Browsing by Author "Chamberlain, Michael J."
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- Draft Genome Sequences of 158 Listeria monocytogenes Strains Isolated from Black Bears (Ursus americanus) in the United StatesBrown, Phillip; Chen, Yi; Ivanova, Mirena; Leekitcharoenphon, Pimlapas; Parsons, Cameron; Niedermeyer, Jeffrey; Gould, Nicholas; Strules, Jennifer; Mesa-Cruz, J. Bernardo; Kelly, Marcella J.; Hooker, Michael J.; Chamberlain, Michael J.; Olfenbuttel, Colleen; DePerno, Christopher; Elhanafi, Driss; Kathariou, Sophia (American Society for Microbiology, 2023-06)Listeria monocytogenes is responsible for severe foodborne disease and major economic losses, but its potential reservoirs in natural ecosystems remain poorly understood. Here, we report the draft genome sequences of 158 L. monocytogenes strains isolated from black bears (Ursus americanus) in the southeastern United States between 2014 and 2017. Listeria monocytogenes is responsible for severe foodborne disease and major economic losses, but its potential reservoirs in natural ecosystems remain poorly understood. Here, we report the draft genome sequences of 158 L. monocytogenes strains isolated from black bears (Ursus americanus) in the southeastern United States between 2014 and 2017.
- Habitat selection and diurnal refugia of gray foxes in southwestern Georgia, USADeuel, Nicholas R.; Conner, L. Mike; Miller, Karl V.; Chamberlain, Michael J.; Cherry, Michael J.; Tannenbaum, Larry V. (PLOS, 2017-10-17)Understanding habitat selection of gray foxes (Urocyon cinereoargenteus) is essential to evaluate their potential response to changes in land use and predator communities. Few studies have evaluated temporal habitat selection or explicitly identified habitats used by gray foxes for diurnal refugia. We used GPS collars to obtain location data for 34 gray foxes (20 males and 14 females) from February 2014 to December 2015 to evaluate temporal (seasonal and diel) habitat selection and selection of diurnal refugia in southwestern Georgia, USA. We analyzed habitat selection at 2 levels, selection of a core area within the home range and selection of locations within the home range. Habitat selection was non-random (P < 0.001) but consistent among seasons, between day and night, and between sexes (P > 0.05). Hardwoods, human use (i.e., areas associated with regular human activity such as buildings, lawns, parking areas, etc.), and roads were selected (P < 0.05), whereas pine dominated stands were used randomly (P > 0.05). Selection of habitats for diurnal refugia did not vary seasonally or by sex (P > 0.05), with foxes selecting (P < 0.05) areas near hardwood forests, roads, agriculture, human use, pastures/food plots, and shrub scrub habitats. Gray foxes were observed on the ground while resting, and we found no evidence of gray foxes diurnally resting in trees. Our results suggest that on our study area, gray foxes are an edge species that prefer forests with a hardwood component in areas near human use and roads.
- Listeria monocytogenes at the human-wildlife interface: black bears (Ursus americanus) as potential vehicles for ListeriaParsons, Cameron; Niedermeyer, Jeff; Gould, Nicholas; Brown, Phillip; Strules, Jennifer; Parsons, Arielle W.; Mesa-Cruz, J. Bernardo; Kelly, Marcella J.; Hooker, Michael J.; Chamberlain, Michael J.; Olfenbuttel, Colleen; DePerno, Christopher; Kathariou, Sophia (2019-11)Listeria monocytogenes is the causative agent of the foodborne illness listeriosis, which can result in severe symptoms and death in susceptible humans and other animals. L. monocytogenes is ubiquitous in the environment and isolates from food and food processing, and clinical sources have been extensively characterized. However, limited information is available on L. monocytogenes from wildlife, especially from urban or suburban settings. As urban and suburban areas are expanding worldwide, humans are increasingly encroaching into wildlife habitats, enhancing the frequency of human-wildlife contacts and associated pathogen transfer events. We investigated the prevalence and characteristics of L. monocytogenes in 231 wild black bear capture events between 2014 and 2017 in urban and suburban sites in North Carolina, Georgia, Virginia and United States, with samples derived from 183 different bears. Of the 231 captures, 105 (45%) yielded L. monocytogenes either alone or together with other Listeria. Analysis of 501 samples, primarily faeces, rectal and nasal swabs for Listeria spp., yielded 777 isolates, of which 537 (70%) were L. monocytogenes. Most L. monocytogenes isolates exhibited serotypes commonly associated with human disease: serotype 1/2a or 3a (57%), followed by the serotype 4b complex (33%). Interestingly, approximately 50% of the serotype 4b isolates had the IVb-v1 profile, associated with emerging clones of L. monocytogenes. Thus, black bears may serve as novel vehicles for L. monocytogenes, including potentially emerging clones. Our results have significant public health implications as they suggest that the ursine host may preferentially select for L. monocytogenes of clinically relevant lineages over the diverse listerial populations in the environment. These findings also help to elucidate the ecology of L. monocytogenes and highlight the public health significance of the human-wildlife interface.
- Space Use and Habitat Selection by Resident and Transient Red Wolves (Canis rufus)Hinton, Joseph W.; Proctor, Christine; Kelly, Marcella J.; van Manen, Frank T.; Vaughan, Michael R.; Chamberlain, Michael J. (PLOS, 2016-12-21)Recovery of large carnivores remains a challenge because complex spatial dynamics that facilitate population persistence are poorly understood. In particular, recovery of the critically endangered red wolf (Canis rufus) has been challenging because of its vulnerability to extinction via human-caused mortality and hybridization with coyotes (Canis latrans). Therefore, understanding red wolf space use and habitat selection is important to assist recovery because key aspects of wolf ecology such as interspecific competition, foraging, and habitat selection are well-known to influence population dynamics and persistence. During 2009–2011, we used global positioning system (GPS) radio-telemetry to quantify space use and 3rd-order habitat selection for resident and transient red wolves on the Albemarle Peninsula of eastern North Carolina. The Albemarle Peninsula was a predominantly agricultural landscape in which red wolves maintained spatially stable home ranges that varied between 25 km2 and 190 km2. Conversely, transient red wolves did not maintain home ranges and traversed areas between 122 km2 and 681 km2. Space use by transient red wolves was not spatially stable and exhibited shifting patterns until residency was achieved by individual wolves. Habitat selection was similar between resident and transient red wolves in which agricultural habitats were selected over forested habitats. However, transients showed stronger selection for edges and roads than resident red wolves. Behaviors of transient wolves are rarely reported in studies of space use and habitat selection because of technological limitations to observed extensive space use and because they do not contribute reproductively to populations. Transients in our study comprised displaced red wolves and younger dispersers that competed for limited space and mating opportunities. Therefore, our results suggest that transiency is likely an important life-history strategy for red wolves that facilitates metapopulation dynamics through short- and long-distance movements and eventual replacement of breeding residents lost to mortality.
- Survival of White-Tailed Deer Neonates in LouisianaShuman, Rebecca M.; Cherry, Michael J.; Simoneaux, Taylor N.; Dutoit, Elizabeth A.; Kilgo, John C.; Chamberlain, Michael J.; Miller, Karl V. (2017-07)Changing predator communities have potential to complicate management focused on ensuring sustainable white-tailed deer (Odocoileus virginianus) populations. Recent research reported that predation on neonates by coyotes (Canis latrans) and bobcats (Lynx rufus) can limit recruitment. However, no research has been conducted in areas of the southeastern United States with 3 sympatric neonate predators such as coyote, American black bear (Ursus americanus), and bobcat. Our objectives were to estimate neonate survival rates, identify causes of neonate mortality, and determine which biological and landscape characteristics were related to neonate survival. During 2013-2015, we captured 70 neonates with the aid of vaginal implant transmitters on Tensas River National Wildlife Refuge in northeastern Louisiana, USA. We monitored neonates every 8 hours until 6 weeks of age and daily until 12 weeks of age, and assigned cause of death from field and DNA evidence. Survival of neonates to 12 weeks was 0.271 (95% CI=0.185-0.398). Of 51 mortalities, 45 (88%) were attributed to predation, 4 (8%) to starvation, 1 (2%) to other causes, and 1 (2%) to unknown causes. We used an information-theoretic approach to compare Cox proportional hazards models containing various combinations of biological and habitat covariates. Our best-supported model contained sex, mass at birth, distance to cropland, young reforestation (planted 2000-2009), and old reforestation (planted 1980-1989). Based on hazard ratios, survival was 81% higher for males than females, and survival increased 81% with every 1-kg increase in birth mass. Survival increased 8% for every 100-m increase in distance from cropland or young reforestation, and decreased 11% with every 100-m increase in distance from old reforestation, which may be a result of spatial variation in predator distribution. Our results emphasize the importance of site-specific monitoring of neonate recruitment rates in areas with burgeoning predator communities. We conclude, however, that although predation pressure was high, survival rates were similar to those observed in 2-predator systems in the region, suggesting the possibility that an upper limit to predation rates may exist for white-tailed deer neonates. (C) 2017 The Wildlife Society.