scholarly journals Infection with endosymbiotic Spiroplasma disrupts tsetse (Glossina fuscipes fuscipes) metabolic and reproductive homeostasis

2021 ◽  
Vol 17 (9) ◽  
pp. e1009539
Author(s):  
Jae Hak Son ◽  
Brian L. Weiss ◽  
Daniela I. Schneider ◽  
Kiswend-sida M. Dera ◽  
Fabian Gstöttenmayer ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Negative Impact ◽  
Reproductive Fitness ◽  
Tsetse Flies ◽  
Glossina Fuscipes Fuscipes ◽  
African Trypanosomes ◽  
Endosymbiotic Bacteria ◽  
Tsetse Population ◽  
Resistance To Infection ◽  
Potential Impact

Tsetse flies (Glossina spp.) house a population-dependent assortment of microorganisms that can include pathogenic African trypanosomes and maternally transmitted endosymbiotic bacteria, the latter of which mediate numerous aspects of their host’s metabolic, reproductive, and immune physiologies. One of these endosymbionts, Spiroplasma, was recently discovered to reside within multiple tissues of field captured and laboratory colonized tsetse flies grouped in the Palpalis subgenera. In various arthropods, Spiroplasma induces reproductive abnormalities and pathogen protective phenotypes. In tsetse, Spiroplasma infections also induce a protective phenotype by enhancing the fly’s resistance to infection with trypanosomes. However, the potential impact of Spiroplasma on tsetse’s viviparous reproductive physiology remains unknown. Herein we employed high-throughput RNA sequencing and laboratory-based functional assays to better characterize the association between Spiroplasma and the metabolic and reproductive physiologies of G. fuscipes fuscipes (Gff), a prominent vector of human disease. Using field-captured Gff, we discovered that Spiroplasma infection induces changes of sex-biased gene expression in reproductive tissues that may be critical for tsetse’s reproductive fitness. Using a Gff lab line composed of individuals heterogeneously infected with Spiroplasma, we observed that the bacterium and tsetse host compete for finite nutrients, which negatively impact female fecundity by increasing the length of intrauterine larval development. Additionally, we found that when males are infected with Spiroplasma, the motility of their sperm is compromised following transfer to the female spermatheca. As such, Spiroplasma infections appear to adversely impact male reproductive fitness by decreasing the competitiveness of their sperm. Finally, we determined that the bacterium is maternally transmitted to intrauterine larva at a high frequency, while paternal transmission was also noted in a small number of matings. Taken together, our findings indicate that Spiroplasma exerts a negative impact on tsetse fecundity, an outcome that could be exploited for reducing tsetse population size and thus disease transmission.

scholarly journals Infection with endosymbiotic Spiroplasma disrupts tsetse (Glossina fuscipes fuscipes) metabolic and reproductive homeostasis

2021 ◽  
Author(s):  
Jae Hak Son ◽  
Brian L Weiss ◽  
Daniela l Schneider ◽  
Dera Kisweda-sida ◽  
Fabian Gstöttenmayer ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Negative Impact ◽  
Reproductive Fitness ◽  
Tsetse Flies ◽  
Glossina Fuscipes Fuscipes ◽  
African Trypanosomes ◽  
Endosymbiotic Bacteria ◽  
Tsetse Population ◽  
Resistance To Infection ◽  
Potential Impact

Tsetse flies ( Glossina spp.) house a population-dependent assortment of microorganisms that can include pathogenic African trypanosomes and maternally transmitted endosymbiotic bacteria, the latter of which mediate numerous aspects of their host’s metabolic, reproductive, and immune physiologies. One of these endosymbionts, Spiroplasma , was recently discovered to reside within multiple tissues of field captured and laboratory colonized tsetse flies grouped in the Palpalis subgenera. In various arthropods, Spiroplasma induces reproductive abnormalities and pathogen protective phenotypes. In tsetse, Spiroplasma infections also induce a protective phenotype by enhancing the fly’s resistance to infection with trypanosomes. However, the potential impact of Spiroplasma on tsetse’s viviparous reproductive physiology remains unknown. Herein we employed high-throughput RNA sequencing and laboratory-based functional assays to better characterize the association between Spiroplasma and the metabolic and reproductive physiologies of G. fuscipes fuscipes ( Gff ), a prominent vector of human disease. Using field-captured Gff , we discovered that Spiroplasma infection induces changes of sex-biased gene expression in reproductive tissues that may be critical for tsetse’s reproductive fitness. Using a Gff line composed of individuals heterogeneously infected with Spiroplasma , we observed that the bacterium and tsetse host compete for finite nutrients, which negatively impact female fecundity by increasing the length of intrauterine larval development. Additionally, we found that when males are infected with Spiroplasma , the motility of their sperm is compromised following transfer to the female spermatheca. As such, Spiroplasma infections appear to adversely impact male reproductive fitness by decreasing the competitiveness of their sperm. Finally, we determined that the bacterium is maternally transmitted to intrauterine larva at a high frequency, while paternal transmission was also noted in a small number of matings. Taken together, our findings indicate that Spiroplasma exerts a negative impact on tsetse fecundity, an outcome that could be exploited for reducing tsetse population size and thus disease transmission.

scholarly journals Implications of Microfauna-Host Interactions for Trypanosome Transmission Dynamics in Glossina fuscipes fuscipes in Uganda

2012 ◽  
Vol 78 (13) ◽  
pp. 4627-4637 ◽  
Author(s):  
Uzma Alam ◽  
Chaz Hyseni ◽  
Rebecca E. Symula ◽  
Corey Brelsfoard ◽  
Yineng Wu ◽  
...  
Keyword(s):  
Univariate Analysis ◽  
Spatial Diversity ◽  
The Other ◽  
Tsetse Flies ◽  
Infection Prevalence ◽  
Host Genotype ◽  
Glossina Fuscipes Fuscipes ◽  
Content Type ◽  
African Trypanosomes ◽  
Host Genetic

ABSTRACTTsetse flies (Diptera: Glossinidae) are vectors for African trypanosomes (Euglenozoa: kinetoplastida), protozoan parasites that cause African trypanosomiasis in humans (HAT) and nagana in livestock. In addition to trypanosomes, two symbiotic bacteria (Wigglesworthia glossinidiaandSodalis glossinidius) and two parasitic microbes,Wolbachiaand a salivary gland hypertrophy virus (SGHV), have been described in tsetse. Here we determined the prevalence of and coinfection dynamics betweenWolbachia, trypanosomes, and SGHV inGlossina fuscipes fuscipesin Uganda over a large geographical scale spanning the range of host genetic and spatial diversity. Using a multivariate analysis approach, we uncovered complex coinfection dynamics between the pathogens and statistically significant associations between host genetic groups and pathogen prevalence. It is important to note that these coinfection dynamics and associations with the host were not apparent by univariate analysis. These associations between host genotype and pathogen are particularly evident forWolbachiaand SGHV where host groups are inversely correlated forWolbachiaand SGHV prevalence. On the other hand, trypanosome infection prevalence is more complex and covaries with the presence of the other two pathogens, highlighting the importance of examining multiple pathogens simultaneously before making generalizations about infection and spatial patterns. It is imperative to note that these novel findings would have been missed if we had employed the standard univariate analysis used in previous studies. Our results are discussed in the context of disease epidemiology and vector control.

scholarly journals Mammalian African trypanosome VSG coat enhances tsetse’s vector competence

2016 ◽  
Vol 113 (25) ◽  
pp. 6961-6966 ◽  
Author(s):  
Emre Aksoy ◽  
Aurélien Vigneron ◽  
XiaoLi Bing ◽  
Xin Zhao ◽  
Michelle O’Neill ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Vector Competence ◽  
Wnt Signaling Pathway ◽  
Sub Saharan Africa ◽  
Parasite Development ◽  
Mammalian Host ◽  
Tsetse Flies ◽  
Insect Vector ◽  
Coat Proteins ◽  
African Trypanosomes

Tsetse flies are biological vectors of African trypanosomes, the protozoan parasites responsible for causing human and animal trypanosomiases across sub-Saharan Africa. Currently, no vaccines are available for disease prevention due to antigenic variation of the Variant Surface Glycoproteins (VSG) that coat parasites while they reside within mammalian hosts. As a result, interference with parasite development in the tsetse vector is being explored to reduce disease transmission. A major bottleneck to infection occurs as parasites attempt to colonize tsetse’s midgut. One critical factor influencing this bottleneck is the fly’s peritrophic matrix (PM), a semipermeable, chitinous barrier that lines the midgut. The mechanisms that enable trypanosomes to cross this barrier are currently unknown. Here, we determined that as parasites enter the tsetse’s gut, VSG molecules released from trypanosomes are internalized by cells of the cardia—the tissue responsible for producing the PM. VSG internalization results in decreased expression of a tsetse microRNA (mir-275) and interferes with the Wnt-signaling pathway and the Iroquois/IRX transcription factor family. This interference reduces the function of the PM barrier and promotes parasite colonization of the gut early in the infection process. Manipulation of the insect midgut homeostasis by the mammalian parasite coat proteins is a novel function and indicates that VSG serves a dual role in trypanosome biology—that of facilitating transmission through its mammalian host and insect vector. We detail critical steps in the course of trypanosome infection establishment that can serve as novel targets to reduce the tsetse’s vector competence and disease transmission.

scholarly journals The impact of Sosnowsky’s Hogweed on feeding guilds of birds

2021 ◽  
Author(s):  
Emilia Grzędzicka ◽  
Jiří Reif
Keyword(s):  
Negative Impact ◽  
Bird Community ◽  
Plant Invasions ◽  
Bird Communities ◽  
Feeding Guilds ◽  
Guild Structure ◽  
Feeding Guild ◽  
Potential Impact ◽  
Underlying Mechanisms ◽  
The Impact

AbstractPlant invasions alter bird community composition worldwide, but the underlying mechanisms still require exploration. The investigation of feeding guild structure of bird communities can be informative in respect to the potential impact of invasion features on the availability of food for birds. For this purpose, we focused on determining the influence of the invasive Sosnowsky’s Hogweed Heracleum sosnowskyi on the abundance of birds from various feeding guilds. In spring and summer 2019, birds were counted three times on 52 pairs of sites (control + Heracleum) in southern Poland, at various stages of Sosnowsky’s Hogweed development (i.e. sprouting, full growth and flowering, all corresponding to respective bird counts). We have shown that the presence of invader negatively affected the abundance of birds from all feeding guilds. However, a closer examination of the invaded sites uncovered that responses of particular guilds differed in respect to development stages expressed by a set of characteristics of the invader. Ground and herb insectivores were more common on plots with a higher number of the invader, while the abundance of bush and tree insectivores was negatively correlated with hogweeds’ height. Granivores were not affected by the invader’s features, while the abundance of omnivores was negatively related to the number of flowering hogweeds. Besides showing the general negative impact of the invader on different feeding guilds, our research has shown that certain aspects of Sosnowsky’s Hogweed invasion may support or depress occurrence of different birds on invaded plots. Knowledge of these aspects may facilitate our capacity for coping with challenges the invasive plants put in front of bird conservationists.

scholarly journals Glucose Signaling Is Important for Nutrient Adaptation during Differentiation of Pleomorphic African Trypanosomes

mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Yijian Qiu ◽  
Jillian E. Milanes ◽  
Jessica A. Jones ◽  
Rooksana E. Noorai ◽  
Vijay Shankar ◽  
...  
Keyword(s):  
Life Cycle ◽  
Glucose Sensing ◽  
Negative Regulator ◽  
Bloodstream Form ◽  
Tsetse Flies ◽  
Insect Vector ◽  
Rapid Reduction ◽  
African Trypanosomes ◽  
Procyclic Form ◽  
African Trypanosome

ABSTRACT The African trypanosome has evolved mechanisms to adapt to changes in nutrient availability that occur during its life cycle. During transition from mammalian blood to insect vector gut, parasites experience a rapid reduction in environmental glucose. Here we describe how pleomorphic parasites respond to glucose depletion with a focus on parasite changes in energy metabolism and growth. Long slender bloodstream form parasites were rapidly killed as glucose concentrations fell, while short stumpy bloodstream form parasites persisted to differentiate into the insect-stage procyclic form parasite. The rate of differentiation was lower than that triggered by other cues but reached physiological rates when combined with cold shock. Both differentiation and growth of resulting procyclic form parasites were inhibited by glucose and nonmetabolizable glucose analogs, and these parasites were found to have upregulated amino acid metabolic pathway component gene expression. In summary, glucose transitions from the primary metabolite of the blood-stage infection to a negative regulator of cell development and growth in the insect vector, suggesting that the hexose is not only a key metabolic agent but also an important signaling molecule. IMPORTANCE As the African trypanosome Trypanosoma brucei completes its life cycle, it encounters many different environments. Adaptation to these environments includes modulation of metabolic pathways to parallel the availability of nutrients. Here, we describe how the blood-dwelling life cycle stages of the African trypanosome, which consume glucose to meet their nutritional needs, respond differently to culture in the near absence of glucose. The proliferative long slender parasites rapidly die, while the nondividing short stumpy parasite remains viable and undergoes differentiation to the next life cycle stage, the procyclic form parasite. Interestingly, a sugar analog that cannot be used as an energy source inhibited the process. Furthermore, the growth of procyclic form parasite that resulted from the event was inhibited by glucose, a behavior that is similar to that of parasites isolated from tsetse flies. Our findings suggest that glucose sensing serves as an important modulator of nutrient adaptation in the parasite.

scholarly journals Modelling the impact of climate change on the distribution and abundance of tsetse in Northern Zimbabwe

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Joshua Longbottom ◽  
Cyril Caminade ◽  
Harry S. Gibson ◽  
Daniel J. Weiss ◽  
Steve Torr ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Spatial Resolution ◽  
Air Temperature ◽  
Mechanistic Model ◽  
Tsetse Flies ◽  
Weather Station ◽  
Catch Data ◽  
Tsetse Population ◽  
The Impact

Abstract Background Climate change is predicted to impact the transmission dynamics of vector-borne diseases. Tsetse flies (Glossina) transmit species of Trypanosoma that cause human and animal African trypanosomiasis. A previous modelling study showed that temperature increases between 1990 and 2017 can explain the observed decline in abundance of tsetse at a single site in the Mana Pools National Park of Zimbabwe. Here, we apply a mechanistic model of tsetse population dynamics to predict how increases in temperature may have changed the distribution and relative abundance of Glossina pallidipes across northern Zimbabwe. Methods Local weather station temperature measurements were previously used to fit the mechanistic model to longitudinal G. pallidipes catch data. To extend the use of the model, we converted MODIS land surface temperature to air temperature, compared the converted temperatures with available weather station data to confirm they aligned, and then re-fitted the mechanistic model using G. pallidipes catch data and air temperature estimates. We projected this fitted model across northern Zimbabwe, using simulations at a 1 km × 1 km spatial resolution, between 2000 to 2016. Results We produced estimates of relative changes in G. pallidipes mortality, larviposition, emergence rates and abundance, for northern Zimbabwe. Our model predicts decreasing tsetse populations within low elevation areas in response to increasing temperature trends during 2000–2016. Conversely, we show that high elevation areas (> 1000 m above sea level), previously considered too cold to sustain tsetse, may now be climatically suitable. Conclusions To our knowledge, the results of this research represent the first regional-scale assessment of temperature related tsetse population dynamics, and the first high spatial-resolution estimates of this metric for northern Zimbabwe. Our results suggest that tsetse abundance may have declined across much of the Zambezi Valley in response to changing climatic conditions during the study period. Future research including empirical studies is planned to improve model accuracy and validate predictions for other field sites in Zimbabwe.

scholarly journals An optimized in vitro blood–brain barrier model reveals bidirectional transmigration of African trypanosome strains

Microbiology ◽  
2011 ◽  
Vol 157 (10) ◽  
pp. 2933-2941 ◽  
Author(s):  
Christopher Untucht ◽  
Janine Rasch ◽  
Elena Fuchs ◽  
Manfred Rohde ◽  
Simone Bergmann ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Tsetse Flies ◽  
African Trypanosomes ◽  
E Coli ◽  
Selective Permeability ◽  
Blood Brain ◽  
Blood Brain Barrier Model ◽  
The Central Nervous System

The transmigration of African trypanosomes across the human blood–brain barrier (BBB) is the critical step during the course of human African trypanosomiasis. The parasites Trypanosoma brucei gambiense and T. b. rhodesiense are transmitted to humans during the bite of tsetse flies. Trypanosomes multiply within the bloodstream and finally invade the central nervous system (CNS), which leads to the death of untreated patients. This project focused on the mechanisms of trypanosomal traversal across the BBB. In order to establish a suitable in vitro BBB model for parasite transmigration, different human cell lines were used, including ECV304, HBMEC and HUVEC, as well as C6 rat astrocytes. Validation of the BBB models with Escherichia coli HB101 and E. coli K1 revealed that a combination of ECV304 cells seeded on Matrigel as a semi-synthetic basement membrane and C6 astrocytes resulted in an optimal BBB model system. The BBB model showed selective permeability for the pathogenic E. coli K1 strain, and African trypanosomes were able to traverse the optimized ECV304–C6 BBB efficiently. Furthermore, coincubation indicated that paracellular macrophage transmigration does not facilitate trypanosomal BBB traversal. An inverse assembly of the BBB model demonstrated that trypanosomes were also able to transmigrate the optimized ECV304–C6 BBB backwards, indicating the relevance of the CNS as a possible reservoir of a relapsing parasitaemia.

scholarly journals Adaptability and responsiveness: keys to operational measures in a regional hospital radiology department during the current COVID-19 pandemic

BJR|Open ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 20200017
Author(s):  
Pratik Mukherjee ◽  
Tze Chwan Lim ◽  
Ashish Chawla ◽  
Hong Chou ◽  
Wilfred C G Peh
Keyword(s):  
Disease Transmission ◽  
Healthcare Systems ◽  
Regional Hospital ◽  
Control Measures ◽  
Radiology Department ◽  
Public Healthcare ◽  
The Past ◽  
Infection Control Measures ◽  
Potential Impact ◽  
Operational Practices

The rapid and mostly uncontrolled spread of the coronavirus disease 2019 pandemic over the past 4 months has overwhelmed many healthcare systems worldwide. In Singapore, while our public healthcare institutions were considered well prepared due to our prior experience with the SARS outbreak, there was an unexpected surge of infected patients over the recent 2 months to deal with. We describe our radiology department’s experience in modifying operational practices and implementing strict infection control measures aimed at minimizing disease transmission and mitigating the potential impact of possible staff infection. From the perspective of serving a medium-sized regional hospital and limited by physical and manpower constraints, our radiology department had to adapt quickly and modify our initial responses and practices as the disease scenario changed. We have also enumerated some guidelines for planning future radiology departments.

Australian female athlete perceptions of the challenges associated with training and competing when menstrual symptoms are present

2020 ◽  
Vol 15 (3) ◽  
pp. 316-323
Author(s):  
Mike Armour ◽  
Kelly A Parry ◽  
Kylie Steel ◽  
Caroline A Smith
Keyword(s):  
Menstrual Cycle ◽  
Contraceptive Use ◽  
Negative Impact ◽  
Management Strategies ◽  
Chi Square ◽  
Contraceptive Usage ◽  
Menstrual Symptoms ◽  
Potential Risks ◽  
Potential Impact ◽  
The Impact

Coaches consider various competencies (e.g. conditioning, nutrition, skills and tactics), when planning sessions, though rarely the impact of menstruation on the efficacy of training and competition performance for athletes. Given the impact menstrual symptoms can have on athletes, the management strategies that athletes may use to minimise any potential impact, and the mechanisms that provide barriers to greater coach athlete interaction require investigation and consideration. Therefore, this study aimed to investigate the strategies used by athletes to manage menstrual symptoms and the role coaches played in this process. An anonymous, 36-item questionnaire was developed and hosted on Qualtrics. Descriptive statistics and Chi-square statistics were used to analyse the data. One hundred and twenty-four valid responses from Australian athletes 16–45, with a mean age of 29 years, were received. Period pain (82%) and pre-menstrual symptoms (83%) were commonly reported and contributed to fatigue and to perceived reductions in performance during or just prior to the period (50.0% in training, 58.7% on ‘game day’). Contraceptive use was reported by 42% of athletes. Those reporting heavy menstrual bleeding (29.7%) were more likely to report increased fatigue (relative risk 1.6, 95% CI 1.07 to 2.32). Over three-quarters of athletes reported neither they nor their coaches altered training due to the menstrual cycle. Most athletes (76%) did not discuss menstruation with their coaches. Given the perceived negative impact on performance and potential risks with contraceptive usage during adolescence, coaches, trainers and athletes need to have a more open dialogue around the menstrual cycle.

Detection of trypanosome infections in the saliva of tsetse flies and buffy-coat samples from antigenaemic but aparasitaemic cattle

Parasitology ◽  
1994 ◽  
Vol 108 (3) ◽  
pp. 313-322 ◽  
Author(s):  
P. A. O. Majiwa ◽  
R. Thatthi ◽  
S. K. Moloo ◽  
J. H. P. Nyeko ◽  
L. H. Otieno ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Buffy Coat ◽  
Dna Probes ◽  
Tsetse Flies ◽  
Chain Reaction ◽  
African Trypanosomes ◽  
Polymerase Chain

SUMMARYRelatively simple protocols employing non-radioactive DNA probes have been used for the detection of African trypanosomes in the blood of mammalian hosts and the saliva of live tsetse flies. In combination with the polymerase chain reaction (PCR), the protocols revealed trypanosomes in buffy-coat samples from antigenaemic but aparasitaemic cattle and in the saliva of live, infected tsetse flies. Furthermore, the protocols were used to demonstrate concurrent natural infections of single tsetse flies with different species of African trypanosomes.

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