Institut Pasteur Tuberculosis MOOC: Comprehensive Medical & Microbiological Review

Vocabulary practice flashcards covering bacteriology, immunology, diagnosis, clinical presentations, and therapeutics of tuberculosis based on the Institut Pasteur MOOC.

White Plague (Peste Blanche)

A historical term used during the 18th and 19th centuries to designate tuberculosis as a chronic, wasting infectious disease, contrasting it with the acute and devastating nature of the Black Death.

Robert Koch

The German physician and scientist who discovered in Berlin in 1882 that the bacterium Mycobacterium tuberculosis is the definitive causative agent of tuberculosis.

Bacille Calmette-Guérin (BCG)

A live-attenuated vaccine developed in France through over 100 serial passages of Mycobacterium bovis on potato slices steeped in ox bile, protecting infants against severe forms of TB like tuberculous meningitis.

Ghon Focus

The initial tuberculous granulomatous parenchymal lesion formed within the lung tissue following the inhalation and primary infection of Mycobacterium tuberculosis bacilli.

Ranke Complex

The combination of a primary pulmonary Ghon focus and secondary draining lymph node lesions, which together undergo fibrosis and calcification to contain the bacilli.

Miliary Tuberculosis

A severe, life-threatening form of tuberculosis resulting from hematogenous dissemination of bacilli throughout the body, radiologically characterized by diffuse, millet-seed-sized micronodules ($< 2\,mm$ in diameter).

Tree-in-Bud Pattern

A characteristic computed tomography (CT) finding indicating bronchogenic dissemination of bacilli, reflecting centrilobular branching impaction and endobronchial spread.

Cavitary Tuberculosis

A highly contagious, advanced pulmonary manifestation characterized by localized lung tissue necrosis and cavitation containing high bacterial burdens ($\approx 10^8\,CFU$) with fibrotic margins that limit drug and immune penetration.

Paucibacillary Tuberculosis

A clinical presentation common in pediatric tuberculosis characterized by low bacillary numbers, resulting in low smear positivity ($< 5\%$) and culture yields ($< 10\%$).

Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome (TB-IRIS)

An exaggerated, dysregulated inflammatory response occurring within weeks of initiating antiretroviral therapy (ART) in HIV-coinfected patients, presenting as clinical worsening despite initial microbial improvement under anti-TB therapy.

Central Nervous System TB-IRIS (CNS-TB-IRIS)

A severe, high-mortality manifestation of IRIS developing at a median of $14\,days$ following ART initiation in patients with tuberculous meningitis or intracranial tuberculomas, requiring delayed ART initiation ($4\text{ to }8\,weeks$).

Subclinical Tuberculosis

A form of active tuberculosis disease in individuals who have confirmed positive cultures or molecular assays and may be contagious, but report no detectable symptoms.

Computer-Aided Detection (CAD)

Deep learning and artificial intelligence software using convolutional neural networks to automatically interpret digital chest radiographs for tuberculosis screening, recommended by the WHO with thresholds of $\ge 90\%$ sensitivity and $\ge 70\%$ specificity.

Interferon-Gamma Release Assay (IGRA)

An in vitro blood test (e.g., QuantiFERON-TB Gold, T-SPOT.TB) measuring IFN-$\gamma$ released by sensitized T lymphocytes upon stimulation with specific M. tuberculosis antigens (ESAT-6, CFP-10) that are absent in BCG.

Acid-Fast Bacilli (AFB)

Bacteria containing high concentrations of long-chain mycolic acids in their cell walls that resist destaining by acidified alcohol solutions when stained with carbolfuchsin (Ziehl-Neelsen) or fluorochromes (Auramine O).

MPT64 Antigen

A specific protein antigen secreted by multiplying members of the Mycobacterium tuberculosis complex, utilized in rapid lateral flow immunochromatographic assays to confirm MTBC in positive culture media.

Nucleic Acid Amplification Test (NAAT)

A rapid molecular diagnostic technique that amplifies specific target DNA or RNA sequences of the Mycobacterium tuberculosis complex, drastically reducing diagnostic turnaround time from weeks to hours.

GeneXpert MTB/RIF

A cartridge-based automated real-time PCR platform that simultaneously detects Mycobacterium tuberculosis complex DNA and rifampicin-resistance mutations within the rpoB gene in under 2 hours directly from raw clinical specimens.

Line Probe Assay (LPA)

A strip-based reverse hybridization molecular assay where amplified mycobacterial DNA is hybridized against immobilized wild-type and mutation-specific probes to detect drug resistance mutations.

Deeplex Myc-TB

A targeted deep-amplicon next-generation sequencing assay that profiles resistance-associated mutations across 13 anti-TB drugs with a low-frequency variant detection threshold of $3\%$.

Isoniazid (INH)

A frontline bactericidal prodrug activated by the mycobacterial catalase-peroxidase KatG that inhibits enoyl-ACP reductase (InhA), thereby preventing mycolic acid biosynthesis.

Rifampicin (RIF)

A foundational first-line bactericidal and sterilizing rifamycin that blocks transcription by binding to and inhibiting the $\beta$-subunit of mycobacterial DNA-dependent RNA polymerase encoded by rpoB.

Pyrazinamide (PZA)

A sterilizing first-line prodrug converted by pyrazinamidase (PncA) into pyrazinoic acid; highly active against semi-dormant persistent bacilli within acidic caseous lesions.

Ethambutol (EMB)

A first-line bacteriostatic anti-TB medication that interferes with the biosynthesis of cell wall arabinogalactan by inhibiting arabinosyl transferases.

Multidrug-Resistant Tuberculosis (MDR-TB)

Tuberculosis caused by Mycobacterium tuberculosis strains exhibiting in vitro resistance to at least both isoniazid and rifampicin simultaneously.

Extensively Drug-Resistant Tuberculosis (XDR-TB)

MDR-TB strains that demonstrate additional resistance to at least one fluoroquinolone and at least one Group A medication (bedaquiline or linezolid).

Bedaquiline (BDQ)

A Group A diarylquinoline antibiotic that selectively inhibits mycobacterial ATP synthase, acting on the bacterial respiratory chain to treat drug-resistant TB.

Linezolid (LZD)

A Group A synthetic oxazolidinone antibacterial that binds the bacterial 50S ribosomal subunit to inhibit protein synthesis, demonstrating potent activity against multidrug-resistant MTBC.

Pretomanid (PA-824)

A nitroimidazole prodrug that inhibits mycolic acid biosynthesis in aerobically replicating bacilli and induces nitric oxide release under hypoxic conditions, forming a core component of the BPaL/BPaLM regimens.

Telacebec (Q203)

An experimental antimycobacterial compound that targets the cytochrome bc1-aa3 supercomplex of the electron transport chain, exhibiting synergistic activity when combined with bedaquiline.

Mycobacterium canettii

An early-branching smooth-colony outgroup of the MTBC predominantly isolated in the Horn of Africa, characterized by high genomic divergence, lipo-oligosaccharide (LOS) synthesis, and demonstrable chromosomal horizontal gene transfer.

Mycobacterium africanum

Two distinct lineages of the MTBC restricted to West Africa (Lineage 5/West African 1 and Lineage 6/West African 2), possessing an RD9 deletion, microaerophilic preference, and slower clinical progression.

Dysgonic Growth

A slow, fine, smooth, non-confluent cultural growth phenotype characteristic of Mycobacterium bovis and Mycobacterium africanum on egg-based media, contrasted with the rough, crumbly, eugonic growth of Mycobacterium tuberculosis.

Region of Difference 4 (RD4)

A specific genomic region absent in all strains of Mycobacterium bovis, serving as a reliable PCR-based deletion marker to differentiate M. bovis from other MTBC species.

Zoonotic Tuberculosis

Tuberculosis in humans caused by animal-adapted MTBC species, primarily Mycobacterium bovis and Mycobacterium orygis, typically transmitted through direct contact with livestock or ingestion of unpasteurized dairy.

Mendelian Susceptibility to Mycobacterial Diseases (MSMD)

A rare set of congenital primary immunodeficiencies affecting the interleukin-12, interleukin-23, and interferon-gamma signaling pathways, resulting in severe clinical susceptibility to poorly virulent mycobacteria.

Host-Directed Therapy (HDT)

An adjunct treatment paradigm that manipulates host biological pathways (e.g., enhancing macrophage autophagy with metformin or vitamin D, or blunting tissue-damaging inflammation) rather than directly targeting bacterial components.

MTBVAC

A live-attenuated human Mycobacterium tuberculosis candidate vaccine engineered with two independent, stable deletions in the virulence genes phoP and fadD26 while retaining the immunogenic RD1 region.

M72/AS01

A recombinant subunit tuberculosis vaccine candidate consisting of two fused M. tuberculosis antigens (Mtb32A and Mtb39A) combined with the AS01 adjuvant, demonstrating approximately $50\%$ efficacy against pulmonary disease in latent individuals.

Early Bactericidal Activity (EBA)

The rate of decline in viable colony-forming units (CFU) in the sputum of pulmonary TB patients during the first 2 to 14 days of antimicrobial therapy, predominantly driven by isoniazid in standard regimens.