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Accession numbers of newly sequenced material including taxa (with closest match using blastn searches in parentheses) and sequence origin (directly sequenced organism, or sequenced clone from gut/mouthpart content).
Source publication
The extra-oral digestion of creeping water bugs (Naucoridae: Hemiptera) hinders the study of their diet using the standard method of identifying prey body parts in the gut. Genetic methods are available, but rely on PCR tests or similar diagnostics to confirm suspected prey. Where the potential prey is unknown and a broad search for all possible pr...
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![Figure 2 Geographic distribution of BU cases in the world [4].](profile/Issaka-Maman/publication/339339130/figure/fig1/AS:859983377862657@1582047423506/Geographic-distribution-of-BU-cases-in-the-world-4_Q320.jpg)
Buruli ulcer (BU) is a serious skin disease caused by Mycobacterium ulcerans infection. Over the last 10 years, the understanding of the epidemiology, ecology, aetiology and physiopathology of BU has progressed considerably. This paper reviews the current knowledge of BU and the options for future prevention. Currently, the BU is distributed in are...
Citations
... These species coexist in the same type of habitat but differ in terms of microhabitat preferences, food spectra and foraging strategies (figure 1). Ilyocoris cimicoides, N. glauca and N. cinerea are strict predators of insects [16][17][18][19][20], crustaceans [16,[21][22][23], tadpoles [24,25] and fish [26][27][28], but the dietary habits of C. punctata are not yet fully understood. Different studies have reported inconsistent feeding styles for C. punctata, ranging from strict zoophagy [29] to saprophagy [30] and omnivorous behaviour, including the unusual ability to ingest solid food [31]. ...
... Microhabitat preferences are also likely to affect feeding habits because the abundance and availability of food vary within a water body. Notonecta glauca, I. cimicoides and N. cinerea are generalist predators that feed on insects and crustaceans [16][17][18][19][21][22][23]29,30], and also on vertebrates such as fish and tadpoles in the case of N. glauca and I. cimicoides [24][25][26][27][28]. We identified a protein in N. glauca and I. cimicoides PMG venom that is homologous to venom 5 0 nucleotidase 1 from the belastomatid L. distinctifemur [13]. ...
True water bugs (Nepomorpha) are mostly predacious insects that live in aquatic habitats. They use their piercing-sucking mouthparts to inject venomous saliva that facilitates the capture and extra-oral digestion of prey animals, but their venom can also be deployed for defence. In Central Europe, nepomorph species representing different families coexist in the same habitat. However, their feeding ecology, including venom composition and deployment, has not been investigated in detail. We used an integrated proteotranscriptomic and bioactivity-based approach to test whether venom composition and activity differ between four water bug species sharing the same habitat but occupying different ecological niches. We found considerable species-dependent differences in the composition of digestive enzymes and venom components that probably evolved as adaptations to particular food sources, foraging strategies and/or microhabitats. The venom of Corixa punctata differed substantially from that of the three strictly predatory species (Ilyocoris cimicoides, Notonecta glauca and Nepa cinerea), and the abundance of herbivory-associated proteins confirms a mostly plant-based diet. Our findings reveal independent adaptations of the digestive and defensive enzyme repertoires accompanied by the evolution of distinct feeding strategies in aquatic bugs.
... The exact mode of transmission remains unclear; however, outbreaks of BU have usually been reported from areas close to aquatic environments (6,16). Aquatic insects have repeatedly been found positive for the M. ulcerans DNA target sequence IS2404 (6,17,18). The involvement of mosquitoes as vectors and possums as reservoir have been suggested in Australia (12,19,20). ...
Background
Buruli ulcer (BU) is a subcutaneous necrotic infection of the skin caused by Mycobacterium ulcerans. There has been increasing BU incidence in Victoria, Australia. The aim of this study to provide an epidemiological update of BU cases in Victoria to understand the pattern of distribution over time and space and attempt to identify local risk factors.
Methods
A comprehensive descriptive epidemiological analyses were performed on BU notification data from 1994 to 2016. In addition, retrospective temporal, spatial and spatio-temporal analyses were conducted to understand the distribution of cases. Quantum GIS was used to generate maps. Demographic, new housing settlements and historical rainfall data were analysed to assess their effects on BU incidence in Victoria.
Findings
There were a total of 902 patients notified from 1994-2016. The incidence rate was 0.8/100,000 persons in Victoria. Space and time analyses showed that the most likely disease cluster was the Bellarine and Mornington Peninsulas with incidence rate 50 times higher than the State of Victoria rate. Gender was not a risk factor, but age was, with increased susceptibility among the over 60 year old group. There was an unusual high risk in the 15-24 age group in Point Lonsdale. Correlation analyses indicated that increase in population and construction of new settlements might be some of the reasons contributing to the rise in cases in Victoria.
Interpretation
The findings agreed with published works in Australia of the increase in BU cases in Victoria. However, our findings also highlights the endemic nature of cases. The identified spatial disease clusters could be relevant for future environmental sampling studies or screening tests for M. ulcerans exposure.
... The development of DNA barcoding using standardized genetic markers provides an alternative method to characterize the dietary breadth of insect predators (Hebert et al. 2003(Hebert et al. , 2004. The use of approximately 700-bp fragments of mitochondrial CO1 gene was successful in dietary identification of many insect groups, for example, the gut contents of parasitoid wasps (Rougerie et al. 2011) and natural prey of water bugs (Gamboa et al. 2012). Molecular identification of prey species from the feces ("biodiversity capsules") of generalist predators was recently proposed as a new tool for biodiversity and ecological assessment (Boyer et al. 2015). ...
Odonate larvae are commonly considered opportunistic general predators in freshwater ecosystems. However, the dietary breadth of most odonate larvae in forest streams is still poorly documented. We characterized the prey species and estimated the level of dietary niche overlap of two damselflies, Euphaea formosa Hagen 1869 and Matrona cyanoptera H€ am€ al€ ainen and Yeh, 2000 in a forest stream of central Taiwan on the basis of DNA barcoding of larval feces. A collection of 23 successfully identified cytochrome c oxidase 1 (CO1) barcoding sequences suggested that the mayflies (Ephemeroptera), caddisflies (Trichoptera), and midges (Diptera) comprise the majority (43%, 6/14) of prey species consumed by E. formosa larvae, whereas the identified prey for M. cyanoptera were mainly zooplankton (56%, 5/9). Statistical analysis of dietary overlap indicated that these two species occupy different dietary niches (Pianka's index ¼ 0.219). DNA barcoding analysis of damselfly larval feces was effective in detecting less sclerotized prey such as vertebrates (fish and frog) and small zooplankton. However, a moderately successful rate (<70%) of PCR amplification by universal CO1 primers and a low percentage (<60%) of identifiable sequences in public databases indicate the limitations of naive DNA barcoding in fecal analysis.
... Cependant, la prolifération des Naucoridés représente une menace émergente pour la santé publique dans de nombreuses régions intertropicales humides puisqu'ils seraient impliqués dans la transmission de l'ulcère de Buruli (infection à Mycobacterium ulcerans) à l'Homme (OMS, 2004 ;Aubry, 2011). Leur comportement migratoire favorise la dissémination de M. ulcerans, ainsi que sa transmission, hors de l'environnement aquatique (Gamboa et al, 2012 ;Ebong et al, 2012). La famille des Naucoridae est représentée par environ 36 genres connus, avec environ 370 espèces décrites (Sites et al, 2011). ...
Objectifs : Une étude conduite au laboratoire de Zoologie et de Biologie Générale de l’Université de Yaoundé I a porté sur l’écologie de la punaise aquatique Ilyocoris cimicoïdes Linné 1758 (Heteroptera : Naucoridae) prélevée dans le lac d’Obili (Yaoundé, Cameroun). Méthodologie et résultats : L’analyse physico-chimique montre que ce lac est dans un état eutrophe à hypereutrophe et ses eaux sont fortement chargées en matière organique. Les observations morphologiques et l’illustration des stades de développement ainsi que l’étude de leurs fluctuations numériques montrent que I. cimicoïdes à six stades post-embryonnaires parmi lesquels cinq sont larvaires. La taille des individus augmente de la larve de 1er stade jusqu’au stade adulte. Les stades larvaires d’I. cimicoïdes se distinguent les uns des autres par la présence ou l’absence du ptérothèque, la forme de la marge postérieure du mésotergum et la taille relative du ptérothèque par rapport à la base du mésotergum. Conclusions : L’abondance des stades de développement d’I.cimicoïdes est influencée par la saisonnalité et l’évolution de certaines variables physico-chimiques. Les larves pullulent pendant la saison sèche et les oeufs et adultes pendant la saison des pluies.Mots clés : Pollution aquatique, morphologie, développement, Ilyocoris cimicoïdes. Objectives : A study conducted at the Laboratory of Zoology and General Biology, University of Yaoundé I focused on the ecology of aquatic bug Ilyocoris cimicoides Linnaeus 1758 (Heteroptera : Naucoridae) taken from Lake Obili (Yaoundé, Cameroon). Methodology and Results: The physico-chemical analysis showed that this lake is in a eutrophic state and its waters are heavily loaded with organic matter. Morphological observations and illustration stages of development and the study of their digital fluctuations show that I. cimicoides, has six post-embryonic stages of which five are breeding. The sizes of individuals increase the first stage larva to adult. Larval stages of I.cimicoides are distinguished from each other by the presence or absence of pterotheque, the shape of the posterior margin and mesotergum pterotheque relative size with respect to the base of mesotergum. Conclusions : Abundance stages of development I. cimicoides is influenced by seasonality and the evolution of certain physico-chemical variables. Larvae swim in the dry season and eggs and adults during the rainy season.
... In regions with a rich but largely unknown fauna, for example, many tropical regions, data base development is far behind, but DNA barcoding may promote regional description of biodiversity patterns of the aquatic fauna (Pereira et al., 2013) or ecological studies. For example, Gamboa et al. (2012) used a barcoding approach to identify the gut contents of an aquatic hemipteran (Naucoris sp.) for an assessment of the role of this species in a West African aquatic food web. ...
Molecular genetic techniques have been used in freshwater biology for more than 30 years. Early work focussed on studies of population structure, systematics and taxonomy. More recently, the range of studies has broadened to include ecology and adaptation. Advances in analytical methods and in technology (e.g. next‐generation sequencing) and decreasing costs of data production ensure that the field will continue to develop and broaden in scope.
At least three factors make the application of molecular techniques to freshwater biology exciting. First, the highly variable nature of many aquatic habitats makes them excellent models for the study of environmental change on ecological and evolutionary time scales. Second, the mature state of the field of freshwater biology provides an extensive foundation of ecological knowledge of freshwater organisms and their distinct adaptations. Third, the methodological advances allow researchers to focus more on merging molecular and ecological research and less on designing studies around technical limitations.
We identified eight research areas in freshwater biology in which the integration of molecular and ecological approaches provides exceptional opportunities. The list is not exhaustive, but considers a broad range of topics and spans the continuum from basic to applied research. The areas identified use a combination of natural, experimental and in silico approaches.
With advancing molecular techniques, freshwater biology is in an unusually strong position to link the genetic basis and ecological importance of adaptations across a wide range of taxa, ecosystems and spatiotemporal scales. Our aim was to identify opportunities for the integration of molecular and ecological approaches, to motivate greater collaboration and crossover, and to promote exploitation of the synergies of bridging ecological and evolutionary freshwater research.
... We suggest that for organisms with complex life-cycles, the adult stages should be sampled over their entire flight periods to assess the potential for progressive changes in the isotopic signatures of species with longer-lived adults. To definitively determine the contributions of ''isotopically cryptic'' prey types to the diet of terrestrial predators, investigators need to apply other methods such as field observations of predation behaviour of different predator types, gut contents analysis or PCR bases methods in cases of extra-oral digestion as in spiders (Gamboa et al. 2012;Greenstone and Shufran 2003). ...
Stable isotopes (13C and 15N) are widely applied in studies of trophic links. We used this method to investigate the contribution of aquatic and terrestrial prey to the diet of riparian predatory arthropods in two mountain headwater streams in Colorado, USA. Aquatic and terrestrial prey and riparian predators were collected during summer 2009. To evaluate the reliability of conclusions based on stable isotope ratios, we compared the isotopic signatures of aquatic larval and terrestrial adult stages of three abundant stream insect species and assessed variation in mixing model estimates for spider diet composition under varying assumptions for trophic fractionation. Adult isotopic signatures of some aquatic prey species were indistinguishable from those of prey species with exclusively terrestrial life histories (stoneflies: 13C and 15N, chironomids: 13C). Other prey had distinctly aquatic isotopic signatures as both larvae and adults (a mayfly and a caddisfly). There was no evidence that prey with aquatic isotopic signatures contributed to the diet of the spiders near one stream. For the other stream, mixing model analysis suggested that chironomids were included in the diets of lycosid, linyphiid and liocranid spiders. Reliable estimates of the contributions of prey sources were compromised by the sensitivity of mixing models to assumptions on trophic fractionation and the presence of “isotopically cryptic” prey. This study emphasizes the importance of supporting isotope-based studies on cross-boundary trophic links with data on isotopic shifts in prey with complex life cycles and assessment of fractionation rates specific to the study system.
We developed species-specific primers of five microcrustacean preys, Ceriodaphnia richardi, Diaphanosoma cf. brevireme, Daphnia gessneri, Simocephalus serrulatus, Thermocyclops decipiens and Mesocyclops sp., to analyze food-web interactions involving their two insect predators Rheumatobates crassifemur and Martarega uruguayensis distributed in a tropical shallow lake. We designed internal primers of the cOi gene (177-282 bp), and tested them, by means of PcR, for specificity and sensitivity. in our tests for specificity, all primers successfully amplified the DNa target but were species-specific failing to amplify the biomarker from any of the other species tested, even in a mixed DNa sample, including predators' DNa. in tests for sensitivity, primers successfully amplified zooplankton biomarkers from low concentration of DNa extractions and also from digestive tract of predators, even after many hours of ingestion. this technique provides a framework as an efficient tool for evaluation of food-web research in natural aquatic environments, where it is impossible to observe if predation occurs. Furthermore, this technique provides an effective solution for the identification of zooplankton species from the predator's digestive tract, where morphological identification alone is sometimes difficult because predators do not consume the prey but feeds using extra-oral digestion, such is the case of heteropterans.
Background:
Biting aquatic insects belonging to the order Hemiptera have been suggested as potential vectors of Mycobacterium ulcerans in endemic areas for Buruli ulcer (BU). If this is the case, these insects would be expected to co-exist with M. ulcerans in the same geographical areas. Here, we studied the geographical distribution of six aquatic Hemiptera families that are thought to be vectors of M. ulcerans and explored their potential geographical overlapping with communities reporting BU cases in endemic countries.
Methods:
We have developed ensemble ecological models of predicted distribution for six families of the Hemiptera (Naucoridae, Belostomatidae, Notonectidae, Nepidae, Corixidae and Gerridae) applying a robust modelling framework over a collection of recorded presences and a suite of environmental and topographical factors. Ecological niche factor analysis (ENFA) was first used to identify factors that best described the ecological niches for each hemipteran family. Finally, we explored the potential geographical co-occurrence of these insects and BU in two endemic countries, Cameroon and Ghana.
Results:
Species of the families Naucoridae and Belostomatidae, according to our models, are widely distributed across Africa, although absent from drier and hotter areas. The other two families of biting Hemiptera, the Notonectidae and Nepidae, would have a more restricted distribution, being more predominant in western and southern Africa. All these four families of biting water bugs are widely distributed across coastal areas of West Africa. They would thrive in areas where annual mean temperature varies between 15-22 °C, with moderate annual precipitation (i.e. 350-1000 mm/annual) and near to water courses. Species of all hemipteran families show preference for human-made environments such as agricultural landscapes and urbanized areas. Finally, our analysis suggests that M. ulcerans and species of these aquatic insects might coexist in the same ecological niches, although there would be variation in species diversity between BU endemic areas.
Conclusions:
Our findings predict the geographical co-existence of some species of aquatic hemipteran families and BU. Considering the existing biological evidence that points to some of these aquatic insects as potential phoretic vectors of M. ulcerans, its presence in BU endemic areas should be considered a risk factor. The ecological models here presented may be helpful to inform future environmental based models intended to delineate the potential geographical distribution of BU in the African region.
Swinger DNA are sequences whose homology with known sequences is detected only assuming systematic exchanges between nucleotides. Nine symmetric (X<->Y, i.e. A<->C) and fourteen asymmetric (X->Y->Z, i.e. A->C->G) exchanges exist. All swinger DNA previously detected in GenBank follow the A<->T+C<->G exchange, while mitochondrial swinger RNAs distribute among different swinger types. Here different alignment criteria detect 87 additional swinger mitochondrial DNAs (86 from insects), including the first swinger gene embedded within a complete genome, corresponding to the mitochondrial 16S rDNA of the stonefly Kamimuria wangi. Other Kamimuria mt genome regions are ‘regular’, stressing unanswered questions on a) swinger polymerization regulation; b) swinger 16S rDNA functions; c) specificity to rDNA, in particular 16S rDNA. Sharp switches between regular and swinger replication, together with previous observations on swinger transcription, suggest that swinger replication might be due to a switch in polymerization mode of regular polymerases and the possibility of swinger-encoded information, predicted in primordial genes such as rDNA. .
Infection with Mycobacterium ulcerans causes Buruli Ulcer, a neglected tropical disease. Mosquito vectors are suspected to participate in the transmission and environmental maintenance of the bacterium. However, mechanisms and consequences of mosquito contamination by M. ulcerans are not well understood. We evaluated the metabolome of the Anopheles gambiae mosquito to profile the metabolic changes associated with bacterial colonization. Contamination of mosquitoes with live M. ulcerans bacilli results in disruptions to lipid metabolic pathways of the mosquito, specifically the utilization of glycerolipid molecules, an affect that was not observed in mosquitoes exposed to dead M. ulcerans. These results are consistent with aberrations of lipid metabolism described in other mycobacterial infections, implying global host-pathogen interactions shared across diverse saprophytic and pathogenic mycobacterial species. This study implicates features of the bacterium, such as the putative M. ulcerans encoded phospholipase enzyme, which promote virulence, survival, and active adaptation in concert with mosquito development, and provides significant groundwork for enhanced studies of the vector-pathogen interactions using metabolomics profiling. Lastly, metabolic and survival data suggest an interaction which is unlikely to contribute to transmission of M. ulcerans by A. gambiae and more likely to contribute to persistence of M. ulcerans in waters cohabitated by both organisms.
