scholarly journals Odour of domestic dogs infected with Leishmania infantum is attractive to female but not male sand flies: evidence for parasite manipulation

2020 ◽  
Author(s):  
Monica E. Staniek ◽  
James G.C. Hamilton
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Infantum ◽  
Feeding Activity ◽  
Blood Feeding ◽  
Human Infection ◽  
T Test ◽  
Domestic Dogs ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Paired T Test

AbstractGlobally visceral leishmaniasis (VL) causes thousands of human deaths every year. In South America, the etiologic agent, Leishmania infantum, is transmitted from an infected canine reservoir to human hosts by the blood-feeding activity of the sand fly vector, predominantly, Lutzomyia longipalpis. Previous evidence from model rodent systems have suggested that the odour of infected hosts is altered by the parasite making them more attractive to the vector leading to an increased biting rate and improved transmission prospects for the pathogen. However, the effect of Le. infantum infection on the attractiveness of naturally infected dogs which are integral to human infection, has not been assessed.Hair collected from infected and uninfected dogs residing in a VL endemic city in Brazil. was entrained to collect the volatile chemical odours present in the headspace. Female and male Lu. longipalpis sand flies were offered a choice of infected or uninfected odour in a series of behavioural experiments. Control experiments established that female and male Lu. longipalpis were equally attracted to uninfected dog odour, female Lu. longipalpis were significantly more attracted to infected dog odour than uninfected dog odour in all 15 experimental replicates (average 45.7±0.87 females attracted to infected odour; 23.9±0.82 to uninfected odour; paired T-test, P=0.000). Male Lu. longipalpis did not significantly prefer either infected or uninfected odour (average 36.1±0.4 males to infected odour; 35.7±0.6 to uninfected odour; paired T-test, P=0.722). A significantly greater proportion of females chose the infected dog odour compared to the males (paired T-test, P=0.000).The results show that dogs infected with Le. infantum are significantly more attractive to blood-feeding female than male sand flies. This is strong evidence for parasite manipulation of the host odour in a natural transmission system and indicates that infected dogs may have a disproportionate significance in maintaining infection in canine and human infection.Author SummaryVisceral leishmaniasis (VL) is a disease caused by the Protist parasite Leishmania infantum. In Brazil and other South and Central American countries, the parasite is transmitted by the blood-feeding activity of infected female Lutzomyia longipalpis sand flies. The disease leads to thousands of human cases and deaths every year. Domestic dogs are the reservoir of infection for humans therefore understanding the effect of infection on dogs is important in developing an understanding of the epidemiology of the disease. Although previous studies on rodent models of Le. infantum infection have shown that infected Golden Hamsters are more attractive to Lu. longipalpis the attractiveness of naturally infected dogs to the insect vector has not been previously been investigated. In this study we showed that the odour of infected dogs is significantly more attractive to female sand flies which can transmit the pathogen than to male sand flies which do not. This clear-cut difference in attraction of female and males suggests that the females are preferentially attracted by parasite infected hosts and may lead to enhanced infection and transmission opportunities for the parasite.

scholarly journals Odour of domestic dogs infected with Leishmania infantum is attractive to female but not male sand flies: Evidence for parasite manipulation

2021 ◽  
Vol 17 (3) ◽  
pp. e1009354
Author(s):  
Monica E. Staniek ◽  
James G. C. Hamilton
Keyword(s):  
Leishmania Infantum ◽  
Etiologic Agent ◽  
Human Infection ◽  
T Test ◽  
Sand Fly ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Control Female ◽  
Behavioural Experiments ◽  
Paired T Test

Globally visceral leishmaniasis (VL) causes thousands of human deaths every year. In South America, the etiologic agent, Leishmania infantum, is transmitted from an infected canine reservoir to human hosts by the bite of the sand fly vector; predominantly Lutzomyia longipalpis. Previous evidence from model rodent systems have suggested that the odour of infected hosts is altered by the parasite making them more attractive to the vector leading to an increased biting rate and improved transmission prospects for the pathogen. However, there has been no assessment of the effect of Le infantum infection on the attractiveness of dogs, which are the natural reservoirs for human infection. Hair collected from infected and uninfected dogs residing in a VL endemic city in Brazil was entrained to collect the volatile chemical odours present in the headspace. Female and male Lu. longipalpis sand flies were offered a choice of odour entrained from infected and uninfected dogs in a series of behavioural experiments. Odour of uninfected dogs was equally attractive to male or female Lu. longipalpis when compared to a solvent control. Female Lu. longipalpis were significantly more attracted to infected dog odour than uninfected dog odour in all 15 experimental replicates (average 45.7±0.87 females attracted to infected odour; 23.9±0.82 to uninfected odour; paired T-test, P = 0.000). Male Lu. longipalpis did not significantly prefer either infected or uninfected odour (average 36.1±0.4 males to infected odour; 35.7±0.6 to uninfected odour; paired T-test, P = 0.722). A significantly greater proportion of females chose the infected dog odour compared to the males (paired T-test, P = 0.000). The results showed that the odour of dogs infected with Le. infantum was significantly more attractive to blood-seeking female sand flies than it was to male sand flies. This is strong evidence for parasite manipulation of the host odour in a natural transmission system and indicates that infected dogs may have a disproportionate significance in maintaining infection in the canine and human population.

scholarly journals Ecology of Lutzomyia longipalpis and Lutzomyia migonei in an endemic area for visceral leishmaniasis

2014 ◽  
Vol 23 (3) ◽  
pp. 320-327 ◽  
Author(s):  
Rafaella Albuquerque Silva ◽  
Fabricio Kassio Moura Santos ◽  
Lindemberg Caranha de Sousa ◽  
Elizabeth Ferreira Rangel ◽  
Claudia Maria Leal Bevilaqua
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Infantum ◽  
Indoor Environment ◽  
Endemic Area ◽  
Natural Infection ◽  
Sampling Site ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Sampling Points ◽  
Lutzomyia Migonei

The main vector for visceral leishmaniasis (VL) in Brazil is Lutzomyia longipalpis. However, the absence of L. longipalpis in a region of autochthonous VL demonstrates the participation of other species in the transmission of the parasite. Studies conducted in La Banda, Argentina, and São Vicente Férrer, Pernambuco State, Brazil, have correlated the absence of L. longipalpisand the presence of L. migonei with autochthonous cases of VL. In São Vicente Férrer, Pernambuco, there was evidence for the natural infection of L. migonei with Leishmania infantum chagasi. Thus, the objective of this work was to assess the ecology of the sand flies L. longipalpis and L. migonei in Fortaleza, an endemic area for VL. Insect capture was conducted at 22 sampling points distributed across four regions of Fortaleza. In total, 32,403 sand flies were captured; of these, 18,166 (56%) were identified as L. longipalpis and 14,237 (44%) as L. migonei. There were significant density differences found between the vectors at each sampling site (indoors and outdoors) (p <0.0001). These findings confirm that L. migonei and L. longipalpis are distributed throughout Fortaleza, where they have adapted to an indoor environment, and suggest that L. migonei may share the role as a vector with L. longipalpis in the transmission of VL in Fortaleza.

scholarly journals Leishmania infantumGenetic Diversity andLutzomyia longipalpisMitochondrial Haplotypes in Brazil

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Paulo Eduardo Martins Ribolla ◽  
Letícia Tsieme Gushi ◽  
Maria do Socorro Pires e Cruz ◽  
Carlos Henrique Nery Costa ◽  
Dorcas Lamounier Costa ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Visceral Leishmaniasis ◽  
Disease Transmission ◽  
Leishmania Infantum ◽  
Domestic Dogs ◽  
Etiological Agent ◽  
Lutzomyia Longipalpis ◽  
Geographic Structure ◽  
Reservoir Hosts

Leishmania infantumis the etiological agent of visceral leishmaniasis (VL) in the Americas with domestic dogs being its major reservoir hosts. The main VL vector is the sandflyLutzomyia longipalpis, while otherLutzomyiaspecies may play a role in disease transmission. Although the genetic structure ofL. infantumpopulations has been widely evaluated, only a few studies have addressed this subject coupled to the genetic structure of the respective sandfly vectors. In this study, we analyzed the population structure ofL. infantumin three major VL endemic areas in Brazil and associated it withLutzomyia longipalpisgeographic structure.

scholarly journals Detection of multiple circulating Leishmania species in Lutzomyia longipalpis in the city of Governador Valadares, southeastern Brazil

2018 ◽  
Author(s):  
Mariana Santos Cardoso ◽  
Gabrielle Ariadine Bento ◽  
Laila Viana de Almeida ◽  
Joseane Camilla de Castro ◽  
João Luís Reis Cunha ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Infection Rate ◽  
Control Strategies ◽  
Minas Gerais ◽  
Domestic Dogs ◽  
Effective Control ◽  
Lutzomyia Longipalpis ◽  
Insect Vector ◽  
Sand Flies ◽  
The City

AbstractBackgroundLeishmaniasis encompasses a group of diverse clinical diseases caused by protozoan parasites of the Leishmania genus. This disease is a major public health problem in the New World affecting people exposed in endemic regions. The city of Governador Valadares (Minas Gerais/Brazil) is a re-emerging area for visceral leishmaniasis, with 191 human cases reported from 2008 to 2017 and a lethality rate of 14.7%. The transmission of the parasite occurs intensely in this region with up to 22% of domestic dogs with positive serology for the visceral form. Lu. longipalpis is one of the most abundant sand fly species in this area. Despite this scenario, so far there is no information regarding the circulating Leishmania species in the insect vector Lutzomyia longipalpis in this focus.Methodology/Principal FindingsWe collected 616 female Lutzomyia longipalpis sand flies between January and September 2015 in the Vila Parque Ibituruna neighborhood (Governador Valadares/MG), which is located on a transitional area between the sylvatic and urban environments with residences built near a preserved area. After DNA extraction of individual sand flies, the natural Leishmania infections in Lu. longipalpis were detected by end-point PCR, using primers derived from kDNA sequences, specific for L. (Leishmania) or L. (Viannia) subgenus. The sensitivity of these PCR reactions was 0.1 pg of DNA for each Leishmania subgenus and the total infection rate of 16.2% (100 positive specimens). Species-specific PCR detected the presence of multiple Leishmania species in infected Lu. longipalpis specimens in Governador Valadares, including L. amazonensis (n=3), L. infantum (n=28), L. (Viannia) spp. (n=20), coinfections with L. infantum and L. (Viannia) spp. (n=5), and L. (Leishmania) spp (n=44).ConclusionsOur results demonstrate that multiple Leishmania species circulate in Lu. longipalpis in Governador Valadares and reveal a potential increasing risk of transmission of the different circulating parasite species. This information is a key factor for planning surveillance and effective control strategies against leishmaniasis in this endemic focus.Author summaryLeishmaniasis is a neglected tropical disease transmitted to mammals by the bite of sand flies infected with parasites of the Leishmania genus. This disease affects millions of people in various regions of the world, including Brazil. The municipality of Governador Valadares (Minas Gerais/Brazil) is a re-emergent focus of intense transmission of leishmaniasis, with a high number of human cases and a high prevalence of infected domestic dogs. To develop better leishmaniasis control strategies for the region, we performed a surveillance study of Lu. longipalpis, the main vector of visceral leishmaniasis in Brazil, and identified circulating species of Leishmania in this insect vector. We estimate that the natural infection rate of Lu. longipalpis for these parasites was of 16.2% in the study area. We also detected the presence of multiple circulating Leishmania species (L. amazonensis, L. infantum and Viannia subgenus) in Lu. longipalpis in Governador Valadares city, including 5 sand flies coinfected with L. infantum and L. (Viannia). Thus, our results reinforce the need for a rigid and systematic control of the sand flies monitoring in this area, due to the potential risk of transmission of different species of the Leishmania parasites.

Detection of Pintomyia fischeri (Diptera: Psychodidae) With Leishmania infantum (Trypanosomatida: Trypanosomatidae) Promastigotes in a Focus of Visceral Leishmaniasis in Brazil

2020 ◽  
Author(s):  
Fredy Galvis-Ovallos ◽  
Adriele Eiko Ueta ◽  
Gabriella de Oliveira Marques ◽  
Ana Maria Casagrande Sarmento ◽  
Gabriela Araujo ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Infantum ◽  
Species Complex ◽  
Natural Infection ◽  
Metropolitan Region ◽  
Sand Fly ◽  
Surveillance Program ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Vector Surveillance

Abstract Visceral leishmaniasis is spreading in Brazil where the main vector of its agent, Leishmania infantum Nicolle, 1908, is the Lutzomyia longipalpis (Lutz & Neiva, 1912) species complex (Diptera: Psychodidae: Phlebotominae), on which many of the activities of the visceral leishmaniasis surveillance program are based. However, there are areas where canine, and/or human cases have been occurring without the presence of this species complex as in the western part of the Greater São Paulo Metropolitan region, where Embu das Artes municipality is situated. In this area, Pintomyia fischeri (Pinto, 1926) has been implicated as potential vector of Le. infantum but so far its natural infection with this parasite has not yet been ascertained. Therefore, the present study sought to investigate the natural infection in sand flies of a CVL focus in Embu das Artes. The sand fly collections were undertaken with Shannon and CDC traps, monthly, between 1800 and 2100 hours from November 2018 to October 2019, inclusive. A total of 951 sand flies (457 males and 494 females), belonging to 10 species, were captured. Pintomyia fischeri was the predominant species (89.5%); of which 426 females were dissected and one of them (0.23%) was found to be harboring flagellates in its midgut. A sample of these flagellates was isolated in culture and characterized by a 234 base pair fragment of Leishmania heat-shock protein 70 gene (hsp70) and restriction fragment length polymorphism with Hae III restriction enzyme as Le. infantum. This finding reinforces previous evidence of Pi. fischeri as a vector of Le. infantum in foci of visceral leishmaniasis and highlights the importance of vector surveillance in areas where this species occurs.

scholarly journals Sexual and vertical transmission of visceral leishmaniasis

2014 ◽  
Vol 8 (04) ◽  
pp. 403-407 ◽  
Author(s):  
Andreia P Turchetti ◽  
Tayse D Souza ◽  
Tatiane A Paixão ◽  
Renato L. Santos
Keyword(s):  
Visceral Leishmaniasis ◽  
Vertical Transmission ◽  
Leishmania Infantum ◽  
Vertebrate Host ◽  
Domestic Dog ◽  
Sand Flies ◽  
Phlebotomine Sand Flies

Visceral leishmaniasis (VL) is an important zoonosis caused by Leishmania infantum, which has in the domestic dog its principal vertebrate host. VL is usually transmitted by phlebotomine sand flies, however atypical routes of transmission have been described. In this review we discuss the the role of sexual and vertical transmissions, and their role in the maintenance of VL in canine populations.

scholarly journals Leishmania infantum Infection Modulates the Jak-STAT Pathway in Lutzomyia longipalpis LL5 Embryonic Cells and Adult Females, and Affects Parasite Growth in the Sand Fly

2021 ◽  
Vol 2 ◽  
Author(s):  
Erich Loza Telleria ◽  
Daisy Aline Azevedo-Brito ◽  
Barbora Kykalová ◽  
Bruno Tinoco-Nunes ◽  
André Nóbrega Pitaluga ◽  
...  
Keyword(s):  
Post Infection ◽  
Leishmania Infantum ◽  
Janus Kinase ◽  
Sand Fly ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Embryonic Cells ◽  
Adult Females ◽  
Parasite Survival ◽  
Stat Pathway

Phlebotomine sand flies (Diptera, Psychodidae) belonging to the Lutzomyia genus transmit zoonoses in the New World. Lutzomyia longipalpis is the main vector of Leishmania infantum, which is the causative agent of visceral leishmaniasis in Brazil. To identify key molecular aspects involved in the interaction between vector and pathogens and contribute to developing disease transmission controls, we investigated the sand fly innate immunity mediated by the Janus kinase/signal transducer and activator of transcription (Jak-STAT) pathway in response to L. infantum infection. We used two study models: L. longipalpis LL5 embryonic cells co-cultured with L. infantum and sand fly females artificially infected with the parasite. We used qPCR to follow the L. longipalpis gene expression of molecules involved in the Jak-STAT pathway. Also, we modulated the Jak-STAT mediated immune response to understand its role in Leishmania parasite infection. For that, we used RNAi to silence the pathway regulators, protein inhibitor of activated STATs (PIAS) in LL5 cells, and STAT in adult females. In addition, the pathway suppression effect on parasite development within the vector was assessed by light microscopy in late-phase infection. The silencing of the repressor PIAS in LL5 cells led to a moderate increase in a protein tyrosine phosphatase 61F (PTP61F) expression. It suggests a compensatory regulation between these two repressors. L. infantum co-culture with LL5 cells upregulated repressors PIAS, suppressor of cytokine signaling (SOCS), and PTP61F. It also downmodulated virus-induced RNA-1 (VIR-1), a pathway effector, indicating that the parasite could repress the Jak-STAT pathway in LL5 cells. In Leishmania-infected L. longipalpis females, STAT and the antimicrobial peptide attacin were downregulated on the third day post-infection, suggesting a correlation that favors the parasite survival at the end of blood digestion in the sand fly. The antibiotic treatment of infected females showed that the reduction of gut bacteria had little effect on the Jak-STAT pathway regulation. STAT gene silencing mediated by RNAi reduced the expression of inducible nitric oxide synthase (iNOS) and favored Leishmania growth in sand flies on the first day post-infection. These results indicate that STAT participated in the iNOS regulation with subsequent effect on parasite survival.

Entomological Studies in Itaúna, Brazil, an Area With Visceral Leishmaniasis Transmission: Fauna Survey, Natural Leishmania Infection, and Molecular Characterization of the Species Circulating in Phlebotomine Sand Flies (Diptera: Psychodidae)

2019 ◽  
Vol 56 (5) ◽  
pp. 1368-1376 ◽  
Author(s):  
Josiane V Lopes ◽  
Erika M Michalsky ◽  
Nathalia C L Pereira ◽  
Adão J V de Paula ◽  
Fabiana O Lara-Silva ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Natural Infection ◽  
Local Population ◽  
Influential Factor ◽  
Sand Fly ◽  
Health Concern ◽  
Leishmania Infection ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Phlebotomine Sand Flies

Abstract Among neglected tropical diseases, visceral leishmaniasis (VL) shows great relevance in global terms and is a serious public health concern due to the possibility of severe and lethal forms in humans. In this study, we evaluate entomological factors such as diversity and abundance of phlebotomine sand flies (Diptera:Psychodidae) and the Leishmania species circulating in these species in possible association with VL transmission in the Brazilian town Itaúna. The entomological collections were performed during three consecutive nights, always in the third week of each month, within a period of 12 mo. A total of 1,786 sand fly specimens were collected, from which 20% were collected inside houses. The influence of three local climatic variables (temperature, rainfall, relative humidity) on the population sizes of these insects was evaluated. Temperature was the most influential factor, with a significant positive correlation with the local population size of phlebotomine sand flies collected per month. Lutzomyia longipalpis (Lutz & Neiva, 1912) was the predominant species in the study area. Leishmania DNA was detected in nine out of 133 pools of sand fly females, using nested/PCR, which resulted in a minimal natural infection rate of 2.91%. DNA from Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatida), was detected in Evandromyia cortelezzii (Bréthes, 1923), Ev. evandroi (Costa, Lima & Antunes, 1936), Ev. lenti (Mangabeira, 1938), and Ev. termitophila (Martins, Falcão & Silva, 1964), besides Lu. longipalpis. Our study indicates favorable conditions for VL spreading in Itaúna due to the presence of Lu. longipalpis and Le. infantum-infected phlebotomine sand flies.

scholarly journals Physiological Age Structure andLeishmaniaspp. Detection inPhlebotomus (Larroussius) orientalis(Parrot, 1936) (Diptera: Psychodidae) at an Endemic Focus of Visceral Leishmaniasis in Northern Ethiopia

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Araya Gebresilassie ◽  
Ibrahim Abbasi ◽  
Oscar David Kirstein ◽  
Essayas Aklilu ◽  
Solomon Yared ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Age Structure ◽  
Leishmania Donovani ◽  
Age Determination ◽  
Blood Feeding ◽  
Physiological Age ◽  
Agricultural Fields ◽  
Northern Ethiopia ◽  
Sand Flies ◽  
Endemic Focus

Visceral leishmaniasis (VL) caused byLeishmania donovaniis endemic in northern Ethiopia, whereP. orientalisis the most important presumed vector. This study was designed to determine the physiological age structure and the occurrence ofLeishmaniainfection in the vector of VL in Tahtay Adiyabo district, northern Ethiopia. Sand flies were collected using CDC light traps from peridomestic and agricultural fields between May 2011 and April 2012 andP. orientalisfemales were dissected for age determination and detection ofLeishmaniapromastigotes. Sand flies were also analyzed forL. donovanidetection using molecular methods. Of 1,282P. orientalisexamined for abdominal stages and age characterization, 66.2%, 28.2%, 4.1%, and 1.6% were unfed, freshly fed, half-gravid, and gravid. Parous rate in unfed females was 34.1% and 35.4% in peridomestic and agricultural fields, respectively. Out of 921P. orientalisfemales dissected, one specimen (0.1%) was found naturally infected with promastigotes. Five pools (25 females) of unfedP. orientaliswere also found with DNA ofLeishmaniaspp. In particular, a singleP. orientaliswas positive forL. donovani(0.5%). Based on this and other evidences (abundance, human blood feeding, and xenodiagnostic studies),P. orientalisis the principal vector of VL in this endemic focus.

Sign in / Sign up

Export Citation Format

Share Document