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1.
Proc Natl Acad Sci U S A ; 121(12): e2322453121, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38470919

RESUMO

The phlebotomine sandfly, Lutzomyia longipalpis, a major vector of the Leishmania parasite, uses terpene pheromones to attract conspecifics for mating. Examination of the L. longipalpis genome revealed a putative terpene synthase (TPS), which-upon heterologous expression in, and purification from, Escherichia coli-yielded a functional enzyme. The TPS, termed LlTPS, converted geranyl diphosphate (GPP) into a mixture of monoterpenes with low efficiency, of which ß-ocimene was the major product. (E,E)-farnesyl diphosphate (FPP) principally produced small amounts of (E)-ß-farnesene, while (Z,E)- and (Z,Z)-FPP yielded a mixture of bisabolene isomers. None of these mono- and sesquiterpenes are known volatiles of L. longipalpis. Notably, however, when provided with (E,E,E)-geranylgeranyl diphosphate (GGPP), LlTPS gave sobralene as its major product. This diterpene pheromone is released by certain chemotypes of L. longipalpis, in particular those found in the Ceará state of Brazil. Minor diterpene components were also seen as products of the enzyme that matched those seen in a sandfly pheromone extract.


Assuntos
Diterpenos , Psychodidae , Animais , Feromônios/metabolismo , Psychodidae/metabolismo , Diterpenos/metabolismo , Terpenos , Monoterpenos
2.
PLoS One ; 19(3): e0296777, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38478521

RESUMO

Leishmaniasis refers to a disease with a wide range of manifestations; and there are three main forms of disease, cutaneous, mucocutaneous, and visceral. Leishmaniasis is one of the diseases with a protozoan agent which is vector-borne. Visceral leishmaniasis (VL) is the most severe form that can be fiercely life-threatening if left untreated. VL can be caused by members of Leishmania donovani complex, in Iran, Leishmania infantum is considered the primary causative agent of VL, resulting in a zoonotic form of VL. The two main goals of our work, which followed our prior sero-epidemiological and entomological survey, were to characterize and conduct a phylogenetic analysis of the Leishmania species that infect people, dogs, and sandflies. The samples were collected throughout 2017, from January to December, so blood samples were collected from humans and dogs, while sandfly samples were collected with sticky traps. DNA extracted from all seropositive samples of humans and dogs, 10% of sero-negative human samples, and all collected sandflies were subjected to kDNA-nested-PCR for tracing parasites. A total of 30 samples, including 20 human samples, 8 dog samples, and 2 sandfly samples, were found positive for the kDNA gene of L. infantum. Sequences were evaluated to study the genetic diversity among the six discovered L. infantum. Based on kDNA, the phylogenetic study of L. infantum demonstrated a high level of genetic variety and a relationship between the host, the parasite's geographic origin, and its genetic diversity.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Psychodidae , Humanos , Animais , Cães , DNA de Cinetoplasto/genética , Psychodidae/parasitologia , Leishmania infantum/genética , Filogenia , Irã (Geográfico)/epidemiologia , Reação em Cadeia da Polimerase/métodos , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/veterinária , Leishmaniose Visceral/diagnóstico , Doenças do Cão/diagnóstico
3.
PLoS Negl Trop Dis ; 18(3): e0012028, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38452055

RESUMO

BACKGROUND: India is going through the maintenance phase of VL elimination programme which may be threatened by the persistence of hidden parasite pools among asymptomatic leishmanial infection (ALI) and PKDL. The present work was designed to determine the burden of VL, PKDL, and ALI and to assess the role of treatment of ALI in maintaining post-elimination phase. METHODS AND FINDING: The study was undertaken in Malda district, West Bengal, India during October 2016 to September 2021. Study areas were divided into 'Study' and 'Control' arms. VL and PKDL cases of both the arms were diagnosed by three active mass surveys with an interval of one year and treated as per National guideline. ALI of 'Study' arm was treated like VL. ALI of 'Control' arm was followed up to determine their fate. Fed sand-fly pools were analysed for parasitic DNA. No significant difference was noted between the incidence of VL and PKDL in both the arms. Incidence of ALI declined sharply in 'Study' arm but an increasing trend was observed in 'Control' arm. Significantly higher rate of sero-conversion was noted in 'Control' arm and was found to be associated with untreated ALI burden. Parasitic DNA was detected in 22.8% ALI cases and 2.2% sand-fly pools. CONCLUSION: Persistence of a significant number of PKDL and ALI and ongoing transmission, as evidenced by new infection and detection of leishmanial DNA in vector sand-flies, may threaten the maintenance of post-elimination phase. Emphasis should be given for elimination of pathogen to prevent resurgence of VL epidemics.


Assuntos
Leishmania donovani , Leishmaniose Cutânea , Leishmaniose Visceral , Phlebotomus , Psychodidae , Animais , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/prevenção & controle , Leishmaniose Visceral/complicações , Areia , Psychodidae/parasitologia , Infecções Assintomáticas/epidemiologia , Índia/epidemiologia , DNA , Leishmaniose Cutânea/epidemiologia
4.
PLoS Negl Trop Dis ; 18(3): e0011938, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38446789

RESUMO

BACKGROUND: Visceral leishmaniasis (VL), or kala-azar, is a vector-borne tropical disease caused by a group of intracellular hemoflagellate protozoa belonging to the family of Trypanosomatide and the genus Leishmania. The disease is distributed around the world and transmitted via the bite of infected female Phlebotomine sandflies, and there is variation in the diagnostic accuracy. Therefore, this systematic review and meta-analysis aimed to determine the pooled global sensitivity and specificity of the rk-39 test and to evaluate if there is a difference between the different parts of the world. METHODS: A systematic review and meta-analysis have been conducted on the diagnostic accuracy of dermoscopy. After setting eligibility criteria, literature was searched in four databases and one searching engine. Articles were screened, critically appraised, and extracted independently by two reviewers, and any disagreements were resolved with the involvement of a third person. The quality of the included studies had been assessed by the Quality Assessment of Diagnostic Accuracy Studies (QUADAS 2) tool. Pooled sensitivity and specificity were determined by bivariate random effect analysis. Heterogeneity was assessed by Higgins's I2, and when it was present, mitigation was conducted by using sensitivity analysis. RESULT: A total of 409 studies were identified, and finally 18 articles were eligible for the review with a total sample size of 5, 253. The bivariate random effect meta-analysis of the 7 diagnostic accuracy studies showed a pooled sensitivity of 0.89 (0.76-0.95) and specificity of 0.86 (0.72-0.94). The +LR was 6.32 (95% CI: 2.85-14.02), the-LR was 0.13 (95% CI: 0.06-0.30), and the diagnostic odds ratio (DOR) was 47.8 (95% CI: 11.3-203.2). Abdel-Latif (2018) was both an outlier and influential for sensitivity, and Walter (2011) was both an outlier and influential for specificity, and removing them from sensitivity and specificity, respectively, was beneficial for reducing the heterogeneity. CONCLUSION: Rk-39 is found to have highly accurate measures in the diagnosis of visceral leishmaniasis. Both sensitivity and specificity were found to be highly accurate in the diagnosis of leishmaniasis, with a pooled sensitivity of 0.91 (0.88-0.93) and a pooled specificity of 0.89 (0.85-0.91). ETHICAL CONSIDERATION: As we will use secondary data for the systematic review and meta-analysis, ethical concerns are not necessary.


Assuntos
Leishmania , Leishmaniose Visceral , Psychodidae , Feminino , Humanos , Animais , Leishmaniose Visceral/diagnóstico , Bases de Dados Factuais , Razão de Chances
5.
Vet Parasitol Reg Stud Reports ; 49: 100988, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38462297

RESUMO

The incidence of human Visceral Leishmaniasis (VL) has decreased in Brazil; however, the number of areas reporting human and canine cases has increased, with Leishmania infantum usually preceding human infection. This study aimed to analyze the profile of infectious diseases that are endemic for both human and canine VL, in dogs housed in a shelter located in the state of Rio Grande do Norte, Northeast Brazil. Data was obtained between November/2021 to April/2022. All dogs residing at the shelter (98 dogs) were examined and blood was collected for testing for L. infantum, Ehrlichia canis, and Babesia sp. Statistical analyses considered the clinical and laboratory findings. Of the 98 animals, approximately 43% were positive for L. infantum antibodies, 19% were positive for L. infantum kDNA, and 18% were L. infantum positive by culture. Greater levels of anti-leishmania antibodies were observed in dogs with symptoms suggestive of VL. The dogs tested positive for E. canis (19/98) and B. canis (18/98). Lutzomyia longipalpis was captured inside the shelter, representing 74.25% (n = 225) of whole sandflies in the dog shelter. Concomitant infection by L. infantum and E. canis increased the odds of death. Treatment of VL included the use of allopurinol (n = 48) and miltefosine (n = 8). Treated animals showed more signs of Leishmania infection. Tickborn parasites and Leishmania were prevalent in sheltered dogs in a VL-endemic area, which increases the odds of death and poses an additional challenge for caring for abandoned dogs and at the same time setting protocols to manage reservoirs of L. infantum.


Assuntos
Babesia , Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Psychodidae , Humanos , Animais , Cães , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/veterinária , Leishmaniose/tratamento farmacológico , Leishmaniose/veterinária , Leishmania infantum/genética , Psychodidae/parasitologia , Doenças do Cão/epidemiologia
6.
Parasit Vectors ; 17(1): 54, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321481

RESUMO

BACKGROUND: Armenia is considered particularly vulnerable to life-threatening vector-borne diseases (VBDs) including malaria, West Nile virus disease and leishmaniasis. However, information relevant for the control of the vectors of these diseases, such as their insecticide resistance profile, is scarce. The present study was conducted to provide the first evidence on insecticide resistance mechanisms circulating in major mosquito and sand fly populations in Armenia. METHODS: Sampling sites were targeted based mainly on previous historical records of VBD occurrences in humans and vertebrate hosts. Initially, molecular species identification on the collected vector samples was performed. Subsequently, molecular diagnostic assays [polymerase chain reaction (PCR), Sanger sequencing, PCR-restriction fragment length polymorphism (RFLP), quantitative PCR (qPCR)] were performed to profile for major insecticide resistance mechanisms, i.e. target site insensitivity in voltage-gated sodium channel (vgsc) associated with pyrethroid resistance, acetylcholinesterase (ace-1) target site mutations linked to organophosphate (OP) and carbamate (CRB) resistance, chitin synthase (chs-1) target site mutations associated with diflubenzuron (DFB) resistance and gene amplification of carboxylesterases (CCEs) associated with resistance to the OP temephos. RESULTS: Anopheles mosquitoes were principally represented by Anopheles sacharovi, a well-known malaria vector in Armenia, which showed no signs of resistance mechanisms. Contrarily, the knockdown resistance (kdr) mutations V1016G and L1014F/C in the vgsc gene were detected in the arboviral mosquito vectors Aedes albopictus and Culex pipiens, respectively. The kdr mutation L1014S was also detected in the sand fly, vectors of leishmaniasis, Phlebotomus papatasi and P. tobbi, whereas no mutations were found in the remaining collected sand fly species, P. sergenti, P. perfiliewi and P. caucasicus. CONCLUSIONS: This is the first study to report on molecular mechanisms of insecticide resistance circulating in major mosquito and sand fly disease vectors in Armenia and highlights the need for the establishment of systematic resistance monitoring practices for the implementation of evidence-based control applications.


Assuntos
Aedes , Anopheles , Culex , Inseticidas , Leishmaniose , Malária , Phlebotomus , Psychodidae , Piretrinas , Animais , Humanos , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Mosquitos Vetores/genética , Acetilcolinesterase/genética , Anopheles/genética , Armênia , Phlebotomus/genética , Mutação
7.
Mem Inst Oswaldo Cruz ; 119: e230173, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38324879

RESUMO

BACKGROUND: The incidence of visceral leishmaniasis (VL) has increased in the Southern region of Brazil in recent years, especially in the State of Paraná. New species have been suggested with potential to act as vector in VL endemic areas. OBJECTIVES: Identify the Leishmania species in sand fly specimens collected from 2016 to 2018 in the municipality of Itaperuçu, Vale do Ribeira, Paraná, Brazil. METHODS: Light traps were used for collections and for the analysis of sand fly were used the multiplex polymerase chain reaction (PCR) methodology and subsequent sequencing. FINDINGS: Among the collected specimens, 88.62% were attributed to the species Nyssomyia neivai, which were grouped into 176 pools. Three positive pools were detected: two with Leishmania (Viannia) braziliensis and one with L. (Leishmania) infantum. The positivity rate for the parasite was 0.25% based on the presence of at least one infected insect in the pool. MAIN CONCLUSIONS: The detection of L. infantum in Ny. neivai draws attention due to its abundance and anthropophily in the State of Paraná. Moreover, this finding is considered as an alert and suggests that the vector competence of Ny. neivai and the criteria for its incrimination should be carried out, given its wide distribution in southern of Brazil.


Assuntos
Leishmania braziliensis , Leishmania infantum , Leishmaniose Visceral , Phlebotomus , Psychodidae , Animais , Leishmania infantum/genética , Brasil/epidemiologia , Psychodidae/parasitologia , Leishmania braziliensis/genética , DNA
8.
J Comp Pathol ; 209: 6-12, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38320331

RESUMO

Phlebotomine sand flies (Diptera: Phlebotominae) are vectors of human and animal pathogens, including Leishmania species protozoan parasites and viruses of the genus Phlebovirus. In Europe, visceral zoonotic leishmaniasis caused by Leishmania infantum, a deadly disease when left untreated, is endemic in southern countries, and dogs are the main reservoir hosts for human infection. Most phleboviruses cause asymptomatic infections or flu-like syndromes in humans, but Toscana phlebovirus can cause meningitis and encephalitis. These diseases are likely to re-emerge, posing a growing threat to public and animal health. Potential triggers include the movement of humans and dogs, increasing numbers of immunosuppressive conditions, climate change and other human-mediated environmental changes. An overview of the main epidemiological characteristics of the pathogens transmitted by sand flies in Europe and the potential triggers involved in their emergence and re-emergence are reviewed here. There is a need to implement mandatory notification of human and canine leishmaniases and human phleboviruses and coordinated epidemiological surveillance programmes at a European level, and to raise awareness among healthcare professionals and citizens about sand fly-borne diseases, following a One Health approach.


Assuntos
Doenças do Cão , Encefalite , Leishmania infantum , Leishmaniose Visceral , Psychodidae , Animais , Cães , Humanos , Europa (Continente)/epidemiologia , Leishmaniose Visceral/veterinária , Encefalite/veterinária , Doenças do Cão/epidemiologia
9.
J Clin Microbiol ; 62(3): e0120023, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38363141

RESUMO

Several psychodid flies are commonly associated with human-inhabited environments and have been increasingly implicated in cases of human myiasis. However, the basic biology of psychodid larvae is not well-suited for survival in the human intestinal or urogenital tract, making true, prolonged myiasis unlikely. In this review, we performed a systematic literature review of published cases of purported myiasis caused by psychodid flies, their identification, associated clinical findings, and treatment. We also discuss the anatomy and lifecycle of psychodid flies in relation to their purported ability to use human tissue as a nutritive source and survive in the human alimentary or urogenital tracts. Based on the range of non-specific and varied reported clinical manifestations, lack of observed collections, life cycle patterns of psychodid flies, the mechanics of their mouthparts, and breathing requirements, we conclude that most cases likely represent incidental findings, or in rare cases possibly pseudomyiasis, rather than true myiasis, and provide recommendations for clinical evaluation and reporting so that disease misclassification and unnecessary therapy do not occur.


Assuntos
Miíase , Psychodidae , Animais , Humanos , Miíase/tratamento farmacológico , Larva , Sistema Urogenital , Intestinos
10.
EMBO Rep ; 25(3): 1075-1105, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38396206

RESUMO

Leishmania parasites undergo differentiation between various proliferating and non-dividing forms to adapt to changing host environments. The mechanisms that link environmental cues with the parasite's developmental changes remain elusive. Here, we report that Leishmania TORC1 is a key environmental sensor for parasite proliferation and differentiation in the sand fly-stage promastigotes and for replication of mammalian-stage amastigotes. We show that Leishmania RPTOR1, interacts with TOR1 and LST8, and identify new parasite-specific proteins that interact in this complex. We investigate TORC1 function by conditional deletion of RPTOR1, where under nutrient-rich conditions RPTOR1 depletion results in decreased protein synthesis and growth, G1 cell cycle arrest and premature differentiation from proliferative promastigotes to non-dividing mammalian-infective metacyclic forms. These parasites are unable to respond to nutrients to differentiate into proliferative retroleptomonads, which are required for their blood-meal induced amplification in sand flies and enhanced mammalian infectivity. We additionally show that RPTOR1-/- metacyclic promastigotes develop into amastigotes but do not proliferate in the mammalian host to cause pathology. RPTOR1-dependent TORC1 functionality represents a critical mechanism for driving parasite growth and proliferation.


Assuntos
Leishmania , Phlebotomus , Psychodidae , Animais , Psychodidae/parasitologia , Phlebotomus/parasitologia , Nutrientes , Proliferação de Células , Mamíferos
11.
PLoS Pathog ; 20(2): e1012054, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38416776

RESUMO

The unicellular parasite Leishmania has a precisely defined cell architecture that is inherited by each subsequent generation, requiring a highly coordinated pattern of duplication and segregation of organelles and cytoskeletal structures. A framework of nuclear division and morphological changes is known from light microscopy, yet this has limited resolution and the intrinsic organisation of organelles within the cell body and their manner of duplication and inheritance is unknown. Using volume electron microscopy approaches, we have produced three-dimensional reconstructions of different promastigote cell cycle stages to give a spatial and quantitative overview of organelle positioning, division and inheritance. The first morphological indications seen in our dataset that a new cell cycle had begun were the assembly of a new flagellum, the duplication of the contractile vacuole and the increase in volume of the nucleus and kinetoplast. We showed that the progression of the cytokinesis furrow created a specific pattern of membrane indentations, while our analysis of sub-pellicular microtubule organisation indicated that there is likely a preferred site of new microtubule insertion. The daughter cells retained these indentations in their cell body for a period post-abscission. By comparing cultured and sand fly derived promastigotes, we found an increase in the number and overall volume of lipid droplets in the promastigotes from the sand fly, reflecting a change in their metabolism to ensure transmissibility to the mammalian host. Our insights into the cell cycle mechanics of Leishmania will support future molecular cell biology analyses of these parasites.


Assuntos
Leishmania mexicana , Leishmania , Parasitos , Psychodidae , Animais , Leishmania mexicana/genética , Ciclo Celular , Divisão Celular , Psychodidae/parasitologia , Mamíferos
12.
Parasit Vectors ; 17(1): 11, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38183132

RESUMO

BACKGROUND: Vector sand fly colonies are a critical component of studies aimed at improving the understanding of the neglected tropical disease leishmaniasis and alleviating its global impact. However, among laboratory-colonized arthropod vectors of infectious diseases, the labor-intensive nature of sand fly rearing coupled with the low number of colonies worldwide has generally discouraged the widespread use of sand flies in laboratory settings. Among the different factors associated with the low productivity of sand fly colonies, mite infestations are a significant factor. Sand fly colonies are prone to infestation by mites, and the physical interactions between sand flies and mites and metabolites have a negative impact on sand fly larval development. METHODS: Mites were collected from sand fly larval rearing pots and morphologically identified using taxonomic keys. Upon identification, they were photographed with a scanning electron microscope. Several mite control measures were adopted in two different laboratories, one at the Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases-National Institutes of Health (Rockville, MD, USA), and the other at the University of Calgary (Calgary, AB, Canada). RESULTS: The mite species associated with sand fly colonies in the two laboratories were morphologically identified as Tyrophagus sp. and Stratiolaelaps scimitus. While complete eradication of mites in sand fly colonies is considered unrealistic, drastically reducing their population has been associated with higher sand fly productivity. CONCLUSIONS: We report a case of detrimental interaction between sand flies and Tyrophagus sp. and S. scimitus in a closed laboratory sand fly colony, discuss their impact on sand fly production and provide guidelines for limiting the mite population size in a closed laboratory colony leading to improved sand fly yields.


Assuntos
Infestações por Ácaros , Ácaros , Phlebotomus , Psychodidae , Doenças Transmitidas por Vetores , Estados Unidos , Animais , Laboratórios
13.
PLoS Negl Trop Dis ; 18(1): e0011920, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38295092

RESUMO

Sand fly transmitted Leishmania species are responsible for severe, wide ranging, visceral and cutaneous leishmaniases. Genetic exchange can occur among natural Leishmania populations and hybrids can now be produced experimentally, with limitations. Feeding Phlebotomus orientalis or Phlebotomus argentipes on two strains of Leishmania donovani yielded hybrid progeny, selected using double drug resistance and fluorescence markers. Fluorescence activated cell sorting of cultured clones derived from these hybrids indicated diploid progeny. Multilocus sequence typing of the clones showed hybridisation and nuclear heterozygosity, although with inheritance of single haplotypes in a kinetoplastid target. Comparative genomics showed diversity of clonal progeny between single chromosomes, and extraordinary heterozygosity across all 36 chromosomes. Diversity between progeny was seen for the HASPB antigen, which has been noted previously as having implications for design of a therapeutic vaccine. Genomic diversity seen among Leishmania strains and hybrid progeny is of great importance in understanding the epidemiology and control of leishmaniasis. As an outcome of this study we strongly recommend that wider biological archives of different Leishmania species from endemic regions should be established and made available for comparative genomics. However, in parallel, performance of genetic crosses and genomic comparisons should give fundamental insight into the specificity, diversity and limitations of candidate diagnostics, vaccines and drugs, for targeted control of leishmaniasis.


Assuntos
Leishmania donovani , Leishmaniose Cutânea , Leishmaniose Visceral , Phlebotomus , Psychodidae , Animais , Phlebotomus/genética , Leishmania donovani/genética , Psychodidae/genética , Cruzamentos Genéticos , Genômica , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/prevenção & controle , Leishmaniose Visceral/epidemiologia
14.
Parasitol Res ; 123(1): 82, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38175278

RESUMO

Leishmaniasis is a zoonotic vector-borne disease with worldwide distribution. All current approaches in leishmaniasis control or development of vaccines/cures showed only limited success. Recently, paratransgenesis has been marked as a promising strategy for leishmaniasis control. Thus, the investigations of the gut microbial content of sand flies have gained popularity. Gut microbial composition of the laboratory colony of Phlebotomus papatasi was investigated via microbial culturomics approach which refers to the combination of multiple culture conditions and different selective and/or enriched culture mediums, followed by 16S rDNA sequencing. Investigations were conducted on three offspring generations, with six samplings of immature stages (four larval samplings, one pre-pupa, one pupa) and samplings of adults before and after blood feeding. The aim was to determine if microbiome changes during the sand fly development and to identify bacteria with transstadial potential. The presence of 8 bacterial taxa (Bacillus sp., Terribacillus sp., Staphylococcus sp., Alcaligenes sp., Microbacterium sp., Leucobacter sp., Ochrobactrum sp. and Enterobacter sp.), 2 fungi (Fusarium sp. and Acremonium sp.) and 1 yeast (Candida sp.) were recorded. Gram-positive bacteria were more diverse, but gram-negative bacteria were more abundant. All taxa were recorded among immature stage samples, while only one bacterium was detected in adults. Microbial diversity among larval samples was stable, with a steady decrease in pre-pupa and pupa, resulting in the survival of only Ochrobactrum sp. in adults. Abundance of microbes was higher when larvae were actively feeding, with a gradual decrease after larvae stopped feeding and commenced pupation. Ochrobactrum sp. is the bacteria with transstadial potential, worthy of future in-depth analysis for the application in paratransgenic approach for the control of Leishmania sp.


Assuntos
Leishmaniose , Phlebotomus , Psychodidae , Animais , Bactérias/genética , Meios de Cultura
15.
PLoS Negl Trop Dis ; 18(1): e0011875, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38198499

RESUMO

BACKGROUND: Leishmaniasis is caused by infection with intracellular protozoans of the genus Leishmania. Transmission occurs predominantly by the bite of phlebotomine sandflies, other routes, including congenital transmission, are rare. The disease manifests as either cutaneous, visceral or mucosal/mucocutaneous leishmaniasis. In recent years, changes in the epidemiological pattern have been reported from Europe. PRINCIPAL FINDINGS: A total of 311 new and 29 published leishmaniasis cases occurring between 01/01/2000 and 12/31/2021 in Austria were collected and analyzed. These encompassed 146 cutaneous (CL), 14 visceral (VL), 4 mucosal, and 3 cases with concurrent VL and CL. In addition, asymptomatic infections, comprising 11 unspecified cases with Leishmania DNA detectable only in the blood and 162 cases with anti-Leishmania antibodies were reported. Particularly since 2016, the incidence of leishmaniasis has steadily risen, mainly attributable to increasing numbers of CL and cases with positive serology against Leishmania species, whereas the incidence of VL has slowly decreased. Analysis revealed that a shift in the causative species spectrum had occurred and that a substantial number of CL cases were caused by members of the Leishmania donovani/infantum complex. Simultaneous occurrence of VL and CL was identified in immunocompromised individuals, but also in a not yet reported case of an immunocompetent child after vertical transmission. CONCLUSIONS: The incidence of leishmaniasis has risen in the recent years. The numbers are anticipated to keep rising due to increasing human mobility, including travel and forced migration, growing reservoir host populations as well as expansion and dispersal of vector species caused by climate and habitat changes, urbanization and globalization. Hence, elevated awareness for the disease, including possible transmission in previously non-endemic regions and non-vector transmission modes, support of sandfly surveillance efforts and implementation and establishment of public health interventions in a One Health approach are pivotal in the global efforts to control and reduce leishmaniasis.


Assuntos
Leishmania , Leishmaniose Cutânea , Leishmaniose Mucocutânea , Leishmaniose Visceral , Leishmaniose , Psychodidae , Animais , Criança , Humanos , Áustria/epidemiologia , Leishmania/genética , Leishmaniose/epidemiologia , Leishmaniose Cutânea/epidemiologia , Leishmaniose Visceral/epidemiologia , Pele
16.
Artigo em Inglês | MEDLINE | ID: mdl-38224901

RESUMO

Clogmia albipunctata (Williston, 1893) is a non-hematophagous insect belonging to the order Diptera, suborder Nematocera (Lower Diptera) and family Psychodidae. In the present work, we investigated how C. albipunctata control their midgut pH under different physiological conditions, comparing their midgut physiology with some nematoceran hematophagous species. The C. albipunctata midgut pH was measured after ingestion of sugar, protein and under the effect of the alkalinizing hormone released in the hemolymph of the hematophagous sand fly Lutzomyia longipalpis obtained just after a blood meal. The midgut pH of unfed or sugar-fed C. albipunctata is 5.5-6, and its midgut underwent alkalinization after protein ingestion or under treatment with hemolymph collected from blood fed L. longipalpis. These results suggested that in nematocerans, mechanisms for pH control seem shared between hematophagous and non-hematophagous species. This kind of pH control is convenient for successful blood digestion. The independent evolution of many hematophagous groups from the Lower Diptera suggests that characteristics involved in midgut pH control were already present in non-hematophagous species and represent a readiness for adaptation to this feeding mode.


Assuntos
Psychodidae , Animais , Psychodidae/fisiologia , Sistema Digestório , Concentração de Íons de Hidrogênio , Açúcares
17.
Viruses ; 16(1)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38257803

RESUMO

Wuxiang virus (WUXV) is the first sandfly-borne Phlebovirus isolated from Phlebotomus chinensis collected in China and has been established as a consistent viral presence in the local sandfly populations of both Wuxiang County and Yangquan City. However, its distribution in the Shanxi Province remains unclear. In this study, three novel WUXV strains were isolated from sandflies collected from Jiexiu City, Shanxi Province, China, in 2022. Subsequently, whole-genome sequences of these novel strains were generated using next-generation sequencing. The open reading frame (ORF) sequences of the WUXV strains from the three locations were subjected to gene analysis. Phylogenetic analysis revealed that WUXV belongs to two distinct clades with geographical differences. Strains from Wuxiang County and Yangquan City belonged to clade 1, whereas strains from Jiexiu City belonged to clade 2. Reassortment and recombination analyses indicated no gene reassortment or recombination between the two clades. However, four reassortments or recombination events could be detected in clade 1 strains. By aligning the amino acid sequences, eighty-seven mutation sites were identified between the two clades, with seventeen, sixty, nine, and one site(s) in the proteins RdRp, M, NSs, and N, respectively. Additionally, selection pressure analysis identified 17 positively selected sites across the entire genome of WUXV, with two, thirteen, one, and one site(s) in the proteins RdRp, M, NSs, and N, respectively. Notably, sites M-312 and M-340 in the M segment not only represented mutation sites but also showed positive selective pressure effects. These findings highlight the need for continuous nationwide surveillance of WUXV.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Psychodidae , Animais , Filogenia , China/epidemiologia , Sequência de Aminoácidos , RNA Polimerase Dependente de RNA
18.
Parasit Vectors ; 17(1): 19, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38217054

RESUMO

BACKGROUND: Understanding aspects related to the physiology and capacity of vectors is essential for effectively controlling vector-borne diseases. The sand fly Lutzomyia longipalpis has great importance in medical entomology for disseminating Leishmania parasites, the causative agent of Leishmaniasis, one of the main neglected diseases listed by the World Health Organization (WHO). In this respect, it is necessary to evaluate the transmission potential of this species and the success of vector control interventions. Near-infrared spectroscopy (NIRS) has been used to estimate the age of mosquitoes in different conditions (laboratory, semi-field, and conservation), taxonomic analysis, and infection detection. However, no studies are using NIRS for sand flies. METHODS: In this study, we developed analytic models to estimate the age of L. longipalpis adults under laboratory conditions, identify their copulation state, and evaluate their gonotrophic cycle and diet. RESULTS: Sand flies were classified with an accuracy of 58-82% in 3 age groups and 82-92% when separating them into young (<8 days) or old (>8 days) insects. The classification between mated and non-mated sandflies was 98-100% accurate, while the percentage of hits of females that had already passed the first gonotrophic cycle was only 59%. CONCLUSIONS: We consider the age and copula estimation results very promising, as they provide essential aspects of vector capacity assessment, which can be obtained quickly and at a lower cost with NIRS.


Assuntos
Leishmania , Leishmaniose , Phlebotomus , Psychodidae , Feminino , Animais , Psychodidae/parasitologia , Espectroscopia de Luz Próxima ao Infravermelho , Mosquitos Vetores , Leishmania/fisiologia
19.
Euro Surveill ; 29(4)2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38275016

RESUMO

BackgroundHuman leishmaniasis is a protozoan disease transmitted by sand flies and endemic in the Mediterranean region. In Italy, leishmaniasis is present in the south and the western coastal regions, with an epidemic peak detected in northern Italy in the early 1970s.AimTo examine temporal trends, and demographic, clinical, geographical and environmental features of human leishmaniasis cases recorded by the local health unit (LHU) of Bologna, northern Italy.MethodsIn this retrospective observational study, we analysed human leishmaniasis cases recorded from 2004 to 2022 within the Bologna LHU. We also conducted serological investigations for canine leishmaniasis in owned dogs living near the place of infection of human cases.ResultsIn total, 173 cases of human leishmaniasis were detected, and 154 cases were considered autochthonous. An increase of human cases was observed since 2004, with incidence peaks above 2 cases/100,000 inhabitants in 2013, 2018 and 2022; epidemic peaks were preceded by dry summers. Most cases lived in the plain and hilly areas less than 400 m above sea level and many resided in isolated housing, in city outskirts, and/or near uncultivated areas, watercourses and railway sections. The incidence of canine leishmaniasis did not increase in the study period.ConclusionAn epidemic of human leishmaniasis with fluctuating annual numbers of cases, probably related to environmental and climatic factors, was identified in the Bologna LHU. Understanding the risk factors and the environmental characteristics related to places of infection is crucial to evaluate the public health implications of leishmaniasis.


Assuntos
Doenças do Cão , Leishmania infantum , Leishmaniose Visceral , Leishmaniose , Psychodidae , Humanos , Animais , Cães , Leishmaniose Visceral/epidemiologia , Estudos Retrospectivos , Leishmaniose/epidemiologia , Leishmaniose/veterinária , Itália/epidemiologia , Doenças do Cão/epidemiologia
20.
Med Vet Entomol ; 38(1): 83-98, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37867259

RESUMO

In this study, we analysed the molecular and morphometric differences of several populations of the putative sand fly vector Psychodopygus davisi (Root, 1934) (Diptera, Psychodidae, Phlebotominae) in Brazil. We amplified the 658 base pair fragments of the DNA barcoding region-cytochrome c oxidase subunit 1 (COI) gene-for 57 specimens of P. davisi and three specimens of Psychodopygus claustrei (Abonnenc, Léger & Fauran, 1979). We merged our data with public sequences of the same species available from GenBank. Then, the combined dataset-87 sequences and 20 localities-was analysed using population structure analysis and different species delimitation approaches. Geometric morphometry of wings was performed for 155 specimens of P. davisi populations from the North, Midwest and Southeast Brazilian regions, analysing the differences in centroid sizes and canonical variates. Molecular analysis indicated high intraspecific genetic distance values for P. davisi (maximum p distance = 5.52%). All algorithms identified P. davisi and P. claustrei as distinct molecular taxonomic units, despite the low interspecific distance (p distance to the nearest neighbour = 4.79%). P. davisi sequences were split into four genetic clusters by population structure analysis and at least five genetic lineages using intermediate scenarios of the species delimitation algorithms. The species validation analysis of BPP strongly supported the five-species model in our dataset. We found high genetic diversity in this taxon, which is in agreement with its wide geographic distribution in Brazil. Furthermore, the wing analysis showed that specimens from the Southeast Region of Brazil are different from those in the North and the Midwest. The evolutionary patterns of P. davisi populations in Brazil suggest the presence of candidate species, which need to be validated in future studies using a more comprehensive approach with both genomic data and morphological characters.


Assuntos
Phlebotomus , Psychodidae , Animais , Brasil , Psychodidae/genética , Evolução Biológica , Algoritmos , Código de Barras de DNA Taxonômico/veterinária , Filogenia
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