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Liu F, Chen Z, Ye Z, Liu N. The Olfactory Chemosensation of Hematophagous Hemipteran Insects. Front Physiol 2021; 12:703768. [PMID: 34434117 PMCID: PMC8382127 DOI: 10.3389/fphys.2021.703768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/09/2021] [Indexed: 11/13/2022] Open
Abstract
As one of the most abundant insect orders on earth, most Hemipteran insects are phytophagous, with the few hematophagous exceptions falling into two families: Cimicidae, such as bed bugs, and Reduviidae, such as kissing bugs. Many of these blood-feeding hemipteran insects are known to be realistic or potential disease vectors, presenting both physical and psychological risks for public health. Considerable researches into the interactions between hemipteran insects such as kissing bugs and bed bugs and their human hosts have revealed important information that deepens our understanding of their chemical ecology and olfactory physiology. Sensory mechanisms in the peripheral olfactory system of both insects have now been characterized, with a particular emphasis on their olfactory sensory neurons and odorant receptors. This review summarizes the findings of recent studies of both kissing bugs (including Rhodnius prolixus and Triatoma infestans) and bed bugs (Cimex lectularius), focusing on their chemical ecology and peripheral olfactory systems. Potential chemosensation-based applications for the management of these Hemipteran insect vectors are also discussed.
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Affiliation(s)
- Feng Liu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States.,Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Zhou Chen
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States.,Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States
| | - Zi Ye
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States.,Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Nannan Liu
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
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Campetella F, Ignell R, Beutel R, Hansson BS, Sachse S. Comparative dissection of the peripheral olfactory system of the Chagas disease vectors Rhodnius prolixus and Rhodnius brethesi. PLoS Negl Trop Dis 2021; 15:e0009098. [PMID: 33857145 PMCID: PMC8078792 DOI: 10.1371/journal.pntd.0009098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/27/2021] [Accepted: 03/24/2021] [Indexed: 11/19/2022] Open
Abstract
American trypanosomiasis, or Chagas disease, is transmitted by both domestic and sylvatic species of Triatominae which use sensory cues to locate their vertebrate hosts. Among them, odorants have been shown to play a key role. Previous work revealed morphological differences in the sensory apparatus of different species of Triatomines, but to date a comparative functional study of the olfactory system is lacking. After examining the antennal sensilla with scanning electronic microscopy (SEM), we compared olfactory responses of Rhodnius prolixus and the sylvatic Rhodnius brethesi using an electrophysiological approach. In electroantennogram (EAG) recordings, we first showed that the antenna of R. prolixus is highly responsive to carboxylic acids, compounds found in their habitat and the headspace of their vertebrate hosts. We then compared responses from olfactory sensory neurons (OSNs) housed in the grooved peg sensilla of both species, as these are tuned to these compounds using single-sensillum recordings (SSRs). In R. prolixus, the SSR responses revealed a narrower tuning breath than its sylvatic sibling, with the latter showing responses to a broader range of chemical classes. Additionally, we observed significant differences between these two species in their response to particular volatiles, such as amyl acetate and butyryl chloride. In summary, the closely related, but ecologically differentiated R. prolixus and R. brethesi display distinct differences in their olfactory functions. Considering the ongoing rapid destruction of the natural habitat of sylvatic species and the likely shift towards environments shaped by humans, we expect that our results will contribute to the design of efficient vector control strategies in the future.
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Affiliation(s)
- Florencia Campetella
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Rickard Ignell
- Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Rolf Beutel
- Institute for Zoology and Evolutionary Biology, Friedrich Schiller University, Jena, Germany
| | - Bill S. Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Silke Sachse
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
- * E-mail:
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Orientation of Belminus triatomines to cockroaches and cockroaches’ fecal volatiles: an ethological approach. Acta Ethol 2021. [DOI: 10.1007/s10211-021-00361-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Verly T, Costa S, Lima N, Mallet J, Odêncio F, Pereira M, Moreira CJDC, Britto C, Pavan MG. Vector competence and feeding-excretion behavior of Triatoma rubrovaria (Blanchard, 1843) (Hemiptera: Reduviidae) infected with Trypanosoma cruzi TcVI. PLoS Negl Trop Dis 2020; 14:e0008712. [PMID: 32970687 PMCID: PMC7544132 DOI: 10.1371/journal.pntd.0008712] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 10/08/2020] [Accepted: 08/13/2020] [Indexed: 01/22/2023] Open
Abstract
Background Several studies addressed changes on the insect vector behavior due to parasite infection, but little is known for triatomine bugs, vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. We assessed infection rates and metacyclogenesis of T. cruzi (TcVI) in fifth-instar nymphs of Triatoma rubrovaria comparing with the primary vector Triatoma infestans. Also, biological parameters related to feeding-excretion behavior were evaluated aiming to identify which variables are most influenced by T. cruzi infection. Methodology/principal findings Fifth-instar nymphs of T. rubrovaria and T. infestans were fed on mice infected with T. cruzi (TcVI). We compared the presence and the number of parasite evolutive forms in excreta of both triatomine species at 30, 60 and 90 days post-infection (dpi) with traditional statistical analyses. Moreover, both species were analyzed through generalized linear models and multinomial logistic regression hypotheses for seven behavioral parameters related to host-seeking and feeding-excretion. Triatoma rubrovaria and T. infestans had similar overall infection and metacyclogenesis rates of T. cruzi TcVI in laboratory conditions. Regarding vector behavior, we confirmed that the triatomine’s tendency is to move away from the bite region after a blood meal, probably to avoid being noticed by the vertebrate host. Interspecific differences were observed on the volume of blood ingested and on the proportion of individuals that excreted after the blood meal, revealing the higher feeding efficiency and dejection rates of T. infestans. The amount of ingested blood and the bite behavior of T. rubrovaria seems to be influenced by TcVI infection. Infected specimens tended to ingest ~25% more blood and to bite more the head of the host. Noteworthy, in two occasions, kleptohematophagy and coprophagy behaviors were also observed in T. rubrovaria. Conclusions/significance Laboratory infections revealed similar rate of T. cruzi TcVI trypomatigotes in excreta of T. rubrovaria and T. infestans, one of the most epidemiological important vectors of T. cruzi. Therefore, TcVI DTU was able to complete its life cycle in T. rubrovaria under laboratory conditions, and this infection changed the feeding behavior of T. rubrovaria. Considering these results, T. rubrovaria must be kept under constant entomological surveillance in Rio Grande do Sul, Brazil. Chagas disease is caused by the etiological agent Trypanosoma cruzi and is mainly transmitted through the excreta of triatomine vectors. It is endemic in Latin America and the Caribbean, affecting ~8 million people. Control programs are based on the elimination of domestic vectors through insecticide-spraying indoors, since there is no vaccine or efficient treatment for chronic patients. However, this strategy is not sustainable where native triatomine species are capable of colonizing peridomestic structures and reinvading human dwellings. Since the ‘virtual’ elimination of Triatomainfestans in Brazil (residual foci remain in Rio Grande do Sul and Bahia), specimens of the native Triatoma rubrovaria have been constantly collected inside human dwellings and peridomiciliary ecotopes in Rio Grande do Sul, southern Brazil, which might represent a real risk for human infections. Here we analyzed a unique and large dataset through classical and modern statistical methods to evaluate T. cruzi infection in T. rubrovaria and to identify host-seeking, and also feeding/excretion behavioral traits that could be influenced by the parasite. Our results indicated that the parasite infection caused changes in T. rubrovaria feeding behavior that could increase T. cruzi TcVI transmission. Moreover, this vector species had similar infection rate to one of the main important Chagas disease vectors in South America, T. infestans. Therefore, T. rubrovaria must be kept under constant entomological surveillance in Rio Grande do Sul, Brazil.
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Affiliation(s)
- Thaiane Verly
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Stephanie Costa
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Nathanielly Lima
- Laboratório Interdisciplinar de Vigilância Entomológica em Diptera e Hemiptera, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Jacenir Mallet
- Laboratório Interdisciplinar de Vigilância Entomológica em Diptera e Hemiptera, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
- Universidade Iguaçu - UNIG, Rio de Janeiro, Brazil
| | - Francisco Odêncio
- Laboratório de Ultraestrutura Celular, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Mirian Pereira
- Laboratório de Ultraestrutura Celular, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | | | - Constança Britto
- Laboratório de Biologia Molecular e Doenças Endêmicas, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Márcio G. Pavan
- Laboratório de Mosquitos Transmissores de Hematozoários, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
- * E-mail:
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Ramírez M, Ortiz MI, Guerenstein P, Molina J. Novel repellents for the blood-sucking insects Rhodnius prolixus and Triatoma infestans, vectors of Chagas disease. Parasit Vectors 2020; 13:142. [PMID: 32188498 PMCID: PMC7079506 DOI: 10.1186/s13071-020-04013-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/10/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Studying the behavioral response of blood-sucking disease-vector insects to potentially repellent volatile compounds could shed light on the development of new control strategies. Volatiles released by human facial skin microbiota play different roles in the host-seeking behavior of triatomines. We assessed the repellency effect of such compounds of bacterial origin on Triatoma infestans and Rhodnius prolixus, two important vectors of Chagas disease in Latin America. METHODS Using an exposure device, insects were presented to human odor alone (control) and in the presence of three individual test compounds (2-mercaptoethanol, dimethyl sulfide and 2-phenylethanol, the latter only tested in R. prolixus) and the gold-standard repellent NN-diethyl-3-methylbenzamide (DEET). We quantified the time the insects spent in the proximity of the host and determined if any of the compounds evaluated affected the behavior of the insects. RESULTS We found volatiles that significantly reduced the time spent in the proximity of the host. These were 2-phenylethanol and 2-mercaptoethanol for R. prolixus, and dimethyl sulfide and 2-mercaptoethanol for T. infestans. Such an effect was also observed in both species when DEET was presented, although only at the higher doses tested. CONCLUSIONS The new repellents modulated the behavior of two Chagas disease vectors belonging to two different triatomine tribes, and this was achieved using a dose up to three orders of magnitude lower than that needed to evoke the same effect with DEET. Future efforts in understanding the mechanism of action of repellent compounds such as 2-mercaptoethanol, as well as an assessment of their temporal and spatial repellent properties, could lead to the development of novel control strategies for these insect vectors, refractory to DEET.
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Affiliation(s)
- Melanie Ramírez
- Centro de Investigaciones en Microbiología y Parasitología Tropical (CIMPAT), Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, Colombia
| | - Mario I Ortiz
- Centro de Investigaciones en Microbiología y Parasitología Tropical (CIMPAT), Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, Colombia
| | - Pablo Guerenstein
- Laboratorio de Estudio de la Biología de Insectos, Centro de Investigación Científica y de Transferencia Tecnológica a la Producción (CONICET-Prov. Entre Rios-Uader), Diamante, Argentina.,Facultad de Ingenieria, Universidad Nacional de Entre Ríos, Concepción del Uruguay, Entre Rios, Argentina
| | - Jorge Molina
- Centro de Investigaciones en Microbiología y Parasitología Tropical (CIMPAT), Departamento de Ciencias Biológicas, Universidad de los Andes, Bogotá, Colombia.
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Sandoval Ramírez CM, Nieves Blanco E, Esteban Adarme L, Angulo Silva VM, Otálora-Luna F, Galvão C, Catalá S. Comparative Study of the Antennal Phenotype in Species of the Belminus (Hemiptera: Triatominae) Genus Using Optical and Scanning Electron Microscopy. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:1260-1269. [PMID: 31329909 DOI: 10.1093/jme/tjz053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Indexed: 06/10/2023]
Abstract
The genus Belminus Stål, 1859 is distinguished by markedly entomophagous species. This genus is a poorly studied group of the Triatominae (Jeannel, 1919), which includes hematophagous species that are vectors of Trypanosoma cruzi (Chagas, 1909), the etiological agent of Chagas disease. This study reports for the first time the description of the antennal sensilla of Belminus corredori (Galvão & Angulo, 2003), Belminus herreri (Lent & Wygodzinsky, 1979), and Belminus ferroae (Sandoval, Pabón, Jurberg & Galvão, 2007) nymphs and adults throughout scanning electron microscopy and optical microscopy. Nine morphological types of sensilla were identified in the three species, including bristles I and II, trichobothria, tapered hairs, thin-walled trichoid, thick-walled trichoid, basiconic, campaniform, and coeloconica sensilla. The analysis of the most abundant types of sensilla and their distribution in nymphs and adults shows similarities with the antennal phenotypes described in other Triatominae. Quantitative differences showed the important phenotypic plasticity of this morphological trait in the genus and allowed for the separation of the species in both sexes. These differences were associated with sexual dimorphism and wing condition (macropterous and brachypterous). The role of the antennal phenotype in sexual behavior, its usefulness as a taxonomic tool, and its relationship with the dispersal capacity of these species are discussed.
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Affiliation(s)
- Claudia Magaly Sandoval Ramírez
- Facultad de Ciencias Exactas, Naturales y Agropecuarias, Grupo de Investigaciones en Ciencias Básicas y Aplicadas para la Sostenibilidad (CIBAS), Universidad de Santander, Bucaramanga, Colombia
- Facultad de Ciencias, Laboratorio de Parasitología Experimental (LAPEX), Universidad de los Andes, Mérida, República Bolivariana de Venezuela
| | - Elsa Nieves Blanco
- Facultad de Ciencias, Laboratorio de Parasitología Experimental (LAPEX), Universidad de los Andes, Mérida, República Bolivariana de Venezuela
| | - Lida Esteban Adarme
- Centro de Investigaciones en Enfermedades Tropicales CINTROP-UIS, Universidad Industrial de Santander, Santander, Colombia
| | - Víctor M Angulo Silva
- Centro de Investigaciones en Enfermedades Tropicales CINTROP-UIS, Universidad Industrial de Santander, Santander, Colombia
| | - Fernando Otálora-Luna
- Facultad de Ciencias, Laboratorio de Entomología 'Herman Lent', Universidad de Los Andes, Mérida, República Bolivariana de Venezuela
- Department of Biology, School of Art & Sciences, University of Richmond, Richmond, VA
| | - Cleber Galvão
- Fundação Oswaldo Cruz, Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Instituto Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Silvia Catalá
- Centro Regional de Investigación Científica y Transferencia Tecnológica de La Rioja, CRILAR-CONICET, Anillaco, Argentina
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Tabares M, Ortiz M, Gonzalez M, Carazzone C, Vives Florez MJ, Molina J. Behavioral responses of Rhodnius prolixus to volatile organic compounds released in vitro by bacteria isolated from human facial skin. PLoS Negl Trop Dis 2018; 12:e0006423. [PMID: 29684012 PMCID: PMC5933807 DOI: 10.1371/journal.pntd.0006423] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/03/2018] [Accepted: 04/02/2018] [Indexed: 12/12/2022] Open
Abstract
Background Previous studies have demonstrated the role of volatile organic compounds (VOCs) produced by skin microbiota in the attraction of mosquitoes to humans. Recently, behavioral experiments confirmed the importance of VOCs released by skin microbiota in the attraction of Rhodnius prolixus (Hemiptera: Triatominae), a vector of Chagas disease. Methods/Findings In this study, we screened for VOCs released in vitro by bacteria isolated from human facial skin that were able to elicit behavioral responses in R. prolixus. The VOCs released in vitro by eight bacterial species during two growth phases were tested with adult Rhodnius prolixus insects using a dual-choice “T”-shaped olfactometer. In addition, the VOCs released by the bacteria were analyzed with headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). The VOCs produced by Staphylococcus capitis 11C, Staphylococcus warneri and Staphylococcus epidermidis 1 were attractive to R. prolixus, while the VOCs released by Citrobacter koseri 6P, Brevibacterium epidermidis and Micrococcus luteus 23 were non-attractive. Conclusions The results shown here indicate that VOCs released by bacteria isolated from human facial skin have a potential for biotechnological uses as a strategy to prevent the vectorial transmission of Chagas disease mediated by Rhodnius prolixus. Volatile organic compounds released by bacteria growing on human skin are mediating human-blood-sucking insects interactions. In this study we were interested in those volatile organic compounds produced in vitro by skin bacterial metabolism that are involved in the Rhodnius prolixus interaction with humans. Rhodnius prolixus is the main vector of Chagas disease in Northern South America. Using behavioral experiments, chemical analysis and microbiological techniques we determined the volatile organic compounds released in vitro by bacteria isolated from human faces and its effects on Rhodnius prolixus. We found that most of the Staphylococcus species tested here are mediating attraction, while non-Staphylococcus species are non-attractive. As a conclusion, our results showed that volatile organic compounds released by bacteria isolated from human faces have a potential for biotechnological uses as a strategy to control the vectorial transmission of Chagas disease mediated by Rhodnius prolixus.
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Affiliation(s)
- Marcela Tabares
- Centro de Investigaciones Microbiológicas (CIMIC), Universidad de los Andes, Bogotá, Colombia
| | - Mario Ortiz
- Centro de Investigaciones en Microbiología y Parasitología Tropical (CIMPAT), Universidad de los Andes, Bogotá, Colombia
| | - Mabel Gonzalez
- Laboratory of Advanced Analytical Techniques in Natural Products (LATNAP), Universidad de los Andes, Bogotá, Colombia
| | - Chiara Carazzone
- Laboratory of Advanced Analytical Techniques in Natural Products (LATNAP), Universidad de los Andes, Bogotá, Colombia
| | - Martha J. Vives Florez
- Centro de Investigaciones Microbiológicas (CIMIC), Universidad de los Andes, Bogotá, Colombia
| | - Jorge Molina
- Centro de Investigaciones en Microbiología y Parasitología Tropical (CIMPAT), Universidad de los Andes, Bogotá, Colombia
- * E-mail:
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Otálora-Luna F, Guerin PM. Amines from vertebrates guide triatomine bugs to resources. JOURNAL OF INSECT PHYSIOLOGY 2014; 71:52-60. [PMID: 25260571 DOI: 10.1016/j.jinsphys.2014.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 07/16/2014] [Accepted: 09/03/2014] [Indexed: 06/03/2023]
Abstract
Most triatomine bugs (Heteroptera: Reduviidae) are nest-living insects that require vertebrate blood or invertebrate haemolymph to complete their life cycle. Vertebrates accumulate excretory products in or near their nesting sites and we hypothesize that triatomines use emanations from such host wastes when searching for resources. Here we recount how triatomine bugs increase upwind locomotion on a servosphere in response to volatile amine constituents of vertebrate excretions. Fresh chicken faeces is strongly attractive to Rhodnius prolixus nymphs. Ammonia induces attraction and an increase in both speed and total path length by R. prolixus on the servosphere. Whereas ethylamine and dimethylamine attract R. prolixus, Triatoma infestans and Panstrongylus geniculatus, other amine constituents of vertebrate excretions such as isobutylamine and hexylamine induce R. prolixus nymphs to walk faster and for a longer period. These amines are derived from generally occurring metabolites of vertebrates and from gut flora metabolism. We conclude that amines and other products associated with nesting hosts serve as signals for foraging triatomines.
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Affiliation(s)
- Fernando Otálora-Luna
- Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2009 Neuchâtel, Switzerland.
| | - Patrick M Guerin
- Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2009 Neuchâtel, Switzerland
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Pinto EG, Antoniazzi MM, Jared C, Tempone AG. Antileishmanial and antitrypanosomal activity of the cutaneous secretion of Siphonops annulatus. J Venom Anim Toxins Incl Trop Dis 2014; 20:50. [PMID: 25873939 PMCID: PMC4396788 DOI: 10.1186/1678-9199-20-50] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 10/07/2014] [Indexed: 11/10/2022] Open
Abstract
Background Among the tropical parasitic diseases, those caused by protozoans are considered a challenge to public health, being represented by leishmaniasis and Chagas disease. In view of the low effectiveness and toxicity of the current therapy, animal venoms such as amphibian secretions have been used as a promising source of new drug prototypes. The present work aimed to achieve bioguided fractionation of metabolites present in a cutaneous secretion of the caecilian Siphonops annulatus (Amphibia: Gymnophiona: Siphonopidae) with antileishmanial and antitrypanosomal activity. Methods Through liquid-liquid partition and chromatographic techniques, the secretion was fractionated using bioguided assays. The 50% inhibitory concentration (IC50) of the main fraction (SaFr1) was studied against Leishmania (L.) infantum promastigotes and intracellular amastigotes, trypomastigotes of Trypanosoma cruzi and mammalian cells; viability was detected by the colorimetric MTT assay. By using a spectrofluorimetric assay with the probe SYTOX® Green and transmission electron microscopy (TEM), we also investigated the potential damage caused by SaFr1 in the plasma membrane and mitochondria of Leishmania. Results The bioguided assay enabled isolation of a highly purified fraction (SaFr1) with an IC50 of 0.065 μg/mL against promastigotes and 2.75 μg/mL against trypomastigotes. Due to its high toxicity to peritoneal macrophages, SaFr1 showed no selectivity towards the intracellular forms of Leishmania. Ultrastructural studies with Leishmania demonstrated severe mitochondrial damage and the formation of large cytoplasmic vacuoles, leading to the parasite’s death within a few hours. Nevertheless, it caused no alteration in the plasma membrane permeability as detected by the fluorescent probe and TEM. Conclusions The present study demonstrated for the first time the antiparasitic activity of the skin secretion of the caecilian S. annulatus against Leishmania and T. cruzi, confirming that skin secretions of these amphibians, similarly to those of anurans and salamanders, are also potential tools for the development of new drug candidates against neglected diseases.
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Affiliation(s)
- Erika Gracielle Pinto
- Departamento de Parasitologia e Micologia, Instituto Adolfo Lutz, Av. Dr. Arnaldo, 351, 8° andar, CEP 01246-000 São Paulo, SP Brasil ; São Paulo Institute of Tropical Medicine, University of São Paulo (USP), São Paulo, São Paulo State Brazil
| | | | - Carlos Jared
- Laboratory of Cell Biology, Butantan Institute, São Paulo, São Paulo State Brazil
| | - Andre Gustavo Tempone
- Departamento de Parasitologia e Micologia, Instituto Adolfo Lutz, Av. Dr. Arnaldo, 351, 8° andar, CEP 01246-000 São Paulo, SP Brasil
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Pinto EG, Pimenta DC, Antoniazzi MM, Jared C, Tempone AG. Antimicrobial peptides isolated from Phyllomedusa nordestina (Amphibia) alter the permeability of plasma membrane of Leishmania and Trypanosoma cruzi. Exp Parasitol 2013; 135:655-60. [PMID: 24113627 DOI: 10.1016/j.exppara.2013.09.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 09/13/2013] [Accepted: 09/22/2013] [Indexed: 11/27/2022]
Abstract
Nature has provided inspiration for Drug Discovery studies and amphibian secretions have been used as a promising source of effective peptides which could be explored as novel drug prototypes for neglected parasitic diseases as Leishmaniasis and Chagas disease. In this study, we isolated four antimicrobial peptides (AMPs) from Phyllomedusa nordestina secretion, and studied their effectiveness against Leishmania (L.) infantum and Trypanosoma cruzi. The antiparasitic fractions were characterized by mass spectrometry and Edman degradation, leading to the identification of dermaseptins 1 and 4 and phylloseptins 7 and 8. T. cruzi trypomastigotes were susceptible to peptides, showing IC50 values in the range concentration of 0.25-0.68 μM. Leishmania (L.) infantum showed susceptibility to phylloseptin 7, presenting an IC50 value of 10 μM. Except for phylloseptin 7 which moderate showed cytotoxicity (IC50=34 μM), the peptides induced no cellular damage to mammalian cells. The lack of mitochondrial oxidative activity of parasites detected by the MTT assay, suggested that peptides were leishmanicidal and trypanocidal. By using the fluorescent probe SYTOX(®) Green, dermaseptins 1 and 4 and phylloseptins 7 and 8 showed time-dependent plasma membrane permeabilization of T. cruzi; phylloseptin 7 also showed a similar effect in Leishmania parasites. The present study demonstrates for the first time that AMPs target the plasma membrane of Leishmania and T. cruzi, leading to cellular death. Considering the potential of amphibian peptides against protozoan parasites and the reduced mammalian toxicity, they may contribute as scaffolds for drug design studies.
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Affiliation(s)
- Erika Gracielle Pinto
- Departament of Parasitology, Instituto Adolfo Lutz, Av. Dr. Arnaldo 351, 8(o) Andar, 01246-000 São Paulo, SP, Brazil; Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 470, 05403-000 São Paulo, SP, Brazil
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