Science Snippets: Rapid Resistance to Antibiotics Documented

Draft script:

Since we developed antibiotics in this modern world, we have assumed we were safe from many diseases than previously posed significant threats to human survival. In a classic case of going back in time, our days of dreading diseases are making a comeback. Today’s video describes an example.

From Science Alert on 21 November 2025 comes a story titled Ancient Killer Is Rapidly Becoming Resistant to Antibiotics, Scientists Warn. Here’s the lede, followed by another sentence to complete the first paragraph: “Despite having plagued humans for millennia, typhoid fever is rarely considered a threat in developed countries today. But this ancient killer is still very much a danger in our modern world.”

Yes, I’m known for relaying bad news. However, typhoid fever hasn’t posed a threat to humans in the developed world since the late 1940s. Contrary to the days of typhoid fever spreading rapidly in several regions, the risk of serious illness or death has descended greatly throughout most of the world.

Back to the article at Science Alert, we read that typhoid fever is making a comeback: “Research published in 2022 revealed the bacterium that causes typhoid fever is evolving extensive drug resistance, and is rapidly replacing strains that aren’t resistant.”

Importantly, “antibiotics are the only way to effectively treat typhoid, which is caused by the bacterium Salmonella enterica serovar Typhi ... Yet over the past three decades, the bacterium’s resistance to oral antibiotics has been growing and spreading.”

A potentially horrifying outcome is explained in the following three short paragraphs: “In their study, scientists from multiple countries sequenced the genomes of 3,489 S Typhi strains contracted from 2014 to 2019 in Nepal, Bangladesh, Pakistan, and India, and found a rise in extensively drug-resistant … Typhi.

[Extensively drug-resistant] Typhi is not only impervious to frontline antibiotics, like ampicillin, chloramphenicol, and trimethoprim/sulfamethoxazole, but it is also growing resistant to newer antibiotics, like fluoroquinolones and third-generation cephalosporins.

Even worse, these strains are spreading globally at a rapid rate.”

The concern and severity of a typhoid outbreak has been expressed for several years: “Scientists have been warning about drug-resistant typhoid for years now. In 2016, the first … drug-resistant typhoid strain was identified in Pakistan. By 2019, it had become the dominant genotype in the nation.

Historically, most … drug-resistant typhoid strains have been fought with third-generation antimicrobials, like quinolones, cephalosporins, and macrolides.

But by the early 2000s, mutations that confer resistance to quinolones accounted for more than 85 percent of all cases in Bangladesh, India, Pakistan, Nepal, and Singapore. At the same time, cephalosporin resistance was also taking over.

Today, only one oral antibiotic is left: the macrolide, azithromycin. And this medicine might not work for much longer.”

I will turn to the peer-reviewed paper after this introduction: “South Asia might be the main hub for typhoid fever, accounting for 70 percent of all cases, but if COVID-19 taught us anything, it is that disease variants in our modern, globalized world are easily spread.”

The peer-reviewed, open-access paper was published in August 2022 in The Lancet Microbe. It is titled The international and intercontinental spread and expansion of antimicrobial-resistant Salmonella Typhi: a genomic epidemiology study. The peer-reviewed paper was created by 27 scholars. It opens with a Background subsection: “The emergence of increasingly antimicrobial-resistant Salmonella enterica serovar Typhi threatens to undermine effective treatment and control. Understanding where antimicrobial resistance in … [Salmonella enterica serovar Typhi] is emerging and spreading is crucial towards formulating effective control strategies.”

The Findings subsection reads: “Our analysis revealed a declining trend of multidrug resistant typhoid in south Asia, except for Pakistan, where extensively drug-resistant … S Typhi emerged in 2016 and rapidly replaced less-resistant strains. Mutations in the quinolone-resistance determining region … of S Typhi have independently arisen and propagated on at least 94 occasions, nearly all occurring in south Asia. Strains with multiple QRDR mutations, including triple mutants with high-level fluoroquinolone resistance, have been increasing in frequency and displacing strains with fewer mutations. Strains containing acrB mutations, conferring azithromycin resistance, emerged in Bangladesh around 2013 and effective population size of these strains has been steadily increasing. We found evidence of frequent international (n=138) and intercontinental transfers (n=59) of antimicrobial-resistant S Typhi, followed by local expansion and replacement of drug-susceptible clades.”

A short Interpretation subsection follows: “Independent acquisition of plasmids and homoplastic mutations conferring antimicrobial resistance have occurred repeatedly in multiple lineages of S Typhi, predominantly arising in South Asia before spreading to other regions.”

In other words, contrary to my introductory remarks in this video, we are not safe from seemingly ancient diseases. Antibiotics are no longer sufficient to maintain our survival. Our future appears to reflect our past, with dreaded diseases posing a threat to our continued survival.