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Medical Microbiology and Immunology Jun 2024Endogenous antimicrobial peptides (AMPs) play a key role in the host defense against pathogens. AMPs attack pathogens preferentially at the site of entry to prevent...
Endogenous antimicrobial peptides (AMPs) play a key role in the host defense against pathogens. AMPs attack pathogens preferentially at the site of entry to prevent invasive infection. Mycobacterium tuberculosis (Mtb) enters its host via the airways. AMPs released into the airways are therefore likely candidates to contribute to the clearance of Mtb immediately after infection. Since lysozyme is detectable in airway secretions, we evaluated its antimicrobial activity against Mtb. We demonstrate that lysozyme inhibits the growth of extracellular Mtb, including isoniazid-resistant strains. Lysozyme also inhibited the growth of non-tuberculous mycobacteria. Even though lysozyme entered Mtb-infected human macrophages and co-localized with the pathogen we did not observe antimicrobial activity. This observation was unlikely related to the large size of lysozyme (14.74 kDa) because a smaller lysozyme-derived peptide also co-localized with Mtb without affecting the viability. To evaluate whether the activity of lysozyme against extracellular Mtb could be relevant in vivo, we incubated Mtb with fractions of human serum and screened for antimicrobial activity. After several rounds of sub-fractionation, we identified a highly active fraction-component as lysozyme by mass spectrometry. In summary, our results identify lysozyme as an antimycobacterial protein that is detectable as an active compound in human serum. Our results demonstrate that the activity of AMPs against extracellular bacilli does not predict efficacy against intracellular pathogens despite co-localization within the macrophage. Ongoing experiments are designed to unravel peptide modifications that occur in the intracellular space and interfere with the deleterious activity of lysozyme in the extracellular environment.
Topics: Muramidase; Humans; Mycobacterium tuberculosis; Macrophages; Antimicrobial Peptides; Microbial Sensitivity Tests; Microbial Viability
PubMed: 38900248
DOI: 10.1007/s00430-024-00793-0 -
BMC Infectious Diseases Jun 2024Although the Mini Nutritional Assessment (MNA) is recognized as a useful tool for evaluating nutritional status in patients with various diseases, its applicability in...
Usefulness of the mini nutritional assessment short-form for evaluating nutritional status in patients with nontuberculous mycobacterial pulmonary disease: a prospective cross-sectional study.
BACKGROUND
Although the Mini Nutritional Assessment (MNA) is recognized as a useful tool for evaluating nutritional status in patients with various diseases, its applicability in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) remains undetermined.
METHODS
We designed a prospective cross-sectional study to investigate whether the MNA Short-Form (MNA-SF) score can serve as a screening tool to assess the nutritional status of patients with NTM-PD. The MNA-SF was conducted upon patient enrollment, and correlation analyses were performed to compare MNA-SF scores with other nutritional measurements and disease severity. Multivariable logistic regression analyses were conducted to evaluate the association between MNA-SF scores and NTM-PD severity.
RESULTS
The 194 patients with NTM-PD included in the analysis had a median age of 65.0 (59.0-69.0) years; 59.3% (n = 115) had low MNA-SF scores (< 12). The low MNA-SF group exhibited a lower body mass index (19.7 vs. 22.4 kg/m, p < 0.001) and fat-free mass index (14.7 vs. 15.6 kg/m, p < 0.001) than the normal MNA-SF group, as well as higher incidences of sarcopenia (20.0% vs. 6.3%, p = 0.008) and adipopenia (35.7% vs. 5.1%, p < 0.001). However, no significant differences in calorie and protein intakes were observed between the two groups. Low MNA-SF scores were associated with radiographic severity (adjusted odds ratio 2.72, 95% confidence interval 1.38-5.36) but not with forced vital capacity.
CONCLUSIONS
The MNA-SF can effectively assess the nutritional status of patients with NTM-PD and can serve as an important clinical indicator in NTM-PD where treatment timing is determined by clinical judgment.
Topics: Humans; Cross-Sectional Studies; Male; Female; Aged; Middle Aged; Prospective Studies; Nutritional Status; Nutrition Assessment; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Lung Diseases
PubMed: 38898397
DOI: 10.1186/s12879-024-09499-3 -
Microbes and Environments 2024To investigate mycobacterial cases of farmed yellowtail fish in coastal areas of western Japan (Kagoshima, Kyushu), where aquaculture fisheries are active, Mycobacterium...
To investigate mycobacterial cases of farmed yellowtail fish in coastal areas of western Japan (Kagoshima, Kyushu), where aquaculture fisheries are active, Mycobacterium pseudoshottsii, the causative agent, was isolated from six neighboring fishing ports in 2012 and 2013. A phylogenetic ana-lysis revealed that the strains isolated from one fishing port were closely related to those isolated from other regions of Japan, suggesting the nationwide spread of a single strain. However, strains from Japan were phylogenetically distinct from those from the Mediterranean and the United States; therefore, worldwide transmission was not observed based on the limited data obtained on the strains exami-ned in this study. The present results demonstrate that a bacterial genomic ana-lysis of infected cases, a mole-cular epidemiology strategy for public health, provides useful data for estimating the prevalence and transmission pathways of M. pseudoshottsii in farmed fish. A bacterial genome ana-lysis of strains, such as that performed herein, may play an important role in monitoring the prevalence of this pathogen in fish farms and possible epidemics in the future as a result of international traffic, logistics, and trade in fisheries.
Topics: Japan; Animals; Fish Diseases; Phylogeny; Mycobacterium Infections; Genome, Bacterial; Aquaculture; Mycobacterium; Fishes; Fisheries; Genomics; Molecular Epidemiology; Prevalence
PubMed: 38897967
DOI: 10.1264/jsme2.ME24011 -
ELife Jun 2024Tuberculosis is a major global health problem and is one of the top 10 causes of death worldwide. There is a pressing need for new treatments that circumvent emerging...
Tuberculosis is a major global health problem and is one of the top 10 causes of death worldwide. There is a pressing need for new treatments that circumvent emerging antibiotic resistance. parasitises macrophages, reprogramming them to establish a niche in which to proliferate, therefore macrophage manipulation is a potential host-directed therapy if druggable molecular targets could be identified. The pseudokinase Tribbles1 (Trib1) regulates multiple innate immune processes and inflammatory profiles making it a potential drug target in infections. Trib1 controls macrophage function, cytokine production, and macrophage polarisation. Despite wide-ranging effects on leukocyte biology, data exploring the roles of Tribbles in infection in vivo are limited. Here, we identify that human Tribbles1 is expressed in monocytes and is upregulated at the transcript level after stimulation with mycobacterial antigen. To investigate the mechanistic roles of Tribbles in the host response to mycobacteria in vivo, we used a zebrafish (Mm) infection tuberculosis model. Zebrafish Tribbles family members were characterised and shown to have substantial mRNA and protein sequence homology to their human orthologues. overexpression was host-protective against Mm infection, reducing burden by approximately 50%. Conversely, knockdown/knockout exhibited increased infection. Mechanistically, overexpression significantly increased the levels of proinflammatory factors and nitric oxide. The host-protective effect of was found to be dependent on the E3 ubiquitin kinase Cop1. These findings highlight the importance of Trib1 and Cop1 as immune regulators during infection in vivo and suggest that enhancing macrophage TRIB1 levels may provide a tractable therapeutic intervention to improve bacterial infection outcomes in tuberculosis.
Topics: Animals; Humans; Disease Models, Animal; Host-Pathogen Interactions; Intracellular Signaling Peptides and Proteins; Macrophages; Monocytes; Mycobacterium Infections, Nontuberculous; Mycobacterium marinum; Protein Serine-Threonine Kinases; Zebrafish; Male; Female
PubMed: 38896446
DOI: 10.7554/eLife.95980 -
Protein Science : a Publication of the... Jul 2024Tuberculosis necrotizing toxin (TNT) is a protein domain discovered on the outer membrane of Mycobacterium tuberculosis (Mtb), and the fungal pathogen Aspergillus...
Tuberculosis necrotizing toxin (TNT) is a protein domain discovered on the outer membrane of Mycobacterium tuberculosis (Mtb), and the fungal pathogen Aspergillus fumigatus. TNT domains have pure NAD(P) hydrolytic activity, setting them apart from other NAD-cleaving domains such as ADP-ribosyl cyclase and Toll/interleukin-1 receptor homology (TIR) domains which form a wider set of products. Importantly, the Mtb TNT domain has been shown to be involved in immune evasion via depletion of the intracellular NAD pool of macrophages. Therefore, an intriguing hypothesis is that TNT domains act as "NAD killers" in host cells facilitating pathogenesis. Here, we explore the phylogenetic distribution of TNT domains and detect their presence solely in bacteria and fungi. Within fungi, we discerned six TNT clades. In addition, X-ray crystallography and AlphaFold2 modeling unveiled clade-specific strategies to promote homodimer stabilization of the fungal enzymes, namely, Ca binding, disulfide bonds, or hydrogen bonds. We show that dimer stabilization is a requirement for NADase activity and that the group-specific strategies affect the active site conformation, thereby modulating enzyme activity. Together, these findings reveal the evolutionary lineage of fungal TNT enzymes, corroborating the hypothesis of them being pure extracellular NAD (eNAD) cleavers, with possible involvement in microbial warfare and host immune evasion.
Topics: Mycobacterium tuberculosis; NAD; Protein Domains; Fungal Proteins; Crystallography, X-Ray; Aspergillus fumigatus; Evolution, Molecular; Models, Molecular; Phylogeny; NAD+ Nucleosidase
PubMed: 38895984
DOI: 10.1002/pro.5071 -
Frontiers in Cellular and Infection... 2024subsp. (Map) is the etiological agent of paratuberculosis (PTB), a chronic intestinal inflammatory disease that causes high economical losses in dairy livestock...
subsp. (Map) is the etiological agent of paratuberculosis (PTB), a chronic intestinal inflammatory disease that causes high economical losses in dairy livestock worldwide. Due to the absence of widely available preventive or therapeutical treatments, new alternative therapies are needed. In this study, the effect of a probiotic alone or in combination with a commercial vaccine has been evaluated in a rabbit model. Vaccination enhanced the humoral response, exerted a training effect of peripheral polymorphonuclear neutrophils (PMNs) against homologous and heterologous stimuli, stimulated the release of pro-inflammatory cytokines by gut-associated lymphoid tissue (GALT) macrophages, and reduced the bacterial burden in GALT as well. However, the administration of the probiotic after vaccination did not affect the PMN activity, increased metabolic demand, and supressed pro-inflammatory cytokines, although humoral response and bacterial burden decrease in GALT was maintained similar to vaccination alone. The administration of the probiotic alone did not enhance the humoral response or PMN activity, and the bacterial burden in GALT was further increased compared to the only challenged group. In conclusion, the probiotic was able to modulate the immune response hampering the clearance of the infection and was also able to affect the response of innate immune cells after vaccination. This study shows that the administration of a probiotic can modulate the immune response pathways triggered by vaccination and/or infection and even exacerbate the outcome of the disease, bringing forward the importance of verifying treatment combinations in the context of each particular infectious agent.
Topics: Animals; Probiotics; Paratuberculosis; Mycobacterium avium subsp. paratuberculosis; Rabbits; Neutrophils; Cytokines; Vaccination; Bacterial Vaccines; Macrophages; Disease Models, Animal; Lymphoid Tissue; Female; Immunity, Humoral; Antibodies, Bacterial
PubMed: 38895731
DOI: 10.3389/fcimb.2024.1394070 -
International Journal of Molecular... Jun 2024() is the causative agent of tuberculosis (TB), a prevalent infectious disease affecting populations worldwide. A classic trait of TB pathology is the formation of... (Review)
Review
() is the causative agent of tuberculosis (TB), a prevalent infectious disease affecting populations worldwide. A classic trait of TB pathology is the formation of granulomas, which wall off the pathogen, via the innate and adaptive immune systems. Some key players involved include tumor necrosis factor-alpha (TNF-α), foamy macrophages, type I interferons (IFNs), and reactive oxygen species, which may also show overlap with cell death pathways. Additionally, host cell death is a primary method for combating and controlling within the body, a process which is influenced by both host and bacterial factors. These cell death modalities have distinct molecular mechanisms and pathways. Programmed cell death (PCD), encompassing apoptosis and autophagy, typically confers a protective response against by containing the bacteria within dead macrophages, facilitating their phagocytosis by uninfected or neighboring cells, whereas necrotic cell death benefits the pathogen, leading to the release of bacteria extracellularly. Apoptosis is triggered via intrinsic and extrinsic caspase-dependent pathways as well as caspase-independent pathways. Necrosis is induced via various pathways, including necroptosis, pyroptosis, and ferroptosis. Given the pivotal role of host cell death pathways in host defense against , therapeutic agents targeting cell death signaling have been investigated for TB treatment. This review provides an overview of the diverse mechanisms underlying -induced host cell death, examining their implications for host immunity. Furthermore, it discusses the potential of targeting host cell death pathways as therapeutic and preventive strategies against infection.
Topics: Humans; Mycobacterium tuberculosis; Tuberculosis; Animals; Cell Death; Host-Pathogen Interactions; Apoptosis; Immunity, Innate; Autophagy; Signal Transduction; Macrophages
PubMed: 38892443
DOI: 10.3390/ijms25116255 -
International Journal of Molecular... Jun 2024Phenotypic susceptibility testing of the complex (MTBC) isolate requires culture growth, which can delay rapid detection of resistant cases. Whole genome sequencing...
Phenotypic susceptibility testing of the complex (MTBC) isolate requires culture growth, which can delay rapid detection of resistant cases. Whole genome sequencing (WGS) and data analysis pipelines can assist in predicting resistance to antimicrobials used in the treatment of tuberculosis (TB). This study compared phenotypic susceptibility testing results and WGS-based predictions of antimicrobial resistance (AMR) to four first-line antimicrobials-isoniazid, rifampin, ethambutol, and pyrazinamide-for MTBC isolates tested between the years 2018-2022. For this 5-year retrospective analysis, the WGS sensitivity for predicting resistance for isoniazid, rifampin, ethambutol, and pyrazinamide using Mykrobe was 86.7%, 100.0%, 100.0%, and 47.8%, respectively, and the specificity was 99.4%, 99.5%, 98.7%, and 99.9%, respectively. The predictive values improved slightly using Mykrobe corrections applied using TB Profiler, i.e., the WGS sensitivity for isoniazid, rifampin, ethambutol, and pyrazinamide was 92.31%, 100%, 100%, and 57.78%, respectively, and the specificity was 99.63%. 99.45%, 98.93%, and 99.93%, respectively. The utilization of WGS-based testing addresses concerns regarding test turnaround time and enables analysis for MTBC member identification, antimicrobial resistance prediction, detection of mixed cultures, and strain genotyping, all through a single laboratory test. WGS enables rapid resistance detection compared to traditional phenotypic susceptibility testing methods using the WHO TB mutation catalog, providing an insight into lesser-known mutations, which should be added to prediction databases as high-confidence mutations are recognized. The WGS-based methods can support TB elimination efforts in Canada and globally by ensuring the early start of appropriate treatment, rapidly limiting the spread of TB outbreaks.
Topics: Whole Genome Sequencing; Mycobacterium tuberculosis; Antitubercular Agents; Humans; Microbial Sensitivity Tests; Retrospective Studies; Drug Resistance, Bacterial; Genome, Bacterial; Ethambutol; Isoniazid; Pyrazinamide; Tuberculosis; Rifampin
PubMed: 38892433
DOI: 10.3390/ijms25116245 -
International Journal of Molecular... Jun 2024() is the causative agent of bovine tuberculosis (bTb). Genetic selection aiming to identify less susceptible animals has been proposed as a complementary measure in...
Genome-Wide Association Study Reveals Quantitative Trait Loci and Candidate Genes Associated with High Interferon-gamma Production in Holstein Cattle Naturally Infected with .
() is the causative agent of bovine tuberculosis (bTb). Genetic selection aiming to identify less susceptible animals has been proposed as a complementary measure in ongoing programs toward controlling infection. However, individual animal phenotypes for bTb based on interferon-gamma (IFNɣ) and its use in bovine selective breeding programs have not been explored. In the current study, IFNɣ production was measured using a specific IFNɣ ELISA kit in bovine purified protein derivative (bPPD)-stimulated blood samples collected from Holstein cattle. DNA isolated from the peripheral blood samples collected from the animals included in the study was genotyped with the EuroG Medium Density bead Chip, and the genotypes were imputed to whole-genome sequences. A genome-wide association analysis (GWAS) revealed that the IFNɣ in response to bPPD was associated with a specific genetic profile (heritability = 0.23) and allowed the identification of 163 SNPs, 72 quantitative trait loci (QTLs), 197 candidate genes, and 8 microRNAs (miRNAs) associated with this phenotype. No negative correlations between this phenotype and other phenotypes and traits included in the Spanish breeding program were observed. Taken together, our results define a heritable and distinct immunogenetic profile associated with strong production of IFNɣ in response to .
Topics: Animals; Cattle; Quantitative Trait Loci; Mycobacterium bovis; Genome-Wide Association Study; Interferon-gamma; Tuberculosis, Bovine; Polymorphism, Single Nucleotide; Phenotype; Genotype
PubMed: 38892353
DOI: 10.3390/ijms25116165 -
BMC Genomic Data Jun 2024The rising of antibiotic resistance has sparked a renewed interest in mycobacteriophage as alternative therapeutic strategies against mycobacterial infections. So far,...
OBJECTIVES
The rising of antibiotic resistance has sparked a renewed interest in mycobacteriophage as alternative therapeutic strategies against mycobacterial infections. So far, the vast majority of mycobacteriophages have been isolated using the model species Mycobacterium smegmatis, implying an overwhelming majority of mycobacteriophages in the environment remain uncultured, unclassified, and their specific hosts and infection strategies are still unknown. This study was undertaken to isolate and characterize novel mycobacteriophages targeting Mycobacterium septicum.
DATA DESCRIPTION
Here a novel mycobacteriophage WXIN against M. septicum was isolated from soil samples in Wuhan, China. Whole genome analysis indicates that the phage genome consists of 115,158 bp with a GC content of 61.9%. Of the 260 putative open reading frames, 46 may be associated with phage packaging, structure, lysis, lysogeny, genome modification/replication, and other functional roles. The limited genome-wide similarity, along with phylogenetic trees constructed based on viral proteome and orthologous genes show that phage WXIN represents a novel cluster distantly related to cluster J mycobacteriophages (genus Omegavirus). Overall, these results provide novel insights into the genomic properties of mycobacteriophages, highlighting the great genetic diversity of mycobacteriophages in relation to their hosts.
Topics: Genome, Viral; Mycobacteriophages; China; Phylogeny; Open Reading Frames; Mycobacterium; Soil Microbiology; Base Composition
PubMed: 38890591
DOI: 10.1186/s12863-024-01244-8