Emerging Resistance to Antibiotics and Antivirals

Flashcards covering the history of penicillin, mechanisms of antibiotic and antiviral resistance, global health threats (AMR, MRSA, drug-resistant TB), and modern pharmaceutical developments.

Antibiotics

Also called antimicrobials; drugs that kill bacteria or inhibit bacterial growth.

Penicillin

The first antibiotic discovered, derived from the fungus Penicillium natatum; its discovery led to the 1945 Nobel Prize.

Antimicrobial Resistance (AMR)

A global health threat driven by the misuse and overuse of antimicrobials, making pathogens drug-resistant and increasing the risk of infections during surgery or chemotherapy.

MDR-TB (Multi-Drug Resistant Tuberculosis)

Tuberculosis that is resistant to at least Isoniazid and Rifampicin.

XDR-TB (Extensively Drug Resistant Tuberculosis)

A form of tuberculosis that is multi-drug resistant (MDR) plus resistance to fluoroquinolones and at least 1 of 3 injectable drugs.

TDR-TB (Totally Drug Resistant Tuberculosis)

A form of tuberculosis resistant to all first and second line TB drugs.

Antibiotics Paradox

The simultaneous occurrence of increasing bacterial resistance and fewer new antibiotic discoveries.

Efflux Pumps

A mechanism of antimicrobial resistance that removes antibiotics (such as Erythromycin, tetracyclines, and quinolones) from the bacterial cell.

Modifying or Degrading Enzymes

A resistance mechanism where enzymes render antibiotics ineffective by changing their conformation or degrading them; applies to aminoglycosides, $\beta\text{-lactam}$ antibiotics, and chloramphenicol.

Plasmids

Transmissible mobile genetic elements that allow bacteria to transfer drug-resistant DNA to other bacteria.

KPC (Klebsiella pneumoniae carbapenemase)

A gene conferring resistance to carbapenems, first found in a 1996 sample from a North Carolina hospital.

NDM (New Delhi metallo-beta-lactamase)

A carbapenem-resistance gene traced back to India and discovered by doctors in Sweden in 2008.

MRSA (Methicillin-Resistant Staphylococcus aureus)

A superbug resistant to $\beta\text{-lactam}$ antibiotics including penicillins (methicillin, oxacillin) and cephalosporins; causes approximately 20,000 deaths annually in the U.S.

iChip

A technology used for the culture of previously unculturable bacteria to identify new antibiotics.

Sirturo

A drug approved for MDR-TB that targets the $F_1F_o\text{-ATP synthase}$.

Adamantanes Resistance

Resistance in influenza A (H3N2) viruses typically caused by a change at amino acid 31 ($S31N$) in the M2 gene.

Neuraminidase Inhibitors

Drugs like Oseltamivir and Zanamivir that prevent the virus from cleaving sialic acid on the cell surface, thereby preventing the infection of new cells.

RdRp (RNA-Dependent-RNA Polymerase)

An emerging target for broad-spectrum antivirals like Favipiravir, used for influenza and other viral infections.

Xofluza (Baloxavir marboxil)

A treatment targeting the PA protein of the flu virus, capable of killing the virus within 24 hours.

Remdesivir

A broad-spectrum ribonucleotide analogue inhibitor of viral RNA polymerase, originally developed for Hepatitis C and repurposed for Ebola and SARS-CoV-2.

Paxlovid

A COVID-19 treatment combination of Nirmatrelvir (booster) and Ritonavir (MPRO viral protease).

Post-Antibiotic Era

A 21st-century possibility defined by the WHO where common infections and minor injuries can once again be fatal.