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At least 1,279 records · Page 71Linked to original sources

USGS2010

The green alga, Cladophora, promotes Escherichia coli growth and contamination of recreational waters in Lake Michigan

A linkage between Cladophora mats and exceedances of recreational water quality criteria has been suggested, but not directly studied. Th is study investigates the spatial and temporal association between Escherichia coli concentrations within and near Cladophora mats at two northwestern Lake Michigan beaches in Door County, Wisconsin. Escherichia coli concentrations in water underlying mats were significantly greater than surrounding water (p < 0.001). Below mat E. coli increased as the stranded mats persisted at the beach swash zone. Water adjacent to Cladophora mats had lower E. coli concentrations, but surpassed EPA swimming criteria the majority of sampling days. A signifi cant positive association was found between E. coli concentrations attached to Cladophora and in underlying water (p < 0.001). The attached E. coli likely acted as a reservoir for populating water underlying the mat. Fecal bacterial pathogens, however, could not be detected by microbiological culture methods either attached to mat biomass or in underlying water. Removal of Cladophora mats from beach areas may improve aesthetic and microbial water quality at affected beaches. These associations and potential natural growth of E. coli in bathing waters call into question the efficacy of using E. coli as a recreational water quality indicator of fecal contaminations. Copyright ?? 2010 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Journal of Environmental Quality↗

USGS2006

The toxicological geochemistry of Earth materials: An overview of processes and the interdisciplinary methods used to understand them

A broad spectrum of earth materials have been linked to, blamed for, and/or debated as sources for disease. In some cases, the links are clear. For example, excessive exposures to mineral dusts have long been recognized for their role in diseases such as: asbestosis, mesothelioma, and lung cancers (asbestos); silicosis and lung cancer (silica dusts); and coal-workers pneumoconiosis (coal dust). Lead poisoning, particularly in toddlers and young children, has been conclusively linked to involuntary ingestion of soils or other materials contaminated with lead-rich paint particles, leaded gasoline combustion byproducts, and some types of lead-rich mine wastes or smelter particulates. Waters with naturally elevated arsenic contents are common in many regions of the globe, and consumption of these waters has been documented as the source of arsenic-related diseases affecting thousands of people in south Asia and other regions. Exposure to dusts or soils containing pathogens has been documented as the cause of regionally common diseases such as valley fever (coccidioidomycosis) and much rarer diseases such as anthrax. Links between many other earth materials and specific diseases, although suspected, are less clear or are debated. For example, it has been suggested that geographic clusters of diseases such as leukemia are related to exposures to waters or atmospheric particulates containing organic or metal contaminants; however, for many clusters the exact causal relationships between disease and environmental exposure are difficult to prove conclusively. Even for many diseases in which the causal relationship is clear, such as in asbestosis and mesothelioma triggered by asbestos exposure, the minimum exposures needed to trigger disease, the influence of genetic factors, and the exact mechanisms of toxicity are still incompletely understood and are the focus of considerable debate within the public health community. Hence, understanding the health effects resulting from occupational and environmental exposures to a wide variety of earth materials remains a very active and fruitful area of research.

Reviews in Mineralogy and Geochemistry↗

USGS2006

Seasonal persistence and population characteristics of Escherichia coli and entercocci in deep backshore sand of two freshwater beaches

We studied the shoreward and seasonal distribution of E. coli and enterococci in sand (at the water table) at two southern Lake Michigan beaches—Dunbar and West Beach (in Indiana). Deep, backshore sand (∼20 m inland) was regularly sampled for 15 months during 2002–2003. E. coli counts were not significantly different in samples taken at 5-m intervals from 0–40 m inland (P=0.25). Neither E. coli nor enterococci mean counts showed any correlation or differences between the two beaches studied. In laboratory experiments, E. coli readily grew in sand supplemented with lake plankton, suggesting that in situ E. coli growth may occur when temperature and natural organic sources are adequate. Of the 114 sand enterococci isolates tested, positive species identification was obtained for only 52 (46%), with E. faecium representing the most dominant species (92%). Genetic characterization by ribotyping revealed no distinct genotypic pattern (s) for E. coli , suggesting that the sand population was rather a mixture of numerous strains (genotypes). These findings indicate that E. coli and enterococci can occur and persist for extended periods in backshore sand at the groundwater table. Although this study was limited to two beaches of southern Lake Michigan, similar findings can be expected at other temperate freshwater beaches. The long-term persistence of these bacteria, perhaps independent of pollution events, complicates their use as indicator organisms. Further, backshore sand at the water table may act as a reservoir for these bacteria and potentially for human pathogens.

Michigan, Indiana↗

USGS2010

Cladophora in the Great Lakes: Impacts on beach water quality and human health

Cladophora in the Great Lakes grows rapidly during the warm summer months, detaches, and becomes free-floating mats as a result of environmental conditions, eventually becoming stranded on recreational beaches. Cladophora provides protection and nutrients, which allow enteric bacteria such as Escherichia coli , enterococci, Shigella , Campylobacter , and Salmonella to persist and potentially regrow in the presence of the algae. As a result of wind and wave action, these microorganisms can detach and be released to surrounding waters and can influence water quality. Enteric bacterial pathogens have been detected in Cladophora mats; E. coli and enterococci may populate to become part of the naturalized microbiota in Cladophora ; the high densities of these bacteria may affect water quality, resulting in unnecessary beach closures. The continued use of traditional fecal indicators at beaches with Cladophora presence is inadequate at accurately predicting the presence of fecal contamination. This paper offers a substantial review of available literature to improve the knowledge of Cladophora impacts on water quality, recreational water monitoring, fecal indicator bacteria and microorganisms, and public health and policy.

Water Science and Technology↗

USGS2004

Efficacy of single calfhood vaccination of elk with Brucella abortus strain 19

Brucellosis has been eradicated from cattle in the states of Wyoming, Montana, and Idaho, USA. However, free-ranging elk (Cervus elaphus) that use feedgrounds in the Greater Yellowstone Area (GYA) and bison (Bison bison) in Yellowstone and Grand Teton national parks still have high seroprevalence to the disease and have caused loss of brucellosis-free status in Wyoming. Management tools to control or eliminate the disease are limited; however, wildlife vaccination is among the methods currently used by wildlife managers in Wyoming. We conducted a controlled challenge study of single calfhood vaccination. Elk calves, caught in January and February of 1999 and 2000 and acclimated to captivity for 3 weeks, were randomly assigned to control or vaccinate groups. The vaccinate groups received Brucetta abortus vaccine strain 19 (S19) by hand-delivered intramuscular injection. Calves were raised to adulthood and bred at either 2.5 or 3.5 years of age for 2000 and 1999 captures, respectively. Eighty-nine (44 controls, 45 vaccinates) pregnant elk entered the challenge portion of the study. We challenged elk at mid-gestation with pathogenic B. abortus strain 2308 by intraconjunctival instillation. Abortion occurred in significantly more (P = 0.002) controls (42; 93%) than vaccinates (32; 71%), and vaccine protected 25% of the vaccinate group. We used Brucella culture of fetus/calf tissues to determine the efficacy of vaccination for preventing infection, and we found that the number of infected fetuses/calves did not differ between controls and vaccinates (P = 0.14). Based on these data, single calfhood vaccination with S19 has low efficacy, will likely have only little to moderate effect on Brucella prevalence in elk, and is unlikely to eradicate the disease in wildlife of the GYA.

Journal of Wildlife Management↗

USGS1961

Trichomonad infection in mourning doves, Zenaidura macroura, in Maryland

During the 10-year period 1950-1960 the incidence of Trichomonas gallinae among several series of mourning doves shot or trapped in Maryland has varied from zero to 12 1/2 percent. Prior to 1959, all isolations of T. gallinae from doves during such surveys had been from birds with well-developed lesions. In 1959, trichomonads were demonstrated in three of 54 normal hunter-killed doves examined in Howard County. The incidence of trichomonad infection among doves which were submitted to the laboratory because they were obviously diseased was much higher. Of 44 clinically ill doves submitted during the period 1950-1960,25 were found to be infected with T. gallinae. In the Maryland area the incidence of trichomonad infection among mourning doves appears to be low, but when infection does occur it is usually due to a pathogenic strain which produces a typical fatal canker.

Maryland↗

USGS1988

Field validation of a habitat suitability index model for the American oyster

A habitat suitability index (HSI) model, developed for the American oyster, Crassostrea virginica , along the Gulf of Mexico, was field tested on 38 0.1-ha reef and nonreef sites in Galveston Bay, Texas. The HSI depends upon six (HSI1) or, optionally, eight (HSI2) variables. The six variables are percent of bottom covered with suitable cultch (V 1 ), mean summer water salinity (V 2 ), mean abundance of living oysters (V 3 ) (a gregarious settling factor), historic mean water salinity (V 4 ), frequency of killing floods (V 5 ), and substrate firmness (V 6 ). The optional variables are the abundance of the southern oyster drill Thais haemostoma (V 7 ), and the intensity of the oyster pathogen Perkinsus marinus (V 8 ). The HSI values were lowest at high and low salinity sites and highest at intermediate-salinity sites. To validate the model, the hypothesis that the output of the HSI model was correlated with oyster density was therefore tested. A significant correlation was found between HSI1 and oyster density (Kendall Tau Beta correlation coefficient, τ=0.674, p<0.001, n=38); however, a statistical independence problem exists with the above test, that is, oyster density is both the independent standard for the test and a variable in the model. A regression model was constructed to test the relationship between log-transformed oyster density values (dependent variable) and the other variables of the model (independent variables). Most variation (r 2 =0.72, r=0.85) in the log-transformed density values were explained by a regression model that contained V 2 , V 4 , V 5 , V 6 , V 7 , and V 8 as independent variables. The regression model was useful in constructing a modified HSI model (MHSI). A significant correlation (τ=0.674, p<0.05, n=10) was found between MHSI1 values and oyster densities from reefs closed to harvesting. The MHSI improves upon the original model by (i) simplifying the model structure, (ii) removing the requirement to measure V 3 , (iii) accounting better for the negative effects of high salinity, disease, and parasitism upon oysters, and (iv) eliminating the statistical independence problem by dropping V 3 from the model. The MHSI should be tested against a new, independently-collected data set.

Texas↗

USGS1990

Kidney lesions associated with mortality in chickens inoculated with waterfowl influenza viruses

Seventy-six type A influenza viruses recovered from waterfowl in Wisconsin, California, South Dakota, Florida, Texas, Alabama, and Nebraska were tested for virulence in chickens. The challenge to chickens was intravenous inoculation of first-, second-, or third-egg-passage virus. Each of the virus strains was tested separately in three or four chickens. Eighteen of the 76 viruses caused the death of one or more chickens following inoculation. Postmortem lesions were similar in all dead birds. In decreasing order of frequency, gross lesions included: swollen kidneys evident as accentuated lobular patterns, urates in the pericardial sac, and urates on the surface of the liver. Microscopic lesions present in kidneys were consistent with visceral gout. Mortality was associated with inoculations having higher concentrations of infectious virus. These results indicate that the influenza A viruses circulating in duck populations may include strains potentially pathogenic for chickens.

Alabama, California, Florida, Nebraska, South Dako↗

USGS1961

Chemotherapy of hexamitiasis in fish

Heramita salmonis , the causative agent of hexamitiasis in salmonoid fishes, is endemic in most trout and salmon hatcheries throughout North America. The etiologic agent, a protozoan flagellate, ostensibly causes cellular damage in the caecal mucosa of afflicted fishes. It is also believed that heavy infections may interfere with normal growth by direct competition with the host for available nutrients in the intestinal tract. While the role of this supposed pathogen is relatively unclear, its presence in test fishes at this laboratory has caused considerable concern during the conduct of controlled nutritional studies. Although McNeil et al (1941) showed that the incidence of Hexamita infections is widespread, hexamitiasis appears to be commercially important only in turkeys (Almquist and Johnson, 1951) and fish (Davis, 1953). Very little has been reported on the protozoacidal effects of various drugs on the Hexamita infections in fish (Fish and McKernan, 1940; Smith and Quistorff, 1940; and Nelson, 1941). The most widely used chemotherapeutic agents are p-carbamidobenzene arsonic acid (carbarsone) and mild mercurous chloride (calomel). Initial attempts at this laboratory to control the parasite in infected fish populations using these two drugs at the recommended concentrations demonstrated that the former was erratic in effectiveness and the latter was toxic and produced loss in fish weight. The present study, therefore, was undertaken to find more effective therapeutic agents which would be palatable, non-toxic, and still effectively eradicate the protozoan from fish.

Journal of Parasitology↗

USGS1990

Human impacts on bear habitat use

: Human effects on bear habitat use are mediated through food biomass changes, bear tolerance of humans and their impacts, and human tolerance of bears. Large-scale changes in bear food biomass have been caused by conversion of wildlands and waterways to intensive human use, and by the introduction of exotic pathogens. Bears consume virtually all human foods that have been established in former wildlands, but bear use has been limited by access. Air pollution has also affected bear food biomass on a small scale and is likely to have major future impacts on bear habitat through climatic warming. Major changes in disturbance cycles and landscape mosaics wrought by humans have further altered temporal and spatial pulses of bear food production. These changes have brought short-term benefits in places, but have also added long-term stresses to most bear populations. Although bears tend to avoid humans, they will also use exotic and native foods in close proximity to humans. Subadult males and adult females are more often impelled to forage closer to humans because of their energetic predicament and because more secure sites are often preempted by adult males. Although male bears are typically responsible for most livestock predation, adult females and subadult males are more likely to be habituated to humans because they tend to forage closer to humans. Elimination of human-habituated bears predictably reduces effective carrying capacity and is more likely to be a factor in preserving bear populations where humans are present in moderate-to-high densities. If humans desire to preserve viable bear populations, they will either have to accept increased risk of injury associated with preserving habituated animals, or continue to crop habituated bears while at the same time preserving large tracts of wildlands free from significant human intrusion.

Bears: Their Biology and Management↗

USGS2014

Book review: Fowler's zoo and wild animal medicine (volume 8)

In the eighth volume of Fowler's Zoo and Wild Animal Medicine , the editors have returned to the original, comprehensive, taxa-based format last used in the fifth volume that was released in 2003. The book consists of 82 chapters, divided into taxonomic classes that include amphibians, reptiles, birds, and mammals, and a general topics section. The editors deliberately selected new senior authors who are expert veterinary advisors for the various taxa. This international assemblage of authors is impressive, although the book would have benefited from a greater diversity of disciplinary expertise. Synthesis of the large and expanding body of knowledge about zoo and wild animal medicine is a Sisyphean task, but one that the editors have accomplished well. The chapters were well written and are beautifully illustrated with high-quality images and generally well referenced. Much of the information is summarized in tabular format, which I found both a blessing and a curse. Tabulation of hematologic variables and anesthetic doses is helpful; however, tabulation of information regarding infectious and parasitic diseases results in a loss of detail. For example, methods of diagnosis for some diseases are omitted from some tables. The need for succinctness results in trade-offs, and statements such as “ Batrachochytrium dendrobatidis … is one of the most well described pathogens of anurans” with no further information leaves readers unsated. In addition, the book does not have any chapters on fish or invertebrates, which are notable omissions given the importance of these species. Those quibbles aside, this is a must-have book for all zoo and wild animal medicine students and practitioners. However, perhaps it is time to recognize that, during the 36 years since the first volume was published, this discipline has become too large to be contained in 1 book. This is largely because of the success of this book series, and it is a nice problem to have. Review info: Fowler's Zoo and Wild Animal Medicine (Volume 8). By R. Eric Miller & Murray E. Fowler, 2015. ISBN 978-1455773978, 773 pp.

Journal of the American Veterinary Medical Associa↗

USGS2022

Arctic geese in North America

Multiple species of geese spend part of their annual cycle in the circumpolar Arctic and serve as a source of nutrition and cultural affirmation for many peoples. Arctic geese function as important indicators of environmental changes and some species also have the potential to alter ecosystem processes when they become overabundant. In 2022, despite an outbreak of highly pathogenic avian influenza in North America and variable spring weather conditions, the population sizes of most Arctic geese remained at or above historical levels.

arctic and sub-arctic North America↗

USGS2011

Predominant bacteria isolated from moribund Fusconaia ebena ebonyshells experiencing die-offs in Pickwick Reservoir, Tennessee River, Alabama

Mussel die-offs have been noted in recent years in Pickwick Reservoir, Tennessee River, Alabama. The primary affected species was Fusconaia ebena, but also affected to lesser degrees were Ellipsaria lineolata, Quadrula pustulosa, and Quadrula quadrula. These events were characterized by large numbers of empty shells—fresh-dead and live individuals that were presumed to be diseased because of weak and slow valve closure responses to external stimuli. Anecdotal evidence suggested the possible involvement of an etiological agent, such as a bacterial pathogen. The die-offs have occurred in Pickwick Reservoir (river miles 236–256) in sequential years during the past approximately 10 y. These timeframes have coincided with reduced basin inflows and warmer water temperatures. The majority of the moribund and freshly dead F. ebena were females possibly predisposed to infection and disease from ongoing reproductive activity. Affected and healthy-cohort mussels were collected to characterize the bacterial flora prior to, during, and after a July 2006 die-off, and during a subsequent die-off in September 2008. The numbers of total bacteria from both the 2006 and 2008 die-offs were significantly greater from the diseased specimens. For example, from the September 2008 die-off, the mean count from diseased F. ebena soft tissues was 9.75 × 10 6 cfu/g, which was more than 100 times greater (P = 0.025) than the mean from healthy cohorts (6.74 × 10 4 cfu/g). The predominant bacteria from affected F. ebena from July 2006 were Hafnia alvei and Aeromonas sobria, whereas from September 2008 the predominant bacteria were Enterobacter spp., Aeromonas schubertii, Aeromonas veronii bv. veronii, and Aeromonas veronii bv. sobria.

Alabama↗

USGS2017

Endozoicomonas dominates the gill and intestinal content microbiomes of Mytilus edulis from Barnegat Bay, New Jersey

Blue mussels, Mytilus edulis, Linnaeus 1758 from southern Barnegat Bay, New Jersey were examined to determine the make-up of the normal blue mussel microbiome. Sequencing of 16S ribosomal DNA amplicons from gill and intestinal content microbiomes using the Illumina® MiSeq platform yielded 1,276,161 paired end sequence reads from the gill libraries and 1,092,333 paired end sequence reads from the intestinal content libraries. General bioinformatic analyses were conducted with the open-source packages Qiime and Mothur. Phylotype assignments to the genus level were made using the commercial One Codex platform. This resulted in 1,697,852 gill and 988,436 intestinal content sequences being classified to genus. A majority of these (67.6% and 37.2% respectively) were assigned to a single operational taxonomic unit (Mytilus edulis Symbiont, MeS) that has homologies with other recently described Endozoicomonas pathogens and symbionts of marine invertebrates. MeS shares 98% identity with an uncultured bacterium from the gill tissue of an invasive indo-Pacific oyster and with HQE1 and HQE2 isolated from the sea squirt, Styela clava. Other than MeS, most of the detected bacterial species are known from marine sediments and seawater.

New Jersey↗

USGS2010

Occurrence of avian Plasmodium and West Nile virus in culex species in Wisconsin

The occurrence of multiple pathogens in mosquitoes and birds could affect the dynamics of disease transmission. We collected adult Culex pipiens and Cx. restuans (Cx. pipiens/restuans hereafter) from sites in Wisconsin and tested them for West Nile virus (WNV) and for avian malaria (Plasmodium). Gravid Cx. pipiens/restuans were tested for WNV using a commercial immunoassay, the RAMP?? WNV test, and positive results were verified by reverse transcriptasepolymerase chain reaction. There were 2 WNV-positive pools of Cx. pipiens/restuans in 2006 and 1 in 2007. Using a bias-corrected maximum likelihood estimation, the WNV infection rate for Cx. pipiens/restuans was 5.48/1,000 mosquitoes in 2006 and 1.08/1,000 mosquitoes in 2007. Gravid Cx. pipiens or Cx. restuans were tested individually for avian Plasmodium by a restriction enzymebased assay. Twelve mosquitoes were positive for avian Plasmodium (10.0), 2 were positive for Haemoproteus, and 3 were positive for Leucocytozoon. There were 4 mixed infections, with mosquitoes positive for >1 of the hemosporidian parasites. This work documents a high rate of hemosporidian infection in Culex spp. and illustrates the potential for co-infections with other arboviruses in bird-feeding mosquitoes and their avian hosts. In addition, hemosporidian infection rates may be a useful tool for investigating the ecological dynamics of Culex/avian interactions. ?? 2010 by The American Mosquito Control Association, Inc.

Wisconsin↗

USGS2008

Fisheries and aquatic resources—fish health

Fish health research at Leetown had its origin in the 1930’s when the Leetown Fish Hatchery and Experiment Station was constructed. In 1978, the National Fish Health Research Laboratory, now a component of the Leetown Science Center, was established to solve emerging and known disease problems affecting fish and other aquatic organisms critical to species restoration programs. Center scientists develop methods for the isolation, detection, and identification of fish pathogens and for prevention and control of fish diseases.

Fact Sheet↗

USGS1998

Windrow composting as an effective method to dispose of large numbers of fish

During July 1998, at the USGS Leetown Science Center, Kearneysville, West Virginia, an epizootic occurred in 16-month-old Atlantic salmon (Salmo salar). The cause ofmortality was diagnosed as furunculosis, a serious disease in salmonid fishes caused by the bacterium Aeromonas salmonicida. The fish were being maintained as part ofongoing research and were held in uncovered 30-m-Iong concrete raceways, each supplied with about 757 L per minute of 12 ?C pathogen-free spring water. The means by which the fish became infected could not be determined, and there was no recent history offurunculosis in the hatchery system.

Biological Information and Technology Notes↗

USGS2006

Disease emergence and resurgence—the wildlife-human connection

In 2000, the Global Outbreak Alert and Response Network (GOARN) was organized as a global disease watchdog group to coordinate disease outbreak information and health crisis response. The World Health Organization (WHO) is the headquarters for this network. Understandably, the primary focus for WHO is human health. However, diseases such as the H5N1 avian influenza epizootic in Asian bird populations demonstrate the need for integrating knowledge about disease emergence in animals and in humans. Aside from human disease concerns, H5N1 avian influenza has major economic consequences for the poultry industry worldwide. Many other emerging diseases, such as severe acute respiratory syndrome (SARS), monkeypox, Ebola fever, and West Nile fever, also have an important wildlife component. Despite these wildlife associations, the true integration of the wildlife component in approaches towards disease emergence remains elusive. This separation between wildlife and other species’ interests is counterproductive because the emergence of zoonotic viruses and other pathogens maintained by wildlife reservoir hosts is poorly understood. This book is about the wildlife component of emerging diseases. It is intended to enhance the reader’s awareness of the role of wildlife in disease emergence. By doing so, perhaps a more holistic approach to disease prevention and control will emerge for the benefit of human, domestic animal, and free-ranging wildlife populations alike. The perspectives offered are influenced by more than four decades of my experiences as a wildlife disease practitioner. Although wildlife are victims to many of the same disease agents affecting humans and domestic animals, many aspects of disease in free-ranging wildlife require different approaches than those commonly applied to address disease in humans or domestic animals. Nevertheless, the broader community of disease investigators and health care professionals has largely pursued a separatist approach for human, domestic animal, and wildlife rather than embracing the periodically proposed concept of “one medicine.” We especially need to embrace this concept as the human population increases because there will be more contact, direct and indirect, among humans, domestic animals, and wildlife. An “Ecology for a Crowded Planet” will be an even more pressing concern, and that includes increasing our understanding of disease ecology, especially that of the zoonoses.

Circular↗