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1.
PLoS Pathog ; 17(10): e1009995, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34648607

RESUMO

Yersinia murine toxin (Ymt) is a phospholipase D encoded on a plasmid acquired by Yersinia pestis after its recent divergence from a Yersinia pseudotuberculosis progenitor. Despite its name, Ymt is not required for virulence but acts to enhance bacterial survival in the flea digestive tract. Certain Y. pestis strains circulating in the Bronze Age lacked Ymt, suggesting that they were not transmitted by fleas. However, we show that the importance of Ymt varies with host blood source. In accordance with the original description, Ymt greatly enhanced Y. pestis survival in fleas infected with bacteremic mouse, human, or black rat blood. In contrast, Ymt was much less important when fleas were infected using brown rat blood. A Y. pestis Ymt- mutant infected fleas nearly as well as the Ymt+ parent strain after feeding on bacteremic brown rat blood, and the mutant was transmitted efficiently by flea bite during the first weeks after infection. The protective function of Ymt correlated with red blood cell digestion kinetics in the flea gut. Thus, early Y. pestis strains that lacked Ymt could have been maintained in flea-brown rat transmission cycles, and perhaps in other hosts with similar blood characteristics. Acquisition of Ymt, however, served to greatly expand the range of hosts that could support flea-borne plague.


Assuntos
Toxinas Bacterianas/metabolismo , Peste/transmissão , Sifonápteros/microbiologia , Yersinia pestis/genética , Yersinia pestis/metabolismo , Animais , Humanos , Insetos Vetores/microbiologia , Camundongos , Plasmídeos , Ratos , Virulência
2.
Sci Rep ; 11(1): 17608, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34475464

RESUMO

The recent emergence of Xylella fastidiosa in Europe is a major threat to agriculture, including olive, almond and grape. Philaenus spumarius is the predominant vector of X. fastidiosa in Europe. Understanding vector movement is critical for developing effective control measures against bacterial spread. In this study, our goal was to set up a flight-mill protocol to assess P. spumarius flight potential and to analyse how different variables may affect its flight behaviour. We found that P. spumarius was able to fly ≈ 500 m in 30 min with a maximum single flight of 5.5 km in 5.4 h. Based on the observations, the flight potential of the females was higher in spring and autumn than in summer, and that of the males was highest in autumn. Moreover, we found that P. spumarius had a higher flight potential during the morning and the night than during the afternoon. Our results revealed that P. spumarius is likely to disperse much further than the established sizes of the infected and buffer zones designated by the EU. This knowledge on the flight potential of P. spumarius will be critical for improving management actions against P. spumarius and the spread of X. fastidiosa in Europe.


Assuntos
Hemípteros/fisiologia , Insetos Vetores/fisiologia , Doenças das Plantas/microbiologia , Xylella/fisiologia , Distribuição Animal , Animais , Europa (Continente) , Feminino , Voo Animal , Hemípteros/microbiologia , Insetos Vetores/microbiologia , Masculino
3.
PLoS Pathog ; 17(9): e1009539, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34529715

RESUMO

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.


Assuntos
Insetos Vetores/microbiologia , Insetos Vetores/fisiologia , Spiroplasma , Simbiose/fisiologia , Moscas Tsé-Tsé/microbiologia , Moscas Tsé-Tsé/fisiologia , Animais , Feminino , Masculino
4.
Biomed Environ Sci ; 34(7): 581-586, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34353424

RESUMO

Pathogens like bacteria and protozoa, which affect human and animal health worldwide, can be transmitted by vectors like ticks. To investigate the epidemiology and genetic diversity of bacteria and protozoans carried by ticks in Chengmai county of Hainan province, China, 285 adult hard ticks belonging to two species [ Rhipicephalus sanguineus ( sensu lato): 183, 64.21% and Rhipicephalus microplus: 102, 35.79%] from dogs, cattle, and goats were collected. Microbial families were identified in these ticks by amplifying the 18S rRNA, 16S rRNA ( rrs), citrate synthase ( gltA), and heat shock protein ( groEL) genes. Our data revealed the presence of four recognized species and two Candidatus spp. of Anaplasmataceae and Coxiellaceae. In sum, these data reveal an extensive diversity of Anaplasmataceae bacteria, Coxiellaceae bacteria, Babesiidae, and Hepatozoidae in ticks from Hainan Island, highlighting the need to understand the tick-borne pathogen infection in local animals and humans.


Assuntos
Anaplasmataceae/genética , Coccídios/genética , Coxiellaceae/genética , Insetos Vetores/microbiologia , Ixodidae/microbiologia , Piroplásmios/genética , Anaplasmataceae/isolamento & purificação , Animais , Chaperonina 60/genética , China , Citrato (si)-Sintase/genética , Coccídios/isolamento & purificação , Coxiellaceae/isolamento & purificação , Ilhas , Filogenia , Piroplásmios/isolamento & purificação , RNA Ribossômico 16S/genética , RNA Ribossômico 18S/genética
5.
J Med Microbiol ; 70(7)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34296984

RESUMO

Introduction. Bartonellosis is an emerging zoonotic disease caused by bacteria of the genus Bartonella. Mixed Bartonella infections are a well-documented phenomenon in mammals and their ectoparasites. The accurate identification of Bartonella species in single and mixed infections is valuable, as different Bartonella species have varying impacts on infected hosts.Gap Statement. Current diagnostic methods are inadequate at identifying the Bartonella species present in mixed infections.Aim. The aim of this study was to adopt a Next Generation Sequencing (NGS) approach using Illumina sequencing technology to identify Bartonella species and demonstrate that this approach can resolve mixed Bartonella infections.Methodology. We used Illumina PCR amplicon NGS to target the ssrA and gltA genes of Bartonella in fleas collected from cats, dogs and a hedgehog in Israel. We included artificially mixed Bartonella samples to demonstrate the ability for NGS to resolve mixed infections and we compared NGS to traditional Sanger sequencing.Results. In total, we identified 74 Ctenocephalides felis, two Ctenocephalides canis, two Pulex irritans and three Archaeopsylla e. erinacei fleas. Real-time PCR of a subset of 48 fleas revealed that twelve were positive for Bartonella, all of which were cat fleas. Sanger sequencing of the ssrA and gltA genes confirmed the presence of Bartonella henselae, Bartonella clarridgeiae and Bartonella koehlerae. Illumina NGS of ssrA and gltA amplicons further confirmed the Bartonella species identity in all 12 flea samples and unambiguously resolved the artificially mixed Bartonella samples.Conclusion. The adaptation and multiplexing of existing PCR assays for diversity profiling via NGS is a feasible approach that is superior to traditional Sanger sequencing for Bartonella speciation and resolving mixed Bartonella infections. The adaptation of other PCR primers for Illumina NGS will be useful in future studies where mixed bacterial infections may be present.


Assuntos
Proteínas de Bactérias/genética , Infecções por Bartonella/microbiologia , Infecções por Bartonella/veterinária , Bartonella/isolamento & purificação , Animais , Bartonella/classificação , Bartonella/genética , Infecções por Bartonella/diagnóstico , Infecções por Bartonella/transmissão , Doenças do Gato/diagnóstico , Doenças do Gato/microbiologia , Doenças do Gato/parasitologia , Gatos , Coinfecção/diagnóstico , Coinfecção/microbiologia , Coinfecção/veterinária , DNA Bacteriano/genética , Doenças do Cão/diagnóstico , Doenças do Cão/microbiologia , Doenças do Cão/parasitologia , Cães , Ouriços-Cacheiros , Sequenciamento de Nucleotídeos em Larga Escala , Insetos Vetores/classificação , Insetos Vetores/genética , Insetos Vetores/microbiologia , Israel , Análise de Sequência de DNA , Sifonápteros/classificação , Sifonápteros/genética , Sifonápteros/microbiologia
6.
Insect Biochem Mol Biol ; 136: 103620, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34216781

RESUMO

Fleas (Order Siphonaptera) transmit numerous bacterial pathogens that cause severe human diseases (e.g., cat scratch disease, flea-borne spotted fever, murine typhus, plague). Because initial entry of these infectious agents occurs while blood feeding, the immune response in the flea gut is considered to be the first line of defense against invading microbes. However, relatively few studies have identified the flea immune molecules that effectively resist or limit infection in the gut. In other hematophagous insects, an immediate immune response to imbibed pathogens is the generation of reactive oxygen species (ROS). In this study, we utilized cat fleas (Ctenocephalides felis) to investigate whether oral infection with a well-known insect bacterial pathogen (Serratia marcescens) induces ROS synthesis in the flea gut, and whether production of ROS provides a defense mechanism against microbial colonization. Specifically, we treated fleas with an antioxidant to limit the number of free radicals in the digestive tract prior to infection, and then measured the following: S. marcescens infection loads, hydrogen peroxide (ROS) levels, and mRNA abundance of ROS signaling pathway genes. Overall, our data shows that ROS levels increase in response to infection in the flea gut, and that this increase helps to strengthen the flea immune response through the microbicidal activity of ROS.


Assuntos
Infecções Bacterianas/imunologia , Ctenocephalides , Espécies Reativas de Oxigênio/imunologia , Animais , Antioxidantes/farmacologia , Ctenocephalides/imunologia , Ctenocephalides/metabolismo , Ctenocephalides/microbiologia , Insetos Vetores/imunologia , Insetos Vetores/metabolismo , Insetos Vetores/microbiologia , Intestinos/microbiologia , Serratia/efeitos dos fármacos , Serratia/imunologia
7.
PLoS Negl Trop Dis ; 15(7): e0009517, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34260585

RESUMO

BACKGROUND: In Peru, the information regarding sand fly vectors of leishmaniasis and bartonellosis in the Amazon region is limited. In this study, we carried out sand fly collections in Peruvian lowland and highland jungle areas using different trap type configurations and screened them for Leishmania and Bartonella DNA. METHODOLOGY/PRINCIPAL FINDINGS: Phlebotomine sand flies were collected in Peruvian Amazon jungle and inter Andean regions using CDC light trap, UV and color LED traps, Mosquito Magnet trap, BG Sentinel trap, and a Shannon trap placed outside the houses. Leishmania spp. screening was performed by kDNA PCR and confirmed by a nested cytochrome B gene (cytB) PCR. Bartonella spp. screening was performed by ITS PCR and confirmed by citrate synthase gene (gltA). The PCR amplicons were sequenced to identify Leishmania and Bartonella species. UV and Blue LED traps collected the highest average number of sand flies per hour in low jungle; UV, Mosquito Magnet and Shannon traps in high jungle; and Mosquito Magnet in inter Andean region. Leishmania guyanensis in Lutzomyia carrerai carrerai and L. naiffi in Lu. hirsuta hirsuta were identified based on cytB sequencing. Bartonella spp. related to Bartonella bacilliformis in Lu. whitmani, Lu. nevesi, Lu. hirsuta hirsuta and Lu. sherlocki, and a Bartonella sp. related to Candidatus B. rondoniensis in Lu. nevesi and Lu. maranonensis were identified based on gltA gene sequencing. CONCLUSIONS/SIGNIFICANCE: UV, Blue LED, Mosquito Magnet and Shannon traps were more efficient than the BG-Sentinel, Green, and Red LED traps. This is the first report of L. naiffi and of two genotypes of Bartonella spp. related to B. bacilliformis and Candidatus B. rondoniensis infecting sand fly species from the Amazon region in Peru.


Assuntos
Infecções por Bartonella/transmissão , Bartonella bacilliformis/isolamento & purificação , Controle de Insetos/métodos , Insetos Vetores/fisiologia , Leishmania/isolamento & purificação , Leishmaniose/transmissão , Phlebotomus/fisiologia , Animais , Infecções por Bartonella/microbiologia , Bartonella bacilliformis/classificação , Bartonella bacilliformis/genética , Humanos , Controle de Insetos/instrumentação , Insetos Vetores/microbiologia , Insetos Vetores/parasitologia , Leishmania/classificação , Leishmania/genética , Leishmaniose/parasitologia , Peru , Phlebotomus/microbiologia , Phlebotomus/parasitologia
8.
Parasit Vectors ; 14(1): 317, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34112224

RESUMO

BACKGROUND: The human flea, Pulex irritans, is widespread globally and has a long association with humans, one of its principal hosts. Its role in plague transmission is still under discussion, although its high prevalence in plague-endemic regions and the presence of infected fleas of this species during plague outbreaks has led to proposals that it has been a significant vector in human-to-human transmission in some historical and present-day epidemiologic situations. However, based on a limited number of studies, P. irritans is considered to be a poor vector and receives very little attention from public health policymakers. In this study we examined the vector competence of P. irritans collected from foxes and owls in the western United States, using a standard protocol and artificial infection system. METHODS: Wild-caught fleas were maintained in the laboratory and infected by allowing them to feed on human or rat blood containing 2 × 108 to 1 × 109 Y. pestis/ml. The fleas were then monitored periodically for infection rate and bacterial load, mortality, feeding rate, bacterial biofilm formation in the foregut (proventricular blockage), and ability to transmit Y. pestis after their single infectious blood meal. RESULTS: P. irritans were susceptible to infection, with more than 30% maintaining high bacterial loads for up to 20 days. Transmission during this time was infrequent and inefficient, however. Consistent with previous studies, a low level of early-phase transmission (3 days after the infectious blood meal) was detected in some trials. Transmission at later time points was also sporadic, and the incidence of proventricular blockage, required for this mode of transmission, was low in fleas infected using rat blood and never occurred in fleas infected using human blood. The highest level of blockage and transmission was seen in fleas infected using rat blood and allowed to feed intermittently rather than daily, indicating that host blood and feeding frequency influence vector competence. CONCLUSIONS: Our results affirm the reputation of P. irritans as a feeble vector compared to rodent flea species examined similarly, and its vector competence may be lower when infected by feeding on bacteremic human blood.


Assuntos
Insetos Vetores/microbiologia , Peste/transmissão , Sifonápteros/microbiologia , Yersinia pestis/fisiologia , Animais , Sangue/metabolismo , Surtos de Doenças , Feminino , Infestações por Pulgas/transmissão , Raposas/parasitologia , Humanos , Peste/microbiologia , Estrigiformes/parasitologia , Estados Unidos
9.
Sci Rep ; 11(1): 11222, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-34045641

RESUMO

The flavescence dorée phytoplasma undergoes a propagative cycle in its insect vectors by first interacting with the insect cell surfaces, primarily in the midgut lumen and subsequently in the salivary glands. Adhesion of flavescence dorée phytoplasma to insect cells is mediated by the adhesin VmpA. We hypothesize that VmpA may have lectin-like activity, similar to several adhesins of bacteria that invade the insect gut. We first demonstrated that the luminal surface of the midgut and the basal surface of the salivary gland cells of the natural vector Scaphoideus titanus and those of the experimental vector Euscelidius variegatus were differentially glycosylated. Using ELISA, inhibition and competitive adhesion assays, and protein overlay assays in the Euva-6 insect cell line, we showed that the protein VmpA binds insect proteins in a lectin-like manner. In conclusion, the results of this study indicate that N-acetylglucosamine and mannose present on the surfaces of the midgut and salivary glands serve as recognition sites for the phytoplasma adhesin VmpA.


Assuntos
Adesinas Bacterianas/metabolismo , Insetos Vetores/microbiologia , Lectinas/metabolismo , Phytoplasma/fisiologia , Animais , Glicosilação , Proteínas de Insetos/metabolismo
10.
Sci Rep ; 11(1): 10151, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980962

RESUMO

Microsporidian infections of insects are important natural constraints of population growth, often reducing lifespan, fecundity and fertility of the infected host. The recently discovered Tubulinosema suzukii infects Drosophila suzukii (spotted wing drosophila, SWD), an invasive pest of many fruit crops in North America and Europe. In laboratory tests, fitness effects on larval and adult stages were explored. High level infection after larval treatment caused up to 70% pupal mortality, a decreased lifespan and a 70% reduced oviposition of emerging adults in biparental infection clusters. A shift to higher proportion of female offspring compared to controls suggested a potential parthenogenetic effect after microsporidian infection. A clear sex-linkage of effects was noted; females were specifically impaired, as concluded from fecundity tests with only infected female parents. Additive effects were noted when both parental sexes were infected, whereas least effects were found with only infected male parents, though survival of males was most negatively affected if they were fed with T. suzukii spores in the adult stage. Although most negative effects on fitness parameters were revealed after larval treatment, infection of offspring was never higher than 4%, suggesting limited vertical transmission. For that reason, a self-reliant spread in natural SWD populations would probably only occur by spore release from cadavers or frass.


Assuntos
Drosophila/microbiologia , Microsporídios , Animais , Contagem de Colônia Microbiana , Fertilidade , Controle de Insetos , Insetos Vetores/microbiologia , Estimativa de Kaplan-Meier , Larva , Longevidade , Mortalidade , Esporos Fúngicos
11.
Sci Rep ; 11(1): 10686, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-34021230

RESUMO

Arthropod vectors carry vector-borne pathogens that cause infectious disease in vertebrate hosts, and arthropod-associated microbiota, which consists of non-pathogenic microorganisms. Vector-borne pathogens and the microbiota can both influence the fitness of their arthropod vectors, and hence the epidemiology of vector-borne diseases. The bacterium Borrelia afzelii, which causes Lyme borreliosis in Europe, is transmitted among vertebrate reservoir hosts by Ixodes ricinus ticks, which also harbour a diverse microbiota of non-pathogenic bacteria. The purpose of this controlled study was to test whether B. afzelii and the tick-associated microbiota influence the fitness of I. ricinus. Eggs obtained from field-collected adult female ticks were surface sterilized (with bleach and ethanol), which reduced the abundance of the bacterial microbiota in the hatched I. ricinus larvae by 28-fold compared to larvae that hatched from control eggs washed with water. The dysbiosed and control larvae were subsequently fed on B. afzelii-infected or uninfected control mice, and the engorged larvae were left to moult into nymphs under laboratory conditions. I. ricinus larvae that fed on B. afzelii-infected mice had a significantly faster larva-to-nymph moulting time compared to larvae that fed on uninfected control mice, but the effect was small (2.4% reduction) and unlikely to be biologically significant. We found no evidence that B. afzelii infection or reduction of the larval microbiota influenced the four other life history traits of the immature I. ricinus ticks, which included engorged larval weight, unfed nymphal weight, larva-to-nymph moulting success, and immature tick survival. A retrospective power analysis found that our sampling effort had sufficient power (> 80%) to detect small effects (differences of 5% to 10%) of our treatments. Under the environmental conditions of this study, we conclude that B. afzelii and the egg surface microbiota had no meaningful effects on tick fitness and hence on the R0 of Lyme borreliosis.


Assuntos
Grupo Borrelia Burgdorferi , Insetos Vetores/microbiologia , Ixodes/microbiologia , Doença de Lyme/epidemiologia , Doença de Lyme/transmissão , Aptidão Física , Animais , Anticorpos Antibacterianos/imunologia , Grupo Borrelia Burgdorferi/imunologia , Modelos Animais de Doenças , Reservatórios de Doenças/microbiologia , Interações Hospedeiro-Patógeno/imunologia , Imunoglobulina G/imunologia , Ixodes/crescimento & desenvolvimento , Larva/microbiologia , Estágios do Ciclo de Vida , Doença de Lyme/imunologia , Camundongos , Prevalência , Picadas de Carrapatos
12.
Elife ; 102021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33904402

RESUMO

Mosquitoes are major infectious disease-carrying vectors. Assessment of current and future risks associated with the mosquito population requires knowledge of the full repertoire of pathogens they carry, including novel viruses, as well as their blood meal sources. Unbiased metatranscriptomic sequencing of individual mosquitoes offers a straightforward, rapid, and quantitative means to acquire this information. Here, we profile 148 diverse wild-caught mosquitoes collected in California and detect sequences from eukaryotes, prokaryotes, 24 known and 46 novel viral species. Importantly, sequencing individuals greatly enhanced the value of the biological information obtained. It allowed us to (a) speciate host mosquito, (b) compute the prevalence of each microbe and recognize a high frequency of viral co-infections, (c) associate animal pathogens with specific blood meal sources, and (d) apply simple co-occurrence methods to recover previously undetected components of highly prevalent segmented viruses. In the context of emerging diseases, where knowledge about vectors, pathogens, and reservoirs is lacking, the approaches described here can provide actionable information for public health surveillance and intervention decisions.


Assuntos
Doenças Transmissíveis Emergentes/transmissão , Culicidae/genética , Reservatórios de Doenças , Perfilação da Expressão Gênica , Insetos Vetores/genética , Aedes/genética , Animais , California , Doenças Transmissíveis Emergentes/microbiologia , Doenças Transmissíveis Emergentes/virologia , Culex/genética , Culicidae/microbiologia , Culicidae/virologia , Reservatórios de Doenças/microbiologia , Reservatórios de Doenças/virologia , Perfilação da Expressão Gênica/métodos , Insetos Vetores/microbiologia , Insetos Vetores/virologia , Sequenciamento Completo do Exoma/métodos
13.
Sci Rep ; 11(1): 6536, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33753809

RESUMO

Sharpshooter leafhoppers (Hemiptera: Cicadellidae: Cicadellinae) are important vectors of the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadaceae). This pathogen causes economically significant diseases in olive, citrus, and grapes on multiple continents. Bacterial acquisition and inoculation mechanisms are linked to X. fastidiosa biofilm formation and fluid dynamics in the functional foregut of sharpshooters, which together result in egestion (expulsion) of fluids likely carrying bacteria. One key X. fastidiosa vector is the blue-green sharpshooter, Graphocephala atropunctata (Signoret, 1854). Herein, a 3D model of the blue-green sharpshooter functional foregut is derived from a meta-analysis of published microscopy images. The model is used to illustrate preexisting and newly defined anatomical terminology that is relevant for investigating fluid dynamics in the functional foregut of sharpshooters. The vivid 3D illustrations herein and supplementary interactive 3D figures are suitable resources for multidisciplinary researchers who may be unfamiliar with insect anatomy. The 3D model can also be used in future fluid dynamic simulations to better understand acquisition, retention, and inoculation of X. fastidiosa. Improved understanding of these processes could lead to new targets for preventing diseases caused by X. fastidiosa.


Assuntos
Sistema Digestório/ultraestrutura , Hemípteros/ultraestrutura , Insetos Vetores/ultraestrutura , Doenças das Plantas/microbiologia , Animais , Citrus/microbiologia , Sistema Digestório/anatomia & histologia , Hemípteros/anatomia & histologia , Hemípteros/microbiologia , Insetos Vetores/anatomia & histologia , Insetos Vetores/microbiologia , Olea/microbiologia , Vitis/microbiologia , Xylella/patogenicidade
14.
Arch Microbiol ; 203(5): 1891-1915, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33634321

RESUMO

Insects and bacteria are the most widespread groups of organisms found in nearly all habitats on earth, establishing diverse interactions that encompass the entire range of possible symbiotic associations from strict parasitism to obligate mutualism. The complexity of their interactions is instrumental in shaping the roles of insects in the environment, meanwhile ensuring the survival and persistence of the associated bacteria. This review aims to provide detailed insight on the multifaceted symbiosis between one of the most versatile bacterial genera, Pseudomonas (Gammaproteobacteria: Pseudomonadaceae) and a diverse group of insect species. The Pseudomonas engages with varied interactions with insects, being either a pathogen or beneficial endosymbiont, as well as using insects as vectors. In addition, this review also provides updates on existing and potential applications of Pseudomonas and their numerous insecticidal metabolites as biocontrol agents against pest insects for the improvement of integrated pest management strategies. Here, we have summarized several known modes of action and the virulence factors of entomopathogenic Pseudomonas strains essential for their pathogenicity against insects. Meanwhile, the beneficial interactions between pseudomonads and insects are currently limited to a few known insect taxa, despite numerous studies reporting identification of pseudomonads in the guts and haemocoel of various insect species. The vector-symbiont association between pseudomonads and insects can be diverse from strict phoresy to a role switch from commensalism to parasitism following a dose-dependent response. Overall, the pseudomonads appeared to have evolved independently to be either exclusively pathogenic or beneficial towards insects.


Assuntos
Insetos/microbiologia , Pseudomonas/fisiologia , Animais , Agentes de Controle Biológico , Interações Hospedeiro-Patógeno , Insetos Vetores/classificação , Insetos Vetores/microbiologia , Insetos/classificação , Pseudomonas/metabolismo , Simbiose , Fatores de Virulência/metabolismo
15.
Parasit Vectors ; 14(1): 100, 2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33557932

RESUMO

BACKGROUND: Culicoides imicola (Diptera: Ceratopogonidae) is an important Afrotropical and Palearctic vector of disease, transmitting viruses of animal health and economic significance including African horse sickness and bluetongue viruses. Maternally inherited symbiotic bacteria (endosymbionts) of arthropods can alter the frequency of COI (cytochrome c oxidase subunit I) mitochondrial haplotypes (mitotypes) in a population, masking the true patterns of host movement and gene flow. Thus, this study aimed to assess the mtDNA structure of C. imicola in relation to infection with Candidatus Cardinum hertigii (Bacteroides), a common endosymbiont of Culicoides spp. METHODS: Using haplotype network analysis, COI Sanger sequences from Cardinium-infected and -uninfected C. imicola individuals were first compared in a population from South Africa. The network was then extended to include mitotypes from a geographic range where Cardinium infection has previously been investigated. RESULTS: The mitotype network of the South African population demonstrated the presence of two broad mitotype groups. All Cardinium-infected specimens fell into one group (Fisher's exact test, P = 0.00071) demonstrating a linkage disequilibrium between endosymbiont and mitochondria. Furthermore, by extending this haplotype network to include other C. imicola populations from the Mediterranean basin, we revealed mitotype variation between the Eastern and Western Mediterranean basins (EMB and WMB) mirrored Cardinium-infection heterogeneity. CONCLUSIONS: These observations suggest that the linkage disequilibrium of Cardinium and mitochondria reflects endosymbiont gene flow within the Mediterranean basin but may not assist in elucidating host gene flow. Subsequently, we urge caution on the single usage of the COI marker to determine population structure and movement in C. imicola and instead suggest the complementary utilisation of additional molecular markers.


Assuntos
Infecções Bacterianas/transmissão , Ceratopogonidae/genética , Ceratopogonidae/microbiologia , DNA Mitocondrial/genética , Insetos Vetores/microbiologia , Simbiose , Animais , Bacteroidetes/genética , DNA Mitocondrial/química , Fluxo Gênico , Cavalos , Região do Mediterrâneo , Filogenia , Filogeografia , Análise de Sequência de DNA , África do Sul
16.
Sci Rep ; 11(1): 2760, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33531619

RESUMO

Candidatus Liberibacter asiaticus (CLas), a bacterium transmitted by the Asian citrus psyllid, Diaphorina citri, is the causal agent of citrus greening disease, or Huanglongbng (HLB). Currently, vector population suppression with insecticides and tree removal are the most effective strategies for managing the HLB pathosystem. In this study, we assessed the bactericidal capabilities of 2'-deoxy-2'-fluoro-D-arabinonucleic acid antisense oligonucleotides (FANA ASO) both in vitro and in vivo by (1) confirming their capacity to penetrate insect cells, (2) silencing bacterial essential genes, and (3) quantifying reductions in bacterial titer and D. citri transmission. We confirmed that FANA ASO are able to penetrate insect cells without the use of a delivery agent. Expression of an essential gene in the D. citri endosymbiont, Wolbachia (wDi), significantly decreased by 30% following incubation with a wDi-specific FANA ASO. Viability of isolated wDi cells also decreased in response to the FANA ASO treatment. Delivery of a CLas-specific FANA ASO to infected adult D. citri in feeding assays resulted in significant silencing of a CLas essential gene. CLas relative density and transmission were significantly lower among D. citri fed FANA ASO in diet compared to untreated insects. Root infusions of a CLas-specific FANA ASO into infected Citrus trees significantly reduced CLas titer during a 30-day trial. Our results suggest that FANA ASO targeting insect-transmitted plant bacteria or insect endosymbionts may be useful tool for integrated management of agricultural pathogens.


Assuntos
Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Hemípteros/microbiologia , Oligonucleotídeos Antissenso/administração & dosagem , Doenças das Plantas/prevenção & controle , Rhizobiaceae/efeitos dos fármacos , Animais , Arabinonucleotídeos/administração & dosagem , Arabinonucleotídeos/genética , Linhagem Celular , Citrus/microbiologia , Drosophila , Inativação Gênica , Hemípteros/efeitos dos fármacos , Insetos Vetores/efeitos dos fármacos , Insetos Vetores/microbiologia , Oligonucleotídeos Antissenso/genética , Doenças das Plantas/microbiologia , Rhizobiaceae/genética , Rhizobiaceae/patogenicidade , Simbiose/efeitos dos fármacos , Simbiose/genética
17.
Parasit Vectors ; 14(1): 73, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33482884

RESUMO

BACKGROUND: Two species of deer ked (Lipoptena cervi and L. mazamae) have been identified as vectors of Bartonella bacteria in cervids in Europe and the USA. In an earlier study we showed that Japanese sika deer (Cervus nippon) harbor three Bartonella species, namely B. capreoli (lineage A) and two novel Bartonella species (lineages B and C); however, there is currently no information on the vector of Bartonella bacteria in sika deer. The aim of this study was to clarify potential vectors of Bartonella in Japanese sika deer. METHODS: Thirty-eight wingless deer keds (L. fortisetosa) and 36 ticks (Haemaphysalis and Ixodes species) were collected from sika deer. The prevalence of Bartonella in the arthropods was evaluated by real-time PCR targeting the 16S-23S internal transcribed spacer (ITS) and by culture of the organisms. The total number of Bartonella bacteria were quantified using real-time PCR. The distribution of Bartonella bacteria in deer ked organs was examined by immunofluorescence analysis. The relationship of Bartonella strains isolated from sika deer and arthropods were examined by a phylogenetic analysis based on concatenated sequences of the gltA, rpoB, ftsZ, and ribC genes, followed by a BLAST search for gltA and rpoB. RESULTS: Bartonella prevalence in deer keds was 87.9% by real-time PCR and 51.5% in culture and that in the ticks was 8.3% by real-time PCR and 2.8% in culture. The mean number of Bartonella bacteria per ked was calculated to be 9.2 × 105 cells. Bartonella aggregates were localized in the midgut of the keds. The phylogenetic analysis and BLAST search showed that both the host deer and the keds harbored two Bartonella species (lineages B and C), while B. capreoli (lineage A) was not detected in the keds. Two novel Bartonella species (lineages D and E) were isolated from one ked. CONCLUSIONS: Lipoptena fortisetosa likely serves as a vector of at least two Bartonella species (lineages B and C), whereas ticks do not seem to play a significant role in the transmission of Bartonella between sika deer based on the lower detection rates of Bartonella in ticks compared to keds. Bartonella species in lineages D and E appear to be L. fortisetosa-specific strains.


Assuntos
Infecções por Bartonella/veterinária , Bartonella/isolamento & purificação , Cervos/microbiologia , Cervos/parasitologia , Dípteros/microbiologia , Insetos Vetores/microbiologia , Animais , Bartonella/genética , Infecções por Bartonella/epidemiologia , DNA Bacteriano/genética , Japão/epidemiologia , Filogenia , Carrapatos/microbiologia
18.
Parasit Vectors ; 14(1): 31, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413518

RESUMO

Biting midges of the genus Culicoides transmit disease-causing agents resulting in a significant economic impact on livestock industries in many parts of the world. Localized control efforts, such as removal of larval habitat or pesticide application, can be logistically difficult, expensive and ineffective if not instituted and maintained properly. With these limitations, a population-level approach to the management of Culicoides midges should be investigated as a means to replace or supplement existing control strategies. Next-generation control methods such as Wolbachia- and genetic-based population suppression and replacement are being investigated in several vector species. Here we assess the feasibility and applicability of these approaches for use against biting midges. We also discuss the technical and logistical hurdles needing to be addressed for each method to be successful, as well as emphasize the importance of addressing community engagement and involving stakeholders in the investigation and development of these approaches.


Assuntos
Ceratopogonidae/parasitologia , Controle de Insetos/métodos , Insetos Vetores/parasitologia , Animais , Ceratopogonidae/genética , Ceratopogonidae/microbiologia , Ecossistema , Insetos Vetores/genética , Insetos Vetores/microbiologia , Larva/genética , Larva/microbiologia , Larva/parasitologia , Gado/parasitologia , Wolbachia/patogenicidade
19.
Lancet Infect Dis ; 21(2): e17-e25, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33035476

RESUMO

The rodent-murine ectoparasite-human model of plague transmission does not correspond with historical details around plague pandemics in Europe. New analysis of ancient genomes reveal that Yersinia pestis was unable to be transmitted by rat fleas until around 4000 Before Present, which challenges the rodent-murine ectoparasite-human model of plague transmission and historical details around plague pandemics in Europe. In this Review, we summarise data regarding Y pestis transmission by human lice in the context of genomic evolution and co-transmission of other major epidemic deadly pathogens throughout human history, with the aim of broadening our view of plague transmission. Experimental models support the efficiency of human lice as plague vectors through infected faeces, which suggest that Y pestis could be a louse-borne disease, similar to Borrelia recurrentis, Rickettsia prowazekii, and Bartonella quintana. Studies have shown that louse-borne outbreaks often involve multiple pathogens, and several cases of co-transmission of Y pestis and B quintana have been reported. Furthermore, an exclusive louse-borne bacterium, namely B recurrentis, was found to be circulating in northern Europe during the second plague pandemic (14th-18th century). Current data make it possible to attribute large historical pandemics to multiple bacteria, and suggests that human lice probably played a preponderant role in the interhuman transmission of plague and pathogen co-transmission during previous large epidemics, including plague pandemics.


Assuntos
Insetos Vetores/microbiologia , Ftirápteros/microbiologia , Peste/história , Peste/transmissão , Animais , Fezes/microbiologia , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História Medieval , Humanos , Infestações por Piolhos/complicações , Pandemias/história
20.
J Med Entomol ; 58(2): 913-920, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33145599

RESUMO

Although different feeding habits have been reported for Sarcophaginae (Diptera, Sarcophagidae), most species are associated with decomposing organic matter such as feces and decaying corpses. This study provides the synanthropy index for males of species of Sarcophaginae collected during a 12-mo period in three different environments (urban, rural, and wild) of the state of Rio Grande do Sul, in Southern Brazil, linking this parameter with the sanitary issue. This article also investigated the presence of pathogenic bacteria on the external surface of Oxysarcodexia paulistanensis (Mattos), the most abundant species collected using a sanitized entomological net. Almost all the species collected most abundantly, including O. paulistanensis (n = 241), Ravinia advena (Walker) (n = 87), and O. thornax (Walker) (n = 58), were classified as synanthropic; O. thornax was the species with the highest synanthropy index (+80.3). Escherichia coli (Escherich), Shigella spp. (Enterobacteriaceae), and Staphylococcus aureus (Rosenbach) (Staphylococcaceae) were isolated and identified from the external surface of O. paulistanensis. The isolation and identification of pathogenic bacteria, and their synanthropic behavior, adds weight to potential role of some flesh flies, as O. paulistanensis, in a sanitary context.


Assuntos
Infecções Bacterianas/transmissão , Sarcofagídeos , Animais , Brasil/epidemiologia , Cadáver , Dípteros/microbiologia , Dípteros/fisiologia , Enterobacteriaceae/isolamento & purificação , Fezes , Comportamento Alimentar , Humanos , Insetos Vetores/microbiologia , Insetos Vetores/fisiologia , Masculino , População Rural , Levantamentos Sanitários sobre Abastecimento de Água , Sarcofagídeos/microbiologia , Sarcofagídeos/fisiologia
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