Campylobacter jejuni

Campylobacter jejuni, or C. jejuni, is a type of bacterium that is responsible for many cases of food poisoning. It is believed to be the most common bacterial cause of foodborne infection in the United States. Infection with C. jejuni can result in a number of complications. Victims often have diarrhea, fever, nausea, and an inflammation of the intestinal tract called gastroenteritis. However, in more severe cases, exposure to C. jejuni can result in arthritis or Guillain-Barré syndrome, which results in the rapid development of muscle weakness. C. jejuni can even cause a pregnant woman to miscarry. Perhaps equally worrisome, C. jejuni has demonstrated an increasing resistance to most forms of antimicrobial therapy.

C. jejuni commonly affects the bowels. It is most frequently spread through contact with raw or undercooked poultry. The infection is so powerful that a single drop of contaminated juice from an infected chicken can make someone sick. C. jejuni has been reported as one of the most common causes of illnesses around the world and is responsible for vast economic losses due to missed workdays and medical costs. The Campylobacter bacteria as a whole have been identified by the World Health Organization (WHO) as one of the four most common causes of diarrheal diseases and the most common source of gastroenteritis among humans.

Background

C. jejuni was first discovered in 1886 by German-Austrian pediatrician Theodore Escherich (1871–1951). Escherich observed the presence of a series of microscopic “spiral bacteria” in diarrhea samples taken from children who had died in Munich from what he called “cholera infantum.” He discovered further samples of other “spiral-shaped” microorganisms in the samples of thirty-five children suffering from gastroenteric illnesses, although he did not try to link these specimens to the infants’ illnesses. He published a paper in 1886 on his discoveries that helped to establish his reputation as a specialist in the study of bacteria throughout Europe. For his efforts, a genus of bacteria that he discovered is named Escherichia in his honor. Despite this, Escherich’s research was published in German and remained largely unknown until its rediscovery in 1985.

Although Campylobacter bacteria have likely been causing illnesses in humans for centuries, they were not known as human pathogens until the 1970s. Initial studies of the Campylobacter genus primarily linked them to diseases in animals. Research of sheep in 1909 and cows in 1919 by veterinarians both demonstrated the presence of an unknown spiral bacterium in animal fetuses. These researchers initially placed the bacteria in an unrelated class of Vibrio bacteria typically found in saltwater and seafood.

In 1938, more than three hundred inmates at two neighboring correctional facilities in Illinois demonstrated symptoms of diarrhea that were eventually linked back to contaminated milk. Upon examination of the stool samples of some of the victims, bacteria resembling the tentatively described “Vibrio jejuni” were seen in blood cultures grown in the broth of some victims. Researchers believe that this mass infection was likely the first well-established case of Campylobacter infection, even if they were unaware of the cause at the time.

By the late 1950s, doctors had isolated a bacterium they were still tentatively identifying as Vibrio in twelve samples taken from a mix of mostly infants and children. The lack of widescale reports was likely due to the limited techniques available in the 1950s for growing culture samples from bacteria taken from stools. Campylobacter was finally identified as a distinct genus of bacteria in 1963, which led to the proper reclassification of Virbio jejuni as C. jejuni. The first example of Campylobacter being isolated from stools did not occur until 1968 when a research team at the National Institute for Veterinary Research, in Brussels, Belgium, was able to create a culture from the feces of a twenty-year-old woman with diarrhea and fever. The presence of the bacteria in the sample demonstrated that the bacteria were responsible for intestinal infections. Ultimately, using this information, the research team was able to find samples of what would later be classified as C. jejuni in 5.3 percent of 3,800 children with diarrhea, but in only 1.6 percent of 7,200 people without diarrhea. In the course of their work, they discovered that C. jejuni was susceptible to treatment with an antibiotic known as erythromycin.

Overview

C. jejuni belongs to the Campylobacter genus of bacteria that are known to cause campylobacteriosis in both animals and humans. The Centers for Disease Control and Prevention (CDC) estimates that an average of 1.3 million people are infected by the bacteria in this genus each year, although some people may have symptoms that are not severe enough to seek professional treatment, which means that the number of infections per year may be much higher. More cases occur in the summer than in the winter. While C. jejuni is most likely transmitted through poultry, as a whole, infection from Campylobacter bacteria may occur from exposure to untreated milk, physical contact with animals, or contaminated water.

Incidences of illness from C. jejuni occur most often during infancy and young adulthood. Most commonly it manifests as a combination of bloody diarrhea, fever, and abdominal cramps. People with a compromised immune system are at risk for developing more serious conditions because C. jejuni has the ability to enter the bloodstream.

Doctors seeking to determine whether a patient has become infected with C. jejuni will most likely examine a stool sample for the characteristic presence of this bacterium. However, doctors may also use body tissues or bodily fluids to create a culture that will allow them to isolate the C. jejuni bacteria. Most patients recover from C. jejuni infection without treatment within a week. Due to the increased resistance of Campylobacter bacteria to antibiotics, doctors typically reserve their use for very ill patients or patients with a severely weakened immune system.

To prevent exposure to C. jejuni, doctors recommend practicing careful cooking practices. This includes thoroughly cooking all poultry and limiting direct contact with raw meat. Doctors further recommend regularly washing hands with soap after using the bathroom, cooking raw meats, handling trash, tending to the sick, or changing a diaper. Such practices have been demonstrated to greatly reduce the risk of exposure to C. jejuni and other bacterial illnesses.

Bibliography

Acheson, David, and Ban Mishu Allos. “Campylobacter jejuni Infections: Update on Emerging Issues and Trends.” Clinical Infectious Diseases, 32, no. 8 (2001): 1201–6.

Altekruse, Sean F., Norman J. Stern, et al. “Campylobacter jejuni—An Emerging Foodborne Pathogen.” Emerging Infectious Diseases, 5, no. 1 (1999): wwwnc.cdc.gov/eid/article/5/1/99-0104‗article. Accessed 29 Apr. 2019.

Butcher, James, and Alain Stintzi. Campylobacter jejuni: Methods and Protocols. Springer, 2016.

Butzler, J.P. “Campylobacter, From Obscurity to Celebrity.” Clinical Microbiology and Infection, 10, no. 10 (2004): 868–76.

“Campylobacter.” World Health Organization, www.who.int/news-room/fact-sheets/detail/campylobacter. Accessed 29 Apr. 2019.

Lydyard, Peter, Michael Cole, John Holton, et al. Case Studies in Infectious Disease: Campylobacter jejuni. Garland Sciences, 2009.

“Questions and Answers about Campylobacter.” Centers for Diseases Controls, 2 Oct. 2017, www.cdc.gov/campylobacter/faq.html. Accessed 29 Apr. 2019.

Sheppard, Samuel K. Campylobacter Ecology and Evolution. Caister Academic, 2014.