Salmonella Study at Michigan State University: Salmonella is Evolving
With an alarming rise of food recalls from products tainted with salmonella, it is crucial the medical community understands not only how to diagnose patients but also how to treat the specific salmonella bacteria that present. There is a new study out of Michigan State University (MSU) that researched how salmonella is changing and, in particular, its resistance to antibiotics. Shannon Manning, the senior author of the salmonella and a professor at Michigan State University , stated:
“If you get a salmonella infection that is resistant to antibiotics today, you are more likely to be hospitalized longer, and it will take you longer to recover. We need better detection methods at the clinical level to identify resistant pathogens earlier so we can treat them with the right drugs the first time.”
There are over two thousand strains of salmonella bacteria with around 100 strains connected to human infection – with myriad common strains from Salmonella Heidelberg to Salmonella Typhimurium to Salmonella Infantis. Beyond the unique serotypes lie unique DNA compositions, each slightly different then its predecessor. When there is a lapse in correctly diagnosing the exact salmonella infection multiple complications can arise.
Because time is always of the essence in treatment, this study on the evolution of salmonella bacteria and infections is very important. As the bacteria become resistant to antibiotics, new and better diagnosis and treat options are needed for the infected patients. Understanding how each strain of salmonella reacts to medication and how to best diagnosis the infection will help treat patients quickly and effectively. As explained in the salmonella study:
“Losing a day or more to misdiagnosis or improper treatment allows symptoms to get worse. Doctors might kill off a subpopulation of bacteria that are susceptible, but the ones that are resistant grow stronger.”
For a patient ill with food poisoning, each day is crucial if not treated with the correct antibiotic, and delay can cause serious complications
In Michigan where the salmonella study was conducted, doctors are continually experiencing more cases where some strains of salmonella are resistant to antibiotics, specifically ampicillin, which is a common antibiotic prescribed for treatment of salmonella infection. In this salmonella study, Professor Manning explains that there is no clear reason why a drug becomes resistant but suspects it is from over use and that “possessing genes for resistance has allowed these bacteria to grow and thrive in the presence of antibiotics”.
The salmonella study explored various strains of the bacteria and found that patients commonly had infections that were resistant to one or more of the common antibiotics. The study also noted some evidence of seasonal patterns of drug resistant infections, most prominently in the fall, winter, and spring, and that the salmonella strains also varied between rural and urban areas. Specifically, in rural areas where contact with farm animals or untreated water may be more common, the Salmonella Enteritis strain was more prevalent.
Symptoms of a salmonella infection may include diarrhea, stomach cramping and fever. Prolonged symptoms of the infection can result in dehydration and may require hospitalization. The salmonella study explains, “losing a day or more to misdiagnosis or improper treatment allows symptoms to get worse.” Each strain of salmonella responds to antibiotics differently, therefore treatment can be very specialized to the specific strain of salmonella that is contracted and physicians are encouraged to obtain stool cultures and send them to the lab for antibiotic susceptibility testing.