Rocky Mountain Spotted Fever

Scientists  have developed a genome-scale metabolic model or 'subway map' of key metabolic activities of the bacterium that causes Lyme disease. Using this map, they have successfully identified two compounds that selectively target routes only used by Lyme disease to infect a host. Scientists at Tufts University School of Medicine have developed a genome-scale metabolic model or "subway map" of key metabolic activities of the bacterium that causes Lyme disease. Using this map, they have successfully identified two compounds that selectively target routes only used by Lyme disease to infect a host. Their research was published October 19 in the journal mSystems. While neither medication is a viable treatment for Lyme because they have numerous side effects, the successful use of the computational "subway map" to predict drug targets and possible existing treatments demonstrates that it may be possible to develop micro-substances that only block Lyme disease while leaving other helpful bacteria untouched. Genome-scale metabolic models (GEMs) collect all known metabolic information on a biological system, including the genes, enzymes, metabolites, and other information. These models use big data and machine learning to help scientists understand molecular mechanisms, make predictions, and identify new processes that might be previously unknown and even counter-intuitive to known biological processes. Micro-Substances to Target Bacterium Currently, Lyme disease is treated with broad-spectrum antibiotics that kill the Lyme bacterium Borrelia burgdorferi, but simultaneously also kill a wide range of the other bacteria that inhabit a host's microbiome and perform many helpful functions. Some people with chronic Lyme symptoms or recurring Lyme disease take antibiotics for years, although it is against medical guidelines and there is no proof that it works. "Most of the antibiotics we still use are based on discoveries that are decades old, and antibiotic resistance is an increasing problem across many bacterial diseases," says Peter Gwynne, first author on the paper and research assistant professor of molecular biology and microbiology at Tufts University School of Medicine and the Tufts Lyme Disease Initiative. "There is a growing movement to find micro-substances that target a specific pathway in a single bacterium, rather than treating patients with broad spectrum antibiotics that wipe out the microbiome and cause antibiotic resistance." The two compounds identified using the "subway map" computational model are an anticancer drug with significant side effects that make it impractical to use in treating Lyme, and an asthma medication taken off the market because of its side effects. Both drugs identified by the model were tested in the lab and found to successfully kill Lyme bacteria -- and only Lyme -- in culture. "The Lyme bacterium is a great test case for narrow spectrum drugs because it is so limited in what it can do and so highly dependent upon its environment. This leaves it vulnerable in ways other bacteria are not," says Linden Hu, the Paul and Elaine Chervinsky Professor of Immunology, a professor of molecular biology and microbiology, and senior author on the study. Speeding Treatment Discovery Use of the computational model -- which Gwynne and collaborators developed during COVID when they couldn't work onsite in the lab -- has the potential to enable scientists to skip some painstaking basic science steps and lead to swifter testing and development of more targeted treatments. "We can now use this model to screen for similar compounds that don't have the same toxicity of the anticancer and asthma medications but could potentially stop the same or another part of the Lyme disease process," says Gwynne, a recent recipient of the Emerging Leader Award from the Bay Area Lyme Foundation. Gwynne and Hu are conducting other research to determine whether people with chronic Lyme symptoms are still infected or are suffering from an immune malfunction that creates chronic symptoms. "I can imagine a day when people take a targeted Lyme treatment for two weeks rather than a broad-spectrum antibiotic, are tested and determined to be clear of the infection, and then take drugs to tame their immune response if chronic symptoms persist," says Gwynne. Gwynne says similar computational "subway maps" can be developed for other bacteria with relatively small genomes, such as those that cause the sexually transmitted diseases Syphilis and Chlamydia, and Rickettsia, which causes Rocky Mountain Spotted Fever. Gwynne's team is looking at developing maps for some of these bacteria. Research reported in this article was supported by the Bay Area Lyme Foundation and by the National Institute of Allergy and Infectious Diseases at the National Institutes of Health under award R01AI122286. Co-authors include Kee-Lee Stocks, a Ph.D. student at Tufts Graduate School of Biomedical Sciences (GSBS); research assistant Aarya Pandit, E25, at GSBS; and former research assistant Elysse S. Karozichian, E23, at GSBS. Complete information on authors, funders, methodology, and conflicts of interest is available in the published paper.

A bacterium that causes a disease called scrub typhus -- a disease not previously reported in the United States -- has been detected in North Carolina, according to a new study. A bacterium that causes a disease called scrub typhus -- a disease not previously reported in the United States -- has been detected in North Carolina, according to a new study by researchers at North Carolina State University and UNC-Greensboro. The researchers stress that scrub typhus, which can cause fever, headache and body aches -- and can be fatal if left untreated by antibiotics -- has not yet been detected in animals or people in the state. The NC State researchers detected the bacterium -- the genus is Orientia in the family Rickettsiaceae -- at a high frequency while testing free living, larval (ready to bite) trombiculid mites, commonly called chiggers, in several different recreational parks in North Carolina. "We wanted to see if chiggers in the United States carried Orientia," said Loganathan Ponnusamy, an NC State principal research scholar in entomology and co-corresponding author of a paper that describes the research. "We haven't in the past had the diagnostic tools to test for this specific bacterium at the genus level." "We set a black tile on the ground in 10 different North Carolina state parks and picked up chiggers as they crossed the tile. Microbiome studies allowed us to characterize all the bacteria in the chiggers. One park showed a 90% positivity rate for the bacterium (nine out of 10 chiggers captured); another showed an 80% positivity rate (eight of 10 chiggers captured). Other parks showed positivity rates of just 10%." Trombiculid mites are only parasitic in their larval stage. They search for vertebrate hosts -- including humans -- to bite, Ponnusamy says. "Chiggers can spread bacteria to people or rodents when they bite but can also pass bacteria to future generations of mites through their eggs," he added. The researchers say that scrub typhus presents symptoms similar to those of Rocky Mountain spotted fever, a disease generally ascribed to tick bites. Scrub typhus is found more commonly in Asia and the Pacific, but in recent years has been detected in Africa and the Middle East. It is uncertain whether spread is caused by people or goods carrying chiggers from one place to another. "We don't know if this is a recent introduction into the state or if the bacterium has been here for years," said R. Michael Roe, William Neal Reynolds Distinguished Professor of Entomology at NC State and co-author of the paper. "We also don't know if the infected chiggers found in North Carolina actually will cause disease; this has to be determined in future work." "We also don't have information about whether the chigger infection rate is decreasing or increasing," said Kaiying Chen, a postdoctoral research scholar at NC State and lead author of the paper. The NC State and UNC-Greensboro researchers are resampling chiggers in the recreational park sites to see if the reported findings remain consistent. The paper appears in the journal Emerging Infectious Diseases. Other co-authors include Nicholas V. Travanty and Charles S. Apperson from North Carolina State University; Reuben Garshong and Gideon Wasserberg from the University of North Carolina Greensboro; and Dac Crossley from the Georgia Museum of Natural History. Funding was provided by a grant from the National Institutes of Health, National Institute of Allergy and Infectious Diseases (grant no. 1R03AI166406-01); a grant from the Southeast Center for Agricultural Health and Injury Prevention, and from the Department of the Army, U.S. Army Contracting Command, Aberdeen Proving Ground, Natick Contracting Division, Ft Detrick MD. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the position or the policy of the Government and no official endorsement should be inferred.

AUSTIN, Texas, May 9, 2023 /PRNewswire/ -- Today, Thrive Pet Healthcare, a leading veterinary service network with about 400 locations across the U.S., advised dog and cat owners about the household health risks when pets are not protected year-round from external parasites such as fleas and ticks. According to a Zoonoses Public Health study, pet owning households are at increased risk of finding ticks crawling on or attached to household members compared to households without pets. Continue Reading Thrive Pet Healthcare Advises Pet Owners About Household Health Risks When Pets Are Not Protected from Parasites Tweet this Many flea- and tick-borne illnesses that may affect dogs and cats can equally affect humans. Bites from ticks that are infected with Lyme disease or Rocky Mountain spotted fever can result in serious health conditions for pets and humans. Although less common, fleas can transmit infections and diseases to both pets and humans, including plague and murine typhus. "Parasites are not picky. Fleas and ticks will bite humans just as easily as they will bite our pets, potentially putting everyone in the household at risk for illness or disease when dogs and cats are not on a year-round preventative regimen," said Thrive Pet Healthcare Vice President of Medical Excellence and Education Dr. Kelly Cairns. "Veterinarian-prescribed flea and tick preventatives are the best way to protect your pet from harmful and sometimes deadly parasite-related illnesses." Dogs and cats can also be infected with heartworm disease, a potentially fatal illness carried by mosquitoes. Heartworms are spread by mosquito bites and can grow up to a foot long, living in the heart and lungs of the pet. Symptoms are often unnoticeable until irreversible damage has been done. "Once your dog or cat is infected with heartworm disease, treatment can be very costly, have possible side effects, and is not always successful," said Dr. Cairns. "Ultimately, the risks of infection and high cost of treatment outweighs the cost of prevention." Some of the common myths about external parasite exposure in pets include: Myth: Indoor pets are not at risk. Many parasites are mobile and can easily gain access to your home through an open door or window or be carried in by people or other pets. Myth: Parasites are not a problem for pets during the winter. Climates can be unpredictable. While infection rates decrease in cold weather, the warm climate inside most homes during the winter months can be an attractive breeding ground for parasites. Also, pet owners who travel with their pets could potentially expose them to parasites. Myth: Only certain geographic regions of the country are prone to parasites. Heartworm is found within mosquitoes in all 50 states. Anywhere there is soil, grass, moisture or vegetation, there is a potential for external parasites. To encourage pet owners to invest in the long-term health and well-being of their pets, through May 31, select Thrive Pet Healthcare primary care hospitals will offer a 10% discount on 6- and 12-month supplies of Simparica, Simparica TRIO, Revolution PLUS, and the annual injectable ProHeart 12.Thrive Plus™ members will receive an additional 10% off. To learn more about this parasite prevention promotion, common pet parasites and prevention options, visit . Thrive Plus membership makes it easier and more cost-effective for pets to receive frequent, high-quality care throughout their life. Starting at $14.95 per month, members receive unlimited free exams, unlimited $5 nail trims, and 10% off primary care services. About Thrive Pet Healthcare: Thrive Pet Healthcare is a leading veterinary service network that uniquely delivers a continuum of care to pet families and services to veterinary hospitals. With an industry-first membership program and about 400 acute, primary, and specialty providers, Thrive Pet Healthcare offers personalized, accessible care through every stage of a pet's life and health. The veterinarian-founded organization provides premier benefits for practice staff while elevating privately held veterinary hospitals with innovative service and technology solutions. By focusing on the needs and aspirations of veterinary care providers, Thrive Pet Healthcare is supporting the well-being of the industry and raising the national bar for veterinary excellence. To learn more about Thrive Pet Healthcare, please visit . SOURCE Thrive Pet Healthcare