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Prithviraj M, Kado T, Mayfield JA, Young DC, Huang AD, Motooka D, Nakamura S, Siegrist MS, Moody DB, Morita YS. Tuberculostearic Acid Controls Mycobacterial Membrane Compartmentalization. mBio 2023; 14:e0339622. [PMID: 36976029 PMCID: PMC10127668 DOI: 10.1128/mbio.03396-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 03/08/2023] [Indexed: 03/29/2023] Open
Abstract
The intracellular membrane domain (IMD) is a laterally discrete region of the mycobacterial plasma membrane, enriched in the subpolar region of the rod-shaped cell. Here, we report genome-wide transposon sequencing to discover the controllers of membrane compartmentalization in Mycobacterium smegmatis. The putative gene cfa showed the most significant effect on recovery from membrane compartment disruption by dibucaine. Enzymatic analysis of Cfa and lipidomic analysis of a cfa deletion mutant (Δcfa) demonstrated that Cfa is an essential methyltransferase for the synthesis of major membrane phospholipids containing a C19:0 monomethyl-branched stearic acid, also known as tuberculostearic acid (TBSA). TBSA has been intensively studied due to its abundant and genus-specific production in mycobacteria, but its biosynthetic enzymes had remained elusive. Cfa catalyzed the S-adenosyl-l-methionine-dependent methyltransferase reaction using oleic acid-containing lipid as a substrate, and Δcfa accumulated C18:1 oleic acid, suggesting that Cfa commits oleic acid to TBSA biosynthesis, likely contributing directly to lateral membrane partitioning. Consistent with this model, Δcfa displayed delayed restoration of subpolar IMD and delayed outgrowth after bacteriostatic dibucaine treatment. These results reveal the physiological significance of TBSA in controlling lateral membrane partitioning in mycobacteria. IMPORTANCE As its common name implies, tuberculostearic acid is an abundant and genus-specific branched-chain fatty acid in mycobacterial membranes. This fatty acid, 10-methyl octadecanoic acid, has been an intense focus of research, particularly as a diagnostic marker for tuberculosis. It was discovered in 1934, and yet the enzymes that mediate the biosynthesis of this fatty acid and the functions of this unusual fatty acid in cells have remained elusive. Through a genome-wide transposon sequencing screen, enzyme assay, and global lipidomic analysis, we show that Cfa is the long-sought enzyme that is specifically involved in the first step of generating tuberculostearic acid. By characterizing a cfa deletion mutant, we further demonstrate that tuberculostearic acid actively regulates lateral membrane heterogeneity in mycobacteria. These findings indicate the role of branched fatty acids in controlling the functions of the plasma membrane, a critical barrier for the pathogen to survive in its human host.
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Affiliation(s)
- Malavika Prithviraj
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Takehiro Kado
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jacob A. Mayfield
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - David C. Young
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Annie D. Huang
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Daisuke Motooka
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Shota Nakamura
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - M. Sloan Siegrist
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
| | - D. Branch Moody
- Division of Rheumatology, Inflammation and Immunity, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Yasu S. Morita
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, Massachusetts, USA
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Brandenburg J, Heyckendorf J, Marwitz F, Zehethofer N, Linnemann L, Gisch N, Karaköse H, Reimann M, Kranzer K, Kalsdorf B, Sanchez-Carballo P, Weinkauf M, Scholz V, Malm S, Homolka S, Gaede KI, Herzmann C, Schaible UE, Hölscher C, Reiling N, Schwudke D. Tuberculostearic Acid-Containing Phosphatidylinositols as Markers of Bacterial Burden in Tuberculosis. ACS Infect Dis 2022; 8:1303-1315. [PMID: 35763439 PMCID: PMC9274766 DOI: 10.1021/acsinfecdis.2c00075] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
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One-fourth of the
global human population is estimated to be infected
with strains of the Mycobacterium tuberculosis complex (MTBC), the causative agent of tuberculosis (TB). Using
lipidomic approaches, we show that tuberculostearic acid (TSA)-containing
phosphatidylinositols (PIs) are molecular markers for infection with
clinically relevant MTBC strains and signify bacterial burden. For
the most abundant lipid marker, detection limits of ∼102 colony forming units (CFUs) and ∼103 CFUs
for bacterial and cell culture systems were determined, respectively.
We developed a targeted lipid assay, which can be performed within
a day including sample preparation—roughly 30-fold faster than
in conventional methods based on bacterial culture. This indirect
and culture-free detection approach allowed us to determine pathogen
loads in infected murine macrophages, human neutrophils, and murine
lung tissue. These marker lipids inferred from mycobacterial PIs were
found in higher levels in peripheral blood mononuclear cells of TB
patients compared to healthy individuals. Moreover, in a small cohort
of drug-susceptible TB patients, elevated levels of these molecular
markers were detected at the start of therapy and declined upon successful
anti-TB treatment. Thus, the concentration of TSA-containing PIs can
be used as a correlate for the mycobacterial burden in experimental
models and in vitro systems and may prospectively also provide a clinically
relevant tool to monitor TB severity.
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Affiliation(s)
- Julius Brandenburg
- Division of Microbial Interface Biology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Jan Heyckendorf
- Division of Clinical Infectious Disease, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Clinical Tuberculosis Center, 23845 Borstel, Germany
| | - Franziska Marwitz
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Thematic Translational Unit Tuberculosis, Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany
| | - Nicole Zehethofer
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Thematic Translational Unit Tuberculosis, Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany
| | - Lara Linnemann
- Division of Cellular Microbiology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Nicolas Gisch
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Hande Karaköse
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Thematic Translational Unit Tuberculosis, Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany
| | - Maja Reimann
- Division of Clinical Infectious Disease, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Clinical Tuberculosis Center, 23845 Borstel, Germany
| | - Katharina Kranzer
- National Reference Center for Mycobacteria, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Barbara Kalsdorf
- Division of Clinical Infectious Disease, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Clinical Tuberculosis Center, 23845 Borstel, Germany
| | - Patricia Sanchez-Carballo
- Division of Clinical Infectious Disease, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Clinical Tuberculosis Center, 23845 Borstel, Germany
| | - Michael Weinkauf
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Verena Scholz
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Sven Malm
- Division of Molecular and Experimental Mycobacteriology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Susanne Homolka
- Division of Molecular and Experimental Mycobacteriology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Karoline I Gaede
- BioMaterialBank Nord, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Lung Research (DZL), Airway Research Center North (ARCN), Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Christian Herzmann
- Center for Clinical Studies, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Ulrich E Schaible
- German Center for Infection Research, Thematic Translational Unit Tuberculosis, Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany.,Division of Cellular Microbiology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Christoph Hölscher
- German Center for Infection Research, Thematic Translational Unit Tuberculosis, Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany.,Division of Infection Immunology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
| | - Norbert Reiling
- Division of Microbial Interface Biology, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Thematic Translational Unit Tuberculosis, Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany
| | - Dominik Schwudke
- Division of Bioanalytical Chemistry, Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany.,German Center for Infection Research, Thematic Translational Unit Tuberculosis, Partner Site Hamburg-Lübeck-Borstel-Riems, 23845 Borstel, Germany.,German Center for Lung Research (DZL), Airway Research Center North (ARCN), Research Center Borstel, Leibniz Lung Center, 23845 Borstel, Germany
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Pfyffer GE, Kissling P, Wirth R, Weber R. Direct detection of Mycobacterium tuberculosis complex in respiratory specimens by a target-amplified test system. J Clin Microbiol 1994; 32:918-23. [PMID: 8027344 PMCID: PMC263163 DOI: 10.1128/jcm.32.4.918-923.1994] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A total of 938 respiratory specimens (633 sputa, 249 bronchial and tracheal aspirates, and 56 bronchoalveolar lavages) from 589 patients were tested for direct detection of Mycobacterium tuberculosis complex by the Gen-Probe amplified Mycobacterium tuberculosis direct test (MTD), and the results were compared with those of the conventional methods of fluorescence microscopy and cultivation (solid and radiometric media). One series of specimens (n = 515) was decontaminated with N-acetyl-L-cysteine (NALC)-NaOH: the other one (n = 423) was decontaminated with sodium dodecyl (lauryl) sulfate (SDS)-NaOH. Of the specimens decontaminated with NALC, 39 were MTD and culture positive, 455 were MTD and culture negative, 18 were MTD positive and culture negative, and 3 were MTD negative and culture positive, indicating a sensitivity of 92.9% and a specificity of 96.2% for the MTD. Of the specimens decontaminated with SDS, 35 were MTD and culture positive, 372 were MTD and culture negative, 15 were MTD positive and culture negative, and 1 was MTD negative and culture positive, indicating a sensitivity of 97.2% and a specificity of 96.1% for the MTD. After resolution of discrepant results by review of the patients' clinical data, the sensitivity of the MTD was 93.9%, the specificity was 97.6%, the positive predictive value was 80.7%, and the negative predictive value was 99.3% for the NALC series; the corresponding values were 97.4, 96.9, 76.0, and 99.7%, respectively, for the SDS series. In conclusion, the MTD is a highly sensitive and specific technique for detecting M. tuberculosis complex within hours in both smear-positive and smear-negative respiratory specimens.
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Affiliation(s)
- G E Pfyffer
- Swiss National Center for Mycobacteria, Department of Medical Microbiology, University of Zurich
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Abstract
More than ever, new technology is having an impact on the tools of clinical microbiologists. The analysis of cellular fatty acids by gas-liquid chromatography (GLC) has become markedly more practical with the advent of the fused-silica capillary column, computer-controlled chromatography and data analysis, simplified sample preparation, and a commercially available GLC system dedicated to microbiological applications. Experience with applications in diagnostic microbiology ranges from substantial success in work with mycobacteria, legionellae, and nonfermentative gram-negative bacilli to minimal involvement with fungi and other nonbacterial agents. GLC is a good alternative to other means for the identification of mycobacteria or legionellae because it is rapid, specific, and independent of other specialized testing, e.g., DNA hybridization. Nonfermenters show features in their cellular fatty acid content that are useful in identifying species and, in some cases, subspecies. Less frequently encountered nonfermenters, including those belonging to unclassified groups, can ideally be characterized by GLC. Information is just beginning to materialize on the usefulness of cellular fatty acids for the identification of gram-positive bacteria and anaerobes, despite the traditional role of GLC in detecting metabolic products as an aid to identification of anaerobes. When species identification of coagulase-negative staphylococci is called for, GLC may offer an alternative to biochemical testing. Methods for direct analysis of clinical material have been developed, but in practical and economic terms they are not yet ready for use in the clinical laboratory. Direct analysis holds promise for detecting markers of infection due to an uncultivable agent or in clinical specimens that presently require cultures and prolonged incubation to yield an etiologic agent.
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Affiliation(s)
- D F Welch
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City 73126
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