Gortazar C.,Animal Health |
Che Amat A.,University Putra Malaysia |
O'Brien D.J.,Wildlife Disease Laboratory
Mammal Review | Year: 2015
Animal tuberculosis (TB) control is globally important for public health, economics and conservation. Wildlife species are often part of the Mycobacterium tuberculosis complex (MTC) maintenance community, complicating TB control attempts. We describe the current knowledge on global TB distribution and the significance of wildlife hosts; identify insufficiently known aspects of host pathology, ecology and epidemiology; present selected time series in wildlife TB; and summarize ongoing research on TB control, providing additional insight on vaccination. Six specific research needs are identified and discussed, namely: 1) complete the world map of wildlife MTC reservoirs and describe the structure of each local MTC host community; 2) identify the origin and behaviour of generalized diseased individuals within populations, and study the role of factors such as co-infections, re-infections and individual condition on TB pathogenesis; 3) quantify indirect MTC transmission within and between species; 4) define and harmonize wildlife disease monitoring protocols, and apply them in a way that allows proper population and prevalence trend comparisons in both space and time; 5) carry out controlled and replicated wildlife TB control experiments using single intervention tools; 6) analyse cost-efficiency and consider knowledge transfer aspects in promising intervention strategies. We believe that addressing these six points would push ahead our capacities for TB control. A remaining question is whether or not interventions on wildlife TB are at all justified. The answer depends on the local circumstances of each TB hotspot, and is likely to evolve during our collective progress towards TB control in livestock and in wildlife. © 2015 The Mammal Society and John Wiley & Sons Ltd.
Crespo R.,Washington State University |
Badcoe L.M.,Animal Health |
Williams C.,Washington State University |
Bary A.I.,Washington State University
Avian Diseases | Year: 2016
Very virulent infectious bursal disease virus (vvIBDV) was diagnosed in a pullet farm in Washington in 2014. Infectious bursal disease virus is resistant to many environmental stresses and often persists on farms for months. There have been conflicting reports as to whether composting can destroy vvIBDV in the manure. This project investigated the composting of litter from the affected house using an aerated static pile to inactivate the virus. Two weeks before the affected pullet flocks were moved to the layer house, specific-pathogen-free (SPF) birds were placed in the barns. Ten days after they were placed, three SPF birds died and were positive for vvIBDV. Thirty percent of the SPF birds were positive for vvIBDV. After the pullets were moved, at 20 wk of age, the litter in the house was composted using the aerated static pile method. The pile was maintained at above 55 C for 4 wk. After this time, 30 additional SPF birds were placed on the composted material. Two weeks later, the birds were healthy and there was no evidence of vvIBDV. The subsequent pullet flock did not break with vvIBDV. These results demonstrate that this composting method can be used to decontaminate the litter from vvIBDV and help prevent the spread of vvIBDV.
The new findings, based on wild house sparrows, and published today, show how changes in DNA that are linked to ageing and lifespan take place as body size gets bigger. Although larger types of animals tend to live longer than smaller ones – elephants live longer than mice – within many species the bigger individuals have shorter life spans than their smaller counterparts – a Jack Russell has a much longer life than a St Bernard. In humans, a recent study has shown that taller people are more prone to diseases including cancer. But biologists haven't been able to fully explain why. Research into telomeres, special DNA structures that all animals have at the ends of their chromosomes, described as functioning like "the protective plastic caps at the end of shoelaces" may provide the answer. The study, conducted jointly by the University of Glasgow's Institute of Biodiversity, Animal Health & Comparative Medicine and the Centre of Biodiversity Dynamics at the Norwegian University of Science and Technology, focused on a population of wild house sparrows on the isolated island of Leka in Norway. The research, published in the Proceedings of the Royal SocietyB: Biological Sciences, found that skeletally bigger house sparrows had shorter telomeres. This relationship was maintained during a period when a selective breeding programme on the island resulted in the sparrows becoming even larger. In tandem, their telomeres became even shorter. Everyone's telomeres erode over time, and telomere shortening has been linked to ageing and disease risk including cancer. Having naturally longer telomeres appears to give individuals an advantage when it comes to health and the biological aging process. The results shed light on a paradox that has puzzled biologists for a long time. If being bigger gives you a competitive advantage, why don't animals just get bigger and bigger? Part of the answer is that growing big can mean more telomere loss and faster ageing. Professor Pat Monaghan, Regius Chair of Zoology at the University of Glasgow, who supervised the telomere analysis, said: "Growing a bigger body means that cells have to divide more. As a result, telomeres become eroded faster and cells and tissues function less well as a result. "The reason why the bigger individuals have shorter telomeres might also be related to increased DNA damage due to growing faster. Being big can have advantages, of course, but this study shows that it can also have costs." Associate professor in population ecology Thor Harald Ringsby at Norwegian University of Science and Technology who was running the fieldwork together with his colleagues in Norway said: 'The results from this study are very exciting and broad reaching. It is especially interesting that we obtained these results in a natural population. The reduction in telomere size that followed the increase in body size suggests one important mechanism that limits body size evolution in wild animal populations" The study, entitled 'On being the right size: increased body size is associated with reduced telomere length under natural conditions' is published in the Proceedings of the Royal Society B: Biological Sciences journal. The research was funded by the European Research Council and the Research Council of Norway. Explore further: Researchers show telomere lengths predict life expectancy in the wild More information: On being the right size: increased body size is associated with reduced telomere length under natural conditons, Proceedings of the Royal Society B: Biological Sciences, rspb.royalsocietypublishing.org/lookup/doi/10.1098/rspb.2015.2331
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.
Jones L.A.,Animal Health |
Jones L.A.,A+ Network |
Houdijk J.G.M.,Animal Health |
Sakkas P.,Animal Health |
And 5 more authors.
International Journal for Parasitology | Year: 2011
Many mammals exhibit a periparturient relaxation of previously established immune responses (PPRI) to gastrointestinal nematodes culminating in increased worm burdens. It has been suggested that the extent of PPRI may have a nutritional basis as it is considerably augmented when protein supply is scarce. Subsequent studies have shown that increased dietary protein intake can ameliorate this phenomenon. However, this effect is often confounded with increased food intake and thus increased energy levels. Herein, we aimed to dissect the effects of protein and energy nutrition on the immune status and resistance to re-infection with gastrointestinal nematodes in the periparturient host. The lactating, Nippostrongylus brasiliensis re-infected rat was utilised as an established model for mammalian PPRI. Experimental animals were assigned to restricted feeding regimens designed to achieve four pre-determined levels of crude protein (CP) at one of two levels of metabolisable energy (ME) and parasitological and immunological measurements taken at either day 6 or day 9 post re-infection. We clearly show that increased supply of dietary CP, but not increased dietary ME, significantly reduced worm burdens. The increased magnitude of worm expulsion with increased dietary CP supply strongly correlated with mucosal mast cell accumulation in the small intestine. In addition, increased CP and not ME supply increased mucosal eosinophil numbers. Furthermore, increased CP led to higher levels of total IgG at high ME only and there were interactive effects of CP and ME on serum levels of IgG1 and IgG2a. Perhaps surprisingly, CP nutrition did not affect expression of either Th1 (IFN-γ) or Th2 (IL-4, IL-13) cytokines in the mesenteric lymph nodes. These data emphasise the role of immunonutrition, and particularly dietary protein, in combating infectious disease such as gastrointestinal parasitism. © 2011 Australian Society for Parasitology Inc.