2022  Volume 31, Page(s) 394

    Language English
    Publishing date 2022-09-09
    Publishing country Netherlands
    Document type Published Erratum
    ZDB-ID 2710046-7
    ISSN 2213-7173 ; 2213-7173
    ISSN (online) 2213-7173
    ISSN 2213-7173
    DOI 10.1016/j.jgar.2022.08.020
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Carbapenemase-producing Klebsiella pneumoniae strains in Switzerland: human and non-human settings may share high-risk clones.

    Campos-Madueno, Edgar I / Moser, Aline I / Jost, Géraldine / Maffioli, Carola / Bodmer, Thomas / Perreten, Vincent / Endimiani, Andrea

    Journal of global antimicrobial resistance

    2022  Volume 28, Page(s) 206–215

    Abstract: Background: The spread of carbapenemase-producing Klebsiella pneumoniae (CP-Kp) strains belonging to high-risk sequence types (STs) is a concern. For Switzerland, national data about the molecular features (especially the STs) of CP-Kp of human origin ... ...

    Abstract Background: The spread of carbapenemase-producing Klebsiella pneumoniae (CP-Kp) strains belonging to high-risk sequence types (STs) is a concern. For Switzerland, national data about the molecular features (especially the STs) of CP-Kp of human origin is not available. In veterinary clinics, ST11 and ST307 bla
    Methods: We analysed a collection of 285 K. pneumoniae genomes (170 were CP-Kp) isolated in Switzerland from human and non-human sources during 2006-2020. Whole-genome sequencing, core genome phylogenies and public databases were used to present a detailed overview regarding carbapenemases, STs and plasmids.
    Results: The top five STs were (main carbapenemase gene) ST512 (bla
    Conclusions: We described, for the first time, the features of the CP-Kp circulating in Switzerland in human and non-human settings. Our genomic analysis revealed that the emerging high-risk ST11 and ST307 lineages were often isolated from non-human settings. This study provided a baseline for further whole-genome sequencing-based One-Health surveillance of CP-Kp and emphasized the need for metadata to track dissemination routes between the different settings.
    MeSH term(s) Animals ; Bacterial Proteins ; Carbapenem-Resistant Enterobacteriaceae ; Clone Cells ; Humans ; Klebsiella Infections/epidemiology ; Klebsiella Infections/veterinary ; Klebsiella pneumoniae/genetics ; Switzerland ; beta-Lactamases
    Chemical Substances Bacterial Proteins ; beta-Lactamases (EC 3.5.2.6) ; carbapenemase (EC 3.5.2.6)
    Language English
    Publishing date 2022-01-24
    Publishing country Netherlands
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2710046-7
    ISSN 2213-7173 ; 2213-7173
    ISSN (online) 2213-7173
    ISSN 2213-7173
    DOI 10.1016/j.jgar.2022.01.016
    Database MEDical Literature Analysis and Retrieval System OnLINE

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