Mitigating the growing threat of multidrug-resistant Salmonella

Salmonella is a group of bacteria that remains one of the leading causes of diarrhea and foodborne outbreaks worldwide, including in the Philippines. Infection with Salmonella — known as salmonellosis — commonly occurs after consuming contaminated food, particularly products of animal origin such as eggs, poultry, meat, and milk. However, other foods, including vegetables contaminated through manure used as fertilizer, can also transmit the bacteria. Symptoms typically include fever, abdominal pain, diarrhea, nausea, and sometimes vomiting.

In many cases, salmonellosis is self-limiting. Most healthy individuals recover without specific treatment, with supportive care such as fluid and electrolyte replacement sufficient to manage symptoms. Yet the illness is far from trivial. Severe dehydration can develop, particularly among children, older adults, and individuals with weakened immune systems. In such cases, hospitalization may be necessary.

Antibiotics may be required for vulnerable patients or severe infections. However, the World Health Organization (WHO) does not recommend antibiotic treatment for mild or moderate salmonellosis in otherwise healthy individuals. This guidance is grounded in science since unnecessary antibiotic use may not fully eliminate the bacteria and can instead promote the survival of resistant strains. This phenomenon is part of the broader challenge known as antimicrobial resistance (AMR).

AMR is now recognized as one of the most serious global public health threats. The WHO estimates that bacterial AMR directly caused 1.27 million deaths globally in 2019 and contributed to nearly 5 million deaths. The misuse and overuse of antibiotics in humans, animals, and agriculture accelerate this process. Over time, bacteria evolve mechanisms that allow them to survive treatments that once killed them.

Of particular concern is the emergence of multidrug-resistant (MDR) bacteria, sometimes referred to as “superbugs.” These organisms are resistant to multiple antibiotics, severely limiting treatment options. Infections caused by MDR bacteria are often more difficult, more expensive, and sometimes impossible to treat. They lead to longer illnesses, higher healthcare costs, and increased risk of complications and death.

Foodborne pathogens are not exempt from this trend. The Philippines, as both a major producer and consumer of meat, faces heightened vulnerability. This risk was underscored by a study conducted by biologists from the University of the Philippines Diliman examining Salmonella strains isolated from chicken meat sold in retail wet markets across Metro Manila. The findings were concerning as the predominant Salmonella strains exhibited resistance to numerous antibiotics, with some resistant to as many as 12 different drugs.

These results carry important implications for both public health and food safety. Resistant bacteria circulating in food supply chains can lead to infections that are harder to manage clinically. Moreover, wet markets may inadvertently facilitate the spread of resistant organisms through cross-contamination. The risks extend beyond markets into kitchens and households, where improper food handling can enable transmission.

Addressing this challenge requires a coordinated and multi-sectoral response. Surveillance systems must be strengthened to monitor foodborne pathogens and resistance patterns. Equally critical are policies governing antimicrobial use at the farm level. Responsible antibiotic stewardship in animal production is essential to slow the development of resistance.

Investment in research also plays a pivotal role. The development of antimicrobial alternatives, improved diagnostics, and new treatment strategies can help preserve the effectiveness of existing medicines. Policymakers must recognize that AMR is not solely a clinical issue since it is a food security, economic, and national development concern.

Consumers likewise have an indispensable role in mitigation. Basic food safety practices remain among the most effective defenses. Hands, kitchen surfaces, and utensils should be kept clean and sanitized. Raw meat, poultry, and seafood must be handled separately from ready-to-eat foods to prevent cross-contamination. Safe water should always be used in food preparation.

Proper cooking is equally important. Heating food to at least 70°C significantly reduces bacterial risks. Perishable food should be refrigerated promptly, ideally at 5°C or below. Microorganisms multiply rapidly when food is left at room temperature for extended periods.

Finally, combating AMR demands sustained innovation. The research-based pharmaceutical industry continues to invest in antibiotic development, yet scientific and economic barriers remain. Revitalizing the antibiotic pipeline requires supportive policy frameworks, incentives, and global cooperation.

Equally important is stewardship. Preserving the effectiveness of antibiotics, new and old alike, depends on their appropriate use. Preventive measures, including vaccination, must also be fully leveraged. Vaccines that reduce infections ultimately reduce antibiotic demand, slowing the spread of resistance.

Multidrug-resistant Salmonella is more than a laboratory finding. It is a warning signal, one that calls for vigilance, responsible practices, and decisive policy action.

Teodoro B. Padilla is the executive director of Pharmaceutical and Healthcare Association of the Philippines which represents the biopharmaceutical medicines and vaccines industry in the country. Its members are at the forefront of developing, investing and delivering innovative medicines, vaccines, and diagnostics for Filipinos to live healthier and more productive lives.