Did you know a research study on the global burden of nontyphoidal Salmonella gastroenteritis revealed an average of 93.8 million cases of gastroenteritis due to Salmonella species resulting in about 155,000 deaths occurring globally each year, out of which 80.3 million cases were foodborne?

Despite decades of extensive research on developing strategies to conquer Salmonella challenges, the persistent prevalence of Salmonella contamination in the food supply chain continues to be a pressing issue for food industries worldwide. The existing risk management approaches and models to control Salmonella fall short of adequately addressing the potential food safety shocks as their focus lies in assessing measures to reduce risks rather than cultivating resilience capabilities, such as adaptability to sudden risk fluctuations, according to the scientific study, “Building a resilient pork supply chain to.”

The U.S. Department of Agriculture’s Agricultural Research Service (ARS) has introduced the Salmonella Challenge, an extensive nationwide initiative that unites experts from various scientific fields to combat salmonellosis. This sweeping project aligns and complements the sustained efforts of the Food Safety and Inspection Service (FSIS) to enhance mechanisms in minimizing poultry-related human Salmonella illness, marking a significant step forward in resolving Salmonella concerns.

Understanding Salmonella

Salmonella, a genus of gram-negative rod-shaped bacteria, belongs to the Enterobacteriaceae family. It consists of two species, Salmonella bongori and Salmonella enterica, with over 2500 serotypes identified so far. This broad-ranging and hardy bacteria can survive several weeks in a dry environment and several months in water. While all serotypes have the potential to infect humans, some of them are host-specific and can only exist in particular kinds of animals. Enteritidis and Typhimurium are the two most important serotypes of Salmonella transmitted from animals to humans in most parts of the world. Some key points to understanding Salmonella, as elaborated by the World Health Organization (WHO), are given in the sections below:

Salmonellosis

Salmonellosis is an infectious illness caused by the Salmonella bacteria, mainly affecting the gastrointestinal tract. It typically presents with sudden fever, abdominal discomfort, diarrhea, nausea, and occasionally vomiting. The disease symptoms manifest within 6 to 72 hours (usually 12 to 36 hours) after consuming Salmonella-contaminated substances, and the illness usually lasts for 2 to 7 days. The symptoms of salmonellosis are generally mild, and most patients recover without requiring specific treatment. However, in some instances, particularly among children and elderly individuals, severe dehydration can develop and pose a life-threatening risk. Often, 60 to 80% of all salmonellosis cases are not identified as part of a known outbreak and are classified as sporadic or undiagnosed.

Sources & Transmission

The transmission of Salmonella can occur throughout the entire food chain, starting from animal feed, primary production and extending to households, food-service establishments, and institutions. Salmonella bacteria are commonly found in the intestines of animals, especially poultry, livestock, and reptiles, and can contaminate food products derived from these animals, as well as other sources such as fruits, vegetables, and water. Salmonella can be spread by food handlers who do not wash their hands and surfaces properly during food preparation. People can get infected with Salmonella by consuming raw or undercooked foods. Salmonella can also transmit through person-to-person contact, typically via the fecal-oral route. Human cases of salmonellosis can also arise when individuals come into contact with infected animals, including pets.

Difficulty in Eradicating Salmonella

Salmonella is a highly challenging pathogen to eliminate due to several reasons. Firstly, there are more than 2,400 different types of Salmonella, each with its unique characteristics and behaviors. The persistence of Salmonella stems from its numerous variations, the complex and multifaceted nature of Salmonella risk factors across different production systems, and the difficulties posed by undetected transmission through asymptomatic carriers.

Extensive research experience has provided us with valuable insights into various aspects of Salmonella’s survival and persistence in the poultry environment. We have learned about its colonization of the animal’s intestinal tract, its transmission through fecal material, and its spread within processing plants. Still, there are several more challenges industries face and need to overcome regarding the prevalence of Salmonella, such as:

• Wide Host Range: Salmonella has a broad host range, capable of infecting various animal species, making it tedious to control its quick and dispersed transmission in the food industry. This can be attributed to the multiple entry mechanisms that Salmonella possesses, allowing it to invade host cells. It has undergone evolutionary changes to survive and multiply within its host organisms, accompanied by the bacterium’s virulence factors, leading to significant diversity in terms of the hosts it can infect and the severity of the diseases it causes. Furthermore, Salmonella demonstrating an aptitude for adapting to different host environments has escalated the host range.
• Environmental Resilience: Salmonella can survive in low moisture environments, withstand a wide range of temperatures, and tolerate acidic conditions, making it difficult to eliminate through traditional sanitization methods. The ability of Salmonella to form biofilms further enhances its resistance to cleaning agents and disinfectants. This resilience enables the bacterium to persist in food processing facilities and continue to contaminate food products even after standard cleaning and sanitation procedures.
• Intensive Production Systems: Complex supply chains involving multiple stakeholders, including farms, slaughterhouses, processing plants, and distributors, raise opportunities for Salmonella to enter the food supply chain through multiple sources. This can be through contaminated raw materials, cross-contamination during processing, improper storage, or inadequate cooking practices. For example, the meat and poultry industry often relies on intensive production systems, which involve raising large numbers of poultry birds or livestock animals in close proximity.
• Vertical Integration: The meat and poultry industries often operate under a vertically integrated model, where a single company controls multiple stages of production, from breeding to processing. While this model offers efficiency, it can also lead to challenges in managing Salmonella, as the bacterium can persist throughout the production chain, requiring successful control measures at each stage. These industries mostly produce vast quantities of products to meet consumer demand, and hence handling such high volumes increases the likelihood of Salmonella contamination.
• Antibiotic Resistance: Since the 1960s, the frequency of isolation of salmonella strains with resistance towards one or more antimicrobial agents has increased in many countries, including the USA, the UK, and Saudi Arabia. Antibiotic-resistant Salmonella can survive in the presence of antimicrobial treatments used in food processing, making it extremely challenging to eliminate the bacterium from the food supply. The rise of antimicrobial-resistant Salmonella is predominantly facilitated by the utilization of antibiotics in animal feed to enhance the growth of food animals and in veterinary medicine to combat bacterial infections in those animals. This situation creates a paramount concern for zoonotic diseases as it increases the potential for the transmission of multidrug-resistant (MDR) Salmonella strains from animals to humans.

Understanding these many elements for salmonella eradication requires a varied and all-exhaustive collection of data, which can then be used to develop an accurate mitigation system. Such a model would enable the creation of effective prediction tools for producers to monitor their systems and mitigate Salmonella risks in a timely manner.

General Prevention Measures

Curtailing the spread of Salmonella involves applying measures that span from poultry production at the farm to the consumption of products by consumers. Effective prevention of Salmonella requires implementing a systematic and interconnected set of control measures throughout the entire food chain, encompassing agricultural production, processing, manufacturing, and food preparation both in commercial establishments and at home. Some prevention measures for the elimination of Salmonella, specific to the food industry are:

• Good Manufacturing Practices (GMP): Establishing and maintaining strict GMP protocols encompasses proper storage and handling of raw materials and finished products, adequate sanitation and hygiene practices, regular equipment maintenance, effective pest control measures, and strict adherence to temperature controls during processing. This decreases the risk of Salmonella contamination at various stages of food production.
• Hazard Analysis and Critical Control Points (HACCP): A well-defined HACCP system helps identify and control potential sources of Salmonella contamination at critical points in the production process by conducting a hazard analysis, establishing critical control points, setting up monitoring and verification procedures, and administering corrective actions when necessary.
• Supplier Control and Raw Material Testing: Ensuring the safety of raw materials through supplier qualification programs is essential for preventing Salmonella outbreaks. This involves working with reputable suppliers who follow strict quality and safety standards, conducting regular audits and inspections, and maintaining accurate records of suppliers and their products to verify the quality and safety of their raw materials. Regular testing for Salmonella in raw materials, particularly those prone to contamination, can help identify probable sources and prevent their entry into the production process. In the event of a Salmonella outbreak, traceability systems can help identify the source of contamination quickly and inhibit further spread.
• Employee Training and Hygiene Practices: Educating and training employees about appropriate hygiene practices, such as regular training sessions on handwashing, personal hygiene, and proper handling and storage of food products, can bring about a great degree of difference in the existence of Salmonella risks. Employees should be aware of the risks associated with Salmonella and follow proper food handling protocols, thereby reducing the chances of cross-contamination and diminishing its spread.
• Environmental Monitoring: Environmental monitoring of the production environment, surfaces, and equipment can help determine possible locations of Salmonella contamination. Swabbing and testing various surfaces for the presence of Salmonella, monitoring air quality, and ensuring proper sanitation of equipment and utensils. Swift corrective actions should be taken if any positive results are detected.

Furthermore, the establishment of national and regional surveillance systems for foodborne diseases is fundamental in understanding and monitoring the prevalence of these illnesses. Such systems enable the early detection and response to salmonellosis and other enteric infections and contribute to overall prevention efforts.

Addressing all the challenges related to Salmonella propagation necessitates a multifaceted approach that includes implementing stringent preventive measures, improving hygiene practices, enhancing biosecurity on farms, instituting effective monitoring and testing programs, and investing in research and innovation to develop new control techniques. Collaboration between industry stakeholders, regulatory bodies, and public health agencies comes as a non-negotiable action to proficiently limit the prevalence of Salmonella in the meat and poultry industries and ensure the safety of food products.

How Smart Food Safe Assist Global Food Industries Protect Public Health Against Pathogenic Food Illnesses?

With the mission to revolutionize quality and food safety management through intelligent software solutions, Smart Food Safe works toward delivering digital modules capable of assisting food businesses secure public health by preventing pathogenic food illnesses originating from food production operations.

Our software solutions, Smat EMP and Smart HACCP, have become particularly functional in this aspect. Smart EMP provides a comprehensive system that digitalizes any environment monitoring program, enabling real-time monitoring and analysis of the food production environment, detecting potential sources of contamination, and allowing timely corrective actions in case of non-compliance. Food industries can enforce an efficient food safety management system (FSMS) with Smart HACCP through systematic risk assessment and proactive remediation measures to digitally manage the identification and implementation of critical control points throughout food processing.