scholarly journals Seasonal and Gender Differences in Presence of Rickettsia felis and Blood meals Provide Additional Evidence of a Vector Role for Mosquitoes

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Jilei Zhang ◽  
Guangwu Lu ◽  
Patrick John Kelly ◽  
Chengming Wang
Keyword(s):  
Gender Differences ◽  
Blood Meal ◽  
Mosquito Species ◽  
Spotted Fever ◽  
Infection Model ◽  
Spotted Fever Group ◽  
Egg Hatching ◽  
Rickettsia Felis ◽  
And Gender

Rickettsia felis belongs to spotted fever group Rickettsia and is an emerging human pathogen most commonly transmitted by a range of fleas and ticks. While recent evidence has suggested mosquitoes are infected with R. felis, there is little information about the role of mosquitoes in the organism’s transmission. In this study, around 100 mosquitoes were collected monthly between 2013 and 2014 from the same residential dwelling at Yangzhou, China. The collected mosquitoes were identified for their species and gender, followed by gltA-based PCR and hydroxymethylbilane synthase-based PCR to determine the prevalence of Rickettsia and blood meal. Three mosquito species (Culex pipiens: 76%, 996/1,304; C. tritaeniorhynchus: 17%, 216/1,304; Aedes albopictus: 7%, 92/1,304) were identified. For 1,088 female mosquitoes, 31% of them n=336 were positive for blood meal and 7% n=77 carried R. felis DNA. In a strong contrast, none of the 216 male mosquitoes were positive for blood meal but two males were positive for Rickettsia. Interestingly, 63% of R. felis-positive mosquitoes (50/79) were negative for blood meal, being significantly higher than 37% of mosquitoes and being positive for both R. felis and blood meal P=0.008. Furthermore, we compared the prevalence of Rickettsia and blood meal in the mosquitoes collected in the months with temperature below and above 23°C, the minimum temperature required for mosquito egg hatching. Mosquitoes captured in the months below 23°C showed significant higher positivity of R. felis(71/936, 7.6% vs. 8/368, 2.2%; P=0.002) and blood meal (294/936, 31.4% vs. 36/368, 9.8%; P<10−4) than in the months above 23°C. Collectively, the seasonal and gender differences of R. felis and blood meal in mosquitoes add to the existing evidence, supporting a potential vector role of mosquitoes in the transmission of R. felis. Studies with a R. felis infection model covering the full life cycle of mosquitoes is necessary to unambiguously prove the transstadial and transovarial transmission of R. felis in mosquitoes.

scholarly journals Pathogens, endosymbionts, and blood-meal sources of host-seeking ticks in the fast-changing Maasai Mara wildlife ecosystem

2020 ◽  
Author(s):  
Joseph Wang’ang’a Oundo ◽  
Jandouwe Villinger ◽  
Maamun Jeneby ◽  
George Ong’amo ◽  
Moses Yongo Otiende ◽  
...  
Keyword(s):  
Blood Meal ◽  
Spotted Fever ◽  
Spotted Fever Group ◽  
African Buffalo ◽  
Anaplasma Ovis ◽  
Host Seeking ◽  
African Tick Bite Fever ◽  
Questing Ticks ◽  
Blood Meals

AbstractBackgroundThe role of questing ticks in the epidemiology of tick-borne diseases in Kenya’s Maasai Mara National Reserve (MMNR), an ecosystem with intensified human-wildlife-livestock interactions, remains poorly understood. Therefore, we carried out a survey of the diversity of questing ticks, their blood-meal hosts, and tick-borne pathogens to understand potential effects to human and livestock health.MethodsQuesting ticks were collected by flagging and hand picks from vegetation in 25 localities and identified based on morphologic and molecular criteria. We used PCR with high-resolution melting (HRM) analysis, and sequencing to identify Anaplasma, Babesia, Coxiella, Ehrlichia, Rickettsia, and Theileria pathogen diversities and blood meals in 231 tick pools.ResultsA total of 1,465 host-seeking ticks were collected, including Rhipicephalus appendiculatus (n = 1,125), Rhipicephalus pulchellus (n = 6), Rhipicephalus evertsi (n = 5), Amblyomma cf. gemma (n = 178), Amblyomma gemma (n = 145), Amblyomma variegatum (n = 4), Amblyomma sp. (n = 1), and Haemaphysalis leachi (n = 1). Remnant blood-meals from humans, wildebeest, and African buffalo were detected in Rh. appendiculatus, goat in Rh. evertsi, sheep in Am. gemma, and cattle in Am. variegatum. Rickettsia africae was detected in Am. gemma (1/25 pools) that had blood-meal remnant from sheep and Am. variegatum (4/25 pools) that had fed on cattle. Rickettsia spp. were found in Am. gemma (4/25 pools) and Rh. evertsi (1/4 pools). Anaplasma ovis was detected in Rh. appendiculatus (1/172 pools) and Rh. evertsi (1/4 pools), while Anaplasma bovis was detected in Rh. appendiculatus (1/172 pools). Theileria parva was detected in Rh. appendiculatus (27/172 pools). Babesia, Ehrlichia and Coxiella pathogens were not found in any ticks. Unexpectedly, diverse Coxiella sp. endosymbionts were detected in all tick genera (174/231 pools).ConclusionsThe data shows that ticks from the rapidly-changing MMNR are infected with zoonotic R.africae and unclassified Rickettsia spp, demonstrating the persistent risk of African tick-bite fever and other and Spotted Fever Group rickettsioses to local dwellers and visitors to the Maasai Mara ecosystem. Protozoan pathogens that may pose risk to livestock production were also identified. We also highlight possible existence of morphotypic variants of Amblyomma species, based on the observation of Ambyomma cf. gemma, which may be potential human parasites or emergent disease vectors. Our findings also demonstrate that questing ticks in this ecosystem have dynamic vertebrate blood sources including humans, wildlife and domestic animals, which may amplify transmission of tickborne zoonoses and livestock diseases. Further studies are needed to determine the role of Coxiella endosymbionts in tick physiology and vector competence.

Do They Really Mean It? Children’s Inference of Speaker Intentions and the Role of Age and Gender

2019 ◽  
Vol 63 (4) ◽  
pp. 689-712
Author(s):  
K. Rothermich ◽  
O. Caivano ◽  
L.J. Knoll ◽  
V. Talwar
Keyword(s):  
Gender Differences ◽  
Young Adults ◽  
Video Clip ◽  
Age And Gender ◽  
Video Clips ◽  
Age And Gender Differences ◽  
Speaker Intentions ◽  
And Gender

Interpreting other people’s intentions during communication represents a remarkable challenge for children. Although many studies have examined children’s understanding of, for example, sarcasm, less is known about their interpretation. Using realistic audiovisual scenes, we invited 124 children between 8 and 12 years old to watch video clips of young adults using different speaker intentions. After watching each video clip, children answered questions about the characters and their beliefs, and the perceived friendliness of the speaker. Children’s responses reveal age and gender differences in the ability to interpret speaker belief and social intentions, especially for scenarios conveying teasing and prosocial lies. We found that the ability to infer speaker belief of prosocial lies and to interpret social intentions increases with age. Our results suggest that children at the age of 8 years already show adult-like abilities to understand literal statements, whereas the ability to infer specific social intentions, such as teasing and prosocial lies, is still developing between the age of 8 and 12 years. Moreover, girls performed better in classifying prosocial lies and sarcasm as insincere than boys. The outcomes expand our understanding of how children observe speaker intentions and suggest further research into the development of teasing and prosocial lie interpretation.

scholarly journals Exploring Gender Differences in Support for Rightist Parties: The Role of Party and Gender Ideology

2018 ◽  
Vol 14 (01) ◽  
pp. 80-105 ◽  
Author(s):  
Rosie Campbell ◽  
Silvia Erzeel
Keyword(s):  
Gender Differences ◽  
Western Europe ◽  
Gender Ideology ◽  
Radical Right ◽  
Special Issue ◽  
Gender Ideologies ◽  
Populist Radical Right ◽  
And Gender ◽  
The Right

This contribution to the Special Issue on Gender and Conservatism uses expert and election surveys to explore the extent to which the feminist or traditional gender ideology of parties of the right relates to their economic and liberal/authoritarian ideology. We show that although parties of the left generally espouse more feminist ideologies than parties of the right, there are a significant number of rightist parties in Western Europe that combine laissez-faire economic values with liberal feminist ideals. That said, there is more homogeneity among parties of the populist radical right than rightist parties more generally. We find that despite some variation in their gender ideology, parties of the populist radical right overwhelmingly—with the exception of one party in the Netherlands—continue to adopt traditional or antifeminist gender ideologies. In terms of attracting women voters, we find that rightist parties who adopt a feminist gender ideology are able to attract more women voters than other parties of the right. We detect several examples of center-right parties that include feminist elements in their gender ideologies and are able to win over larger proportions of women voters than rightist parties that fail to adopt feminist positions.

The Role of Deceptive Communication and Gender in Shaping Online Dating Interactions

2019 ◽  
pp. 460-474
Author(s):  
Anna Maria Kuzio
Keyword(s):  
Gender Differences ◽  
General Population ◽  
Online Dating ◽  
Significant Others ◽  
Online Environment ◽  
Men And Women ◽  
Significant Difference ◽  
And Gender ◽  
Deceptive Communication

Online dating is becoming an increasingly used method for meeting significant others. As the research of lying behavior has advanced so has the technique of detecting the act of lying, especially in the online environment where deception is more likely to happen. The aim of this chapter is to simplify the perception of lying behavior to the general population and examine gender differences of lying behavior, namely, to verify whether one can observe a statistically significant difference in the speech behavior and exploitation of lying cues among men and women. The study shows correlation between gender and deception in online environment.

Application of the Numerical Characteristic of Formal Order Analysis of the Prokaryotic Genomes for Reclassification within the Genus Rickettsia

2016 ◽  
Vol 11 (2) ◽  
pp. 336-350 ◽  
Author(s):  
С.Н. Шпынов ◽  
S.N. Shpynov
Keyword(s):  
Spotted Fever ◽  
Numerical Characteristic ◽  
Spotted Fever Group ◽  
Rickettsia Felis ◽  
New Approach ◽  
Order Analysis ◽  
Ancestral Group ◽  
Prokaryotic Genomes ◽  
Information Chain

Genomes representing Rickettsiaceae family were analyzed using formal order analysis (FOA) of information chain in order to develop a new approach for the classification of prokaryotes. Average remoteness – the numerical characteristic of order was used to compare the genomes. FOA allows one to directly take into account arrangement of nucleotides in each sequence. The obtained results clarified the previously known classification. In addition Rickettsia felis group was discovered between the ancestral group and spotted fever group (SFG) and R. akari group located between the SFG and genus Orientia. Software used for the analysis of nucleotide sequences with FOA is freely available at http://foarlab.org.

scholarly journals Endothelial Exosome Plays a Functional Role during Rickettsial Infection

mBio ◽  
2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Yakun Liu ◽  
Changcheng Zhou ◽  
Zhengchen Su ◽  
Qing Chang ◽  
Yuan Qiu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Functional Role ◽  
Spotted Fever ◽  
Endothelial Barrier ◽  
Normal Brain ◽  
Spotted Fever Group ◽  
Sequencing Analysis ◽  
Barrier Dysfunction ◽  
Rickettsial Infection

ABSTRACT Spotted fever group rickettsioses (SFRs) are devastating human infections. Vascular endothelial cells (ECs) are the primary targets of rickettsial infection. Edema resulting from EC barrier dysfunction occurs in the brain and lungs in most cases of lethal SFR, but the underlying mechanisms remain unclear. The aim of the study was to explore the potential role of Rickettsia-infected, EC-derived exosomes (Exos) during infection. Using size exclusion chromatography (SEC), we purified Exos from conditioned, filtered, bacterium-free media collected from Rickettsia parkeri-infected human umbilical vein ECs (HUVECs) (R-ECExos) and plasma of Rickettsia australis- or R. parkeri-infected mice (R-plsExos). We observed that rickettsial infection increased the release of heterogeneous plsExos, but endothelial exosomal size, morphology, and production were not significantly altered following infection. Compared to normal plsExos and ECExos, both R-plsExos and R-ECExos induced dysfunction of recipient normal brain microvascular ECs (BMECs). The effect of R-plsExos on mouse recipient BMEC barrier function is dose dependent. The effect of R-ECExos on human recipient BMEC barrier function is dependent on the exosomal RNA cargo. Next-generation sequencing analysis and stem-loop quantitative reverse transcription-PCR (RT-qPCR) validation revealed that rickettsial infection triggered the selective enrichment of endothelial exosomal mir-23a and mir-30b, which potentially target the endothelial barrier. To our knowledge, this is the first report on the functional role of extracellular vesicles following infection by obligately intracellular bacteria. IMPORTANCE Spotted fever group rickettsioses are devastating human infections. Vascular endothelial cells are the primary targets of infection. Edema resulting from endothelial barrier dysfunction occurs in the brain and lungs in most cases of lethal rickettsioses, but the underlying mechanisms remain unclear. The aim of the study was to explore the potential role of Rickettsia-infected, endothelial cell-derived exosomes during infection. We observed that rickettsial infection increased the release of heterogeneous plasma Exos, but endothelial exosomal size, morphology, and production were not significantly altered following infection. Rickettsia-infected, endothelial cell-derived exosomes induced dysfunction of human recipient normal brain microvascular endothelial cells. The effect is dependent on the exosomal RNA cargo. Next-generation sequencing analysis revealed that rickettsial infection triggered the selective enrichment of endothelial exosomal mir-23a and mir-30b, which potentially target the endothelial barrier. To our knowledge, this is the first report on the functional role of extracellular vesicles following infection by obligately intracellular bacteria.

scholarly journals Endothelial exosome plays functional role during rickettsial infection

2020 ◽  
Author(s):  
Yakun Liu ◽  
Changcheng Zhou ◽  
Zhengchen Su ◽  
Qing Chang ◽  
Yuan Qiu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Functional Role ◽  
Spotted Fever ◽  
Endothelial Barrier ◽  
Normal Brain ◽  
Spotted Fever Group ◽  
Sequencing Analysis ◽  
Barrier Dysfunction ◽  
Rickettsial Infection

AbstractSpotted fever group rickettsioses (SFRs) are devastating human infections. Vascular endothelial cells (ECs) are the primary targets of infection. Edema resulting from EC barrier dysfunction occurs in the brain and lungs in most cases of lethal SFR, but the underlying mechanisms remain unclear. The aim of the study is to explore the potential role of Rickettsia (R)-infected, EC-derived exosomes (Exos) during infection. Using size-exclusion chromatography (SEC), we purified Exos from conditioned, filtered, bacteria-free media collected from R-infected human umbilical vein ECs (HUVECs) (R-ECExos) and plasma of R-infected mice (R-plsExos). We observed that rickettsial infection increases the release of heterogeneous plsExos, but endothelial exosomal size, morphology, and production were not significantly altered following infection. Compared to normal plsExos and ECExos, both R-plsExos and R-ECExos induced dysfunction of recipient normal brain microvascular Ecs (BMECs). The effect of R-plsExos on mouse recipient BMEC barrier function is dose-dependent. The effect of R-ECExos on human recipient BMEC barrier function is dependent on exosomal RNA cargo. Next-generation sequencing analysis and stem-loop quantitative reverse transcription PCR (RT-qPCR) validation revealed that R infection triggered the selective enrichment of endothelial exosomal mir-23a and mir-30b, which target the endothelial barrier. To our knowledge, this is the first report on the functional role of extracellular vesicles following infection by obligately intracellular bacteria.ImportanceSpotted fever group rickettsioses are devastating human infections. Vascular endothelial cells are the primary targets of infection. Edema resulting from endothelial barrier dysfunction occurs in the brain and lungs in most cases of lethal rickettsioses, but the underlying mechanisms remain unclear. The aim of the study is to explore the potential role of Rickettsia-infected, endothelial cell-derived exosomes during infection. We observed that rickettsial infection increases the release of heterogeneous plasma Exos, but endothelial exosomal size, morphology, and production were not significantly altered following infection. Rickettsia-infected, endothelial cell-derived exosomes induced dysfunction of recipient normal brain microvascular endothelial cells. The effect is dependent on exosomal RNA cargo. Next-generation sequencing analysis revealed that rickettsial infection triggered the selective enrichment of endothelial exosomal mir-23a and mir-30b, which target the endothelial barrier. To our knowledge, this is the first report on the functional role of extracellular vesicles following infection by obligately intracellular bacteria.

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