Garlic for Yeast Infections? Probably Best To Skip It

Why Antibiotics Fail Against Salmonella Infections

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Summary

Researchers at the University of Basel found that nutrient starvation, not persister cells, helps Salmonella survive antibiotic treatments. Using real-time tracking, they demonstrated that nearly all Salmonella in infected tissues resist antibiotics due to slow growth, challenging long-standing theories. These findings could reshape infection treatment and antibiotic research strategies.

Key Takeaways

Salmonella survival is linked to nutrient scarcity, not hyper-resilient persister cells.

Traditional antibiotic resistance tests may misrepresent bacterial survival and treatment failures.

Real-time bacterial tracking could lead to more effective antibiotic research and infection treatments.

In certain infectious diseases caused by bacteria, antibiotics are less effective than expected. One example is infections caused by Salmonella bacteria, which can lead to illnesses such as typhoid fever. For many years, researchers believed that a small subset of dormant bacteria are the main problem in fighting infections. These so-called persisters can survive antibiotic treatment and cause relapses later. Researchers worldwide have been working on new therapies aimed at targeting and eliminating these "sleeping" bacteria.

In a new study, Professor Dirk Bumann's team from the Biozentrum of the University of Basel challenges the prevailing concept that persisters are the cause of antibiotic ineffectiveness. "Contrary to widespread belief, antibiotic failure is not caused by a small subset of persisters. In fact, the majority of Salmonella in infected tissues are difficult to kill," explains Bumann. "We have been able to demonstrate that standard laboratory tests of antimicrobial clearance produce misleading results, giving a false impression of a small group of particularly resilient persisters."

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Subscribe for FREE Nutrient starvation increases Salmonella resilience

The researchers investigated antimicrobial clearance in both Salmonella-infected mice and tissue-mimicking laboratory models. The body's defense mechanisms against bacteria often include reducing the availability of nutrients. The researchers have now revealed that in fact, this nutrient starvation is the main reason for Salmonella bacteria surviving treatments with antibiotics. The researchers assume that the same applies to other bacterial pathogens.

"Under nutrient-scarce conditions, bacteria grow very slowly," says Bumann. "This may seem good at first, but is actually a problem because most antibiotics only gradually kill slowly growing bacteria." As a result, the drugs are much less effective, and relapses can occur even after prolonged therapy.

Real-time analyses reveal misconception

The scientists used an innovative method to monitor antibiotic action in single bacteria in real time. "We demonstrated that nearly the entire Salmonella population survives antibiotic treatment for extended periods, not just a small subset of hyper-resilient persisters," says Dr. Joseph Fanous, the study's first author.

A major issue with the standard methods used worldwide for decades is their indirect and delayed measurement of bacterial survival, leading to distorted results. "Traditional tests underestimate the number of surviving bacteria," explains Fanous. "And they falsely suggest the presence of hyper-resilient subsets of persisters that do not actually exist." This misinterpretation has influenced research for many years.

Novel tools for antibiotics research

These findings could fundamentally change antibiotics research. "Our work underlines the importance of studying bacterial behavior and antibiotic effects live and under physiologically relevant conditions," emphasizes Bumann. "In a few years, modern methods like real-time single-cell analysis will hopefully become standard." Shifting the focus from persisters to the impact of nutrient starvation is an important step toward more effective therapies against difficult-to-treat infections.

Reference: Fanous J, Claudi B, Tripathi V, Li J, Goormaghtigh F, Bumann D. Limited impact of Salmonella stress and persisters on antibiotic clearance. Nature. 2025. Doi: 10.1038/s41586-024-08506-6

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Salmonella Outbreak With 500+ Cases Linked To Certain Seed

According to a new joint report by the European Centre for Disease Prevention and Control and the European Food Safety Authority, the consumption of sprouted alfalfa seeds has been linked to 509 reported cases of salmonellosis between January 2023 and January 2025.

Of the 10 countries where salmonellosis infections have been recorded, Norway has been the worst impacted with 257 cases, followed by Sweden with 110, Finland with 94 and Germany with 30.

Cases have also been reported in the Netherlands (9), Denmark (4), France (3), UK (1), Belgium (1) and Estonia (1).

Alfalfa is a flowering plant in the legume family that is commonly called Lucerne in the UK.

The outbreak, which remains ongoing, encompasses eight Salmonella serotypes, several of which are rarely reported in Europe.

The sprouts were identified as the vehicle of infection following multiple national investigations across Europe, which was then confirmed by whole genome sequencing analysis conducted on a centralised EU basis.

This analysis, paired with food tracing techniques, also linked the seeds to a single supplier in Italy which had sourced its seeds from three separate growers in the same region of the country.

However, further investigation is needed to determine how the seeds became contaminated and whether there was any cross-contamination along the supply chain.

"Food safety authorities in the countries concerned implemented control measures, including withdrawal and recall of investigated batches, [which] significantly decreased case notifications," the European Centre for Disease Prevention said.

"However, several countries have detected new cases, indicating that contaminated seed batches may still be in circulation and further interventions needed. Cases may continue to occur until the point where the seeds were contaminated with Salmonella can be identified and properly controlled."

Salmonella infection can cause serious illness, particularly in infants, older or frail adults, and individuals with weakened immune systems. The European Centre for Disease Prevention has advised that anyone at risk should avoid eating sprouted seeds unless they have been cooked thoroughly.

Meanwhile, sprouted seed producers have been urged to strictly follow food safety procedures to prevent contaminated products from reaching consumers.

The full report can be found on the European Centre for Disease Prevention website.

Also read → McVitie's owner appoints new UK&I managing director

Are Runny Egg Yolks Safe To Eat?

Sunny side-up, over easy, lightly scrambled, soft-boiled, poached: Americans love eating eggs when they're still runny, despite the general understanding that raw or undercooked eggs aren't good for you.

When you cook an egg, the heat that solidifies its whites and yolks kills pathogens like salmonella and bird flu. That's why food safety officials recommend cooking eggs until both parts are firm.

But how unsafe are runny yolks really?

That depends on how much risk you're willing to accept, said Felicia Wu, a professor of food safety, toxicology and risk assessment at Michigan State University.

"If you look at the eggs typically purchased in the United States, most of them are perfectly safe to eat in a runny state," she said. "It's just that we don't know when there's an individual egg that contains some risk."

Eggs can carry harmful bacteria, including E. Coli and campylobacter. But salmonella — the leading cause of food poisoning-related deaths nationwide — is by far the biggest hazard, said Dr. John Leong, a professor of molecular biology and microbiology at Tufts University.

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