Rapid Gene Silencing Followed by Antimicrobial Susceptibility Testing for Target Validation in Antibiotic Discovery.

Mycobacterium tuberculosis is the main causative agent of tuberculosis (TB)-an ancient yet widespread global infectious disease to which 1.6 million people lost their lives in 2021. Antimicrobial resistance (AMR) has been an ongoing crisis for decades; 4.

Demonstrating the utility of the ex vivo murine mycobacterial growth inhibition assay (MGIA) for high-throughput screening of tuberculosis vaccine candidates against multiple Mycobacterium tuberculosis complex strains.

Human tuberculosis (TB) is caused by various members of the Mycobacterium tuberculosis (Mtb) complex. Differences in host response to infection have been reported, illustrative of a need to evaluate efficacy of novel vaccine candidates against multiple strains in preclinical studies. We previously showed that the murine lung and spleen direct mycobacterial growth inhibition assay (MGIA) can be used to assess control of ex vivo mycobacterial growth by host cells.

Synthesis, biological evaluation and computational studies of pyrazole derivatives as CYP121A1 inhibitors.

A series of imidazole and triazole diarylpyrazole derivatives were prepared using an efficient 5-step synthetic scheme and evaluated for binding affinity with (Mtb) CYP121A1 and antimycobacterial activity against Mtb H37Rv. Antimycobacterial susceptibility was measured using the spot-culture growth inhibition assay (SPOTi): the imidazoles displayed minimum inhibitory concentration (MIC) in the range of 3.95-12.

Defining the Genes Required for Survival of Mycobacterium bovis in the Bovine Host Offers Novel Insights into the Genetic Basis of Survival of Pathogenic Mycobacteria.

Tuberculosis has severe impacts on both humans and animals. Understanding the genetic basis of survival of both Mycobacterium tuberculosis, the human-adapted species, and Mycobacterium bovis, the animal-adapted species, is crucial to deciphering the biology of both pathogens. There are several studies that identify the genes required for survival of M.

Strain Specific Variations in Complement Sensitivity.

The complement system is required for innate immunity against , an important cause of antibiotic resistant systemic infections. strains differ in their susceptibility to the membrane attack complex (MAC) formed from terminal complement pathway proteins, but the reasons for this variation remain poorly understood. We have characterized in detail the complement sensitivity phenotypes of nine clinical strains and some of the factors that might influence differences between strains.

Engineering a suite of E. coli strains for enhanced expression of bacterial polysaccharides and glycoconjugate vaccines.

Background: Glycoengineering, in the biotechnology workhorse bacterium, Escherichia coli, is a rapidly evolving field, particularly for the production of glycoconjugate vaccine candidates (bioconjugation). Efficient production of glycoconjugates requires the coordinated expression within the bacterial cell of three components: a carrier protein, a glycan antigen and a coupling enzyme, in a timely fashion. Thus, the choice of a suitable E.

Probing Differences in Gene Essentiality Between the Human and Animal Adapted Lineages of the Complex Using TnSeq.

Members of the complex (MTBC) show distinct host adaptations, preferences and phenotypes despite being >99% identical at the nucleic acid level. Previous studies have explored gene expression changes between the members, however few studies have probed differences in gene essentiality. To better understand the functional impacts of the nucleic acid differences between and , we used the Mycomar T7 phagemid delivery system to generate whole genome transposon libraries in laboratory strains of both species and compared the essentiality status of genes during growth under identical conditions.

Making a diagnosis of periodic fever syndrome: Experience from a single tertiary centre.

Aim: This study aims to evaluate the utility of genetic testing of patients diagnosed with periodic fever syndromes and to assess the validity of existing scoring criteria.

Methods: This study retrospectively reviewed the clinical history of patients diagnosed with periodic fever syndromes at Queensland Children's Hospital between November 2014 and June 2018.

Results: Forty-three patients were diagnosed with periodic fever syndromes.

Sequential Vaccination With Heterologous Strains Induces Broadly Reactive Antibody Responses.

Antibody therapy may be an alternative treatment option for infections caused by the multi-drug resistant (MDR) bacterium As has multiple capsular serotypes, a universal antibody therapy would need to target conserved protein antigens rather than the capsular polysaccharides. We have immunized mice with single or multiple strains to induce antibody responses to protein antigens, and then assessed whether these responses provide cross-protection against a collection of genetically diverse clinical isolates. Immunized mice developed antibody responses to multiple protein antigens.

Re-sensitization of to Rifampicin Using CRISPR Interference Demonstrates Its Utility for the Study of Non-essential Drug Resistance Traits.

A greater understanding of the genes involved in antibiotic resistance in is necessary for the design of improved therapies. Clustered regularly interspaced short palindromic repeat interference (CRISPRi) has been previously utilized in mycobacteria to identify novel drug targets by the demonstration of gene essentiality. The work presented here shows that it can also be usefully applied to the study of non-essential genes involved in antibiotic resistance.

Antimicrobial resistance and COVID-19: Intersections and implications.

Before the coronavirus 2019 (COVID-19) pandemic began, antimicrobial resistance (AMR) was among the top priorities for global public health. Already a complex challenge, AMR now needs to be addressed in a changing healthcare landscape. Here, we analyse how changes due to COVID-19 in terms of antimicrobial usage, infection prevention, and health systems affect the emergence, transmission, and burden of AMR.

The Antimicrobial Peptide, Bactenecin 5, Supports Cell-Mediated but Not Humoral Immunity in the Context of a Mycobacterial Antigen Vaccine Model.

Bactenecin (Bac) 5 is a bovine antimicrobial peptide (AMP) capable of killing some species of bacteria through the inhibition of protein synthesis. Bac5 and other AMPs have also been shown to have chemotactic properties and can induce inflammatory cytokine expression by innate immune cells. Recently, AMPs have begun to be investigated for their potential use as novel vaccine adjuvants.

Overview of STING-Associated Vasculopathy with Onset in Infancy (SAVI) Among 21 Patients.

Background: Gain-of-function mutations in STING1 underlie a type I interferonopathy termed SAVI (STING-associated vasculopathy with onset in infancy). This severe disease is variably characterized by early-onset systemic inflammation, skin vasculopathy, and interstitial lung disease (ILD).

Objective: To describe a cohort of patients with SAVI.

Glibenclamide alters interleukin-8 and interleukin-1β of primary human monocytes from diabetes patients against Mycobacterium tuberculosis infection.

Type 2 diabetes mellitus (T2DM) is an important risk factor for development of tuberculosis (TB). Our previous study showed glibenclamide, an anti-diabetic drug used to control blood glucose concentration, reduced interleukin (IL)-8 secretion from primary human monocytes challenged with M. tuberculosis (Mtb).

Revisiting aminocoumarins for the treatment of melioidosis.

Burkholderia pseudomallei causes melioidosis, a potentially lethal disease that can establish both chronic and acute infections in humans. It is inherently recalcitrant to many antibiotics, there is a paucity of effective treatment options and there is no vaccine. In the present study, the efficacies of selected aminocoumarin compounds, DNA gyrase inhibitors that were discovered in the 1950s but are not in clinical use for the treatment of melioidosis were investigated.

Virulence of the emerging pathogen, , depends upon the -linked oligosaccharyltransferase, PglL.

We sought to characterize the contribution of the -OTase, PglL, to virulence in two spp. by comparing isogenic mutants in with the related species, . We utilized an array of assays in addition to and murine models to assess virulence of the mutant and wild-type strains in each species.

Adaption of the ex vivo mycobacterial growth inhibition assay for use with murine lung cells.

In the absence of a correlate(s) of protection against human tuberculosis and a validated animal model of the disease, tools to facilitate vaccine development must be identified. We present an optimised ex vivo mycobacterial growth inhibition assay (MGIA) to assess the ability of host cells within the lung to inhibit mycobacterial growth, including Bacille Calmette-Guérin (BCG) and Mycobacterium tuberculosis (MTB) Erdman. Growth of BCG was reduced by 0.

Genome-wide assessment of antimicrobial tolerance in under ciprofloxacin stress.

is a Gram-negative bacterium capable of causing gastrointestinal infection and is closely related to the highly virulent plague bacillus . Infections by both species are currently treatable with antibiotics such as ciprofloxacin, a quinolone-class drug of major clinical importance in the treatment of many other infections. Our current understanding of the mechanism of action of ciprofloxacin is that it inhibits DNA replication by targeting DNA gyrase, and that resistance is primarily due to mutation of this target site, along with generic efflux and detoxification strategies.

The shift to integrated care in the NHS: implications of the new care models for dentistry.

This article explores the implications for dentistry of the policy of integration and collaboration in health and social care. In particular, it explores the advantages and disadvantages for dentistry of involvement in one of the new integrated care models currently being piloted, and the barriers and enabling factors that may need to be addressed if dentistry is to become involved. We argue that the advantages may outweigh the disadvantages and such involvement may be necessary at least in the longer term, otherwise there is a risk of missed opportunities and the possibility of dentistry being left out of major policy decisions affecting health and social care.

In vitro and in vivo properties of the bovine antimicrobial peptide, Bactenecin 5.

Antimicrobial peptides (AMP), part of the innate immune system, are well studied for their ability to kill pathogenic microorganisms. However, many also possess important immunomodulatory effects, and this area has potential for the development of novel therapies to supplement traditional methods such as the use of antibiotics. Here, we characterise the microbicidal and immunomodulatory potential of the proline-rich bovine AMP, Bactenecin 5 (Bac5).

High-throughput analysis of Yersinia pseudotuberculosis gene essentiality in optimised in vitro conditions, and implications for the speciation of Yersinia pestis.

Background: Yersinia pseudotuberculosis is a zoonotic pathogen, causing mild gastrointestinal infection in humans. From this comparatively benign pathogenic species emerged the highly virulent plague bacillus, Yersinia pestis, which has experienced significant genetic divergence in a relatively short time span. Much of our knowledge of Yersinia spp.