California Animal Health and Food Safety Laboratory

Davis, CA, United States

California Animal Health and Food Safety Laboratory

Davis, CA, United States

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Aly S.S.,University of California at Davis | Anderson R.J.,Animal Health Branch | Adaska J.M.,California Animal Health and Food Safety Laboratory | Jiang J.,University of California at Davis | Gardner I.A.,University of California at Davis
Journal of Dairy Science | Year: 2010

The association between Mycobacterium avium ssp. paratuberculosis (MAP) and milk production was estimated on 2 California dairies using longitudinal data from 5,926 cows. Both study herds had moderate MAP seroprevalence, housed cows in freestalls, and had Johne's disease control programs. Cow MAP status was determined using both serum ELISA and fecal culture results from cows tested at dry-off and from whole-herd tests. Potential confounders were evaluated based on a causal diagram. Mixed models with 2 functions (splines) for days in milk (DIM) representing milk production pre- and postpeak used in similar studies were further modified to use each cow's observed DIM at peak and lactation length. Cows that were seropositive produced 2.5. kg less 4% fat-corrected milk (FCM) per day than their seronegative herdmates. In addition, cows that were fecal-culture positive by liquid culture and confirmed by PCR produced 2.2. kg less 4% FCM per day than their fecal-culture negative herdmates. The decrease in milk production in MAP test-positive compared with test-negative cows started in the second lactation. A switch in MAP status in either ELISA or fecal culture results from positive to negative had no significant association with milk production. Modified DIM functions that used the observed DIM at peak had better model fit than another function that assumed a fixed peak at 60 DIM. Cows that tested positive for MAP on serum ELISA or fecal culture produced less milk than cows that tested negative, and the association between MAP and milk production was not confounded by mastitis, elevated somatic cell counts, or uterine or metabolic cow conditions. © 2010 American Dairy Science Association.


Uzal F.A.,California Animal Health and Food Safety Laboratory
Gut microbes | Year: 2014

Clostridium perfringens causes enteritis and enterotoxemia in humans and livestock due to prolific toxin production. In broth culture, C. perfringens uses the Agr-like quorum sensing (QS) system to regulate production of toxins important for enteritis/enterotoxemia, including beta toxin (CPB), enterotoxin, and epsilon toxin (ETX). The VirS/VirR two-component regulatory system (TCRS) also controls CPB production in broth cultures. Both the Agr-like QS and VirS/VirR systems are important when C. perfringens senses enterocyte-like Caco-2 cells and responds by upregulating CPB production; however, only the Agr-like QS system is needed for host cell-induced ETX production. These in vitro observations have pathophysiologic relevance since both the VirS/VirR and Agr-like QS signaling systems are required for C. perfringens strain CN3685 to produce CPB in vivo and to cause enteritis or enterotoxemia. Thus, apparently upon sensing its presence in the intestines, C. perfringens utilizes QS and TCRS signaling to produce toxins necessary for intestinal virulence.


Li L.,Blood Systems Research Institute | Li L.,University of California at San Francisco | Pesavento P.A.,University of California at Davis | Woods L.,California Animal Health and Food Safety Laboratory | And 5 more authors.
Emerging Infectious Diseases | Year: 2011

We used viral metagenomics to identify a novel parvovirus in tissues of a gray fox (Urocyon cinereoargenteus). Nearly full genome characterization and phylogenetic analyses showed this parvovirus (provisionally named gray fox amdovirus) to be distantly related to Aleutian mink disease virus, representing the second viral species in the Amdovirus genus.


Poppenga R.H.,California Animal Health and Food Safety Laboratory | Pitman J.,Research and Survey Office
Journal of Wildlife Diseases | Year: 2011

The perception of prairie dogs (Cynomys spp.) both as a nuisance species and a keystone species presents a significant challenge to land, livestock, and wildlife managers. Anticoagulant and nonanticoagulant rodenticides are commonly employed to control prairie dog populations throughout their range. Chlorophacinone, and to a lesser extent zinc phosphide, are widely used in northwestern Kansas for controlling black-tailed prairie dog (Cynomys ludovicianus) populations. Although zinc phosphide poisoning of gallinaceous birds is not uncommon, there are few published accounts of nontarget chlorophacinone poisoning of wildlife. We report three mortality events involving nontarget rodenticide poisoning in several species, including wild turkeys (Meleagris gallopavo), a raccoon (Procyon lotor), and an American badger (Taxidea taxus). This includes the first documentation of chlorophacinone intoxication in wild turkeys and an American badger in the literature. The extent of nontarget poisoning in this area is currently unknown and warrants further investigation. © Wildlife Disease Association 2011.


PubMed | California Animal Health and Food Safety Laboratory, Northwest ZooPath, California Science Center and University of California at Davis
Type: Journal Article | Journal: Veterinary pathology | Year: 2016

Despite increasing concern for coral reef ecosystem health within the last decade, there is scant literature concerning the histopathology of diseases affecting the major constituents of coral reef ecosystems, particularly marine invertebrates. This study describes histologic findings in 6 species of marine invertebrates (California sea hare [Aplysia californica], purple sea urchin [Strongylocentrotus purpuratus], sunburst anemone [Anthopleura sola], knobby star [Pisaster giganteus], bat star [Asterina miniata], and brittle star [Ophiopteris papillosa]) with spontaneous copper toxicosis, 4 purple sea urchins with experimentally induced copper toxicosis, and 1 unexposed control of each species listed. The primary lesions in the California sea hare with copper toxicosis were branchial and nephridial necrosis. Affected echinoderms shared several histologic lesions, including epidermal necrosis and ulceration and increased numbers of coelomocytes within the water-vascular system. The sunburst anemone with copper toxicosis had necrosis of both epidermis and gastrodermis, as well as expulsion of zooxanthellae from the gastrodermis. In addition to the lesions attributed to copper toxicosis, our results describe normal microscopic features of these animals that may be useful for histopathologic assessment of marine invertebrates.


PubMed | California Animal Health and Food Safety Laboratory and University of California at Davis
Type: | Journal: PeerJ | Year: 2016

The primary objective of this cross-sectional study was to estimate the crude, seasonal and cull-reason stratified prevalence of Salmonella fecal shedding in cull dairy cattle on seven California dairies. A secondary objective was to estimate and compare the relative sensitivity (Se) and specificity (Sp) for pools of 5 and 10 enriched broth cultures of fecal samples for Salmonella sp. detection.Seven dairy farms located in the San Joaquin Valley of California were identified and enrolled in the study as a convenience sample. Cull cows were identified for fecal sampling once during each season between 2014 and 2015, specifically during spring, summer, fall, and winter, and 10 cows were randomly selected for fecal sampling at the day of their sale. In addition, study personnel completed a survey based on responses of the herd manager to questions related to the previous four months herd management. Fecal samples were frozen until testing for Salmonella. After overnight enrichment in liquid broth, pools of enrichment broth (EBP) were created for 5 and 10 samples. All individual and pooled broths were cultured on selective media with putative Salmonella colonies confirmed by biochemical testing before being serogrouped and serotyped.A total of 249 cull cows were enrolled into the study and their fecal samples tested for Salmonella. The survey-weighted period prevalence of fecal shedding of all Salmonella sp. in the cull cow samples across all study herds and the entire study period was 3.42% (N = 249; SE 1.07). The within herd prevalence of Salmonella shed in feces did not differ over the four study seasons (P = 0.074). The Se of culture of EBP of five samples was 62.5% (SE = 17.12), which was not statistically different from the Se of culture of EBP of 10 (37.5%, SE = 17.12, P = 0.48). The Sp of culture of EBP of five samples was 95.24% (SE = 3.29) and for pools of 10 samples was 100.00% (SE = 0). There was no statistical difference between the culture relative specificities of EBP of 5 and 10 (P > 0.99).Our study showed a numerically higher prevalence of Salmonella shedding in the summer, although the results were not significant, most likely due to a lack of power from the small sample size. A higher prevalence in summer months may be related to heat stress. To detect Salmonella, investigators may expect a 62.5% sensitivity for culture of EBP of five, relative to individual fecal sample enrichment and culture. In contrast, culture of EBP of 10 samples resulted in a numerically lower Se. Culture of EBP of size 5 or 10 samples, given similar prevalence and limit of detection, can be expected to yield specificities of 95 and 100%, respectively.


PubMed | Sutter Medical Center Sacramento, California Animal Health and Food Safety Laboratory, Obesity and Metabolism Research Unit and University of California at Davis
Type: Journal Article | Journal: PloS one | Year: 2016

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and hospital admission in infants. An analogous disease occurs in cattle and costs US agriculture a billion dollars a year. RSV causes much of its morbidity indirectly via adverse effects of the host response to the virus. RSV is accompanied by elevated prostaglandin E2 (PGE2) which is followed by neutrophil led inflammation in the lung. Ibuprofen is a prototypical non-steroidal anti-inflammatory drug that decreases PGE2 levels by inhibiting cyclooxygenase.We hypothesized that treatment of RSV with ibuprofen would decrease PGE2 levels, modulate the immune response, decrease clinical illness, and decrease the histopathological lung changes in a bovine model of RSV. We further hypothesized that viral replication would be unaffected.We performed a randomized placebo controlled trial of ibuprofen in 16 outbred Holstein calves that we infected with RSV. We measured clinical scores, cyclooxygenase, lipoxygenase and endocannabinoid products in plasma and mediastinal lymph nodes and interleukin (Il)-4, Il-13, Il-17 and interferon- in mediastinal lymph nodes. RSV shedding was measured daily and nasal Il-6, Il-8 and Il-17 every other day. The calves were necropsied on Day 10 post inoculation and histology performed.One calf in the ibuprofen group required euthanasia on Day 8 of infection for respiratory distress. Clinical scores (p<0.01) and weight gain (p = 0.08) seemed better in the ibuprofen group. Ibuprofen decreased cyclooxygenase, lipoxygenase, and cytochrome P450 products, and increased monoacylglycerols in lung lymph nodes. Ibuprofen modulated the immune response as measured by narrowed range of observed Il-13, Il-17 and IFN- gene expression in mediastinal lymph nodes. Lung histology was not different between groups, and viral shedding was increased in calves randomized to ibuprofen.Ibuprofen decreased PGE2, modulated the immune response, and improved clinical outcomes. However lung histopathology was not affected and viral shedding was increased.


PubMed | California Animal Health and Food Safety Laboratory, University of California at Davis and Sutter Medical Center
Type: Journal Article | Journal: Journal of veterinary pharmacology and therapeutics | Year: 2016

Nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended for various conditions in cattle. Ibuprofen is an inexpensive short-acting NSAID and is readily available in liquid formulation for administration to bottle-fed calves. We compared the adverse effects of a 10-day course of ibuprofen and placebo in 16 five- to six-week-old Holstein bull calves that were being treated for experimentally induced bovine respiratory syncytial virus infection. Ibuprofen was administered as a liquid in milk replacer at 30mg/kg divided three times daily. We found an increased prevalence of abomasal ulceration 5 of 8 in the ibuprofen compared to placebo group 2 of 6 (P=NS). There was one (1 of 8) case of mild interstitial nephritis in the ibuprofen and none (0 of 8) in the placebo group (P=NS). Renal function as measured by serum BUN and creatinine levels was not different between groups; no animal demonstrated an increase in creatinine.


Chen J.,University of Pittsburgh | Ma M.,University of Pittsburgh | Uzal F.A.,California Animal Health and Food Safety Laboratory | McClane B.A.,University of Pittsburgh
Gut Microbes | Year: 2014

Clostridium perfringens causes enteritis and enterotoxemia in humans and livestock due to prolific toxin production. In broth culture, C. perfringens uses the Agr-like quorum sensing (QS) system to regulate production of toxins important for enteritis/enterotoxemia, including beta toxin (CPB), enterotoxin, and epsilon toxin (ETX). The VirS/VirR two-component regulatory system (TCRS) also controls CPB production in broth cultures. Both the Agr-like QS and VirS/VirR systems are important when C. perfringens senses enterocyte-like Caco-2 cells and responds by upregulating CPB production; however, only the Agr-like QS system is needed for host cell-induced ETX production. These in vitro observations have pathophysiologic relevance since both the VirS/VirR and Agr-like QS signaling systems are required for C. perfringens strain CN3685 to produce CPB in vivo and to cause enteritis or enterotoxemia. Thus, apparently upon sensing its presence in the intestines, C. perfringens utilizes QS and TCRS signaling to produce toxins necessary for intestinal virulence. © 2014 Landes Bioscience.


News Article | November 9, 2015
Site: cen.acs.org

A mysterious substance that coated and killed hundreds of birds in the San Francisco Bay appears to be a polymerized oil, derived from plant—as opposed to petroleum—sources. The contamination release, which was apparently a onetime event, made headlines in California when 170 birds were found dead and 323 coated live birds washed up on shore in January. The substance, which had a rubber-cement-like consistency, hardened on feathers like varnish, completely incapacitating the birds. The organization International Bird Rescue (IBR) was unable to clean the birds with traditional soapy water used in oil spills. IBR found that the substance could be removed painstakingly with successive treatments of a baking soda paste, followed by a vinegar rinse, and then a soapy water wash. Labs from all over the world, including those from the U.S. Environmental Protection Agency, the National Oceanic Atmospheric Administration, Chevron, and the California Animal Health and Food Safety Laboratory, joined the effort to identify the goo. Scientists quickly eliminated a petroleum source for the goo based on the lack of polyaromatic hydrocarbon signatures in gas chromatography-mass spectrometry scans. But they did find signals for chlorophyll, suggesting a plant-based source. But even with the suites of analytical techniques, including infrared spectroscopy, mass spectrometry, and high-performance liquid chromatography, the labs still could only identify segments of the polymer. Scientists were stumped, says Daniel Orr, a chemist with the California Department of Fish and Wildlife (CDFW). They have now identified methyl esters of long-chain fatty acids found in vegetable oils and polymeric esters in the sticky substance. But tracing the pieces back to the original polymer has proved impossible. Physical and chemical hurdles hindered the identification. The material was deeply encrusted in the feathers of birds, and each sample from every bird was different due to a range of other contaminants from the animals themselves and the ocean. “We were never able to get a good source sample,” Orr says. “The chemistry is very hard when you have so many possibilities.” Steven Rowland, an organic geochemistry professor at the University of Plymouth, in England, was one of the first scientists to offer assistance. His group had recently successfully identified polyisobutene as the culprit in a massive spill off the coast of the U.K. in 2013. Thousands of birds were killed during that disaster. But Rowland’s lab compared their infrared spectra with those of the California samples, and was able to rule out polyisobutene. Rowland didn’t stop there: He compared spectra from the California samples to those from a library of ocean contaminants that he’s amassed over the years. None were a match. “We still could not identify it conclusively,” Rowland says. “It’s annoying.” The exact source of the contamination remains unknown, and may never be known, given the great number of possible accidental or deliberate release sources, Orr says. For example, the Bay area is home to many food plants that processes large amounts of vegetable oil. Also biodiesel processors, which work with the plant-based oils, have proliferated in the area. The CA agencies are still actively looking for a culprit. People with information on the incident, they say, should contact the organization Californians Turn in Poachers or Polluters (CalTIP) at 1-888-334-2258 or download the free CalTIP smartphone App. All reports are confidential.

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