Scientists reported Wednesday a super-strain of salmonella resistant to antibiotics, notably ciprofloxacin, which is commonly used to treat infections caused by the bacteria.
The reseachers called on national and international health authorities to take measures against the superbug "before it spreads globally," as did another another variant in the 1990s.
Over the last decade, the virulent new strain, known as S. Kentucky, has shown up in parts of Europe, Africa and the Middle East, according to the study, published in the Journal of Infectious Diseases.
People can be infected with salmonella by eating under-cooked meats and eggs, with symptoms including diarrhea, fever, and abdominal cramps. Most cases are not severe, but some can lead to hospitalisation and even death.
Nearly 500 people in France, Britain and Denmark were infected with S. Kentucky between 2000 and 2008, reports the study, led by Francois-Xavier Weill and Simon Le Hello at the Pasteur Institute in Paris.
In France, "we have seen the number of (drug-resistant) cases multiplied by 10 in 10 years," Weill told AFP by phone.
The fact that about ten percent of the patients in European countries had not recently travelled abroad suggests possible contagion within Europe, but most infections there are thought to originate from consumption of contaminated imported foods.
The S. Kentucky strain was isolated in chickens and turkeys from Ethiopia, Morocco and Nigeria, suggesting that poultry is a key agent of infection, the study said. Cases were also reported in Egypt, mainly between 2002 and 2005.
In the United States, meanwhile, health authorities said Tuesday that another multidrug-resistant strain of the disease, called S. Heidelberg, has killed one person and sickened 77.
The infections were spread across 26 states between March 1 and August 1, with ground turkey the likely source, the Centers for Disease Control and Prevention (CDC) said in a statement.
Salmonella infection represents a major public health problem worldwide, with an estimated 1.7 million infections occurring each year in North America alone.
More than 1.6 million cases were reported between 1999 and 2008 in 27 European countries.
The CDC urges consumers to cook meat thoroughly to a final temperature of 74 Celsius (165 degrees Fahrenheit).