Identification of Rv1133c (MetE) as a marker of replication and as a highly immunogenic antigen with potential immunodiagnostic power.

The immunization of mice with the sterile culture medium supernatants of (Mtb) H37Rv permitted the production of several monoclonal antibodies (mAbs) specific for secreted and/or released antigens. Two mAbs bound and immunoprecipitated an 80-kDa protein that was identified by mass spectrometry as Rv1133c, the methionine synthase MetE. The protein MetE is ubiquitous among prokaryota and shows a significant sequence homology in many bacteria.

Eradication of Drug-Tolerant 2022: Where We Stand.

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.

Epidemiology and drug susceptibility of nontuberculous mycobacteria (NTM) in Italy in 2016-2020.

Introduction: Nontuberculous mycobacteria (NTM) are environmental mycobacteria which may cause pulmonary and extrapulmonary diseases. These organisms are difficult to treat due to their intrinsic drug-resistance. In Italy, no major nationwide study on NTM epidemiology and drug susceptibility was performed.

Different configurations of SARS-CoV-2 spike protein delivered by integrase-defective lentiviral vectors induce persistent functional immune responses, characterized by distinct immunogenicity profiles.

Several COVID-19 vaccine strategies utilizing new formulations for the induction of neutralizing antibodies (nAbs) and T cell immunity are still under evaluation in preclinical and clinical studies. Here we used Simian Immunodeficiency Virus (SIV)-based integrase defective lentiviral vector (IDLV) delivering different conformations of membrane-tethered Spike protein in the mouse immunogenicity model, with the aim of inducing persistent nAbs against multiple SARS-CoV-2 variants of concern (VoC). Spike modifications included prefusion-stabilizing double proline (2P) substitutions, mutations at the furin cleavage site (FCS), D614G mutation and truncation of the cytoplasmic tail (delta21) of ancestral and Beta (B.

Decreasing trend of drug-resistant TB in Italy.

TB caused by rifampicin-resistant (RR) and multidrug-resistant (MDR) strains is a major concern to TB control globally. However, in the European Union, MDR-TB notifications among all bacteriologically confirmed TB cases with available drug susceptibility testing (DST) results decreased over the last years. We conducted a retrospective analysis on DST results reported from 2011 to 2020 by 46 laboratories in 19 out of 20 regions in Italy in order to evaluate resistance trends to first- and second-line drugs in MDR/RR-TB strains isolated from Italian-born persons (IBPs) and foreign-born persons (FBPs).

Activity of Drug Combinations against Grown in Aerobic and Hypoxic Conditions.

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).

Novel Putative Transposable Element Associated with the Subtype E5 Botulinum Toxin Gene Cluster of Neurotoxigenic Type E Strains from China.

Previously, a whole-genome comparison of three type E strains from Italy and the United States with different type E strains indicated that the / gene might be transferred between the two clostridia species through transposition. However, transposable elements (TEs) have never been identified close to the / gene. Herein, we report the whole genome sequences for four neurotoxigenic type E strains that originated in China.

Isolation and Characterization of Mouse Monoclonal Antibodies That Neutralize SARS-CoV-2 and Its Variants of Concern Alpha, Beta, Gamma and Delta by Binding Conformational Epitopes of Glycosylated RBD With High Potency.

Antibodies targeting Receptor Binding Domain (RBD) of SARS-CoV-2 have been suggested to account for the majority of neutralizing activity in COVID-19 convalescent sera and several neutralizing antibodies (nAbs) have been isolated, characterized and proposed as emergency therapeutics in the form of monoclonal antibodies (mAbs). However, SARS-CoV-2 variants are rapidly spreading worldwide from the sites of initial identification. The variants of concern (VOC) B.

Moxifloxacin Activates the SOS Response in in a Dose- and Time-Dependent Manner.

Previous studies on demonstrated that sub-minimum inhibitory concentration (MIC) of fluoroquinolones induced the SOS response, increasing drug tolerance. We characterized the transcriptional response to moxifloxacin in . Reference strain H37Rv was treated with moxifloxacin and gene expression studied by qRT-PCR.

Laboratory management for SARS-CoV-2 detection: a user-friendly combination of the heat treatment approach and rt-Real-time PCR testing.

The RNA purification is the gold standard for the detection of SARS-CoV-2 in swab samples, but it is dependent on the availability of chemical reagents. In this study, we evaluated the heat treatment method without RNA extraction as a reliable option to nucleic acid purification.

Use of probiotics in medical devices applied to some common pathologies.

Probiotics, defined as "living microorganisms that, whether ingested in useful amount, may have beneficial effects on human body", are widely used in various products for human use, such as dietary supplements, medical devices and pharmaceutical products. The European Directive on medical devices (MDs) (DDM 93/42), also includes those MDs containing live microorganisms, particularly probiotics, that may have various destinations of use, including that of assisting the therapy of several human pathologies. In this brief note we analyzed the use of probiotics in MDs and how probiotics administration could represent one of the new frontiers of scientific research on the prevention and treatment of various diseases.

The Combination Rifampin-Nitazoxanide, but Not Rifampin-Isoniazid-Pyrazinamide-Ethambutol, Kills Dormant Mycobacterium tuberculosis in Hypoxia at Neutral pH.

The activities of rifampin, nitazoxanide, PA-824, and sutezolid were tested against dormant under conditions mimicking caseous granulomas (hypoxia at pH 7.3) in comparison with those of the combination rifampin-isoniazid-pyrazinamide-ethambutol (R-I-Z-E), which is used for human therapy. Mycobacterial viability was monitored by CFU and regrowth in MGIT 960.

Revisiting problems and solutions to decrease Mycobacterium tuberculosis pyrazinamide false resistance when using the Bactec MGIT 960 system.

Pyrazinamide (PZA) is a first-line key drug used in combination with other agents for the treatment of tuberculosis (TB). Phenotypic and molecular assays for testing susceptibility of Mycobacterium tuberculosis (Mtb) to PZA have been developed, with the assay in liquid medium at acidic pH in the Bactec MGIT 960 (M960) system being routinely used in the mycobacteriology laboratories. However, false resistance to PZA by this method was reported to occur by several investigators, mostly due to high Mtb inoculum, which may impair drug activity by increasing the pH of the medium.

Activity of DNA-targeted C8-linked pyrrolobenzodiazepine-heterocyclic polyamide conjugates against aerobically and hypoxically grown Mycobacterium tuberculosis under acidic and neutral conditions.

Mycobacterium tuberculosis (Mtb) is the aetiological agent of tuberculosis, the leading cause of death worldwide from a single infectious agent. Mtb is a highly adaptable human pathogen that might enter a dormant non-replicating (NR), drug-tolerant stage. Reactivation of dormant Mtb can lead to active disease.

Fighting tuberculosis by drugs targeting nonreplicating bacilli.

Current tuberculosis (TB) treatment requires 6 months of combination therapy with isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), and ethambutol for active TB and 9 months of INH or 3 months of rifapentine (RFP) + INH for latent TB. The lungs of patients with active and latent TB contain heterogeneous mixtures of cellular and caseous granulomas harboring Mycobacterium tuberculosis bacilli ranging from actively replicating (AR) to nonreplicating (NR), phenotypically drug-resistant stages. Several in vitro models to obtain NR cells were reported, including exposure to hypoxia, nutrient starvation, acid + nitric oxide, and stationary phase.

Galleria mellonella as an in vivo model for assessing the protective activity of probiotics against gastrointestinal bacterial pathogens.

The antagonistic activity against gastrointestinal bacterial pathogens is an important property of probiotic bacteria and a desirable feature for pre-selection of novel strains with probiotic potential. Pre-screening of candidate probiotics for antibacterial activity should be based on in vitro and in vivo tests. This study investigated whether the protective activity of probiotic bacteria against gastrointestinal bacterial pathogens can be evaluated using Galleria mellonella larvae as an in vivo model.

Activity of drugs against dormant Mycobacterium tuberculosis.

Objective/background: Heterogeneous mixtures of cellular and caseous granulomas coexist in the lungs of tuberculosis (TB) patients, with Mycobacterium tuberculosis (Mtb) existing from actively replicating (AR) to dormant, nonreplicating (NR) stages. Within cellular granulomas, the pH is estimated to be less than 6, whereas in the necrotic centres of hypoxic, cholesterol/triacylglycerol-rich, caseous granulomas, the pH varies between 7.2 and 7.

Drug-resistant tuberculosis in Naples, 2008-2013.

Background: Drug-resistant tuberculosis (TB) is a serious threat in industrialized countries, but information from Southern Italy is lacking. Here, we present the results of a retrospective study of TB cases diagnosed in 2008-2013 in Naples, the largest city in Southern Italy.

Methods: Six hundred ninety Mycobacterium tuberculosis strains were isolated at the Ospedali dei Colli of Naples, and resistance to first-line and second-line drugs was determined.

Mycobacterium tuberculosis Is Selectively Killed by Rifampin and Rifapentine in Hypoxia at Neutral pH.

The activities of rifampin, rifapentine, bedaquiline, PA-824, clofazimine, nitazoxanide, isoniazid, amikacin, moxifloxacin, niclosamide, thioridazine, and pyrazinamide were tested against nonreplicating (dormant) H37Rv under conditions of hypoxia at pHs 5.8 and 7.3, mimicking environments of cellular granulomas and caseous granulomas, respectively.

Pyrazinamide susceptibility testing: proposed new standard with the BACTECTM MGITTM 960 system.

The susceptibility of 253 Mycobacterium tuberculosis complex isolates to pyrazinamide (PZA) was assessed using the BACTECTM MGITTM 960 (M960) system. Resistant strains underwent paired repeat testing using 1) a critical concentration of 200 g/ml (PZA-200), and 2) a reduced inoculum of 0.25 ml.

Effects of Megaplasmid Loss on Growth of Neurotoxigenic Clostridium butyricum Strains and Botulinum Neurotoxin Type E Expression.

Clostridium butyricum strains that atypically produce the botulinum neurotoxin type E (BoNT/E) possess a megaplasmid of unknown functions in their genome. In this study, we cured two botulinum neurotoxigenic C. butyricum type E strains of their megaplasmids, and compared the obtained megaplasmid-cured strains to their respective wild-type parental strains.