Antimicrobial properties of Tomato juice can kill bacteria causing Typhoid fever

Researchers find 2 antimicrobial peptides effective against bacteria.


Tomatoes are easily accessible and cost-effective vegetables with various health benefits because of their bioactive molecules, including antioxidants and antimicrobials. While the antioxidant properties of tomatoes are well-known, their antimicrobial properties have yet to be explored.

According to new research published this week in Microbiology Spectrum, a journal of the American Society for Microbiology, Tomato juice can kill Salmonella Typhi and other bacteria that can harm people’s digestive and urinary tract health.

Salmonella enterica serovar Typhi (S. Typhi), the bacterium responsible for typhoid fever, is a human-specific pathogen and a major cause of mortality from enteric infections. Typhoid fever leads to 21 million reported cases and 200,000 deaths annually worldwide. While vaccines for typhoid exist, many developing countries struggle to access them. Moreover, the challenge of antibiotic resistance poses a significant threat, particularly among malnourished children.

This new study aims to determine if tomato and tomato juice can kill enteric pathogens, including Salmonella Typhi, and if so, what qualities they have that make them work.

The researchers first confirmed in the laboratory that tomato juice can kill Salmonella Typhi. Once validated, they investigated the tomato’s genome to identify the antimicrobial peptides involved. Antimicrobial peptides are small proteins that disrupt the bacterial membrane, compromising the integrity of the microbes. The team selected four potential antimicrobial peptides and tested their effectiveness against Salmonella Typhi, identifying two successful peptides.

Further tests were conducted on Salmonella Typhi variants prevalent in regions where the disease is common. A computer study was also conducted to understand how the antibacterial peptides function against Salmonella Typhi and other enteric pathogens. The researchers also assessed the efficacy of tomato juice against other bacteria that can impact digestive and urinary tract health.

The key finding is that tomato juice effectively eliminates Salmonella Typhi, including its hypervirulent variants and other bacteria harmful to digestive and urinary tract health. Specifically, two antimicrobial peptides were identified as capable of eliminating these pathogens by disrupting the bacterial membrane, a protective layer surrounding the pathogen.

Principal study investigator Jeongmin Song, Ph.D., Associate Professor, Department of Microbiology & Immunology, Cornell University, said“Our research shows that tomato and tomato juice can get rid of enteric bacteria like Salmonella.”

The researchers hope that when the general public, especially children and teenagers, becomes aware of the study’s findings, they will be motivated to consume more tomatoes and other fruits and vegetables. This increased consumption is encouraged due to the natural antibacterial benefits these foods offer consumers.

Journal Reference:

  1. Ryan S. Kwon, Gi Young Lee, Sohyoung Lee, Jeongmin Song. Antimicrobial properties of tomato juice and peptides against typhoidal Salmonella. Microbiology Spectrum. DOI: 10.1128/spectrum.03102-23


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