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1.
Parasit Vectors ; 17(1): 287, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956689

RESUMO

BACKGROUND: The emergence of pyrethroid resistance has threatened the elimination of Triatoma infestans from the Gran Chaco ecoregion. We investigated the status and spatial distribution of house infestation with T. infestans and its main determinants in Castelli, a municipality of the Argentine Chaco with record levels of triatomine pyrethroid resistance, persistent infestation over 2005-2014, and limited or no control actions over 2015-2020. METHODS: We conducted a 2-year longitudinal survey to assess triatomine infestation by timed manual searches in a well-defined rural section of Castelli including 14 villages and 234 inhabited houses in 2018 (baseline) and 2020, collected housing and sociodemographic data by on-site inspection and a tailored questionnaire, and synthetized these data into three indices generated by multiple correspondence analysis. RESULTS: The overall prevalence of house infestation in 2018 (33.8%) and 2020 (31.6%) virtually matched the historical estimates for the period 2005-2014 (33.7%) under recurrent pyrethroid sprays. While mean peridomestic infestation remained the same (26.4-26.7%) between 2018 and 2020, domestic infestation slightly decreased from 12.2 to 8.3%. Key triatomine habitats were storerooms, domiciles, kitchens, and structures occupied by chickens. Local spatial analysis showed significant aggregation of infestation and bug abundance in five villages, four of which had very high pyrethroid resistance approximately over 2010-2013, suggesting persistent infestations over space-time. House bug abundance within the hotspots consistently exceeded the estimates recorded in other villages. Multiple regression analysis revealed that the presence and relative abundance of T. infestans in domiciles were strongly and negatively associated with indices for household preventive practices (pesticide use) and housing quality. Questionnaire-derived information showed extensive use of pyrethroids associated with livestock raising and concomitant spillover treatment of dogs and (peri) domestic premises. CONCLUSIONS: Triatoma infestans populations in an area with high pyrethroid resistance showed slow recovery and propagation rates despite limited or marginal control actions over a 5-year period. Consistent with these patterns, independent experiments confirmed the lower fitness of pyrethroid-resistant triatomines in Castelli compared with susceptible conspecifics. Targeting hotspots and pyrethroid-resistant foci with appropriate house modification measures and judicious application of alternative insecticides with adequate toxicity profiles are needed to suppress resistant triatomine populations and prevent their eventual regional spread.


Assuntos
Doença de Chagas , Resistência a Inseticidas , Inseticidas , Piretrinas , Triatoma , Animais , Triatoma/efeitos dos fármacos , Triatoma/fisiologia , Piretrinas/farmacologia , Argentina , Inseticidas/farmacologia , Doença de Chagas/transmissão , Doença de Chagas/epidemiologia , Humanos , Estudos Longitudinais , Insetos Vetores/efeitos dos fármacos , Insetos Vetores/fisiologia , Habitação , Ecossistema , Controle de Insetos
2.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 36(3): 243-246, 2024 May 22.
Artigo em Chinês | MEDLINE | ID: mdl-38952309

RESUMO

The insecticide resistance is becoming increasingly severe in malaria vectors and has become one of the most important threats to global malaria elimination. Currently, malaria vectors not only have developed high resistance to conventional insecticides, including organochlorine, organophosphates, carbamates, and pyrethroids, but also have been resistant to recently used neonicotinoids and pyrrole insecticides. This article describes the current status of global insecticide resistance in malaria vectors and global insecticide resistance management strategies, analyzes the possible major challenges in the insecticide resistance management, and proposes the response actions, so as to provide insights into global insecticide resistance management and contributions to global malaria elimination.


Assuntos
Resistência a Inseticidas , Inseticidas , Malária , Animais , Humanos , Insetos Vetores/efeitos dos fármacos , Insetos Vetores/parasitologia , Inseticidas/farmacologia , Malária/prevenção & controle , Malária/transmissão , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/parasitologia
3.
Parasit Vectors ; 17(1): 264, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890667

RESUMO

BACKGROUND: Fleas, considered to be the main transmission vectors of Bartonella, are highly prevalent and show great diversity. To date, no investigations have focused on Bartonella vectors in Southeast China. The aim of this study was to investigate the epidemiological and molecular characteristics of Bartonella in fleas in Southeast China. METHODS: From 2016 to 2022, flea samples (n = 1119) were collected from 863 rodent individuals in seven inland and coastal cities in Southeast China. Flea species, region, gender, host species and habitat were recorded. The DNA samples from each individual flea were screened by real-time PCR for the Bartonella ssrA gene. All positive samples were confirmed by PCR based on the presence of the gltA gene and sequenced. The factors associated with Bartonella infection were analyzed by the Chi-square test and Fisher's exact test. ANOVA and the t-test were used to compare Bartonella DNA load. RESULTS: Bartonella DNA was detected in 26.2% (293/1119) of the flea samples, including in 27.1% (284/1047) of Xenopsylla cheopis samples, 13.2% (5/38) of Monopsyllus anisus samples, 8.3% (2/24) of Leptopsylla segnis samples and 20.0% (2/10) of other fleas (Nosopsyllus nicanus, Ctenocephalides felis, Stivalius klossi bispiniformis and Neopsylla dispar fukienensis). There was a significant difference in the prevalence of Bartonella among flea species, sex, hosts, regions and habitats. Five species of Bartonella fleas were identified based on sequencing and phylogenetic analyses targeting the gltA gene: B. tribocorum, B. queenslandensis, B. elizabethae, B. rochalimae and B. coopersplainsensis. CONCLUSIONS: There is a high prevalence and diversity of Bartonella infection in the seven species of fleas collected in Southeast China. The detection of zoonotic Bartonella species in this study, including B. tribocorum, B. elizabethae and B. rochalimae, raises public health concerns.


Assuntos
Infecções por Bartonella , Bartonella , Infestações por Pulgas , Variação Genética , Insetos Vetores , Roedores , Sifonápteros , Animais , Bartonella/genética , Bartonella/isolamento & purificação , Bartonella/classificação , China/epidemiologia , Sifonápteros/microbiologia , Infecções por Bartonella/epidemiologia , Infecções por Bartonella/veterinária , Infecções por Bartonella/microbiologia , Infecções por Bartonella/transmissão , Roedores/microbiologia , Feminino , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/veterinária , Infestações por Pulgas/parasitologia , Insetos Vetores/microbiologia , Masculino , Filogenia , DNA Bacteriano/genética , Doenças dos Roedores/epidemiologia , Doenças dos Roedores/microbiologia , Doenças dos Roedores/parasitologia , Prevalência
4.
Vet Ital ; 60(2)2024 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-38898790

RESUMO

Trypanosomosis is a well-known sub-Saharan disease. The human form was discovered in The Gambia over 100 years ago. Canine trypanosomosis in The Gambia has never been mentioned in the scientific literature, let alone the involvement of veranus species in its transmission to dogs. The disease's most important vector is the tsetse fly. This fly is abundant in The Gambia, and its infamy for transmitting the disease has been well established. A lot of research efforts have been put into understanding the critical role of this pest in the transmission of the protozoan and the disease in livestock. This report confirms the presence of the disease in domestic dogs in The Gambia, and three canine cases with varied clinical signs, different hematological pictures accompanying the disease, and different effective treatment approaches are reported. Early detection can prevent severe illness and help patients to recover better. This report enhances our understanding on canine trypanosomosis, transmission of the pathogen, and strategies for managing the disease. This report is significant, as it is the first mention of monitor lizards in the 'transmission of trypanosome parasites to dogs during the fighting between them.


Assuntos
Doenças do Cão , Lagartos , Cães , Animais , Doenças do Cão/parasitologia , Doenças do Cão/transmissão , Masculino , Lagartos/parasitologia , Feminino , Gâmbia , Tripanossomíase/veterinária , Tripanossomíase/transmissão , Tripanossomíase/diagnóstico , Insetos Vetores/parasitologia
5.
BMC Plant Biol ; 24(1): 576, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890568

RESUMO

BACKGROUND: Little leaf disease caused by phytoplasma infection is a significant threat to eggplant (also known as brinjal) cultivation in India. This study focused on the molecular characterisation of the phytoplasma strains and insect vectors responsible for its transmission and screening of brinjal germplasm for resistance to little leaf disease. RESULTS: Surveys conducted across districts in the Tamil Nadu state of India during 2021-2022 showed a higher incidence of phytoplasma during the Zaid (March to June), followed by Kharif (June to November) and Rabi (November to March) seasons with mean incidence ranging from 22 to 27%. As the name indicates, phytoplasma infection results in little leaf (reduction in leaf size), excessive growth of axillary shoots, virescence, phyllody, stunted growth, leaf chlorosis and witches' broom symptoms. PCR amplification with phytoplasma-specific primers confirmed the presence of this pathogen in all symptomatic brinjal plants and in Hishimonus phycitis (leafhopper), providing valuable insights into the role of leafhoppers in disease transmission. BLAST search and phylogenetic analysis revealed the phytoplasma strain as "Candidatus Phytoplasma trifolii". Insect population and disease dynamics are highly influenced by environmental factors such as temperature, relative humidity and rainfall. Further, the evaluation of 22 eggplant accessions revealed immune to highly susceptible responses where over 50% of the entries were highly susceptible. Finally, additive main effect and multiplicative interaction (AMMI) and won-where biplot analyses identified G18 as a best-performing accession for little leaf resistance due to its consistent responses across multiple environments. CONCLUSIONS: This research contributes essential information on little leaf incidence, symptoms, transmission and resistance profiles of different brinjal genotypes, which together ensure effective and sustainable management of this important disease of eggplants.


Assuntos
Resistência à Doença , Phytoplasma , Doenças das Plantas , Folhas de Planta , Solanum melongena , Solanum melongena/microbiologia , Solanum melongena/genética , Doenças das Plantas/microbiologia , Phytoplasma/fisiologia , Resistência à Doença/genética , Folhas de Planta/microbiologia , Índia , Filogenia , Animais , Hemípteros/microbiologia , Incidência , Insetos Vetores/microbiologia
6.
Rev Soc Bras Med Trop ; 57: e007062024, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38896655

RESUMO

BACKGROUND: Pressatia choti is a common sand fly found in the Atlantic Forest of Brazil, which is suspected to be involved in the transmission of Leishmania braziliensis. Herein, we aimed to establish a Pr. choti laboratory colony. METHODS: Wild-caught female sand flies were blood fed on hamsters and maintained under controlled conditions (temperature: 26 °C; relative humidity: 70%). RESULTS: Of the 301 collected female sandflies, 288 were identified as Pr. choti. The life cycle duration ranged from 31 to 56 days. CONCLUSIONS: We successfully established a Pr. choti colony, whose biological parameters were similar to those of other neotropical sand flies.


Assuntos
Insetos Vetores , Leishmania braziliensis , Psychodidae , Animais , Psychodidae/classificação , Psychodidae/parasitologia , Feminino , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Brasil , Cricetinae
7.
Parasit Vectors ; 17(1): 246, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831449

RESUMO

BACKGROUND: Arthropods vector a multitude of human disease-causing organisms, and their geographic ranges are shifting rapidly in response to changing climatic conditions. This is, in turn, altering the landscape of disease risk for human populations that are brought into novel contact with the vectors and the diseases they carry. Sand flies in the genera Lutzomyia and Pintomyia are vectors of serious disease-causing agents such as Leishmania (the etiological agent of leishmaniasis) and may be expanding their range in the face of climate change. Understanding the climatic conditions that vector species both tolerate physiologically and prefer behaviorally is critical to predicting the direction and magnitude of range expansions and the resulting impacts on human health. Temperature and humidity are key factors that determine the geographic extent of many arthropods, including vector species. METHODS: We characterized the habitat of two species of sand flies, Lutzomyia longipalpis and Pintomyia evansi. Additionally, we studied two behavioral factors of thermal fitness-thermal and humidity preference in two species of sand flies alongside a key aspect of physiological tolerance-desiccation resistance. RESULTS: We found that Lu. longipalpis is found at cooler and drier conditions than Pi. evansi. Our results also show significant interspecific differences in both behavioral traits, with Pi. evansi preferring warmer, more humid conditions than Lu. longipalpis. Finally, we found that Lu. longipalpis shows greater tolerance to extreme low humidity, and that this is especially pronounced in males of the species. CONCLUSIONS: Taken together, our results suggest that temperature and humidity conditions are key aspects of the climatic niche of Lutzomyia and Pintomyia sand flies and underscore the value of integrative studies of climatic tolerance and preference in vector biology.


Assuntos
Ecossistema , Umidade , Psychodidae , Temperatura , Animais , Psychodidae/fisiologia , Psychodidae/classificação , Feminino , Masculino , Insetos Vetores/fisiologia
8.
Med Trop Sante Int ; 4(1)2024 03 31.
Artigo em Francês | MEDLINE | ID: mdl-38846117

RESUMO

Background - Rationale: Tsetse flies (Diptera: Glossinidae) are obligate bloodfeeders that occur exclusively in Sub-Saharan Africa, where they are the vectors of trypanosomes causing HAT (human African trypanosomiasis) and AAT (African animal trypanosomiasis). In Chad, tsetse flies occur only in the most southern part of the country because of its favorable bioclimatic conditions. However, despite the importance of HAT and AAT in this country, very little is known about the current tsetse distribution, in particular its northern limit, which is of key importance for the surveillance of these diseases. Material and methods - Results: A total of 217 biconical traps were deployed in 2021 and 2022 from the West to the East around the formerly known northern limit, resulting in 1,024 tsetse caught belonging to three different taxa: Glossina morsitans submorsitans (57%), G. tachinoides (39%) and G. fuscipes fuscipes (4%). In addition to the information gathered on the presence/absence of each tsetse taxon, we show a strong North-South shift of the northen tsetse distribution limit as compared to the previous works from 1966 to 1996, and a growing spatial fragmentation in more and more discrete pockets of tsetse presence. Discussion - Conclusion: This North-South shift of the northern tsetse distribution limit in Chad is the likely consequence of the combined effect of severe draughts that affected the country, and increasing human pressure on land. This update of the tsetse northern limit will be of help to the national programmes in charge of HAT and AAT.


Assuntos
Moscas Tsé-Tsé , Chade/epidemiologia , Animais , Distribuição Animal , Mudança Climática , Humanos , Insetos Vetores/parasitologia
9.
J Vector Borne Dis ; 61(2): 236-242, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38922658

RESUMO

BACKGROUND OBJECTIVES: Sandflies are vector insects associated with terrestrial forest ecosystems; in the Ecuadorian Andes, they participate in the transmission of human cutaneous leishmaniasis. This geographical area represents an opportunity to evaluate the role of sandflies as bioindicators of the degree of intervention of tropical humid forest ecosystems (THF) associated with changes in the ecology of the local landscape. METHODS: CDC-light traps were used for collecting adult sandflies in February 2020 in a humid tropical forest within the Chocó Biosphere Reserve. All species were identified using morphological keys. Analysis data about abundance, richness, species accumulation, diversity index, species composition communities, species sex proportion, spatial sandflies environmental, Renyi's Diversity Profile were performed to compare six spatial habitats in Mashpi locality, Ecuador. RESULTS: Sandflies were collected (n-1435); the main species are represented by Trichophoromyia reburra, Nyssomyia trapidoi, Psathyromyia aclydifera, Psychodopygus panamensis and Lutzomyia hartmanni. Only Th. reburra is associated with not intervened forest, while the other three species are associated with intervened forest within Mashpi in the Choco Biosphere Reserve. The secondary forest has major sandflies' richness, while the primary forest exhibits major abundance. INTERPRETATION CONCLUSION: Th. reburra is a sandfly restricted to the Andean Forest and is a bioindicator of the high environmental health quality of the forest, while Ny. trapidoi and Pa. aclydifera are bioindicators of environmental disturbances in the forest. Additionally, Ps. panamensis, Lu. hartmanni and Ny. trapidoi are bioindicators of human impact and the risk of leishmaniasis.


Assuntos
Ecossistema , Florestas , Insetos Vetores , Psychodidae , Animais , Psychodidae/fisiologia , Psychodidae/classificação , Insetos Vetores/fisiologia , Insetos Vetores/classificação , Equador , Masculino , Feminino , Leishmaniose Cutânea/transmissão , Biodiversidade , Humanos
10.
PLoS Pathog ; 20(6): e1012318, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38865374

RESUMO

Many plant arboviruses are persistently transmitted by piercing-sucking insect vectors. However, it remains largely unknown how conserved insect Toll immune response exerts antiviral activity and how plant viruses antagonize it to facilitate persistent viral transmission. Here, we discover that southern rice black-streaked dwarf virus (SRBSDV), a devastating planthopper-transmitted rice reovirus, activates the upstream Toll receptors expression but suppresses the downstream MyD88-Dorsal-defensin cascade, resulting in the attenuation of insect Toll immune response. Toll pathway-induced the small antibacterial peptide defensin directly interacts with viral major outer capsid protein P10 and thus binds to viral particles, finally blocking effective viral infection in planthopper vector. Furthermore, viral tubular protein P7-1 directly interacts with and promotes RING E3 ubiquitin ligase-mediated ubiquitinated degradation of Toll pathway adaptor protein MyD88 through the 26 proteasome pathway, finally suppressing antiviral defensin production. This virus-mediated attenuation of Toll antiviral immune response to express antiviral defensin ensures persistent virus infection without causing evident fitness costs for the insects. E3 ubiquitin ligase also is directly involved in the assembly of virus-induced tubules constructed by P7-1 to facilitate viral spread in planthopper vector, thereby acting as a pro-viral factor. Together, we uncover a previously unknown mechanism used by plant arboviruses to suppress Toll immune response through the ubiquitinated degradation of the conserved adaptor protein MyD88, thereby facilitating the coexistence of arboviruses with their vectors in nature.


Assuntos
Arbovírus , Insetos Vetores , Transdução de Sinais , Receptores Toll-Like , Animais , Arbovírus/imunologia , Receptores Toll-Like/metabolismo , Insetos Vetores/virologia , Insetos Vetores/imunologia , Doenças das Plantas/virologia , Doenças das Plantas/imunologia , Reoviridae/fisiologia , Reoviridae/imunologia , Hemípteros/virologia , Hemípteros/imunologia , Oryza/virologia , Oryza/imunologia , Proteínas de Insetos/metabolismo , Imunidade Inata
11.
BMC Infect Dis ; 24(1): 569, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849747

RESUMO

BACKGROUND: Flies are acknowledged as vectors of diseases transmitted through mechanical means and represent a significant risk to human health. The study aimed to determine the prevalence of enteropathogens carried by flies in Pudong New Area to inform strategies for preventing and controlling flies. METHODS: Samples were collected from various locations in the area using cage trapping techniques between April and November 2021, encompassing various habitats such as parks, residential areas, restaurants, and farmers' markets. The main fly species were identified using cryomicrography and taxonomic enumeration, with 20 samples per tube collected from different habitats. Twenty-five enteropathogens were screened using GI_Trial v3 TaqManTM microbial arrays. RESULTS: A total of 3,875 flies were collected from 6,400 placements, resulting in an average fly density of 0.61 flies per cage. M. domestica were the most common species at 39.85%, followed by L. sericata at 16.57% and B. peregrina at 13.14%. Out of 189 samples, 93 tested positive for enteropathogens, with nine different pathogens being found. 12.70% of samples exclusively had parasites, a higher percentage than those with only bacteria or viruses. The study found that M. domestica had fewer enteropathogens than L. sericata and B. peregrina, which primarily harbored B. hominis instead of bacteria and viruses such as E. coli, Astrovirus, and Sapovirus. During spring testing, all three fly species exhibited low rates of detecting enteropathogens. M. domestica were found in residential areas with the highest number of pathogen species, totaling six. In contrast, L. sericata and B. peregrina were identified in farmers' markets with the highest number of pathogen species, totaling six and seven, respectively. CONCLUSIONS: Flies have the potential to serve as vectors for the transmission of enteropathogens, thereby posing a substantial risk to public health.


Assuntos
Insetos Vetores , Animais , Humanos , Insetos Vetores/microbiologia , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/genética , China/epidemiologia , Dípteros/microbiologia , Vírus/isolamento & purificação , Vírus/classificação , Vírus/genética , Muscidae/microbiologia
12.
Artigo em Inglês | MEDLINE | ID: mdl-38928904

RESUMO

Besides being vectors of the onchocerciasis parasite, blackflies are a source of nuisance in onchocerciasis-endemic communities. We investigated the experience of residents in the Ntui Health District (Cameroon) regarding blackfly nuisance and assessed their perceptions of a novel "Slash and Clear" (S&C) intervention for blackfly control. Focus group discussions were conducted before and after S&C implementation (respectively, in February 2022 and December 2023). Blackflies were known to emerge from the river areas and cause disease. To prevent blackfly bites, the population often covered their body with protective clothing and applied various substances (kerosene, oil, or lemon) to their skin. Post-intervention data showed reduced blackfly nuisance, and the willingness to sustain blackfly control in the long-term was unanimous among community leaders and members, including the village volunteers who implemented the S&C intervention. In conclusion, blackfly nuisance is evident in the Ntui onchocerciasis focus of Cameroon and led to a panoply of coping practices, some of which could be detrimental to their health. Implementing S&C for blackfly control is well accepted and could sustainably alleviate the nuisance caused by blackflies while simultaneously breaking the onchocerciasis transmission cycle.


Assuntos
Controle de Insetos , Oncocercose , Simuliidae , Camarões , Animais , Simuliidae/parasitologia , Humanos , Oncocercose/prevenção & controle , Controle de Insetos/métodos , Feminino , Masculino , Adulto , Insetos Vetores , Pessoa de Meia-Idade , Grupos Focais , Conhecimentos, Atitudes e Prática em Saúde , Adulto Jovem , Mordeduras e Picadas de Insetos/prevenção & controle
14.
PLoS Negl Trop Dis ; 18(6): e0012237, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38885272

RESUMO

BACKGROUND: Leishmaniasis, a neglected disease and public health concern, is associated with various factors such as biological, social, economical conditions and climate, increasing the risk of human infection. Understanding the population dynamics of the vectors, like Pintomyia longiflocosa, and its relationship with ecological variables is crucial for developing effective strategies to control sand fly populations and combat cutaneous leishmaniasis in a tropical country like Colombia. METHODOLOGY: Adult sand flies were collected in three different sample locations: outdoor, indoor, and peri-domestic areas in three houses located in the rural settlement of Campoalegre (Huila) between February 2020 and February 2021, using the CDC light traps. The sand fly density was quantified and associated with the sample locations and the sampling months using Analysis of Variance and Pearson correlations. PRINCIPAL FINDINGS: In the period of the sample, 98.86% of sand fly collected was identified as Pi. longiflocosa. The density of this species was significantly different between males and females, the latter contributing more to density in all sample locations (P<0.0001). The outdoor was the sample location with the highest and most significative density in this study (70%, P = 0.04). The density of these sand flies is related to the seasonality of Campoalegre, revealing a density peak from February and June to October (P < 0.05). Finally, precipitation is the environmental variable prominently linked to the density pattern, showing a negative correlation with it. Months with the highest precipitations show the lowest values of Pi. longiflocosa abundance. CONCLUSIONS/SIGNICANCE: Our investigation reveals a inverse correlation between precipitation levels and the abundance of Pi. longiflocosa in Campoalegre (Huila), particularly in outdoor areas. This suggests that vector control strategies to periods of reduced precipitation in outdoor settings could offer an effective approach to minimizing cases of cutaneous leishmaniasis in the region.


Assuntos
Insetos Vetores , Leishmaniose Cutânea , Psychodidae , Animais , Leishmaniose Cutânea/transmissão , Leishmaniose Cutânea/epidemiologia , Colômbia/epidemiologia , Psychodidae/parasitologia , Psychodidae/fisiologia , Insetos Vetores/fisiologia , Insetos Vetores/parasitologia , Feminino , Masculino , Humanos , Estações do Ano , Dinâmica Populacional , Análise Espaço-Temporal
15.
Front Cell Infect Microbiol ; 14: 1408362, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38938879

RESUMO

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama is the leading vector of Candidatus Liberibacter asiaticus (CLas), the causative agent of citrus Huanglongbing (HLB) disease. The distribution and dynamics of CLas within ACP are critical to understanding how the transmission, spread and infection of CLas occurs within its host vector in nature. In this study, the distribution and titer changes of CLas in various tissues of ACP 5th instar nymphs and adults were examined by fluorescence in situ hybridization (FISH) and real-time quantitative PCR (qPCR) techniques. Results demonstrated that 100% of ACP 5th instar nymphs and adults were infected with CLas following feeding on infected plants, and that CLas had widespread distribution in most of the tissues of ACP. The titers of CLas within the midgut, salivary glands and hemolymph tissues were the highest in both 5th instar nymphs and adults. When compared with adults, the titers of CLas in these three tissues of 5th instar nymphs were significantly higher, while in the mycetome, ovary and testes they were significantly lower than those of adults. FISH visualization further confirmed these findings. Dynamic analysis of CLas demonstrated that it was present across all the developmental ages of ACP adults. There was a discernible upward trend in the presence of CLas with advancing age in most tissues of ACP adults, including the midgut, hemolymph, salivary glands, foot, head, cuticula and muscle. Our findings have significant implications for the comprehensive understanding of the transmission, dissemination and infestation of CLas, which is of much importance for developing novel strategies to halt the spread of CLas, and therefore contribute to the efficient prevention and control of HLB.


Assuntos
Citrus , Hemípteros , Hibridização in Situ Fluorescente , Insetos Vetores , Ninfa , Doenças das Plantas , Animais , Hemípteros/microbiologia , Insetos Vetores/microbiologia , Doenças das Plantas/microbiologia , Ninfa/microbiologia , Citrus/microbiologia , Rhizobiaceae/genética , Rhizobiaceae/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Glândulas Salivares/microbiologia , Hemolinfa/microbiologia
16.
Parasit Vectors ; 17(1): 269, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918858

RESUMO

BACKGROUND: The sand fly Nyssomyia neivai is one of the most abundant species in Southern Brazil. It is frequently found in areas that are foci of visceral leishmaniasis in the state of Santa Catarina, caused by Leishmania infantum. In this region, the main vector of L. infantum, Lutzomyia longipalpis, has not been detected. In the absence of L. longipalpis, this study aimed to identify the sand fly fauna and diagnose any potential Leishmania spp. infection in sand flies and in dogs in a region of Southern Brazil that experienced a recent canine visceral leishmaniasis outbreak. METHODS: This report includes a survey of the sand fly fauna at the Zoonosis Control Center of the Municipality of Tubarão (Santa Catarina, Brazil). Molecular tests were conducted to investigate Leishmania spp. natural infection in sand flies using polymerase chain reaction (PCR). In positive females, in addition to morphological identification, molecular analysis through DNA barcoding was performed to determine the sand fly species. Additionally, the dogs were tested for the presence of Leishmania spp. using a non-invasive technique for the collection of biological material, to be assessed by PCR. RESULTS: A total of 3419 sand flies, belonging to five genera, were collected. Nyssomyia neivai was the most abundant species (85.8%), followed by Migonemyia migonei (13.3%), Pintomyia fischeri (0.8%), Evandromyia edwardsi (< 0.1%), and species of the genus Brumptomyia. (0.1%). Out of the 509 non-engorged females analyzed by PCR, two (0.4%) carried L. infantum DNA. The naturally infected females were identified as Ny. neivai, in both morphological and molecular analysis. In addition, two out of 47 conjunctival swabs from dogs tested positive for L. infantum, yielding an infection rate of 4.2%. CONCLUSIONS: These results confirm the presence of Ny. neivai naturally infected with L. infantum in an area where dogs were also infected by the parasite, suggesting its potential role as a vector in Southern Brazil.


Assuntos
Doenças do Cão , Insetos Vetores , Leishmania infantum , Leishmaniose Visceral , Psychodidae , Animais , Cães , Leishmania infantum/genética , Leishmania infantum/isolamento & purificação , Brasil/epidemiologia , Psychodidae/parasitologia , Psychodidae/classificação , Doenças do Cão/parasitologia , Doenças do Cão/epidemiologia , Leishmaniose Visceral/veterinária , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/transmissão , Feminino , Insetos Vetores/parasitologia , Reação em Cadeia da Polimerase , Masculino
17.
Parasit Vectors ; 17(1): 278, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38943218

RESUMO

BACKGROUND: African swine fever (ASF) is a highly contagious and severe haemorrhagic disease of Suidae, with mortalities that approach 100 percent. Several studies suggested the potential implication of non-biting dipterans in the spread of ASFV in pig farms due to the identification of the ASFV DNA. However, to our knowledge, no study has evaluated the viral DNA load in non-biting dipterans collected in outbreak farms and no risk factors have been analysed. In this context, our study aimed to analyse the risk factors associated with the presence of non-biting dipterans collected from ASF outbreaks in relation to the presence and load of viral DNA. METHODS: Backyard farms (BF), type A farms (TAF), and commercial farms (CF), were targeted for sampling in 2020. In 2021, no BF were sampled. Each farm was sampled only once. The identification of the collected flies to family, genus, or species level was performed based on morphological characteristics using specific keys and descriptions. Pools were made prior to DNA extraction. All extracted DNA was tested for the presence of the ASFV using a real-time PCR protocol. For this study, we considered every sample with a CT value of 40 as positive. The statistical analysis was performed using Epi Info 7 software (CDC, USA). RESULTS: All collected non-biting flies belonged to five families: Calliphoridae, Sarcophagidae, Fanniidae, Drosophilidae, and Muscidae. Of the 361 pools, 201 were positive for the presence of ASFV DNA. The obtained CT values of the positive samples ranged from 21.54 to 39.63, with a median value of 33.59 and a mean value of 33.56. Significantly lower CT values (corresponding to higher viral DNA load) were obtained in Sarcophagidae, with a mean value of 32.56; a significantly higher number of positive pools were noticed in August, mean value = 33.12. CONCLUSIONS: Our study brings compelling evidence of the presence of the most common synanthropic flies near domestic pig farms carrying ASFV DNA, highlighting the importance of strengthening the biosecurity measures and protocols for prevention of the insect life cycle and distribution.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , DNA Viral , Dípteros , Surtos de Doenças , Fazendas , Animais , Vírus da Febre Suína Africana/genética , Vírus da Febre Suína Africana/isolamento & purificação , Vírus da Febre Suína Africana/classificação , Febre Suína Africana/epidemiologia , Febre Suína Africana/virologia , Febre Suína Africana/transmissão , Suínos , Surtos de Doenças/veterinária , DNA Viral/genética , Romênia/epidemiologia , Dípteros/virologia , Dípteros/classificação , Dípteros/genética , Insetos Vetores/virologia , Insetos Vetores/classificação
18.
Plant Physiol Biochem ; 213: 108812, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38875781

RESUMO

Tomato yellow leaf curl virus (TYLCV), a DNA virus belonging to the genus Begomovirus, significantly impedes the growth and development of numerous host plants, including tomatoes and peppers. Due to its rapid mutation rate and frequent recombination events, achieving complete control of TYLCV proves exceptionally challenging. Consequently, identifying resistance mechanisms become crucial for safeguarding host plants from TYLCV-induced damage. This review article delves into the global distribution, dispersal patterns, and defining characteristics of TYLCV. Moreover, the intricate interplay between TYLCV and various influencing factors, such as insect vectors, susceptible host plants, and abiotic stresses, plays a pivotal role in plant-TYLCV interactions. The review offers an updated perspective on recent investigations focused on plant response mechanisms to TYLCV infection, including the intricate relationship between TYLCV, whiteflies, and regulatory factors. This comprehensive analysis aims to establish a foundation for future research endeavors exploring the molecular mechanisms underlying TYLCV infection and the development of plant resistance through breeding programs.


Assuntos
Begomovirus , Doenças das Plantas , Begomovirus/fisiologia , Doenças das Plantas/virologia , Hemípteros/virologia , Hemípteros/fisiologia , Resistência à Doença/genética , Animais , Solanum lycopersicum/virologia , Solanum lycopersicum/genética , Insetos Vetores/virologia
19.
Trop Biomed ; 41(1): 125-133, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38852142

RESUMO

Culicoides oxystoma Kieffer is a vector of viruses, filarial nematodes and protozoa of the genus Leishmania transmitted to humans and other animals. Understanding genetic diversity, genetic structure and genetic relationships among geographically widespread populations will provide important information related to disease epidemiology. In this study, genetic diversity, genetic structure and genetic relationships between Thai C. oxystoma and those reported from other countries were inferred based on mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1) sequences. A high level of genetic diversity was found in C. oxystoma from Thailand. The maximum K2P intraspecific genetic divergence for COI gene and ITS-1 sequences were 4.29% and 6.55%, respectively. Despite high genetic diversity, no significant genetic differentiation was found within the 13 Thai populations. This could be a result of unspecialized habitat requirement of the larval habitat, abundance and continuous distribution of host blood sources, potential for long distance movement with host via trading. Mitochondrial genealogy analysis of the global population of C. oxystoma revealed three (A, B and C) genetically divergent lineages. Specimens from Thailand were included in the main lineage (A) with those from all other countries except those from Senegal that formed lineage B and those of Lineage C that was exclusively found in Bangladesh. The nuclear (ITS-1) genetic markers genealogy indicated that Thai C. oxystoma belong to the same genet.


Assuntos
Ceratopogonidae , Complexo IV da Cadeia de Transporte de Elétrons , Variação Genética , Animais , Ceratopogonidae/genética , Ceratopogonidae/classificação , Tailândia , Complexo IV da Cadeia de Transporte de Elétrons/genética , Filogenia , Genética Populacional , DNA Espaçador Ribossômico/genética , Insetos Vetores/genética , Insetos Vetores/classificação , Análise de Sequência de DNA
20.
Mem Inst Oswaldo Cruz ; 119: e230226, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38865577

RESUMO

BACKGROUND: Monitoring and analysing the infection rates of the vector of Trypanosoma cruzi, that causes Chagas disease, helps assess the risk of transmission. OBJECTIVES: A study was carried out on triatomine in the State of Paraná, Brazil, between 2012 and 2021 and a comparison was made with a previous study. This was done to assess the risk of disease transmission. METHODS: Ecological niche models based on climate and landscape variables were developed to predict habitat suitability for the vectors as a proxy for risk of occurrence. FINDINGS: A total of 1,750 specimens of triatomines were recorded, of which six species were identified. The overall infection rate was 22.7%. The areas with the highest risk transmission of T. cruzi are consistent with previous predictions in municipalities. New data shows that climate models are more accurate than landscape models. This is likely because climate suitability was higher in the previous period. MAIN CONCLUSION: Regardless of uneven sampling and potential biases, risk remains high due to the wide presence of infected vectors and high environmental suitability for vector species throughout the state and, therefore, improvements in public policies aimed at wide dissemination of knowledge about the disease are recommended to ensure the State remains free of Chagas disease.


Assuntos
Doença de Chagas , Insetos Vetores , Triatominae , Trypanosoma cruzi , Doença de Chagas/transmissão , Animais , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Brasil/epidemiologia , Triatominae/classificação , Triatominae/parasitologia , Humanos , Fatores de Risco , Medição de Risco , Ecossistema
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