Project description:The alarming rise of antimicrobial resistance in Mycobacterium tuberculosis coupled with the shortage of new antibiotics has made tuberculosis (TB) control a global health priority. Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit the growth of multi-drug resistant isolates of M. tuberculosis. Repurposing NSAIDs, with known clinical properties and safety records, offers a direct route to clinical trials. Therefore we investigated the novel mechanisms of anti-mycobacterial action of the NSAID, carprofen. Integrative molecular and microbiological approaches revealed that carprofen, a bactericidal drug, inhibited bacterial drug efflux mechanisms. In addition, carprofen restricted mycobacterial biofilm-like growth, highlighting the requirement of efflux-mediated communicative systems for the formation of biofilms. Transcriptome profiling revealed that carprofen likely acts by inhibiting respiration through the disruption of membrane potential, which may explain why spontaneous drug-resistant mutants could not be raised due to the pleiotropic nature of carprofen’s anti-tubercular action. This immunomodulatory drug has the potential to reverse TB antimicrobial resistance by inhibiting drug efflux pumps and biofilm formation, and paves a new chemotherapeutic path for tackling tuberculosis.
Project description:Tuberculosis (TB) is one of the deadliest infectious disorders in the world. To effectively TB manage, an essential step is to gain insight into the lineage of Mycobacterium tuberculosis (MTB) strains and the distribution of drug resistance. Although the Campania region is declared a cluster area for the infection, to contribute to the effort to understand TB evolution and transmission, still poorly known, we have generated a dataset of 159 genomes of MTB strains, from Campania region collected during 2018-2021, obtained from the analysis of whole genome sequence data. The results show that the most frequent MTB lineage is the 4 according for 129 strains (81.11%). Regarding drug resistance, 139 strains (87.4%) were classified as multi susceptible, while the remaining 20 (12.58%) showed drug resistance. Among the drug-resistance strains, 8 were isoniazid-resistant MTB (HR-MTB), 7 were resistant only to one antibiotic (3 were resistant only to ethambutol and 3 isolate to streptomycin while one isolate showed resistance to fluoroquinolones), 4 multidrug-resistant MTB, while only one was classified as pre-extensively drug-resistant MTB (pre-XDR). This dataset expands the existing available knowledge on drug resistance and evolution of MTB, contributing to further TB-related genomics studies to improve the management of TB infection.
Project description:“Viable but non-culturable” (VBNC) states pose challenges for environmental and clinical microbiology, but their biological mechanisms remain obscure. Mycobacterium tuberculosis (Mtb), the leading cause of death from infection until COVID-19, affords a striking example. Mtb can enter into a “differentially detectable” (DD) state associated with phenotypic antimicrobial resistance in which Mtb cells are viable but undetectable as colony-forming units. We found that Mtb cells enter the DD state when they undergo sublethal oxidative stress that damages their DNA, proteins, and lipids, and in addition, their replication is delayed, allowing repair. Mycobacterium bovis and BCG fail to enter the DD state under similar conditions. These findings have implications for TB latency, detection, relapse, treatment monitoring, and development of regimens that overcome phenotypic antimicrobial resistance.
Project description:“Viable but non-culturable” (VBNC) states pose challenges for environmental and clinical microbiology, but their biological mechanisms remain obscure. Mycobacterium tuberculosis (Mtb), the leading cause of death from infection until COVID-19, affords a striking example. Mtb can enter into a “differentially detectable” (DD) state associated with phenotypic antimicrobial resistance in which Mtb cells are viable but undetectable as colony-forming units. We found that Mtb cells enter the DD state when they undergo sublethal oxidative stress that damages their DNA, proteins, and lipids, and in addition, their replication is delayed, allowing repair. Mycobacterium bovis and BCG fail to enter the DD state under similar conditions. These findings have implications for TB latency, detection, relapse, treatment monitoring, and development of regimens that overcome phenotypic antimicrobial resistance.
Project description:"Viable but non-culturable” (VBNC) states pose challenges for environmental and clinical microbiology, but their biological mechanisms remain obscure. Mycobacterium tuberculosis (Mtb), the leading cause of death from infection until COVID-19, affords a striking example. Mtb can enter into a “differentially detectable” (DD) state associated with phenotypic antimicrobial resistance in which Mtb cells are viable but undetectable as colony-forming units. We found that Mtb cells enter the DD state when they undergo sublethal oxidative stress that damages their DNA, proteins, and lipids, and in addition, their replication is delayed, allowing repair. Mycobacterium bovis and BCG fail to enter the DD state under similar conditions. These findings have implications for TB latency, detection, relapse, treatment monitoring, and development of regimens that overcome phenotypic antimicrobial resistance.
Project description:Tuberculosis (TB) still poses a profound burden on global health, owing to significant morbidity and mortality worldwide. Although a fully functional immune system is essential for the control of Mycobacterium tuberculosis infection, the underlying mechanisms and reasons for failure in part of the infected population remain enigmatic. Here, whole-blood microarray gene expression analyses were performed in TB patients and in latently as well as uninfected healthy controls to define biomarkers predictive of susceptibility and resistance. Fc gamma receptor 1B (FCGRIB)was identified as the most differentially expressed gene, and, in combination with four other markers, produced a high degree of accuracy in discriminating TB patients and latently infected donors. We determined differentially expressed genes unique for active disease and identified profiles that correlated with susceptibility and resistance to TB. Elevated expression of innate immune-related genes in active TB and higher expression of particular gene clusters involved in apoptosis and natural killer cell activity in latently infected donors are likely to be the major distinctive factors determining failure or success in controlling M. tuberculosis infection. The gene expression profiles defined in this study provide valuable clues for better understanding of progression from latent infection to active disease and pave the way for defining predictive correlates of protection in TB. Three infection stages. Two-color arrays with independent swap design
Project description:Mycobacteria of the Mycobacterium tuberculosis complex (MTBC) greatly impact on human and animal health worldwide. Mycobacterial life cycle is complex and the mechanisms resulting in pathogen infection and survival in host cells are not fully understood. Eurasian wild boar (Sus scrofa) are natural reservoir hosts for MTBC and a model for mycobacterial infection and tuberculosis (TB). In the wild boar TB model, mycobacterial infection affects the expression of innate and adaptive immune response genes in mandibular lymph nodes and oropharyngeal tonsils and biomarkers have been proposed as correlates with resistance to natural infection. However, the mechanisms used by mycobacteria to manipulate host immune response are not fully characterized. Our hypothesis is that the immune system proteins under-represented in infected animals when compared to uninfected controls are used by mycobacteria to guarantee pathogen infection and transmission. To address this hypothesis, a comparative proteomics approach was used to compare host response between uninfected (TB-) and M. bovis-infected young (TB+) and adult animals with different infection status [TB lesions localized in the head (TB+) or affecting multiple organs (TB++)]. The results identified host immune system proteins that play an important role in host response to mycobacteria. Calcium binding protein A9, Heme peroxidase, Lactotransferrin, Cathelicidin and Peptidoglycan-recognition protein were under-represented in TB+ animals when compared to uninfected TB- controls but protein levels increased as infection progressed in TB++ animals when compared to TB- and/or TB+ adult wild boar. MHCI was the only protein over-represented in TB+ adult wild boar when compared to uninfected TB- controls. The results reported here suggested that M. bovis manipulates host immune response by reducing the production of immune system proteins. However, as infection progresses, wild boar immune response recover to limit pathogen multiplication and promote survival that also facilitates pathogen transmission.
Project description:①Background:Tuberculosis is mainly a respiratory tract infection caused by mycobacterium tuberculosis and one of the leading causes of death worldwide. According to the Global Tuberculosis Report in 2021, About a quarter of the world's population is infected with Mycobacterium tuberculosis and China is the second highest burden of TB. Although TB diagnosis and prevention techniques have become more mature, the number of TB cases is still increasing, mainly due to: the prevalence of drug-resistant tuberculosis bacteria, tuberculosis and HIV co-infection, long incubation time of mycobacterium tuberculosis difficult to early diagnosis and so on. Therefore, it is of great significance to study the pathogenesis of mycobacterium tuberculosis infection.②Method: THP-1 cells were treated with 50ng/ml PMA for 24 hours, so that THP-1 cell can be induced into macrophages. After that THP-1 macrophages were infected with mycobacterium tuberculosis H37Rv(MOI=1), which were collected and applied to RNA-sequencing. The constructed sequencing library was sequenced using an Illumina Novaseq 6000 system.
Project description:Tuberculosis (TB) still poses a profound burden on global health, owing to significant morbidity and mortality worldwide. Although a fully functional immune system is essential for the control of Mycobacterium tuberculosis infection, the underlying mechanisms and reasons for failure in part of the infected population remain enigmatic. Here, whole-blood microarray gene expression analyses were performed in TB patients and in latently as well as uninfected healthy controls to define biomarkers predictive of susceptibility and resistance. Fc gamma receptor 1B (FCGRIB)was identified as the most differentially expressed gene, and, in combination with four other markers, produced a high degree of accuracy in discriminating TB patients and latently infected donors. We determined differentially expressed genes unique for active disease and identified profiles that correlated with susceptibility and resistance to TB. Elevated expression of innate immune-related genes in active TB and higher expression of particular gene clusters involved in apoptosis and natural killer cell activity in latently infected donors are likely to be the major distinctive factors determining failure or success in controlling M. tuberculosis infection. The gene expression profiles defined in this study provide valuable clues for better understanding of progression from latent infection to active disease and pave the way for defining predictive correlates of protection in TB.
Project description:The aim of this study was to compare the transcriptional response to TB in regions of different incidence / prevalence. Experimental Design: Whole blood collected in tempus tubes from patients with different spectra of TB disease. All patients were sampled prior to the initiation of any antimycobacterial therapy. Active Pulmonary TB: PTB - All patients confirmed by isolation of Mycobacterium Tuberculosis on culture of sputum. Latent TB: LTB - All patients were screened at a tuberculosis clinic. All were positive by Interferon-Gamma Release assay(IGRA); specifically Quantiferon Gold In-Tube Assay (Cellestis, Australia). Latent patients had no clinical, or microbiological evidence of active infection and were asymptomatic. Experimental Variables: Patient group: Active PTB; Latent TB. There are no healthy controls in this dataset as it was being used for validation only. Controls: Latent TB individuals are used as a control for PTB in this dataset since there are few to no unexposed adult controls in Cape Town.