Mapping of Mycobacterial Enzymes Involved in Triacylglycerol Accumulation as Intrabacterial Lipid Inclusions Using Activity-Based Multitarget Inhibitor Probes.

Lipids play a critical role in the physiology, life cycle, and pathogenicity of mycobacteria. They largely participate in host-pathogen interactions and fulfill important functions ranging from cell wall biosynthesis/maintenance, bacterial growth dynamics, and long-term persistence. In that context, triacylglycerol, a specific subtype of neutral lipid, is stored as intrabacterial lipid inclusions (ILI), which have been described as important structures for long-term survival and persistence within the host.

A proteomic and functional view of intrabacterial lipid inclusion biogenesis in mycobacteria.

Unlabelled: During infection and granuloma formation, pathogenic mycobacteria store triacylglycerol as intrabacterial lipid inclusions (ILIs). This accumulation of nutrients provides a carbon source for bacterial persistence and slows down intracellular metabolism. (), a rapidly growing non-tuberculous actinobacterium, produces ILI throughout its infection cycle.

Cyclophostin and Cyclipostins analogues counteract macrolide-induced resistance mediated by erm(41) in Mycobacterium abscessus.

Background: Mycobacterium abscessus is an emerging pathogen causing severe pulmonary infections, particularly in individuals with underlying conditions, such as cystic fibrosis or chronic obstructive pulmonary disease. Macrolides, such as clarithromycin (CLR) or azithromycin (AZM), represent the cornerstone of antibiotherapy against the M. abscessus species.

Promising antibacterial efficacy of arenicin peptides against the emerging opportunistic pathogen Mycobacterium abscessus.

Background: Mycobacterium abscessus, a fast-growing non-tuberculous mycobacterium, is an emerging opportunistic pathogen responsible for chronic bronchopulmonary infections in people with respiratory diseases such as cystic fibrosis (CF). Due to its intrinsic polyresistance to a wide range of antibiotics, most treatments for M. abscessus pulmonary infections are poorly effective.

Synthesis and Biological Characterization of Fluorescent Cyclipostins and Cyclophostin Analogues: New Insights for the Diagnosis of Mycobacterial-Related Diseases.

Patients with cystic fibrosis (CF) have a significantly higher risk of acquiring nontuberculous mycobacteria infections, predominantly due to , than the healthy population. Because infections are a major cause of clinical decline and morbidity in CF patients, improving treatment and the detection of this mycobacterium in the context of a polymicrobial culture represents a critical component to better manage patient care. We report here the synthesis of fluorescent Dansyl derivatives of four active cyclipostins and cyclophostin analogues () and provide new insights regarding the 's lack of activity against Gram-negative and Gram-positive bacteria, and above all into their mode of action against intramacrophagic cells.

Direct capture, inhibition and crystal structure of HsaD (Rv3569c) from M. tuberculosis.

A hallmark of Mycobacterium tuberculosis (M. tb), the aetiologic agent of tuberculosis, is its ability to metabolise host-derived lipids. However, the enzymes and mechanisms underlying such metabolism are still largely unknown.

Design, synthesis and antibacterial activity against pathogenic mycobacteria of conjugated hydroxamic acids, hydrazides and O-alkyl/O-acyl protected hydroxamic derivatives.

With the aim to discover new antituberculous molecules, three novel series of 23 hydroxamic acids, 13 hydrazides, and 9O-alkyl/O-acyl protected hydroxamic acid derivatives have been synthesized, and fully characterized by spectral H NMR, C NMR, HRMS) analysis. These compounds were further biologically screened for their in vitro antibacterial activities against three pathogenic mycobacteria - M. abscessus S and R, M.

Transcriptional adaptation of in an original mouse model: New insights into the regulation of mycolactone.

is the causal agent of Buruli ulcer, a chronic infectious disease and the third most common mycobacterial disease worldwide. Without early treatment, provokes massive skin ulcers, caused by the mycolactone toxin, its main virulence factor. However, spontaneous healing may occur in Buruli ulcer patients several months or years after the disease onset.

Intrabacterial lipid inclusions in mycobacteria: unexpected key players in survival and pathogenesis?

Mycobacterial species, including Mycobacterium tuberculosis, rely on lipids to survive and chronically persist within their hosts. Upon infection, opportunistic and strict pathogenic mycobacteria exploit metabolic pathways to import and process host-derived free fatty acids, subsequently stored as triacylglycerols in the form of intrabacterial lipid inclusions (ILI). Under nutrient-limiting conditions, ILI constitute a critical source of energy that fuels the carbon requirements and maintain redox homeostasis, promoting bacterial survival for extensive periods of time.

Nitrogen deprivation induces triacylglycerol accumulation, drug tolerance and hypervirulence in mycobacteria.

Mycobacteria share with other actinomycetes the ability to produce large quantities of triacylglycerol (TAG), which accumulate as intracytoplasmic lipid inclusions (ILI) also known as lipid droplets (LD). Mycobacterium tuberculosis (M. tb), the etiologic agent of tuberculosis, acquires fatty acids from the human host which are utilized to synthesize TAG, subsequently stored in the form of ILI to meet the carbon and nutrient requirements of the bacterium during long periods of persistence.

Dissecting the membrane lipid binding properties and lipase activity of Mycobacterium tuberculosis LipY domains.

The Mycobacterium tuberculosis LipY protein, a prototype of the proline-glutamic acid (PE) family, exhibits a triacylglycerol (TAG) hydrolase activity that contributes to host cell lipid degradation and persistence of the bacilli. LipY is found either as a full-length intracytosolic form or as a mature extracellular form lacking the N-terminal PE domain. Even though the contribution of the extracellular form in TAG consumption has been partly elucidated, very little information is available regarding the potential interactions of either full-length LipY with the cytoplasmic membrane, or mature form LipY with the outer membrane.

LipG a bifunctional phospholipase/thioesterase involved in mycobacterial envelope remodeling.

Tuberculosis caused by is currently one of the leading causes of death from an infectious agent. The main difficulties encountered in eradicating this bacteria are mainly related to a very complex lipid composition of the bacillus cell wall, its ability to hide from the immune system inside the granulomas, and the increasing number of resistant strains. In this context, we were interested in the ( ) gene located upstream to the cluster which is described as being crucial for the production of cell wall components and required for the bacilli adaptation and survival in mouse macrophages Using biochemical experiments combined with the construction of deletion and overexpression mutant strains in , we found that LipG is a cytoplasmic membrane-associated enzyme that displays both phospholipase and thioesterase activities.

Delineating the Physiological Roles of the PE and Catalytic Domains of LipY in Lipid Consumption in Mycobacterium-Infected Foamy Macrophages.

Within tuberculous granulomas, a subpopulation of resides inside foamy macrophages (FM) that contain abundant cytoplasmic lipid bodies (LB) filled with triacylglycerol (TAG). Upon fusion of LB with -containing phagosomes, TAG is hydrolyzed and reprocessed by the bacteria into their own lipids, which accumulate as intracytosolic lipid inclusions (ILI). This phenomenon is driven by many mycobacterial lipases, among which LipY participates in the hydrolysis of host and bacterial TAG.

Infection of Adipose Tissues.

Adipose tissues were shown to host which is persisting inside mature adipocytes. It remains unknown whether this holds true for , a rare representative of the complex responsible for lymphatic and pulmonary tuberculosis. Here, we infected primary murine white and brown pre-adipocytes and murine 3T3-L1 pre-adipocytes and mature adipocytes with and as a positive control.

Scrutiny of Mycobacterium tuberculosis 19 kDa antigen proteoforms provides new insights in the lipoglycoprotein biogenesis paradigm.

Post-translational modifications (PTMs) are essential processes conditioning the biophysical properties and biological activities of the vast majority of mature proteins. However, occurrence of several distinct PTMs on a same protein dramatically increases its molecular diversity. The comprehensive understanding of the functionalities resulting from any particular PTM association requires a highly challenging full structural description of the PTM combinations.

Experimental Models of Foamy Macrophages and Approaches for Dissecting the Mechanisms of Lipid Accumulation and Consumption during Dormancy and Reactivation of Tuberculosis.

Despite a slight decline since 2014, tuberculosis (TB) remains the major deadly infectious disease worldwide with about 1.5 million deaths each year and with about one-third of the population being latently infected with , the etiologic agent of TB. During primo-infection, the recruitment of immune cells leads to the formation of highly organized granulomas.

Mycobacterium abscessus phospholipase C expression is induced during coculture within amoebae and enhances M. abscessus virulence in mice.

Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium involved in pulmonary and cutaneo-mucous infections worldwide, to which cystic fibrosis patients are exquisitely susceptible. The analysis of the genome sequence of M. abscessus showed that this bacterium is endowed with the metabolic pathways typically found in environmental microorganisms that come into contact with soil, plants, and aquatic environments, where free-living amoebae are frequently present.

In vitro digestion of citric acid esters of mono- and diglycerides (CITREM) and CITREM-containing infant formula/emulsions.

CITREM is an emulsifier used in the food industry and contains citric acid esters of mono- and diglycerides (GCFE). It is generally recognized as safe but no publication on its digestibility under gastrointestinal conditions and impact on fat digestion was available. It was shown here that fatty acids are released from CITREM by gastric lipase, pancreatic lipase, pancreatic-lipase-related protein 2 and carboxyl ester hydrolase.