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  1. Article ; Online: Eradication of Drug-Tolerant Mycobacterium tuberculosis 2022

    Alessio Lanni / Angelo Iacobino / Lanfranco Fattorini / Federico Giannoni

    Microorganisms, Vol 11, Iss 1511, p

    Where We Stand

    2023  Volume 1511

    Abstract: The lungs of tuberculosis (TB) patients contain a spectrum of granulomatous lesions, ranging from solid and well-vascularized cellular granulomas to avascular caseous granulomas. In solid granulomas, current therapy kills actively replicating (AR) ... ...

    Abstract The lungs of tuberculosis (TB) patients contain a spectrum of granulomatous lesions, ranging from solid and well-vascularized cellular granulomas to avascular caseous granulomas. In solid granulomas, current therapy kills actively replicating (AR) intracellular bacilli, while in low-vascularized caseous granulomas the low-oxygen tension stimulates aerobic and microaerophilic AR bacilli to transit into non-replicating (NR), drug-tolerant and extracellular stages. These stages, which do not have genetic mutations and are often referred to as persisters, are difficult to eradicate due to low drug penetration inside the caseum and mycobacterial cell walls. The sputum of TB patients also contains viable bacilli called differentially detectable (DD) cells that, unlike persisters, grow in liquid, but not in solid media. This review provides a comprehensive update on drug combinations killing in vitro AR and drug-tolerant bacilli (persisters and DD cells), and sterilizing Mycobacterium tuberculosis -infected BALB/c and caseum-forming C3HeB/FeJ mice. These observations have been important for testing new drug combinations in noninferiority clinical trials, in order to shorten the duration of current regimens against TB. In 2022, the World Health Organization, following the results of one of these trials, supported the use of a 4-month regimen for the treatment of drug-susceptible TB as a possible alternative to the current 6-month regimen.
    Keywords Mycobacterium tuberculosis ; tuberculosis ; drug-resistance ; drug combinations ; drug-tolerance ; persisters ; Biology (General) ; QH301-705.5
    Subject code 572
    Language English
    Publishing date 2023-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Drug-Resistant Tuberculosis 2020

    Angelo Iacobino / Lanfranco Fattorini / Federico Giannoni

    Applied Sciences, Vol 10, Iss 6, p

    Where We Stand

    2020  Volume 2153

    Abstract: The control of tuberculosis (TB) is hampered by the emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis (Mtb) strains, defined as resistant to at least isoniazid and rifampin, the two bactericidal drugs essential for the treatment of the ... ...

    Abstract The control of tuberculosis (TB) is hampered by the emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis (Mtb) strains, defined as resistant to at least isoniazid and rifampin, the two bactericidal drugs essential for the treatment of the disease. Due to the worldwide estimate of almost half a million incident cases of MDR/rifampin-resistant TB, it is important to continuously update the knowledge on the mechanisms involved in the development of this phenomenon. Clinical, biological and microbiological reasons account for the generation of resistance, including: (i) nonadherence of patients to their therapy, and/or errors of physicians in therapy management, (ii) complexity and poor vascularization of granulomatous lesions, which obstruct drug distribution to some sites, resulting in resistance development, (iii) intrinsic drug resistance of tubercle bacilli, (iv) formation of non-replicating, drug-tolerant bacilli inside the granulomas, (v) development of mutations in Mtb genes, which are the most important molecular mechanisms of resistance. This review provides a comprehensive overview of these issues, and releases up-dated information on the therapeutic strategies recently endorsed and recommended by the World Health Organization to facilitate the clinical and microbiological management of drug-resistant TB at the global level, with attention also to the most recent diagnostic methods.
    Keywords tuberculosis ; mycobacterium tuberculosis ; rifampin ; isoniazid ; mechanisms of resistance ; mutations ; granulomas ; caseum ; cell envelope ; dormancy ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Subject code 610
    Language English
    Publishing date 2020-03-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article ; Online: Moxifloxacin Activates the SOS Response in Mycobacterium tuberculosis in a Dose- and Time-Dependent Manner

    Angelo Iacobino / Giovanni Piccaro / Manuela Pardini / Lanfranco Fattorini / Federico Giannoni

    Microorganisms, Vol 9, Iss 2, p

    2021  Volume 255

    Abstract: Previous studies on Escherichia coli demonstrated that sub-minimum inhibitory concentration (MIC) of fluoroquinolones induced the SOS response, increasing drug tolerance. We characterized the transcriptional response to moxifloxacin in Mycobacterium ... ...

    Abstract Previous studies on Escherichia coli demonstrated that sub-minimum inhibitory concentration (MIC) of fluoroquinolones induced the SOS response, increasing drug tolerance. We characterized the transcriptional response to moxifloxacin in Mycobacterium tuberculosis . Reference strain H37Rv was treated with moxifloxacin and gene expression studied by qRT-PCR. Five SOS regulon genes, recA , lexA , dnaE2 , Rv3074 and Rv3776, were induced in a dose- and time-dependent manner. A range of moxifloxacin concentrations induced recA , with a peak observed at 2 × MIC (0.25 μg/mL) after 16 h. Another seven SOS responses and three DNA repair genes were significantly induced by moxifloxacin. Induction of recA by moxifloxacin was higher in log-phase than in early- and stationary-phase cells, and absent in dormant bacilli. Furthermore, in an H37Rv fluoroquinolone-resistant mutant carrying the D94G mutation in the gyrA gene, the SOS response was induced at drug concentrations higher than the mutant MIC value. The 2 × MIC of moxifloxacin determined no significant changes in gene expression in a panel of 32 genes, except for up-regulation of the relK toxin and of Rv3290c and Rv2517c , two persistence-related genes. Overall, our data show that activation of the SOS response by moxifloxacin, a likely link to increased mutation rate and persister formation, is time, dose, physiological state and, possibly, MIC dependent.
    Keywords Mycobacterium tuberculosis ; SOS response ; DNA repair ; fluoroquinolone ; moxifloxacin ; Biology (General) ; QH301-705.5
    Subject code 572
    Language English
    Publishing date 2021-01-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Activity of Drug Combinations against Mycobacterium abscessus Grown in Aerobic and Hypoxic Conditions

    Alessio Lanni / Emanuele Borroni / Angelo Iacobino / Cristina Russo / Leonarda Gentile / Lanfranco Fattorini / Federico Giannoni

    Microorganisms, Vol 10, Iss 7, p

    2022  Volume 1421

    Abstract: Infections caused by Mycobacterium abscessus (Mab), an environmental non-tuberculous mycobacterium, are difficult to eradicate from patients with pulmonary diseases such as cystic fibrosis and bronchiectasis even after years of antibiotic treatments. In ... ...

    Abstract Infections caused by Mycobacterium abscessus (Mab), an environmental non-tuberculous mycobacterium, are difficult to eradicate from patients with pulmonary diseases such as cystic fibrosis and bronchiectasis even after years of antibiotic treatments. In these people, the low oxygen pressure in mucus and biofilm may restrict Mab growth from actively replicating aerobic (A) to non-replicating hypoxic (H) stages, which are known to be extremely drug-tolerant. After the exposure of Mab A and H cells to drugs, killing was monitored by measuring colony-forming units (CFU) and regrowth in liquid medium (MGIT 960) of 1-day-old A cells (A1) and 5-day-old H cells (H5). Mab killing was defined as a lack of regrowth of drug-exposed cells in MGIT tubes after >50 days of incubation. Out of 18 drugs tested, 14-day treatments with bedaquiline-amikacin (BDQ-AMK)-containing three-drug combinations were very active against A1 + H5 cells. However, drug-tolerant cells (persisters) were not killed, as shown by CFU curves with typical bimodal trends. Instead, 56-day treatments with the nitrocompounds containing combinations BDQ-AMK-rifabutin-clarithromycin-nimorazole and BDQ-AMK-rifabutin-clarithromycin-metronidazole-colistin killed all A1 + H5 Mab cells in 42 and 56 days, respectively, as shown by lack of regrowth in agar and MGIT medium. Overall, these data indicated that Mab persisters may be killed by appropriate drug combinations.
    Keywords Mycobacterium abscessus ; cystic fibrosis ; aerobiosis ; anaerobiosis ; nitrocompounds ; colistin ; Biology (General) ; QH301-705.5
    Subject code 630
    Language English
    Publishing date 2022-07-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: TARGETING DORMANT BACILLI TO FIGHT TUBERCULOSIS

    Lanfranco Fattorini / Giovanni Piccaro / Alessandro Mustazzolu / Federico Giannoni

    Mediterranean Journal of Hematology and Infectious Diseases, Vol 5, Iss 1, Pp e2013072-e

    2013  Volume 2013072

    Abstract: Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb), which kills about 2 million people annually. Furthermore, 2 billion people worldwide are latently infected with this organism, with 10% of them reactivating to active ... ...

    Abstract Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb), which kills about 2 million people annually. Furthermore, 2 billion people worldwide are latently infected with this organism, with 10% of them reactivating to active TB due to re-growth of nonreplicating (dormant) Mtb residing in their tissues. Because of the huge reservoir of latent TB it is important to find novel drugs/drug combinations killing dormant bacilli (microaerophiles, anaerobes and drug-tolerant persisters) surviving for decades in a wide spectrum of granulomatous lesions in the lungs of TB patients. Antibiotic treatment of drug-susceptible TB requires administration of isoniazid, rifampin, pyrazinamide, ethambutol for 2 months, followed by isoniazid and rifampin for 4 months. To avoid reactivation of dormant Mtb to active pulmonary TB, up to 9 months of treatment with isoniazid is required. Therefore, a strategy to eliminate dormant bacilli needs to be developed to shorten therapy of active and latent TB and reduce the reservoir of people with latent TB. Finding drugs with high rate of penetration into the caseous granulomas and understanding the biology of dormant bacilli and in particular of persister cells, phenotypically resistant to antibiotics, will be essential to eradicate Mtb from humans. In recent years unprecedented efforts have been done in TB drug discovery, aimed at identifying novel drugs and drug combinations killing both actively replicating and nonreplicating Mtb in vitro , in animal models and in clinical trials in humans.
    Keywords Tuberculosis ; Mycobacterium tuberculois ; anti-TB drugs ; dormancy. ; Diseases of the blood and blood-forming organs ; RC633-647.5 ; Specialties of internal medicine ; RC581-951 ; Internal medicine ; RC31-1245 ; Medicine ; R
    Subject code 610
    Language English
    Publishing date 2013-11-01T00:00:00Z
    Publisher Catholic University
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article: Mycobacterium tuberculosis gene expression at different stages of hypoxia-induced dormancy and upon resuscitation

    Iona, Elisabetta / Manuela Pardini / Alessandro Mustazzolu / Giovanni Piccaro / Roberto Nisini / Lanfranco Fattorini / Federico Giannoni

    journal of microbiology. 2016 Aug., v. 54, no. 8

    2016  

    Abstract: The physiology of dormant Mycobacterium tuberculosis was studied in detail by examining the gene expression of 51 genes using quantitative Reverse-Transcription Polymerase Chain Reaction. A forty-day period of dormancy in the Wayne culture model depicted ...

    Abstract The physiology of dormant Mycobacterium tuberculosis was studied in detail by examining the gene expression of 51 genes using quantitative Reverse-Transcription Polymerase Chain Reaction. A forty-day period of dormancy in the Wayne culture model depicted four major transcription patterns. Some sigma factors and many metabolic genes were constant, whereas genes belonging to the dormancy regulon were activated on day 9. In particular, alpha-crystallin mRNA showed more than a 1,000-fold increase compared to replicating bacilli. Genes belonging to the enduring hypoxic response were up-regulated at day 16, notably, transcription factors sigma B and E. Early genes typical of log-phase bacilli, esat-6 and fbpB, were uniformly down-regulated during dormancy. Late stages of dormancy showed a drop in gene expression likely due to a lack of substrates in anaerobic respiration as demonstrated by the transcriptional activation observed following nitrates addition. Among genes involved in nitrate metabolism, narG was strongly up-regulated by nitrates addition. Dormant bacilli responded very rapidly when exposed to oxygen and fresh medium, showing a transcriptional activation of many genes, including resuscitation-promoting factors, within one hour. Our observations extend the current knowledge on dormant M. tuberculosis gene expression and its response to nutrients and to aerobic and anaerobic respiration.
    Keywords Mycobacterium tuberculosis ; anaerobiosis ; dormancy ; gene expression ; messenger RNA ; models ; nitrates ; nutrients ; oxygen ; regulon ; reverse transcriptase polymerase chain reaction ; sigma factors ; transcriptional activation
    Language English
    Dates of publication 2016-08
    Size p. 565-572.
    Publishing place The Microbiological Society of Korea
    Document type Article
    ZDB-ID 2012399-1
    ISSN 1225-8873
    ISSN 1225-8873
    DOI 10.1007/s12275-016-6150-4
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 5211: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (2.OG)
    ab Jg. 2022: Lesesaal (EG)

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  7. Article: Optimisation, harmonisation and standardisation of the direct mycobacterial growth inhibition assay using cryopreserved human peripheral blood mononuclear cells

    Tanner, Rachel / Steven G. Smith / Krista E. van Meijgaarden / Federico Giannoni / Morven Wilkie / Lucia Gabriele / Carla Palma / Hazel M. Dockrell / Tom H.M. Ottenhoff / Helen McShane

    Journal of immunological methods. 2019 June, v. 469

    2019  

    Abstract: A major challenge to tuberculosis (TB) vaccine development is the lack of a validated immune correlate of protection. Mycobacterial growth inhibition assays (MGIAs) represent an unbiased measure of the ability to control mycobacterial growth in vitro. A ... ...

    Abstract A major challenge to tuberculosis (TB) vaccine development is the lack of a validated immune correlate of protection. Mycobacterial growth inhibition assays (MGIAs) represent an unbiased measure of the ability to control mycobacterial growth in vitro. A successful MGIA could be applied to preclinical and clinical post-vaccination samples to aid in the selection of novel vaccine candidates at an early stage and provide a relevant measure of immunogenicity and protection. However, assay harmonisation is critical to ensure that comparable information can be extracted from different vaccine studies. As part of the FP7 European Research Infrastructures for Poverty Related Diseases (EURIPRED) consortium, we aimed to optimise the direct MGIA, assess repeatability and reproducibility, and harmonise the assay across different laboratories. We observed an improvement in repeatability with increased cell number and increased mycobacterial input. Furthermore, we determined that co-culturing in static 48-well plates compared with rotating 2 ml tubes resulted in a 23% increase in cell viability and a 500-fold increase in interferon-gamma (IFN-γ) production on average, as well as improved reproducibility between replicates, assay runs and sites. Applying the optimised conditions, we report repeatability to be <5% coefficient of variation (CV), intermediate precision to be <20% CV, and inter-site reproducibility to be <30% CV; levels within acceptable limits for a functional cell-based assay. Using relevant clinical samples, we demonstrated comparable results across two shared sample sets at three sites. Based on these findings, we have established a standardised operating procedure (SOP) for the use of the direct PBMC MGIA in TB vaccine development.
    Keywords cell viability ; coculture ; cryopreservation ; growth retardation ; humans ; immunogenicity ; infrastructure ; interferon-gamma ; mononuclear leukocytes ; poverty ; vaccine development ; vaccines
    Language English
    Dates of publication 2019-06
    Size p. 1-10.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 120142-6
    ISSN 1872-7905 ; 0022-1759
    ISSN (online) 1872-7905
    ISSN 0022-1759
    DOI 10.1016/j.jim.2019.01.006
    Database NAL-Catalogue (AGRICOLA)

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 795: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
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