scholarly journals Molecular detection of Rickettsia in fleas from micromammals in Chile

2020 ◽  
Author(s):  
Lucila Moreno Salas ◽  
Mario Espinoza Carniglia ◽  
Nicol Lizama Schmeisser ◽  
Luis Gonzalo Torres Fuentes ◽  
María Carolina Silva de la Fuente ◽  
...  
Keyword(s):  
Human Population ◽  
Linear Models ◽  
Emerging Diseases ◽  
Flea Species ◽  
Natural Areas ◽  
Population Densities ◽  
Dispersal Capacity ◽  
Standard Polymerase Chain Reaction ◽  
Well Differentiated ◽  
Semi Arid Region

Abstract BackgroundRickettsial diseases are considered important in public health due to their dispersal capacity determined by the particular characteristics of their reservoirs and / or vectors. Among the latter, fleas play an important role, since the vast majority of species parasitize wild and invasive rodents, so their detection is relevant to be able to monitor potential emerging diseases. The aim of this study was to detect, characterize, and compare Rickettsia spp. from the fleas of micromammals in areas with different human population densities in Chile.MethodsThe presence of Rickettsia spp. was evaluated by standard polymerase chain reaction (PCR) and sequencing in 1,315 fleas collected from 1,512 micromammals in 29 locations, with different human population densities in Chile. A generalized linear models (GLM) was used to identify the variables that may explain Rickettsia prevalence in fleas.ResultsDNA of Rickettsia spp. was identified in 13.2% (174 of 1,315) of fleas tested. Fifteen flea species were found to be Rickettsia-positive. The prevalence of Rickettsia spp. was higher in winter, semi-arid region and natural areas, and the infections in fleas varied between species of fleas. The prevalence of Rickettsia among flea species ranged from 0%–35.1%. Areas of lower human density have the highest prevalence of Rickettsia. The phylogenetic tree shows two well-differentiated clades. Rickettsia belli is positioned as basal in a clade. Another clade is subdivided into two subclades, and are related to Rickettsia of typhus group.ConclusionsTo our knowledge, this is the first report of the occurrence and molecular characterization of Rickettsia spp. in 15 species of fleas of micromammals in Chile. In this study, fleas were detected carrying Rickettsia DNA with zoonotic potential, mainly in villages and natural areas of Chile. Considering that there are differences in the prevalence of Rickettsia in fleas associated with different factors, more investigations are needed to further understand the ecology of Rickettsia in fleas and their implications for human health.

scholarly journals Molecular detection of Rickettsia in fleas from micromammals in Chile

2020 ◽  
Author(s):  
Lucila Moreno Salas ◽  
Mario Espinoza Carniglia ◽  
Nicol Lizama Schmeisser ◽  
Luis Gonzalo Torres Fuentes ◽  
María Carolina Silva de la Fuente ◽  
...  
Keyword(s):  
Human Population ◽  
Spotted Fever ◽  
Emerging Diseases ◽  
Flea Species ◽  
Spotted Fever Group ◽  
Natural Areas ◽  
Population Densities ◽  
Dispersal Capacity ◽  
Standard Polymerase Chain Reaction ◽  
Semi Arid Region

Abstract Background: Rickettsial diseases are considered important in public health due to their dispersal capacity determined by the particular characteristics of their reservoirs and/or vectors. Among the latter, fleas play an important role, since the vast majority of species parasitize wild and invasive rodents, so their detection is relevant to be able to monitor potential emerging diseases. The aim of this study was to detect, characterize, and compare Rickettsia spp. from the fleas of micromammals in areas with different human population densities in Chile. Methods: The presence of Rickettsia spp. was evaluated by standard polymerase chain reaction (PCR) and sequencing in 1315 fleas collected from 1512 micromammals in 29 locations, with different human population densities in Chile. A generalized linear model (GLM) was used to identify the variables that may explain Rickettsia prevalence in fleas. Results: DNA of Rickettsia spp. was identified in 13.2% (174 of 1315) of fleas tested. Fifteen flea species were found to be Rickettsia-positive. The prevalence of Rickettsia spp. was higher in winter, semi-arid region and natural areas, and the infection levels in fleas varied between species of flea. The prevalence of Rickettsia among flea species ranged between 0–35.1%. Areas of lower human density showed the highest prevalence of Rickettsia. The phylogenetic tree showed two well-differentiated clades with Rickettsia bellii positioned as basal in one clade. The second clade was subdivided into two subclades of species related to Rickettsia of the spotted fever group. Conclusions: To our knowledge, this is the first report of the occurrence and molecular characterization of Rickettsia spp. in 15 flea species of micromammals in Chile. In this study, fleas were detected carrying Rickettsia DNA with zoonotic potential, mainly in villages and natural areas of Chile. Considering that there are differences in the prevalence of Rickettsia in fleas associated with different factors, more investigations are needed to further understand the ecology of Rickettsia in fleas and their implications for human health.

scholarly journals Molecular detection of Rickettsia in fleas from micromammals in Chile

2020 ◽  
Author(s):  
Lucila Moreno Salas ◽  
Mario Espinoza Carniglia ◽  
Nicol Lizama Schmeisser ◽  
Luis Gonzalo Torres Fuentes ◽  
María Carolina Silva de la Fuente ◽  
...  
Keyword(s):  
Human Population ◽  
Linear Models ◽  
Spotted Fever ◽  
Emerging Diseases ◽  
Flea Species ◽  
Spotted Fever Group ◽  
Natural Areas ◽  
Population Densities ◽  
Dispersal Capacity ◽  
Standard Polymerase Chain Reaction

Abstract Background: Rickettsial diseases are considered important in public health due to their dispersal capacity determined by the particular characteristics of their reservoirs and / or vectors. Among the latter, fleas play an important role, since the vast majority of species parasitize wild and invasive rodents, so their detection is relevant to be able to monitor potential emerging diseases. The aim of this study was to detect, characterize, and compare Rickettsia spp. from the fleas of micromammals in areas with different human population densities in Chile.Methods: The presence of Rickettsia spp. was evaluated by standard polymerase chain reaction (PCR) and sequencing in 1,315 fleas collected from 1,512 micromammals in 29 locations, with different human population densities in Chile. A generalized linear models (GLM) was used to identify the variables that may explain Rickettsia prevalence in fleas. Results: DNA of Rickettsia spp. was identified in 13.2% (174 of 1,315) of fleas tested. Fifteen flea species were found to be Rickettsia-positive. The prevalence of Rickettsia spp. was higher in winter, semi-arid region and natural areas, and the infections in fleas varied between species of fleas. The prevalence of Rickettsia among flea species ranged from 0%–35.1%. Areas of lower human density have the highest prevalence of Rickettsia. The phylogenetic tree shows two well-differentiated clades. Rickettsia bellii is positioned as basal in a clade. Another clade is subdivided into two subclades, and are related to Rickettsia of spotted fever group.Conclusions: To our knowledge, this is the first report of the occurrence and molecular characterization of Rickettsia spp. in 15 species of fleas of micromammals in Chile. In this study, fleas were detected carrying Rickettsia DNA with zoonotic potential, mainly in villages and natural areas of Chile. Considering that there are differences in the prevalence of Rickettsia in fleas associated with different factors, more investigations are needed to further understand the ecology of Rickettsia in fleas and their implications for human health.

scholarly journals Molecular detection of Rickettsia in fleas from micromammals in Chile

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Lucila Moreno-Salas ◽  
Mario Espinoza-Carniglia ◽  
Nicol Lizama-Schmeisser ◽  
Luis Gonzalo Torres-Fuentes ◽  
María Carolina Silva-de La Fuente ◽  
...  
Keyword(s):  
Human Population ◽  
Spotted Fever ◽  
Emerging Diseases ◽  
Flea Species ◽  
Spotted Fever Group ◽  
Natural Areas ◽  
Population Densities ◽  
Dispersal Capacity ◽  
Standard Polymerase Chain Reaction ◽  
Semi Arid Region

Abstract Background Rickettsial diseases are considered important in public health due to their dispersal capacity determined by the particular characteristics of their reservoirs and/or vectors. Among the latter, fleas play an important role, since the vast majority of species parasitize wild and invasive rodents, so their detection is relevant to be able to monitor potential emerging diseases. The aim of this study was to detect, characterize, and compare Rickettsia spp. from the fleas of micromammals in areas with different human population densities in Chile. Methods The presence of Rickettsia spp. was evaluated by standard polymerase chain reaction (PCR) and sequencing in 1315 fleas collected from 1512 micromammals in 29 locations, with different human population densities in Chile. A generalized linear model (GLM) was used to identify the variables that may explain Rickettsia prevalence in fleas. Results DNA of Rickettsia spp. was identified in 13.2% (174 of 1315) of fleas tested. Fifteen flea species were found to be Rickettsia-positive. The prevalence of Rickettsia spp. was higher in winter, semi-arid region and natural areas, and the infection levels in fleas varied between species of flea. The prevalence of Rickettsia among flea species ranged between 0–35.1%. Areas of lower human density showed the highest prevalence of Rickettsia. The phylogenetic tree showed two well-differentiated clades with Rickettsia bellii positioned as basal in one clade. The second clade was subdivided into two subclades of species related to Rickettsia of the spotted fever group. Conclusions To our knowledge, this is the first report of the occurrence and molecular characterization of Rickettsia spp. in 15 flea species of micromammals in Chile. In this study, fleas were detected carrying Rickettsia DNA with zoonotic potential, mainly in villages and natural areas of Chile. Considering that there are differences in the prevalence of Rickettsia in fleas associated with different factors, more investigations are needed to further understand the ecology of Rickettsia in fleas and their implications for human health.

scholarly journals Molecular Detection of Rickettsia in Fleas from Micromammals in Chile with Potential Public Health Implications

2020 ◽  
Author(s):  
Lucila Moreno Salas ◽  
Mario Espinoza Carniglia ◽  
Nicol Lizama Schmeisser ◽  
Luis Gonzalo Torres Fuentes ◽  
María Carolina Silva de la Fuente ◽  
...  
Keyword(s):  
Public Health ◽  
Human Population ◽  
Pathogenic Bacteria ◽  
Pcr Amplification ◽  
Urban Environments ◽  
Flea Species ◽  
Population Densities ◽  
Rural And Urban ◽  
Polymerase Chain ◽  
Well Differentiated

Abstract BackgroundFleas are important vectors of pathogenic bacteria that pose public health concerns worldwide, including Rickettsia. Micromammals, and especially rodents, are the main flea hosts, therefore they play a fundamental role in the spread of flea-borne diseases and various species of rodent fleas can also parasitize humans. In addition to this, many rodent species are capable of inhabiting wild environments and adapting to rural and urban environments, which could favor a continuous gradient of transmission between domestic and wild species. The aim of this study was to detect, characterize, and compare Rickettsia spp. from the fleas of micromammals in areas with different human population densities in Chile.MethodsTo determine Rickettsia in fleas of micromammals, we analyzed 1,315 fleas obtained from 1,512 micromammals, which were captured in 29 locations with different human population densities in Chile. We used polymerase chain reaction (PCR) amplification of the gltA, rpoB, and ompB genes to detect Rickettsia in fleas.ResultsThe prevalence of Rickettsia among flea species ranged from 0%–35.1%. Fifteen flea species were found to be Rickettsia-positive. Areas of lower human density have the highest prevalence of Rickettsia. The phylogenetic tree shows two well-differentiated clades. Rickettsia belli is positioned as basal in a clade. Another clade is subdivided into two subclades, and are related to Rickettsia of typhus group.ConclusionsConsidering that fleas are generalist parasites, and that they are frequently found and abundant in rodents, which are closely related to humans, the detection of potential emerging zoonotic pathogens in rodent fleas highlights the risk of infection to humans.

scholarly journals What wild dogs want: habitat selection differs across life stages and orders of selection in a wide-ranging carnivore

BMC Zoology ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Helen M. K. O’Neill ◽  
Sarah M. Durant ◽  
Rosie Woodroffe
Keyword(s):  
Habitat Selection ◽  
Human Population ◽  
Life Stage ◽  
Selection Function ◽  
Order Selection ◽  
Life Stages ◽  
Population Densities ◽  
Selection For ◽  
Wild Dogs ◽  
Selection Of

Abstract Background Habitat loss is a key threat to the survival of many species. Habitat selection studies provide key information for conservation initiatives by identifying important habitat and anthropogenic characteristics influencing the distribution of threatened species in changing landscapes. However, assumptions about the homogeneity of individual choices on habitat, regardless of life stage, are likely to result in inaccurate assessment of conservation priorities. This study addresses a knowledge gap in how animals at different life stages diverge in how they select habitat and anthropogenic features, using a free-ranging population of African wild dogs living in a human-dominated landscape in Kenya as a case study. Using GPS collar data to develop resource selection function and step selection function models, this study investigated differences between second order (selection of home range across a landscape) and third order (selection of habitat within the home range) habitat selection across four life history stages when resource requirements may vary: resident-non-denning, resident-heavily-pregnant, resident-denning and dispersing. Results Wild dogs showed strong second order selection for areas with low human population densities and areas close to rivers and roads. More rugged areas were also generally selected, as were areas with lower percentage tree cover. The strength of selection for habitat variables varied significantly between life stages; for example, dispersal groups were more tolerant of higher human population densities, whereas denning and pregnant packs were least tolerant of such areas. Conclusions Habitat selection patterns varied between individuals at different life stages and at different orders of selection. These analyses showed that denning packs and dispersal groups, the two pivotal life stages which drive wild dog population dynamics, exhibited different habitat selection to resident-non-breeding packs. Dispersal groups were relatively tolerant of higher human population densities whereas denning packs preferred rugged, remote areas. Evaluating different orders of selection was important as the above trends may not be detectable at all levels of selection for all habitat characteristics. Our analyses demonstrate that when life stage information is included in analyses across different orders of selection, it improves our understanding of how animals use their landscapes, thus providing important insights to aid conservation planning.

scholarly journals Changes in Human Population Density and Protected Areas in Terrestrial Global Biodiversity Hotspots, 1995–2015

Land ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 136 ◽  
Author(s):  
Caitlin Cunningham ◽  
Karen Beazley
Keyword(s):  
Population Density ◽  
Protected Areas ◽  
Protected Area ◽  
Human Population ◽  
Area Coverage ◽  
Biodiversity Hotspots ◽  
Population Densities ◽  
Human Population Density ◽  
Global Average ◽  
Global Biodiversity

Biodiversity hotspots are rich in endemic species and threatened by anthropogenic influences and, thus, considered priorities for conservation. In this study, conservation achievements in 36 global biodiversity hotspots (25 identified in 1988, 10 added in 2011, and one in 2016) were evaluated in relation to changes in human population density and protected area coverage between 1995 and 2015. Population densities were compared against 1995 global averages, and percentages of protected area coverage were compared against area-based targets outlined in Aichi target 11 of the Convention on Biological Diversity (17% by 2020) and calls for half Earth (50%). The two factors (average population density and percent protected area coverage) for each hotspot were then plotted to evaluate relative levels of threat to biodiversity conservation. Average population densities in biodiversity hotspots increased by 36% over the 20-year period, and were double the global average. The protected area target of 17% is achieved in 19 of the 36 hotspots; the 17 hotspots where this target has not been met are economically disadvantaged areas as defined by Gross Domestic Product. In 2015, there are seven fewer hotspots (22 in 1995; 15 in 2015) in the highest threat category (i.e., population density exceeding global average, and protected area coverage less than 17%). In the lowest threat category (i.e., population density below the global average, and a protected area coverage of 17% or more), there are two additional hotspots in 2015 as compared to 1995, attributable to gains in protected area. Only two hotspots achieve a target of 50% protection. Although conservation progress has been made in most global biodiversity hotspots, additional efforts are needed to slow and/or reduce population density and achieve protected area targets. Such conservation efforts are likely to require more coordinated and collaborative initiatives, attention to biodiversity objectives beyond protected areas, and support from the global community.

scholarly journals Definition of the Caribbean Islands biogeographic region, with checklist and recommendations for standardized common names of amphibians and reptiles

2019 ◽  
pp. 1-53
Author(s):  
S. Blair Hedges ◽  
Robert Powell ◽  
Robert W. Henderson ◽  
Sarah Hanson ◽  
John C. Murphy
Keyword(s):  
South America ◽  
Human Population ◽  
Biological Study ◽  
Population Densities ◽  
The Bahamas ◽  
Caribbean Islands ◽  
Biogeographic Region ◽  
The Caribbean ◽  
Definition Of ◽  
Conservation Threats

To facilitate biological study we define “Caribbean Islands” as a biogeographic region that includes the Antilles, the Bahamas, and islands bordering Central and South America separated from mainland areas by at least 20 meters of water depth. The advantages of this definition are that it captures nearly all islands with endemic species and with at least some Antillean-derived species, and still circumscribes a region of high biodiversity and biogeographic significance. We argue that Caribbean islands, in this expanded sense, are also cohesive from a conservation standpoint in that they share high human population densities and similar conservation threats. A disadvantage of this definition, strictly applied, is that it includes some islands (e.g., Trinidad) that have mostly mainland species. However, we propose that researchers can increase the stringency of the definition so that it is less inclusive, and make comparisons between different definitions as needed. We provide an updated checklist with standardized common English names for the 1,013 species of amphibians and reptiles occurring in the region, along with principles for constructing common names.

scholarly journals Comparison of Rhesus and Cynomolgus macaques as an authentic model for COVID-19

2020 ◽  
Author(s):  
Francisco J. Salguero ◽  
Andrew D. White ◽  
Gillian S. Slack ◽  
Susan A. Fotheringham ◽  
Kevin R. Bewley ◽  
...  
Keyword(s):  
Immune Responses ◽  
Lower Respiratory Tract ◽  
Human Population ◽  
Emerging Diseases ◽  
Convincing Evidence ◽  
Safety And Efficacy ◽  
Cynomolgus Macaques ◽  
Lung Histopathology ◽  
Novel Coronavirus ◽  
Study Species

ABSTRACTA novel coronavirus, SARS-CoV-2, has been identified as the causative agent of the current COVID-19 pandemic. Animal models, and in particular non-human primates, are essential to understand the pathogenesis of emerging diseases and to the safety and efficacy of novel vaccines and therapeutics. Here, we show that SARS-CoV-2 replicates in the upper and lower respiratory tract and causes pulmonary lesions in both rhesus and cynomolgus macaques, resembling the mild clinical cases of COVID-19 in humans. Immune responses against SARS-CoV-2 were also similar in both species and equivalent to those reported in milder infections and convalescent human patients. Importantly, we have devised a new method for lung histopathology scoring that will provide a metric to enable clearer decision making for this key endpoint. In contrast to prior publications, in which rhesus are accepted to be the optimal study species, we provide convincing evidence that both macaque species authentically represent mild to moderate forms of COVID-19 observed in the majority of the human population and both species should be used to evaluate the safety and efficacy of novel and repurposed interventions against SARS-CoV-2. Accessing cynomolgus macaques will greatly alleviate the pressures on current rhesus stocks.

Rare and Unusual Raptors of Northern Belize

EDIS ◽  
2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Venetia Briggs-Gonzalez ◽  
Elizabeth Scarlett ◽  
Justin Dalaba ◽  
Frank J Mazzotti
Keyword(s):  
Central America ◽  
Human Population ◽  
Natural State ◽  
Natural Areas ◽  
Conservation Ethics

The second smallest country in Central America, Belize has a stunning array of natural areas that is only matched by the remarkable diversity of animals that call them home. A small human population and strong conservation ethics have preserved nearly 75 percent of Belize in its natural state. This guide lists some of the rarer and more unusual raptors you might encounter while birding in northern Belize.

Invasions can drive marine disease dynamics

2020 ◽  
pp. 115-138
Author(s):  
Katrina M. Pagenkopp Lohan ◽  
Gregory M. Ruiz ◽  
Mark E. Torchin
Keyword(s):  
Human Population ◽  
Emerging Diseases ◽  
Marine Invasions ◽  
History Of ◽  
Baseline Knowledge ◽  
Living Organisms ◽  
And Function ◽  
Transfer Mechanisms ◽  
Marine Parasite

Over half the world’s human population lives near the coast, with diverse impacts on the structure and function of coastal ecosystems, including the introduction of parasites that result from shipborne trade, aquaculture, and other human-aided dispersal. The scale of these activities has accelerated through time, expanding the potential for new introductions and subsequent impacts in coastal systems. However, the extent, dynamics, and impacts of marine parasite invasions are relatively unexplored compared to free-living organisms. This chapter (1) advances a framework to consider which parasites are most likely to invade, specifically considering diverse life-history traits, (2) reviews the current baseline knowledge for transfer mechanisms and the history of marine invasions, and (3) considers the ecological and evolutionary implications of parasite invasion. While recent advances have aided our understanding of the intersection of disease and invasion ecology, a closer look at the smallest disease-causing organisms will open new avenues for understanding the full scope of parasite invasions and their role in emerging diseases.

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