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1.
Sci Total Environ ; 945: 174050, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38906290

RESUMO

Anthelmintic residues in livestock dung can adversely affect beneficial organisms. Targeted selective treatment (TST) of a reduced proportion of livestock with anthelmintics can slow resistance development in gastrointestinal nematodes by providing residue-free dung which could also benefit non-target organisms. We tested effects of TST on survival and reproduction of the dung beetle Onthophagus taurus (Scarabaeidae) in a factorial glasshouse experiment (Experimental treatments: five TST levels, 0.00, 0.25, 0.50, 0.75, 1.00 x four ivermectin concentrations, 125, 250, 375, 500 ppb). Each mesocosm comprised a 60 L bin containing sand, four dung pats and six pairs of adult beetles (F0 generation). No effects of TST level and ivermectin concentration on mortality of F0 adults after one week were observed. F0 adult brood ball production was affected by TST level, particularly at high ivermectin concentrations. Brood ball production increased as more untreated pats became available, with greater increases at higher ivermectin concentrations. We tested for evidence of a reported attraction of dung beetles to ivermectin-treated dung using a novel glitter-marker to trace the origin of dung used in brood balls. Where mesocosms contained both dung types, the proportion of brood balls created from untreated dung showed no statistical difference from the null expectation based on untreated dung availability in the mesocosm. Emergence of F1 adults was affected by the increase in TST, with this effect dependent on concentration. Treatments with concentrations of 250-500 ppb had the lowest emergence rates (ca. 5-20 % in mesocosms where all dung pats were treated) but emergence rates increased with TST level, reaching 68-88 % emergence where no dung pats were treated with ivermectin. Ivermectin-induced mortality occurred predominantly at egg and first instar stages. TST can provide refuges for dung beetles offering a strategy for livestock producers to maintain livestock welfare whilst benefiting from ecosystem services provided by important insects.


Assuntos
Besouros , Fezes , Ivermectina , Gado , Animais , Besouros/efeitos dos fármacos , Fezes/parasitologia , Fezes/química , Anti-Helmínticos/uso terapêutico
2.
Proc Biol Sci ; 291(2024): 20232771, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38864334

RESUMO

Land use change alters floral resource availability, thereby contributing to declines in important pollinators. However, the severity of land use impact varies by species, influenced by factors such as dispersal ability and resource specialization, both of which can correlate with body size. Here. we test whether floral resource availability in the surrounding landscape (the 'matrix') influences bee species' abundance in isolated remnant woodlands, and whether this effect varies with body size. We sampled quantitative flower-visitation networks within woodland remnants and quantified floral energy resources (nectar and pollen calories) available to each bee species both within the woodland and the matrix. Bee abundance in woodland increased with floral energy resources in the surrounding matrix, with strongest effects on larger-bodied species. Our findings suggest important but size-dependent effects of declining matrix floral resources on the persistence of bees in remnant woodlands, highlighting the need to incorporate landscape-level floral resources in conservation planning for pollinators in threatened natural habitats.


Assuntos
Abelhas , Tamanho Corporal , Metabolismo Energético , Florestas , Polinização , Densidade Demográfica , Abelhas/anatomia & histologia , Abelhas/metabolismo , Néctar de Plantas/metabolismo , Biodiversidade , Animais
3.
Ecology ; 105(7): e4328, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38782017

RESUMO

Since 1968, the Australian Dung Beetle Project has carried out field releases of 43 deliberately introduced dung beetle species for the biological control of livestock dung and dung-breeding pests. Of these, 23 species are known to have become established. For most of these species, sufficient time has elapsed for population expansion to fill the extent of their potential geographic range through both natural and human-assisted dispersal. Consequently, over the last 20 years, extensive efforts have been made to quantify the current distribution of these introduced dung beetles, as well as the seasonal and spatial variation in their activity levels. Much of these data and their associated metadata have remained unpublished, and they have not previously been synthesized into a cohesive dataset. Here, we collate and report data from the three largest dung beetle monitoring projects from 2001 to 2022. Together, these projects encompass data collected from across Australia, and include records for all 23 species of established dung beetles introduced for biocontrol purposes. In total, these data include 22,718 presence records and 213,538 absence records collected during 10,272 sampling events at 546 locations. Most presence records (97%) include abundance data. In total, 1,752,807 dung beetles were identified as part of these data. The distributional occurrence and abundance data can be used to explore questions such as factors influencing dung beetle species distributions, dung beetle biocontrol, and insect-mediated ecosystem services. These data are provided under a CC-BY-NC 4.0 license and users are encouraged to cite this data paper when using the data.


Assuntos
Besouros , Espécies Introduzidas , Besouros/fisiologia , Animais , Austrália , Fatores de Tempo , Distribuição Animal , Dinâmica Populacional , Densidade Demográfica
4.
Nat Commun ; 15(1): 3236, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38622174

RESUMO

Insects sustain key ecosystem functions, but how their activity varies across the day-night cycle and the underlying drivers are poorly understood. Although entomologists generally expect that more insects are active at night, this notion has not been tested with empirical data at the global scale. Here, we assemble 331 quantitative comparisons of the abundances of insects between day and night periods from 78 studies worldwide and use multi-level meta-analytical models to show that insect activity is on average 31.4% (CI: -6.3%-84.3%) higher at night than in the day. We reveal diel preferences of major insect taxa, and observe higher nocturnal activity in aquatic taxa than in terrestrial ones, as well as in warmer environments. In a separate analysis of the small subset of studies quantifying diel patterns in taxonomic richness (31 comparisons from 13 studies), we detect preliminary evidence of higher nocturnal richness in tropical than temperate communities. The higher overall (but variable) nocturnal activity in insect communities underscores the need to address threats such as light pollution and climate warming that may disproportionately impact nocturnal insects.


Assuntos
Ecossistema , Insetos , Animais , Clima
5.
Proc Biol Sci ; 291(2019): 20232885, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38503337

RESUMO

The ecosystem services provided by dung beetles are well known and valued. Dung beetles bury dung for feeding and breeding, and it is generally thought that the process of burying dung increases nutrient uptake by plant roots, which promotes plant growth. Many studies have tested the effects of dung beetles on plant growth, but there has been no quantitative synthesis of these studies. Here we use a multi-level meta-analysis to estimate the average effect of dung beetles on plant growth and investigate factors that moderate this effect. We identified 28 publications that investigated dung beetle effects on plant growth. Of these, 24 contained the minimum quantitative data necessary to include in a meta-analysis. Overall, we found that dung beetles increased plant growth by 17%; the 95% CI for possible values for the true increase in plant growth that were most compatible with our data, given our statistical model, ranged from 1% to 35%. We found evidence that the dung beetle-plant growth relationship is influenced by the plant measurement type and the number of beetles accessing the dung. However, beetles did not increase plant growth in all quantitative trials, as individual effect sizes ranged from -72% to 806%, suggesting important context-dependence in the provision of ecosystem services.


Assuntos
Besouros , Ecossistema , Animais , Melhoramento Vegetal , Plantas , Fezes
6.
Ecology ; 105(4): e4260, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38353290

RESUMO

There is strong trait dependence in species-level responses to environmental change and their cascading effects on ecosystem functioning. However, there is little understanding of whether intraspecific trait variation (ITV) can also be an important mechanism mediating environmental effects on ecosystem functioning. This is surprising, given that global change processes such as habitat fragmentation and the creation of forest edges drive strong trait shifts within species. On 20 islands in the Thousand Island Lake, China, we quantified intraspecific leaf trait shifts of a widely distributed shrub species, Vaccinium carlesii, in response to habitat fragmentation. Using a reciprocal transplant decomposition experiment between forest edge and interior on 11 islands with varying areas, we disentangled the relative effects of intraspecific leaf trait variation versus altered environmental conditions on leaf decomposition rates in forest fragments. We found strong intraspecific variation in leaf traits in response to edge effects, with a shift toward recalcitrant leaves with low specific leaf area and high leaf dry matter content from forest interior to the edge. Using structural equation modeling, we showed that such intraspecific leaf trait response to habitat fragmentation had translated into significant plant afterlife effects on leaf decomposition, leading to decreased leaf decomposition rates from the forest interior to the edge. Importantly, the effects of intraspecific leaf trait variation were additive to and stronger than the effects from local environmental changes due to edge effects and habitat loss. Our experiment provides the first quantitative study showing that intraspecific leaf trait response to edge effects is an important driver of the decrease in leaf decomposition rate in fragmented forests. By extending the trait-based response-effect framework toward the individual level, intraspecific variation in leaf economics traits can provide the missing functional link between environmental change and ecological processes. These findings suggest an important area for future research on incorporating ITV to understand and predict changes in ecosystem functioning in the context of global change.


Assuntos
Ecossistema , Florestas , Plantas , Clima , Folhas de Planta/fisiologia
7.
Antibiotics (Basel) ; 12(8)2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37627749

RESUMO

The growing threat of antibiotic resistance is a significant global health challenge that has intensified in recent years. The burden of antibiotic resistance on public health is augmented due to its multifaceted nature, as well as the slow-paced and limited development of new antibiotics. The threat posed by resistance is now existential in phage therapy, which had long been touted as a promising replacement for antibiotics. Consequently, it is imperative to explore the potential of combination therapies involving antibiotics and phages as a feasible alternative for treating infections with multidrug-resistant bacteria. Although either bacteriophage or antibiotics can potentially treat bacterial infections, they are each fraught with resistance. Combination therapies, however, yielded positive outcomes in most cases; nonetheless, a few combinations did not show any benefit. Combination therapies comprising the synergistic activity of phages and antibiotics and combinations of phages with other treatments such as probiotics hold promise in the treatment of drug-resistant bacterial infections.

8.
Proc Natl Acad Sci U S A ; 120(37): e2217973120, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37639613

RESUMO

In social animals, success can depend on the outcome of group battles. Theoretical models of warfare predict that group fighting ability is proportional to two key factors: the strength of each soldier in the group and group size. The relative importance of these factors is predicted to vary across environments [F. W. Lanchester, Aircraft in Warfare, the Dawn of the Fourth Arm (1916)]. Here, we provide an empirical validation of the theoretical prediction that open environments should favor superior numbers, whereas complex environments should favor stronger soldiers [R. N. Franks, L. W. Partridge, Anim. Behav. 45, 197-199 (1993)]. We first demonstrate this pattern using simulated battles between relatively strong and weak soldiers in a computer-driven algorithm. We then validate this result in real animals using an ant model system: In battles in which the number of strong native meat ant Iridomyrmex purpureus workers is constant while the number of weak non-native invasive Argentine ant Linepithema humile workers increases across treatments, fatalities of I. purpureus are lower in complex than in simple arenas. Our results provide controlled experimental evidence that investing in stronger soldiers is more effective in complex environments. This is a significant advance in the empirical study of nonhuman warfare and is important for understanding the competitive balance among native and non-native invasive ant species.


Assuntos
Aeronaves , Formigas , Animais , Algoritmos , Pesquisa Empírica , Espécies Introduzidas
9.
Org Lett ; 25(25): 4730-4734, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37345963

RESUMO

Herein, we report the development of a Cu-catalyzed aminoallylation of aldehyde electrophiles through reductive coupling by circumventing the problematic competitive reduction of the aldehyde electrophile by a CuH catalyst. This leads to a highly diastereo- and enantioselective process for the synthesis of chiral 1,2-aminoalcohols containing secondary alcohol substitution. Cleavage of the N substituents on the reaction products was performed, allowing access to the other diastereomer of the aminoalcohol, which was investigated in the context of a synthesis of eligulstat.


Assuntos
Aldeídos , Metais , Estereoisomerismo , Estrutura Molecular , Amino Álcoois , Catálise
10.
Org Lett ; 25(25): 4644-4649, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37338397

RESUMO

Herein, we report the development of a Cu-catalyzed enantioselective borylative aminoallylation of aldehydes using a N-substituted allene to access boryl-substituted 1,2-aminoalcohol synthons for diversification to chiral heteroatom-rich organic compounds. The reported reaction provides access to several different substitution patterns of chiral 1,2-aminoalcohol products from the same readily available starting materials with high diastereo- and enantioselectivity.


Assuntos
Aldeídos , Amino Álcoois , Estereoisomerismo , Catálise
11.
Nat Ecol Evol ; 7(3): 393-404, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36717744

RESUMO

Edge effects often exacerbate the negative effects of habitat loss on biodiversity. In forested ecosystems, however, many pollinators actually prefer open sunny conditions created by edge disturbances. We tested the hypothesis that forest edges have a positive buffering effect on plant-pollinator interaction networks in the face of declining forest area. In a fragmented land-bridge island system, we recorded ~20,000 plant-pollinator interactions on 41 islands over 3 yr. We show that plant richness and floral resources decline with decreasing forest area at both interior and edge sites, but edges maintain 10-fold higher pollinator abundance and richness regardless of area loss. Edge networks contain highly specialized species, with higher nestedness and lower modularity than interior networks, maintaining high robustness to extinction following area loss while forest interior networks collapse. Anthropogenic forest edges benefit community diversity and network robustness to extinction in the absence of natural gap-phase dynamics in small degraded forest remnants.


Assuntos
Ecossistema , Florestas , Biodiversidade , Plantas
12.
J Org Chem ; 87(4): 2142-2153, 2022 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-34807603

RESUMO

Chiral γ-lactones are prevalent organic architectures found in a large array of natural products. In this work, we disclose the development of a modified catalytic system utilizing a commercially available Cu-phosphite catalyst for the diastereoselective reductive coupling of chiral allenamides and ketones to afford chiral γ-lactone precursors in 80:20 to 99:1 dr.


Assuntos
Cetonas , Catálise , Estereoisomerismo
13.
Arrhythm Electrophysiol Rev ; 10(3): 190-197, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34777824

RESUMO

The His-Purkinje system is a network of bundles and fibres comprised of specialised cells that allow for coordinated, synchronous activation of the ventricles. Although the histology and physiology of the His-Purkinje system have been studied for more than a century, its role in ventricular arrhythmias has recently been discovered with the ongoing elucidation of the mechanisms leading to both benign and life-threatening arrhythmias. Studies of Purkinje-cell electrophysiology show multiple mechanisms responsible for ventricular arrhythmias, including enhanced automaticity, triggered activity and reentry. The variation in functional properties of Purkinje cells in different areas of the His-Purkinje system underlie the propensity for reentry within Purkinje fibres in structurally normal and abnormal hearts. Catheter ablation is an effective therapy in nearly all forms of reentrant arrhythmias involving Purkinje tissue. However, identifying those at risk of developing fascicular arrhythmias is not yet possible. Future research is needed to understand the precise molecular and functional changes resulting in these arrhythmias.

14.
BMJ Glob Health ; 6(9)2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34548380

RESUMO

BACKGROUND: Globally, critical illness results in millions of deaths every year. Although many of these deaths are potentially preventable, the basic, life-saving care of critically ill patients are often overlooked in health systems. Essential Emergency and Critical Care (EECC) has been devised as the care that should be provided to all critically ill patients in all hospitals in the world. EECC includes the effective care of low cost and low complexity for the identification and treatment of critically ill patients across all medical specialties. This study aimed to specify the content of EECC and additionally, given the surge of critical illness in the ongoing pandemic, the essential diagnosis-specific care for critically ill patients with COVID-19. METHODS: In a Delphi process, consensus (>90% agreement) was sought from a diverse panel of global clinical experts. The panel iteratively rated proposed treatments and actions based on previous guidelines and the WHO/ICRC's Basic Emergency Care. The output from the Delphi was adapted iteratively with specialist reviewers into a coherent and feasible package of clinical processes plus a list of hospital readiness requirements. RESULTS: The 269 experts in the Delphi panel had clinical experience in different acute medical specialties from 59 countries and from all resource settings. The agreed EECC package contains 40 clinical processes and 67 requirements, plus additions specific for COVID-19. CONCLUSION: The study has specified the content of care that should be provided to all critically ill patients. Implementing EECC could be an effective strategy for policy makers to reduce preventable deaths worldwide.


Assuntos
COVID-19 , Serviços Médicos de Emergência , Consenso , Cuidados Críticos , Humanos , SARS-CoV-2
15.
Org Lett ; 23(16): 6444-6449, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34347500

RESUMO

Herein, we report the development of a catalytic enantioselective addition of N-substituted allyl equivalents to ketone electrophiles through use of Cu-catalyzed reductive coupling to access important chiral 1,2-aminoalcohol synthons in high levels of regio-, diastereo-, and enantioselectivity. Factors affecting enantioinduction are discussed including the identification of a reversible ketone allylation step that has not been previously reported in Cu-catalyzed reductive coupling.

16.
Ecol Evol ; 11(14): 9728-9740, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34306658

RESUMO

In fragmented forests, edge effects can drive intraspecific variation in seedling performance that influences forest regeneration and plant composition. However, few studies have attempted to disentangle the relative biotic and abiotic drivers of intraspecific variation in seedling performance. In this study, we carried out a seedling transplant experiment with a factorial experimental design on three land-bridge islands in the Thousand Island Lake, China, using four common native woody plant species. At different distances from the forest edge (2, 8, 32, 128 m), we transplanted four seedlings of each species into each of three cages: full-cage, for herbivore exclusion; half-cage, that allowed herbivore access but controlled for caging artifacts; and no-cage control. In the 576 cages, we recorded branch architecture, leaf traits, and seedling survival for each seedling before and after the experimental treatment. Overall, after one full growing season, edge-induced abiotic drivers and varied herbivory pressure led to intraspecific variation in seedling performance, including trade-offs in seedling architecture and resource-use strategies. However, responses varied across species with different life-history strategies and depended on the driver in question, such that the abiotic and biotic effects were additive across species, rather than interactive. Edge-induced abiotic variation modified seedling architecture of a shade-tolerant species, leading to more vertical rather than lateral growth at edges. Meanwhile, increased herbivory pressure resulted in a shift toward lower dry matter investment in leaves of a light-demanding species. Our results suggest that edge effects can drive rapid directional shifts in the performance and intraspecific traits of some woody plants from early ontogenetic stages, but most species in this study showed negligible phenotypic responses to edge effects. Moreover, species-specific responses suggest the importance of interspecific differences modulating the degree of trait plasticity, implying the need to incorporate individual-level responses when understanding the impact of forest fragmentation on plant communities.

17.
Oecologia ; 196(1): 275-288, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33871689

RESUMO

Global initiatives to reforest degraded areas have intensified in recent years, in an attempt to reverse the environmental impacts of habitat loss on species and ecosystem provided by them. However, the effectiveness of such reforestation initiatives in re-establishing biodiversity is still poorly understood. Here, we test how reforestation type and intensity applied to deforested areas affect the reestablishment of communities of cavity-nesting bees and wasps. We deployed experimental trap-nests along a reforestation gradient of increasing structural similarity to primary forest, after 18 years of reforestation. We found that reestablishment, in terms of abundance and richness of both bees and wasps, was greatest at an intermediate point along the reforestation gradient. However, these communities were highly dissimilar to primary forest, and recovery of intact insect community composition was only achieved when reforestation was more similar in structure to natural forests. This effect was more pronounced for bees than for wasps. Our findings suggest that along the reforestation gradient, services provided by wasps will be more easily recovered than those provided by bees. Our results have important implications for the challenges of restoring and maintaining species biodiversity as well as their associated ecosystem services.


Assuntos
Vespas , Animais , Abelhas , Biodiversidade , Brasil , Ecossistema , Florestas
18.
Zootaxa ; 4864(1): zootaxa.4864.1.1, 2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33311416

RESUMO

The schizomid fauna of mainland Australia currently comprises 60 species within seven named genera, of which five are endemic to the continent: Attenuizomus Harvey, 2000, Brignolizomus Harvey, 2000, Draculoides Harvey, 1992, Julattenius Harvey, 1992, Notozomus Harvey, 2000. Most Australian schizomids have been described from eastern and northern Australia, but there is also a significant subterranean fauna that has been found in hypogean habitats in the semi-arid Pilbara region of Western Australia. The vast majority of these species can be assigned to the genus Draculoides and this study is the first in a proposed series to revise this highly diverse genus. We treat the species found in the western Pilbara region, which includes 13 new species and 13 previously named species, using morphological characters and multi-locus sequence data. We also incorporate a molecular "mini-barcode" approach for COI, 12S and ITS2 to diagnose the new species. The new species are named: Draculoides akashae Abrams and Harvey, n. sp., D. belalugosii Abrams and Harvey, n. sp., D. carmillae Abrams and Harvey, n. sp., D. christopherleei Abrams and Harvey, n. sp., D. claudiae Abrams and Harvey, n. sp., D. immortalis Abrams and Harvey, n. sp., D. karenbassettae Abrams and Harvey, n. sp., D. mckechnieorum Abrams and Harvey, n. sp., D. minae Abrams and Harvey, n. sp., D. noctigrassator Abrams and Harvey, n. sp., D. nosferatu Abrams and Harvey, n. sp., D. piscivultus Abrams and Harvey, n. sp. and D. warramboo Abrams and Harvey, n. sp. We also provide the first descriptions of males of D. anachoretus (Harvey, Berry, Edward and Humphreys, 2008) and D. gnophicola (Harvey, Berry, Edward and Humphreys, 2008). All of the new species are subterranean-dwelling, short-range endemic species that occur in regions subject to mining activities, rendering them of high conservation significance.


Assuntos
Aracnídeos , Animais , Austrália , Ecossistema , Masculino , Filogenia , Austrália Ocidental
19.
Genes (Basel) ; 11(9)2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32825338

RESUMO

Historical population contraction and expansion events associated with Pleistocene climate change are important drivers of intraspecific population structure in Australian arid-zone species. We compared phylogeographic patterns among arid-adapted Dasyuridae (Sminthopsis and Planigale) with close phylogenetic relationships and similar ecological roles to investigate the drivers of phylogeographic structuring and the importance of historical refugia. We generated haplotype networks for two mitochondrial (control region and cytochrome b) and one nuclear (omega-globin) gene from samples distributed across each species range. We used ΦST to test for a genetic population structure associated with the four Pilbara subregions, and we used expansion statistics and Bayesian coalescent skyline analysis to test for signals of historical population expansion and the timing of such events. Significant population structure associated with the Pilbara and subregions was detected in the mitochondrial data for most species, but not with the nuclear data. Evidence of population expansion was detected for all species, and it likely began during the mid-late Pleistocene. The timing of population expansion suggests that these species responded favorably to the increased availability of arid habitats during the mid-late Pleistocene, which is when previously patchy habitats became more widespread. We interpret our results to indicate that the Pilbara region could have acted as a refugium for small dasyurids.


Assuntos
Mudança Climática , DNA Mitocondrial/análise , Ecossistema , Variação Genética , Genética Populacional , Marsupiais/genética , Refúgio de Vida Selvagem , Animais , Austrália , Teorema de Bayes , DNA Mitocondrial/genética , Haplótipos , Marsupiais/fisiologia , Filogeografia
20.
PLoS Negl Trop Dis ; 14(4): e0007642, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32310947

RESUMO

BACKGROUND: Over the past recent years, Vibrio cholerae has been associated with outbreaks in sub-Saharan Africa, notably in Democratic Republic of the Congo (DRC). This study aimed to determine the genetic relatedness of isolates responsible for cholera outbreaks in eastern DRC between 2014 and 2017, and their potential spread to bordering countries. METHODS/PRINCIPAL FINDINGS: Phenotypic analysis and whole genome sequencing (WGS) were carried out on 78 clinical isolates of V. cholerae associated with cholera in eastern provinces of DRC between 2014 and 2017. SNP-based phylogenomic data show that most isolates (73/78) were V. cholerae O1 biotype El Tor with CTX-3 type prophage. They fell within the third transmission wave of the current seventh pandemic El Tor (7PET) lineage and were contained in the introduction event (T)10 in East Africa. These isolates clustered in two sub-clades corresponding to Multiple Locus Sequence Types (MLST) profiles ST69 and the newly assigned ST515, the latter displaying a higher genetic diversity. Both sub-clades showed a distinct geographic clustering, with ST69 isolates mostly restricted to Lake Tanganyika basin and phylogenetically related to V. cholerae isolates associated with cholera outbreaks in western Tanzania, whereas ST515 isolates were disseminated along the Albertine Rift and closely related to isolates in South Sudan, Uganda, Tanzania and Zambia. Other V. cholerae isolates (5/78) were non-O1/non-O139 without any CTX prophage and no phylogenetic relationship with already characterized non-O1/non-O139 isolates. CONCLUSIONS/SIGNIFICANCE: Current data confirm the association of both DRC O1 7PET (T)10 sub-clades ST69 and ST515 with recurrent outbreaks in eastern DRC and at regional level over the past 10 years. Interestingly, while ST69 is predominantly a locally endemic sequence type, ST515 became adaptable enough to expand across DRC neighboring countries.


Assuntos
Cólera/microbiologia , Genótipo , Vibrio cholerae/classificação , Vibrio cholerae/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Cólera/epidemiologia , Análise por Conglomerados , DNA Bacteriano/genética , República Democrática do Congo/epidemiologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Filogenia , Prófagos/genética , Vibrio cholerae/isolamento & purificação , Sequenciamento Completo do Genoma , Adulto Jovem
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