Salmonella enterica is a Gram-negative, rod-shaped bacterium that causes salmonellosis, an infectious disease affecting the human gastrointestinal tract. There are over 2,600 serovars of this bacterium, but the most common pathogenic ones are S. enterica serovar Typhimurium and S. enterica serovar Enteritidis. They cause both localized gastrointestinal infections and systemic complications.

The danger of Salmonella enterica lies in its high viability in the environment—it can form biofilms and effectively evade the body's immune response. In the context of globalization and intensive livestock farming, the bacterium spreads extremely quickly.

How does Salmonella enterica infection occur?

The primary mechanism of infection is the fecal-oral route. A person can become infected by consuming:

• Undercooked meat, eggs, or dairy products

• Contaminated water

• Contact with sick animals or people

Poultry, especially chickens, are a common source of bacteria. Salmonella can survive on the surfaces of kitchen utensils, making it particularly dangerous in households and the food industry.

Diseases caused by Salmonella enterica and their symptoms

Once in the body, the bacteria passes through the stomach and colonizes the small intestine, from where it can enter the bloodstream and other organs. The main symptoms are:

• Diarrhea

• Fever (38–40 °C)

• Nausea, vomiting

• Stomach ache

• General weakness

In severe cases, typhus may develop—a systemic infection that affects the liver, spleen, and central nervous system.

How does traditional medicine treat this infection?

Mild cases of salmonellosis often resolve on their own—hydration and dietary measures are recommended. In severe cases, antibiotics are used: ciprofloxacin, azithromycin, cefotaxime, and ceftriaxone.

However, since the 2000s, the prevalence of multidrug-resistant Salmonella enterica strains has been increasing , reducing the effectiveness of standard treatment regimens. This has necessitated the development of alternative methods.

Why Salmonella enterica has become resistant

There are several reasons:

• Overuse of antibiotics in veterinary and poultry medicine

• Self-medication and unjustified prescription of antibiotics

• The presence of plasmids with resistance genes that are easily transmitted to other bacteria

As a result, strains resistant to most classes of antibiotics have emerged. For example, S. Typhimurium DT104 is known as one of the most problematic superbugs.

Research results: phages against salmonella

Bacteriophages against intestinal infections.
A team of scientists from the University of Helsinki and Seoul National University investigated the possibility of using bacteriophages to eradicate foodborne pathogens, including Salmonella enterica. Phages were shown to effectively inhibit the growth of these bacteria in contaminated food products, such as pork and milk.
Source: https://bacteriophages.info/ua/news/bakteriofagi-proti-kishkovih-infektsiy/

Use of lytic bacteriophages for food disinfection.
In particular, phages are used to destroy Salmonella enterica in food products, which is a promising method of biocontrol in the food industry.
Source: https://bacteriophages.info/ua/news/zastosuvannya-bakteriofagiv-u-harchoviy-promislovosti/

Benefits and challenges of phage therapy

Advantages:

• High specificity

• Preserving the microbiome

• Possibility of prophylactic use

• Destruction of even antibiotic-resistant strains

Challenges:

• The need for precise matching of phage to bacterial strain

• Lack of clinical trials

• Lack of uniform standards

However, with the development of bioinformatics, genome sequencing and artificial intelligence, precise selection of bacteriophage is becoming increasingly accessible.

Conclusion: The future belongs to phages

Salmonella enterica is a real health threat , particularly due to its ability to mutate. But this is precisely the key to innovation. Phage therapy is already proving its effectiveness in combating this pathogen, both in medicine and in agriculture.

Perhaps, on the threshold of a new decade, we will return not to the mass use of antibiotics, but to intelligent viruses that not only destroy bacteria, but also maintain our internal balance.