Pathogen that causes disease in cattle also associated with Crohn’s disease: Mycobacterium avium paratuberculosis

For File 2008

Contact: Jim Sliwa
jsliwa@asmusa.org
202-942-9297
American Society for Microbiology

Research urgently needed to evaluate potential risks to humans

People with Crohn’s disease (CD) are seven-fold more likely to have in their gut tissues the bacterium that causes a digestive-tract disease in cattle called Johne’s disease. The role this bacterium may or may not play in causing CD is a top research priority, according to a new report released by the American Academy of Microbiology. The reports points out that the cause of CD is unknown, and the possible role of this bacterium—which could conceivably be passed up the food chain to people—has received too little attention from the research community.

The report, Mycobacterium avium paratuberculosis: Incidental Human Pathogen or Public Health Threat?, summarizes conclusions and recommendations from a colloquium convened by the American Academy of Microbiology in June 2007 that brought together experts in microbiology, medicine, veterinary pathology, epidemiology, infectious diseases, and food safety. Colloquium participants described the state of knowledge about the relationship between Mycobacterium avium subspecies paratuberculosis (MAP) and CD and developed a research agenda to move the field forward.

Scientists largely agree that multiple factors cause CD, including an environmental stimulus, a genetic propensity, and an overactive inflammatory and immune system triggered by an unknown event. There is mounting evidence that the unknown trigger may be infectious in origin, with several bacteria currently under consideration. “This complicated network of causation has confounded efforts to understand CD, says Carol Nacy, Ph.D., CEO of Sequella, Inc., who chaired the colloquium and is the report’s co-author. “MAP may be one of the causes of CD,” Nacy adds, “since, among other things, multiple studies identified the pathogen in tissues of CD patients. Treating some of these patients with antibiotics that target Mycobacteria provided relief from symptoms.”

Johne’s disease is a severe and fatal bacterial infection that strikes cattle, sheep, and other livestock. MAP has long been identified as the cause of Johne’s disease. Despite efforts to limit the spread of MAP, roughly 68% of cattle herds in this country are infected, meaning one or more animals in the herd carry the bacterium and may develop Johne’s disease or spread the infection to other animals. MAP has been found in some dairy products—milk and cheese—and beef on supermarket shelves.

The critical steps for research now, according to the report, are to determine whether humans are exposed and infected with MAP by eating infected meat and dairy products and whether MAP causes or incites CD or whether it is only incidentally present in those afflicted with the disease. The prospect that MAP could play a role in the incitement or development of CD is a sobering one, and, once the situation becomes clearer through research, there could be important changes in store for agriculture, food safety, and public health. It is in the best interest of the public that the possible connection between MAP and CD be explored exhaustively, according to the report.

The research agenda, however, is seriously hampered by the lack of reliable methods for isolating and indentifying MAP and for diagnosing people with MAP infection. Public health laboratories and U.S. Centers for Disease Control and Prevention laboratories have made it clear they cannot grow MAP in the laboratory—an inability that hinders diagnosis and screening. The report recommends establishment of a task force to develop a specific road map for improved methods for MAP detection and diagnosis.

 

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A full copy of the report and further recommendations can be found on the Academy website at www.asm.org/colloquia/ext.

The American Academy of Microbiology is the honorific leadership group of the American Society of Microbiology. The mission of the Academy is to recognize scientific excellence, as well as foster knowledge and understanding in the microbiological sciences. For more information about the American Society for Microbiology, contact Barbara Hyde at 202-942-9206 or visit www.asm.org.

Local Outbreak Highlights New Source of Infection – Tattoo Ink

In Rochester, a Tale of Tainted Tattoos

September 06, 2012

The New England Journal of Medicine ©2012

If you end up with a rash on a new tattoo, you should probably think twice before brushing it off as an allergic reaction or a normal part of the healing process.

A recent study in the New England Journal of Medicine documents 19 cases in the Rochester, N.Y., area – the largest ever reported – of tattoos infected with a type of bacteria often found in tap water. Evidence points to a premixed gray ink, the type used in currently popular portrait or photography tattoos, as the culprit.

Mary Gail Mercurio, M.D., a dermatologist at the University of Rochester Medical Center, saw 18 of the 19 individuals infected. She says some people with tattoos have allergies or experience other dermatologic complications, but it’s not common. “I’ve seen people with tattoo-related issues over the years, but never this many: The volume of patients impacted makes this a real public health concern.

“Patients and doctors need to have a certain level of suspicion when they see a rash developing in a tattoo. Many of the patients I saw thought their skin was just irritated and the issue would go away during the healing process. In actuality, they had an infection that needed to be treated with an antibiotic; it wasn’t going to go away easily on its own.”

The investigation of the outbreak, which was also highlighted in the U.S. Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report, started with a previously healthy 20-year-old man who had a history of multiple tattoos in the past without any issues. In October 2011, he received a new tattoo on his arm and subsequently developed a persistent, inflamed rash in that area. After learning of his case, the Monroe County Department of Public Health explored the issue and identified 18 other individuals who developed similar rashes after getting tattoos at the same parlor, from the same artist.

Tests conducted at the Medical Center revealed that a specific type of bacteria, Mycobacterium chelonae, was in the patients’ skin and led to the red, itchy bumps in their tattoos. Further testing found that a premixed gray ink, which the local artist had bought from a manufacturer in Arizona, contained the same bacteria and likely transmitted it to the skin.

Robert F. Betts, M.D., a long-time infectious disease expert at the Medical Center who treated almost all of the patients, confirmed that the infection was only in the areas tattooed with the gray ink. Also called gray wash, it is used to achieve shading and a three-dimensional quality in tattoos.

According to the local tattoo artist, the manufacturer diluted black ink with distilled water to create a gray color. “This organism, M. chelonae, is found in some water supplies,” said Betts. “What probably happened is that the water used to dilute the ink introduced the bacteria into it and the trauma associated with getting the tattoo compromised the circulation to that area of the skin, allowing the organism to enter into the skin and grow.”

Betts says that this species of bacteria grows best at around 86 °F, a little bit below normal body temperature, which is approximately 98.6 °F. The skin is cooler than the rest of the body, which may explain why the bacteria flourished in the tattooed areas.

Following the investigation, the CDC issued a nationwide alert about the outbreak and the manufacturer voluntarily recalled the ink. Betts evaluated and treated 16 of the 19 patients with standard antibiotics – azithromycin and doxycycline – and everyone improved, although at different speeds based on the extent of the infection.

Both Betts and Mercurio believe that tattoo-associated infections are probably more common than we think and that physicians should think about infectious causes if patients aren’t responding to topical or other dermatologic treatments that would typically dispel any sort of allergic reaction to a tattoo.

In addition to Betts and Mercurio, Glynis A. Scott, M.D., Matthew A. Lewis, M.D., and Mark H. Goldgeier, M.D., from the Medical Center contributed to the research. Byron S. Kennedy, M.D., Ph.D., from the Monroe County Department of Public Health was the lead author of the New England Journal of Medicine study. Physicians and scientists from the New York State Department of Health, the CDC and the FDA participated in the research as well.

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