- Author: Elizabeth Grafton-Cardwell
- Author: Barbara Alonso
Candidatus liberibacter asiaticus (CLas), the bacterium thought to cause huanglongbing (HLB), cannot be grown using traditional laboratory methods in petri dishes on agar and nutrients. The inability to culture the HLB bacterium, CLas, in the lab makes it very difficult to develop a cure for the disease.
Dr. Kranthi Mandadi's research team has developed a novel technique for laboratory cultivation of CLas, using so-called hairy roots, which are plant tissues that mimic a microbe's natural environment. Hairy root cultures support CLas bacterial growth and these cultures can be used to screen antimicrobials to find compounds that control and/or suppress CLas. Once discovered, antimicrobials could be applied to citrus trees to prevent establishment or reduce the impact of HLB.
How does it work? Visit the Research Snapshot page to learn more: https://ucanr.edu/sites/scienceforcitrushealth/Research_Snapshots/Mandadi/
About Research Snapshots
- Author: Ben Faber
The recent Huanglongbing Conference in Orlando, FL was chock full of people and ideas. Some of the ideas were still in the fermentation state and some were in practice on farm. One of the ideas that has been put into practice is the use of antibiotics, such as tetracycline and streptomycin to control the bacteria, Candidatus Liberibacter asiaticus (CLas), which causes HLB or citrus greening. This is somewhat disturbing since the rise of antibiotic resistant bacteria which affects humans has been affected by the wide-spread use in animal production facilities. This has led to some food companies to discontinue the sourcing of meat from animals treated with antibiotics for non-health reasons.
Antibiotics are molecules that limit the growth or reproduction of bacteria. They come under the umbrella of bactericides which include antibiotics, but also disinfectants like bleach and copper sulfate and antiseptics like peroxide, iodine and alcohol. Antibiotics when properly used will not harm human tissue and can be derived from bacteria, fungi and synthetically and will often act directly on the bacteria that is causing the disease. Some of these molecules can be simple assemblages of amino acids called peptides (etymology “to digest”) or strings of peptides called proteins. And sometimes they do not work on the bacteria itself, but on steps that lead up to processes that make the bacteria effective at its job.
At the conference, several papers were presented that illustrated this type of antibiotic effect. One of these papers was presented by Robert Shatters for his group. The peptide they are looking at actually inhibits the movement of the CLas bacteria in the gut of the insect, reducing or possibly preventing the transmission of the bacteria to the host plant – citrus.
The following is an abstract from the paper.
Identification of gut epithelium binding peptides that reduce systemic movement of ‘Candidatus' Liberibacter asiaticus within the Asian citrus psyllid vector
Robert G. Shatters, Jr1, Dov Borovsky1, El-Desouky Ammar1, David Hall1, Kasie Sturgeon2, EricaRose Warwick2, Marc Giulianotti3, Radleigh G Santos3 and Clemencia Pinilla4
1USDA, ARS, USHRL, Fort Pierce, FL USA; 2University of Florida, CREC, Lake Alfred, FL USA; 3Torrey Pines Institute for Molecular Studies, Port St Lucie, FL USA; Torrey Pines Institute for Molecular Studies, San Diego, CA USA.
Non-Technical summary: The Asian citrus psyllid is the only known vector of the bacteriumthat causes citrus greening disease. This insect acquires CLas from an infected citrus tree while feeding as a nymph. Transmission to uninfected trees occurs when infected adults emerge and fly off and feed on uninfected trees. Our current understanding of the CLas-psyllid interaction suggests that adults become competent for transmission only after the bacterium moves from the insect gut into the hemolymph and then to the salivary glands. We have identified a set of small peptides that when fed to the psyllid, bind the gut membranes and reduce the ability of the citrus greening bacterium to move from the gut to the salivary glands. These peptides are now being tested to determine if they can be used as an effective way of reducing the spread of citrus greening disease.
This and other paper abstracts will soon be available at: http://irchlb.org/files/33373ab0-7df3-4117-9.pdf
photo: HLB Symptoms
The UC Davis School of Veterinary Medicine and the Farm Foundation recently brought together the state's livestock and poultry producers, their feed suppliers, veterinarians and UC Agriculture and Natural Resources Cooperative Extension specialists to discuss a changing landscape of antibiotic drug use in food animals.
Regional industry leaders were among the speakers at the workshop, held at the UC Davis School of Veterinary Medicine. They included Chuck Ahlem of Hilmar Farms, Bill Mattos of the California Poultry Federation, Dr. Stuart Hall of Feedlot Health Management Services, and Dr. Marit Arana of A.L. Gilbert Company. Dr. Craig Lewis of the U.S. FDA and Dr. Kathe Bjork of the USDA were also present to provide an overview of the complex public health issue of antibiotic resistance, the new guidelines and available to answer questions from the nearly 70 participants.
A welcome by Sheldon Jones with the Farm Foundation, Dean Michael Lairmore with the UC Davis School of Veterinary Medicine and meeting facilitator Kevin Ochsner kicked off the morning. In his address, Lairmore emphasized the important role the school plays in reducing antibiotic resistance and working with its partners to build consumer trust in a safe food supply.
“Our school's role is critical in training the next generation of veterinarians on this issue and providing evidence-based science on the ethical, proper use of antimicrobials in food animals,” said Lairmore said. “Our ability to bring people together around important topics like this and our research and public service programs place UC Davis veterinary scientists at the forefront of this issue."
How to best move forward with the new guidelines was a central theme among featured speakers representing producers, veterinarians and the feed industry.
Chuck Ahlem with Hilmar Farms, the world's largest single site cheese and whey manufacturer that sells products in more than 40 countries, said he believes the changes will help strengthen the relationship between producers and veterinarians. Bill Mattos with the California Poultry Federation emphasized how important the issue is to the state's poultry industry, citing California as producing more chickens this year without antibiotics than any other state.
Afternoon break-out sessions allowed participants to discuss the management challenges and impacts ahead due to the changes, and provided state and federal agency staff, veterinary medicine faculty and UC Agriculture and Natural Resources Cooperative Extension specialists insight into the changes needed to meet the requirements.
The Davis workshop was one of 12 that the Farm Foundation is hosting across the country. A report based on comments gathered at the workshop will be presented at a national summit to be convened by the Farm Foundation later in 2015 to advance the conversation on the industry's adaptation to the changing landscape of antibiotic drug use.
Examples of the UC Davis School of Veterinary Medicine's programs to help prevent unwanted drugs from entering the food supply include the resources of the federally funded Food Animal Residue Avoidance Databank, research and vaccine development through the Center for Food Animal Health, surveillance and diagnostic testing at the California Animal Health and Food Safety Laboratory System and international outreach conducted by the Western Institute for Food Safety and Security. (Read more about these programs and the critical role veterinarians play in food safety and public health in Dean Lairmore's recent op-ed in the Sacramento Bee.)
Author: Monique Garcia Gunther
- Author: John M Harper
The California Beef Cattle Improvement Association (CBCIA) & Merck are sponsoring Cattlemen's Day at the Cow Palace on October 19, 2013. Topics and speakers include:
- Beef Industry Sustainability - Jude Capper, PhD.
- Issues with Antibiotic Use in Beef Cattle - Eric Moore, DVM Merck
- Global Supply & Demand Issues - Andy Gottschalk, PhD., Hedgers Edge
The attached pdf file below has registration and cost information. For questions contact: Abbie Nelson at (916) 804-4990.
2013 Cow Palace
- Author: Kathy Keatley Garvey
“It’s not only supporting the local beekeepers in our flagging economy, but imported honey can be problematic,” said bee breeder-geneticist Susan Cobey. “When you buy imported honey, you don’t always know what you’re getting. The ‘honey’ could be a mixture of corn syrup and water, or blends of honeylike products. It could contain pesticides or antibiotics. It could be mislabeled or from a different country or floral source than indicated on the label.”
“Also,” Cobey said, “you don’t know how it’s been treated after bottling. Heated honey, for example, breaks down the enzymes and causes the honey to lose flavor.”
Some unethical honey importers illegally mark their products or route them through other countries to avoid paying tariffs or to avoid public health safeguards.
A recent investigative report published in the Seattle Post-Intelligencer found that “big shipments of contaminated honey from China are frequently laundered in other countries — an illegal practice called ‘transshipping’ — in order to avoid U.S. import fees, protective tariffs or taxes imposed on foreign products that intentionally undercut domestic prices.”
“In a series of shipments in the past year, tons of honey produced in China passed through the ports of Tacoma and Long Beach, Calif., after being fraudulently marked as a tariff-free product of Russia,” according to the investigative report.
Investigative reporter Andrew Schneider found that laundered Chinese honey is often shipped into the United States from Australia, Cambodia, Hong Kong, India, Indonesia, Malaysia, Mongolia, Russia, Singapore, South Korea, Taiwan, Thailand and Vietnam, then relabeled as coming from there instead of China.
The news is not new, and neither are the "stings." The Associated Press recently related that "a Chinese business agent for several honey import companies was arrested in Los Angeles Tuesday (Feb. 15) on federal charges filed in Chicago for allegedly conspiring to illegally import Chinese-origin honey that was falsely identified to avoid U.S. anti-dumping duties. The charges resulted from an investigation conducted by U.S. Immigration and Customs Enforcement's (ICE) Homeland Security Investigations (HSI)."
The business agent was accused of "conspiring between 2004 and 2006 to illegally import Chinese-origin honey that was falsely identified as originating in South Korea, Taiwan and Thailand to avoid U.S. antidumping duties."
The fact is, the United States doesn't produce enough honey to supply the demand. And due to the lower price, U.S. consumers may reach for the imported honey instead of the locally produced honey.
"Currently U.S. honey producers can supply about half the honey consumed in the U.S. annually,” said Extension apiculturist Eric Mussen of the UC Davis Department of Entomology, who writes and publishes the bimonthly newsletter, from the UC Apiaries. “We have to import substantial amounts of honey. If the foreign sources lower their prices far enough, our honey producers can't sell their honey at competitive, above cost-of-production prices. To maintain our market, we cannot allow low-cost honey to slip past the tariffs now in place to keep domestic sales moving."
The UC Davis bee experts expressed concern that antibiotics banned in the United States are used to treat diseases in bee hives in other countries, and then the honey is shipped here. For example, beekeepers in China sometimes use an animal antibiotic, chloramphenicol, in their hives. When humans ingest the honey, it can cause serious illness and sometimes death.
Show me the money? Or show me the honey?