Salmonella

Salmonella is a genus of bacteria that plays a major role in human and animal health, causing a wide range of infections with varying degrees of severity. It is responsible for one of the most common foodborne illnesses worldwide, with millions of people affected each year. While many may associate Salmonella solely with food poisoning, it is much more complex, comprising over 2,500 serotypes, each with its own specific characteristics and virulence factors. The discovery of Salmonella dates back to the late 19th century, when Theobald Smith, working under the guidance of American bacteriologist Daniel Elmer Salmon, first identified the bacterium. Since then, much has been learned about its biology, transmission, and impact on public health. Originally, the genus was named after Salmon, though today it is classified under the family Enterobacteriaceae, sharing common traits with other enteric bacteria. Despite the significant advances in understanding Salmonella, new challenges continue to emerge, particularly in the form of antibiotic resistance and emerging serotypes with more aggressive characteristics. Salmonella infections are typically categorized into two main types: gastrointestinal infections and systemic infections. The most common manifestation is gastroenteritis, which presents with symptoms such as diarrhea, fever, nausea, and abdominal cramps. These symptoms usually develop within 6 to 72 hours after exposure to the bacteria. Though often self-limiting, severe cases can lead to dehydration and, in rare instances, death. On the other hand, systemic infections like typhoid fever can cause more severe illness, potentially leading to complications such as intestinal perforation, septic shock, or organ failure. Typhoid fever remains a major health issue in many developing countries, while gastrointestinal Salmonella infections are more frequently encountered in industrialized nations.