CSI meets agriculture: WSDA's pathology lab leads next-gen pest detection

Telissa Wilson
WSDA Plant Pathology and Molecular Diagnostics Lab

Northern giant hornets in vials awaiting testing.

Did you know WSDA’s Plant Pathology & Molecular Diagnostics Lab (PPMDL) uses cutting-edge molecular tools to detect unwanted pests and pathogens? Our PPMDL lab runs tests and uses equipment that many of you have probably seen on CSI or heard about in recent years due to COVID-19. PPMDL tests a wide variety of materials and runs an even wider array of tests, all with the shared goal of finding pests early and preventing them from being established. 

Like a forensic lab, PPMDL maintains highly trained staff, follows strict quality control measures, contributes to research and development of detection tools, and often collaborates with a wide array of organizations. Below is a snapshot of some recent work that showcases PPMDL projects straight out of a CSI episode.

Haplotyping invasive weeds

Sometimes it can be difficult to differentiate between species - whether it is a weedy plant or an invasive insect. Is this species a crime suspect or victim? Haplotyping compares genetic information among different samples to better understand how closely the samples are related - whether it is a native species or a wolf in sheep's clothing. 

Enter suspect number 1:  the highly invasive, aquatic grass Phragmites australis. Because the different subspecies of Phragmites grass are so difficult to tell apart visually, their haplotypes are used to assign them a native or non-native status, which is needed to guide treatment plans. 

For this work, PPMDL staff first extract DNA from submitted leaf samples. Then staff use a process called Polymerase Chain Reaction (PCR) to copy the DNA of very specific regions- regions that have been empirically determined to be good markers for haplotyping in a given species. The last step requires sequencing of the resulting PCR product so the sample haplotypes can be compared against a database of known haplotypes. In the case of Phragmites australis, haplotyping has allowed wetland managers across multiple agencies to preserve their native grass stands and only destroy the invaders. In our CSI analogy, you could say that haplotyping ensures that only the true perpetrator - Phragmites australis – does time for the crime. 

Forensic swabbing for trace DNA

Forensic swabbing can detect
where a pest has been. 

One of the biggest challenges in preventing the establishment of an invasive species is detecting the pest very soon after it is introduced. Sometimes WSDA receives reports of suspected invasive species, but the specimen was not collected and a determination cannot be made if a photo was provided. But what if you didn’t need a specimen – or even a photo – to confirm that a pest had been at a particular location?

You have probably seen shows where crime scenes are swabbed for the presence of DNA left behind on surfaces. These swabs are then shipped to a forensic lab, where scientists extract DNA and perform various molecular tests to analyze the sample. Even though forensic scientists have been utilizing trace DNA for decades to confirm presence at a crime scene, using trace DNA to detect agricultural pests is in its infancy. 

eDNA

Our pathology lab is changing that. PPMDL has been using swabs to collect environmental DNA (eDNA) left behind by two invasive insects – the spotted lantern fly (SLF) and the northern giant hornet (NGH). Once validated, these assays can confirm the presence of SLF and NGH at sites where a physical sample cannot be collected and early on before pest density is high enough to use alternative survey methods.

Pathogen detection

An exponential curve corresponds
to positive detection in a qPCR test

When someone passes away and the cause of death is unknown, forensic scientists may test for the presence of certain pathogens. PPMDL uses these same molecular methods to test for plant pathogens that threaten our state’s numerous agricultural resources. Quantitative Polymerase Chain Reaction (qPCR) is a highly specific and sensitive method that PPMDL routinely uses. In fact, PPMDL ran over 2,500 qPCR tests for plant pathogens alone in 2022! These test results help clear exports for trade, certify growing areas free of pests, and help prevent the establishment of high-risk pests through early detection surveys. 

DNA analysis of fecal samples

PPMDL conducts fecal analysis
to determine hornets' diet

One of the strangest-sounding projects that PPMDL has taken on recently involved extracting DNA from giant hornet fecal pellets to discover what the larvae were being fed here in Washington. To do this, PPMDL scraped fecal pellets from inside combs of the four nests that the WSDA Pest Program eradicated. They then extracted the total DNA, which theoretically contains traces of DNA from each organism that was fed to the larval hornet. Next, PPMDL used PCR to amplify a universal genetic segment (called the COI barcoding region) found in all insects and animals. Using advanced molecular magic (aka indexed metabarcoding) PPMDL was able to obtain thousands of genetic sequences that could be correlated to specific prey species. This work allowed researchers to see what NGH has been eating in Whatcom County and how that contrasts with diets in its native habitats. 

What did we find? Well, many folks have heard that northern giant hornets are a major threat to honey bees, but many other pollinators were also on their menu. PPMDL also found that bald-faced hornets made up a majority of the sequences obtained across all nests. Check out this "Wings menu" our Communications folks put together showing some of what they were eating. 

Learn more: 

https://www.researchgate.net/publication/375683005_Cryptostroma_corticale_the_causal_agent_of_sooty_bark_disease_of_maple_appears_widespread_in_western_Washington_State_USA (most recent publication)

https://digitalcommons.linfield.edu/crisscross/111/  (Podcast about early NGH work)

https://www.frontiersin.org/articles/10.3389/finsc.2023.1134781/full (Paper on fecal analysis)

https://www.youtube.com/watch?v=iLFBFrGMHno Bloedel WSU/WSDA

Uncovering the mystery of canine respiratory disease in Washington

Dr. Amber Itle Washington State Veterinarian
Dr. Minden Buswell Reserve Veterinary Corp Coordinator

I just got back from a trip to the east coast to visit my family and we all came home with a ‘cold’.  During the holidays, we all come indoors, congregate (under sometimes stressful conditions) and share holiday cheer and illness alike. Respiratory disease isn’t uncommon in humans, and it certainly isn’t uncommon in our furry friends either, especially this time of year. My sister is a small animal practitioner and the first thing she asked me over Thanksgiving was, “what is going on with this atypical respiratory illness in dogs?”  She wasn’t sure she had seen anything unusual but has heard that other veterinarians are seeing an uptick in a more harsh or prolonged respiratory disease She wanted to know how concerned she should be. 

At the Washington State Veterinarian’s office, we require veterinarians to report new, emerging diseases or diseases with high morbidity and mortality so we can monitor disease trends across the state. Each year, WSDA gets reports of isolated respiratory outbreaks in localized communities or counties, in boarding facilities and kennels. However, the headlines and social media have us all concerned about the claim that there is a mysterious canine respiratory disease sweeping the nation. Certainly, after COVID-19, we are all acutely aware that global pandemics with new, emerging diseases can happen in humans and animals alike and we shouldn’t ignore indicators that suggest that something new and novel could be impacting our canine population. Fortunately, the current illness of concern has a high recovery rate with very few mortalities reported and there is no indication of a public health risk. 

As the Washington State Veterinarian, I want to provide full transparency about what we know, what we need to understand more and what we can do in the meantime.

What do we know about canine respiratory disease?

Canine infectious respiratory disease complex (CIRDC), sometimes called “kennel cough” has been characterized for decades. CIRDC is a highly contagious multifactorial disease and is often the result of concurrent infections with viral and bacterial agents. Viruses are common in dogs (canine adenovirus 2, canine distemper virus, canine herpesvirus 1, canine influenza virus (subtypes H3N8 and H3N2), canine respiratory coronavirus, and canine parainfluenza virus) but sometimes the syndrome can be complicated by secondary bacterial infections (Bordetella bronchiseptica, Streptococcus zooepidemicus, Mycoplasma sp.) resulting in pneumonia.

What are the clinical signs of CIRDC?

CIRDC is characterized by acute or chronic inflammation of the trachea and bronchial airways resulting in clinical signs such as harsh, dry coughing fits, retching and gagging and possible partial anorexia. Some dogs may develop progressing pneumonia. Dogs with pneumonia present with more severe clinical signs such as lethargy, inappetence (lack of appetite), fever, nasal discharge, and respiratory distress at rest. This would be considered typical of what we would expect to see.  

Is a chronic cough a sign of new or atypical disease? 

Cough is a clinical sign that can be triggered by infection, be it bacterial or viral, and often persists even after the infection is over due to inflammation in the airway.  Even after treatment, a cough can persist for weeks even after the virus or bacterial infection has been cleared. Cough can also be caused by other underlying conditions such as allergies, heartworm infection, heart failure, fungal infections and so on.  It is important to work with your veterinarian to rule out other causes. Regular visits and examinations by a veterinarian can help identify individual risk factors especially in older animals. 

What are the risk factors associated with developing the atypical respiratory disease?   

Risk factors for all canine respiratory diseases include 1) elderly dogs and puppies due to age related immunosuppression  2) unvaccinated dogs or dogs that aren’t up to date on vaccines  3) dogs in kennels, doggie daycares or boarding facilities   4) dogs that frequently congregate with other dogs with unknown vaccination or travel history 5) brachiocephalic breeds (dogs with shortened skull bones, giving the face and nose a pushed in appearance)  6) stress (travel, boarding, etc.)

How do I know if my dog has the atypical or mystery respiratory disease?

It is really important to see your veterinarian and pursue diagnostics as early as possible. There are several respiratory diagnostic tests available. However, timing and type of sampling is key to be able to isolate the microorganism(s) responsible for the illness. Some tests, like PCR,  only detect viral particles early in the disease process. That means that if you wait too long to do diagnostics, you may get false negative results or that the dog is no longer shedding the organism. 

If a secondary bacterial infection is suspected, then doing a culture prior to administering antibiotics is key to identifying the infectious agent and determining the right antibiotic that the organism is susceptible to. This improves treatment outcomes and prevents the risk of creating superbugs that no longer respond to antibiotics.  

What does it mean if my dog is not responding to treatment?

If your dog is not responding to antibiotics or has a prolonged disease syndrome, it may be an atypical case. However, keep in mind that not all dogs with respiratory disease need antibiotics. Just like COVID-19 or a cold in humans, viral respiratory illness cannot be treated with antimicrobials and your veterinarian may prescribe cough suppressants and anti-inflammatories instead. When we talk about dogs not being responsive to normal antimicrobial therapy, that may be because viruses don’t respond to antibiotics and clinical signs like a cough, can take weeks to resolve. Dogs that don’t respond to therapy and succumb to disease are a real concern. At this point in time, reports indicate low mortality due to this illness of concern. However, any dog that dies should be submitted to a diagnostic laboratory, such as the Washington Animal Disease Diagnostic Laboratory at Washington State University for a necropsy (animal autopsy) to determine the cause of death.

How do I know if my dog has a common form of CIRDC rather than something new? 

As we try to untangle whether we are dealing with a new or atypical strain of this canine illness, we are asking veterinarians to collect more data on dogs with 1) chronic mild-moderate tracheobronchitis with a prolonged duration (6-8 weeks or longer) that is minimally or not responsive to antibiotics, 2) Chronic pneumonia that is minimally or not responsive to antibiotics, or 3) acute pneumonia that rapidly becomes severe and often leads to death in as little as 24-36 hours. Veterinarians should report cases here: - WSDA Reportable Animal Disease Form and select “Unexplained increase in dead or diseased animals.”

Collecting this data will help us develop a case definition so we can better track trends over time.  If we are dealing with a new or novel strain, we would expect the canine population to have no or little resistance to the illness and we could expect to see widespread outbreaks of disease through our canine populations.  We might also expect to see higher reports of mortality in vulnerable, immunocompromised populations. 

How many reports of atypical respiratory disease has the WSDA received?

Since August 2023, a total of 16 reports from veterinarians have been submitted to the Washington State Department of Agriculture concerning atypical Canine Infectious Respiratory Disease Complex (CIRDC).  Of those 16 reports, two cases have met what WA considers an atypical CIRDC case. The two confirmed cases are recovering. WSDA is still collecting more information on the other 14 reports to ensure we provide accurate information.

Are the cases regionally distributed?

At this time, half of the cases reported in the state are in King County, which may be consistent with urban population distribution. We did have an outbreak reported in a single animal rescue in Spokane County.  Otherwise, we have not been able to link cases to each other.

County	Number of Reports
Clark	1
Island	2
King	7
Pierce	1
Skamania	1
Snohomish	1
Spokane	3

Are laboratories seeing an uptick in cases?

WSDA works very closely with Washington Animal Disease Diagnostic Laboratory at Washington State University (WSU-WADDL) to be sure we are tracking submissions and diagnostics. At this time, WSU WADDL has not reported an uptick in case submissions to the laboratory.  Case reports have identified various causes with no linking cause between cases. It is important to remember that there are many underlying causes of canine respiratory disease. We are continuing to encourage diagnostics to help us better understand trends. 

Have dogs been tested for SARS-COV2 (COVID 19)?

Several laboratories across the United States are working diligently to try to isolate any new pathogen that may be implicated or any correlation with positive COVID 19 households. Although dogs can be susceptible to SARS COV 2, experts reported that so far, all the cases submitted have been negative.

What can I do in the meantime?

1.     1.       Maintain a veterinary-client-patient relationship with annual visits to your veterinarian
2.       Contact you veterinarian immediately if your dog is showing signs of illness
3.       Make sure your pet is fully vaccinated and booster your dog for all canine respiratory diseases                annually
4.       Avoid congregations of dogs, dog parks, boarding facilities, doggie daycare or kennels
5.       Stay away from sick animals or animals with unknown travel or vaccination history
6.       If your dog does get sick, expect laboratory testing to inform best treatment outcomes

In Washington state, we care about our companion animals. Washingtonians have big hearts, compassion for animals and have opened their homes to thousands of rescue dogs in recent years from all over the world. If you have rescued a dog in recent years, please be sure they are up to date on ALL vaccines, in addition to rabies that is required for import. Check your documentation and work with your veterinarian on the best vaccination regimen to protect your dog.  You may think your dog is fully vaccinated or had all the boosters needed, but they may in fact be under vaccinated and extremely vulnerable to disease. Treatment and diagnostics for respiratory disease can be very costly.   We all know that “prevention is better than a cure.” 

If you have any questions, contact WSDA Animal Health Program at (360) 902-1878 or ahealth@agr.wa.gov.

Additional resources

H5N1 Avian Influenza in a Dog: Ontario, Canada

Canine Respiratory Illness Q&A: Free Webinar (November 30) | Worms & Germs Blog (wormsandgermsblog.com)

 

The Brussels sprout: Washington's winter gem

 Kim Vaughn
Communications

During the reign of the ancient Roman empire, athletes devoured Brussels sprouts because they were seen as symbols of endurance and stability. Because Brussels sprouts became so popular in 13th century Belgium, these little veggies were named after the country's capital, Brussels.

In the colder months, this hearty and nutritious green vegetable takes the stage. This blog will explore the world of growing Brussels sprouts, and creative ways to prepare this nutritious superfood for your holiday meals. 

Growing Brussels sprouts in Washington state

Brussels sprouts can be finicky to grow. They do best in cool weather and are usually planted in mid-summer for a bountiful fall harvest. To determine the optimum planting time in your region, count backwards about 4 months from your expected first frost. Plant in a location where they will get at least 6 hours of direct sun in a rich, well-drained soil with a pH between 6.0‐7.5.

Sow seeds about ½ inch deep 2-3 inches apart. When the plants reach about 6 inches tall, thin rows to be at least 12 inches apart. 

Water 1-1 ½ inches a week and add mulch to keep the soil cool during the hot summer. Be sure not to overwater! Because the plant height reaches 2-3 feet, they may require staking. Use a 10-20-10 fertilizer. Too much nitrogen will result in a lot of leafy growth and not enough sprouts.  

Sprouts mature from the bottom of the stalk upwards. Harvest sprouts from the bottom when they reach about 1 inch in diameter. To encourage the sprouts to mature faster, cut off the top leaves 3 to 4 weeks before harvest. Harvest the entire stalk after the first moderate frost by removing the leaves and storing them unwashed, and hanging upside down in a cool, dry area for up to a month. 

As with any Brassica, aphids, cabbage worms, and many other pests can damage your plant so it’s important to keep your eye on them. Remove any fallen plant debris to prevent mildew. Try companion-planting thyme, or place banana and orange peels around the plants, as a pest deterrent. A mild solution of dish soap and water can help to remove pests. You can get more tips on protecting Brassicas in our Broccoli blog. 

Varieties of brussels sprouts

In Washington state, Brussels sprouts are usually available from October through March, making them an ideal choice for your holiday meals. Favorite varieties include:

• Jade Cross
  These small, bright green sprouts are well-suited for cooler climates and boast a mildly sweet, nutty flavor.
• Long Island Improved
  This classic variety produces medium-sized sprouts that are tender and sweet when cooked.
• Rubine
  With a deep red hue, this variety adds a striking visual element to any dish while offering a slightly milder flavor.
• Diablo
  Known for its vivid, dark purple sprouts. 

There are more ways to prepare Brussels sprouts for your holiday meals than just steaming them. Try these delicious options:

• Roasted Brussels sprouts
  Seasoned with olive oil, garlic, and a touch of balsamic vinegar.
• Crispy Brussels sprout chips
  Thinly sliced and lightly fried, a nutritious alternative to traditional potato chips.
• Braised Brussels sprouts
  Slow-cooked in broth or wine, until tender. Often served with complementary ingredients like bacon or pancetta.
• Brussels sprouts in salads
  Add shaved Brussels sprouts in your next salad to provide a crisp, refreshing bite.

Nutritional information

Source: USDA Agricultural Research Service

The vitamins and minerals in Brussels sprouts aid in healing, promote immunity, and support strong bones. One cup of Brussels sprouts provides around 38 calories, 3g of protein, 8g of carbohydrates, and 0.3g of fat. 

Of the 8 grams of carbohydrates in a cup of Brussels sprouts, a little over 3 grams are from fiber. They have a low glycemic index, so they are a good choice for those on a low-carb diet or anyone who is watching their blood sugar. 

Brussels sprouts are a great source of the B-vitamins necessary for cellular energy production, including vitamin B6, thiamine, and folate. They contain 24% of the daily recommended amount of vitamin A, which is important for eyes and immunity. 

Brussels sprouts are an excellent source of vitamins C and K, providing over 100% of your daily value of each based on a 2,000 calorie per day diet. Vitamin K is linked to heart health and longevity and is responsible for blood clotting. Brussels sprouts also contain manganese, which helps with metabolizing carbohydrates, amino acids, and cholesterol.

While Brussels sprouts might not be as famous as other vegetables grown in Washington state, they are a winter gem that is deserving of more recognition. As the culinary world continues to rediscover the delights of Brussels sprouts, these cruciferous vegetables offer a delicious reminder that the Washington state's agricultural tapestry is rich and diverse. So, whether you're savoring a plate of crispy roasted Brussels sprouts during your holiday meal, or trying your hand at growing them, you're participating in the growing appreciation of these nutritious and flavorful gems.

Taste Washington Day Celebrates Local Food and Farm Connections

Annual event highlights the bounty and diversity of Washington-grown foods

The 13th annual Taste Washington Day, a joyful celebration of locally grown foods in school cafeterias across Washington state, kicked off this year with great enthusiasm. Representatives from the farm to school program at the Washington State Department of Agriculture (WSDA) embarked on a special journey to witness firsthand how schools in the Ellensburg School District integrate locally sourced ingredients into their meals.

The first stop on their visit was the Ellensburg High School Central Kitchen. The group had the pleasure of meeting with school nutrition leaders Alexandra Epstein-Solfield, Child Nutrition Director, and Charlotte Green, Nutrition Specialist, and observing the kitchen staff skillfully prepare fresh, locally grown fruits and vegetables. The commitment to providing nutritious and delicious meals to students was evident in the vibrant colors and enticing aromas that filled the kitchen.

Mount Stuart Elementary School was also in the spotlight during Taste Washington Day. Students at this school were treated to a delightful lunch featuring produce from Dagdagan Farm in Wapato, Washington and grass-fed hamburger patties from Green Bow Farm in Ellensburg. Watermelon slices, roasted grey squash (a zucchini-like veggie), and other fresh-made dishes from local producers were enjoyed by the students, who eagerly savored the flavors of their region.

At approximately 12:15 p.m., a moment of excitement filled the cafeteria as students collectively bit into Washington apples, generously donated by Chelan Fresh. The sound of a loud crunch resonated throughout the room, symbolizing the joy and satisfaction that comes from enjoying wholesome, locally grown food.

This year's Taste Washington Day saw an impressive participation of more than 40 schools and nearly 50 farmers and food producers. Taste Washington Day is not just a celebration of farm to school connections, it is also a platform that allows Washington's children to discover and appreciate the bounty and diversity of healthy and delicious foods grown in their home state. It is an opportunity for them to learn about the importance of local agriculture and the positive impact it has on their health and the environment.

For more information about WSDA Farm to School, please visit www.agr.wa.gov/farmtoschool.

Cantaloupes: Cultivating sweet success in Washington state

 Kim Vaughn
Communications

Melons (C. melo) originated in Iran and India around 3000 B.C. and are one of the oldest crops to be domesticated. While not as prominent as some of Washington state's other crops, like apples and cherries, cantaloupe has found its own special place in the heart of the agricultural landscape. In this blog, we'll delve into the world of cantaloupes in Washington, exploring its cultivation, favorite varieties, and its growing popularity in a state dominated by other fruits.

Growing cantaloupes in Washington state

Cantaloupe is a warm-season fruit that typically requires a longer, hotter growing season than the Pacific Northwest provides. However, in the eastern part of Washington, which experiences warmer and drier summers, cantaloupe cultivation has become a niche industry. Regions like the Yakima Valley and Columbia Basin have ideal microclimates for growing cantaloupes. Growing cantaloupes in the northwest’s coldest areas though, can be tough. Cooler temperatures and plant diseases like fungi and sudden wilt can cause growers to lose their crops before harvest.

Choose varieties that will mature in 90 days or less. Start seeds indoors in early May and grow multiple plants to ensure pollination. Keep seedlings moist and provide 16-18 hours of light a day. Harden off your seedlings in June before transplanting them into a warm soil bed when nighttime temperatures don’t fall below 60 degrees Fahrenheit. Plant blooming flowers throughout your row to attract pollinators.

Once transplanted outdoors, use an all-purpose 10-20-20 fertilizer and cover the bed with clear plastic to keep the soil warm. Water 1-2 inches per week. Harvest when the skin has a raised netting look before it starts to turn yellow. Allow the fruit to ripen off the vine for about two days before eating.

Favorite Washington varieties

Washington farmers have embraced a selection of cantaloupe varieties well-suited to the region's unique growing conditions. These suggested varieties mature around 75-80 days.

• Ha’Ogen and Model melons
  Very sweet, with green flesh and a honeydew flavor.
  
• Charentais
  A small French cantaloupe with unrivaled flavor.
  
• Honey Rock and Hale’s Best
  Well-known American cantaloupe varieties that are easy to find seeds and seedlings.
  
• Ineya
  A small Russian melon, with white flesh and a mild honeydew flavor.
  
• Armenian and Metki
  These varieties look like large cucumbers with a mildly sweet flavor.

Nutritional information

Source: USDA Agricultural Research Service

Incorporating cantaloupes into your diet can offer various health benefits. A single serving, equivalent to one cup of fresh cantaloupe cubes, provides 53 calories, 6% of your daily fiber intake, approximately 1 gram of protein, and is free from both fat and cholesterol.

Moreover, cantaloupes are a low-carbohydrate fruit, containing 13 grams per one-cup serving. Opting for fruits low in carbohydrates enables you to consume larger portions while effectively managing your blood glucose levels.

Notably, cantaloupes are rich in essential nutrients, offering:

• 100% of the daily value of vitamin C, a potent antioxidant safeguarding your cells from damage.
  
• The entirety of your daily vitamin A requirements, contributing to the health of your eyes, skin, bones, and immune system.

In Washington State, cantaloupes may not take center stage like apples or cherries, but it has quietly carved out a delicious niche in the state's agricultural mosaic. With its unique sweetness, cantaloupes offer a refreshing alternative to the more famous fruits of the region. Whether enjoyed fresh in the warm Washington sun or incorporated into a delightful summer dish, Washington cantaloupes represent a sweet and healthy surprise amidst the apple and cherry orchards, reminding us that diversity in agriculture is a delicious and valuable asset.