Most cited article - PubMed ID 18761342
Cutaneous leishmaniasis caused by Leishmania infantum transmitted by Phlebotomus tobbi
Toscana virus (TOSV) is an emerging but neglected human pathogen currently circulating around the Mediterranean basin including North Africa. Human illness ranges from asymptomatic or mild flu-like syndromes to severe neurological diseases such as meningitis or meningoencephalitis. Despite its significant impact, understanding of TOSV transmission and epidemiology remains limited. Sand flies (Diptera: Phlebotominae), specifically Phlebotomus perniciosus and Phlebotomus perfiliewi, are believed to be the primary vectors of TOSV. However, the spread of TOSV to new geographical areas and its detection in other sand fly species suggest that additional species play a role in the circulation and transmission of this virus. This study investigated the vector competence of four sand fly species - P. tobbi, P. sergenti, P. papatasi, and Sergentomyia schwetzi - for two TOSV strains: 1500590 (TOSV A lineage) and MRS20104319501 (TOSV B lineage). Sand flies were orally challenged with TOSV via bloodmeals. None of the tested species showed susceptibility to the TOSV A strain. However, for TOSV B strain, P. tobbi demonstrated a high potential as a new vector, exhibiting high infection and dissemination rates. P. sergenti also showed some susceptibility to TOSV B, with the virus dissemination observed in all infected females. These finding suggests that P. tobbi and P. sergenti are new potential vectors for TOSV B. Given that P. tobbi and P. sergenti are the primary vectors of human leishmaniases in the Balkans, Turkey and Middle East, their susceptibility to TOSV could have significant epidemiological consequences. On the other hand, P. papatasi and S. schwetzi appeared refractory to TOSV B infection. Refractoriness of P. papatasi, a highly anthropophilic species distributed from the Mediterranean to the Middle East and India, suggests that this species does not contribute to TOSV circulation.
- MeSH
- Insect Vectors * virology MeSH
- Humans MeSH
- Phlebotomus * virology MeSH
- Psychodidae * virology classification MeSH
- Sandfly fever Naples virus * physiology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Sand fly females require a blood meal to develop eggs. The size of the blood meal is crucial for fecundity and affects the dose of pathogens acquired by females when feeding on infected hosts or during experimental membrane-feeding. METHODS: Under standard laboratory conditions, we compared blood meal volumes taken by females of ten sand fly species from four genera: Phlebotomus, Lutzomyia, Migonomyia, and Sergentomyia. The amount of ingested blood was determined using a haemoglobin assay. Additionally, we weighed unfed sand flies to calculate the ratio between body weight and blood meal weight. RESULTS: The mean blood meal volume ingested by sand fly females ranged from 0.47 to 1.01 µl. Five species, Phlebotomus papatasi, P. duboscqi, Lutzomyia longipalpis, Sergentomyia minuta, and S. schwetzi, consumed about double the blood meal size compared to Migonomyia migonei. The mean body weight of females ranged from 0.183 mg in S. minuta to 0.369 mg in P. duboscqi. In males, the mean body weight ranged from 0.106 mg in M. migonei to 0.242 mg in P. duboscqi. Males were always lighter than females, with the male-to-female weight ratio ranging from 75% (in Phlebotomus argentipes) to 52% (in Phlebotomus tobbi). CONCLUSIONS: Females of most species took a blood meal 2.25-3.05 times their body weight. Notably, the relatively tiny females of P. argentipes consumed blood meals 3.34 times their body weight. The highest (Mbl/Mf) ratios were found in both Sergentomyia species studied; females of S. minuta and S. schwetzi took blood meals 4.5-5 times their body weight. This parameter is substantially higher than that reported for mosquitoes and biting midges.
- Keywords
- Lutzomyia, Phlebotomus, Sergentomyia, Blood meal, Haemoglobin, Prediuresis,
- MeSH
- Blood MeSH
- Phlebotomus physiology MeSH
- Psychodidae * physiology MeSH
- Feeding Behavior * MeSH
- Body Weight * MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Phlebotomine sand flies (Diptera: Psychodidae) are the principal vectors of phleboviruses and Leishmania spp., the causative agents of leishmaniases. The Mediterranean sand fly fauna is diverse, and leishmaniasis, mainly caused by Leishmania infantum, is endemic in the Balkan countries. Despite recent entomological surveys, only some districts of Kosovo have been sampled for sand flies, with no proof/confirmation of L. infantum. This study aimed to gain further insights into the species composition of natural sand fly populations in previously unsampled districts and areas in Kosovo without reports of leishmaniasis and to detect Leishmania DNA in sand flies. A sand fly survey was conducted in 2022 in all seven districts of Kosovo. Collected females were screened for Leishmania DNA by PCR. Positive samples were sequenced and subjected to maximum likelihood analysis with reference sequences for further molecular characterization. The trapping activities at 114 different localities resulted in 3272 caught specimens, comprising seven sand fly species of two genera, namely Phlebotomus neglectus, Ph. perfiliewi, Ph. tobbi, Ph. papatasi, Ph. simici, Ph. balcanicus and Sergentomyia minuta. Leishmania infantum DNA was detected in three individual sand flies of Ph. neglectus and Ph. perfiliewi. This study provides the most extensive sand fly survey in Kosovo and reports the first record of L. infantum DNA in sand flies, indicating autochthonous circulation of L. infantum.
- Keywords
- Balkan, Kosovo, Larroussius, PCR, Phlebotominae, leishmaniasis,
- Publication type
- Journal Article MeSH
An entomological survey at rural and cavernicolous localities in four provinces in southern Thailand provided 155 blood-fed females of sand flies (Diptera: Psychodidae) that were identified based on morphological characters as Idiophlebotomus asperulus (n = 19), Phlebotomus stantoni (n = 4), P. argentipes (n = 3), Sergentomyia anodontis (n = 20), S. barraudi (n = 9), S. hamidi (n = 23), S. hodgsoni (n = 4), S. hodgsoni hodgsoni (n = 32), S. indica (n = 5), S. iyengari (n = 2), S. khawi (n = 17), S. silvatica (n = 11) and Sergentomyia sp. (n = 6). The dominant species in this study was S. hodgsoni hodgsoni, which was collected specifically in a Buddha cave. Screening for DNA of parasitic protozoans revealed eight specimens (5.16%) of four species (S. barraudi, S. indica, S. khawi and Id. asperulus) positive for Trypanosoma sp., while no Leishmania spp. DNA was detected. Blood meals of engorged females were identified by PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) assay on a fragment of cytochrome b (cyt b) gene with a success rate 36%, humans, dogs, and rats being determined as sources of blood. Bloodmeal analysis of two Trypanopsoma-positive females (S. barraudi and Sergentomyia sp.) identified blood from dogs and humans, respectively. Our findings indicate that S. barraudi, S. indica, S. khawi and Id. asperulus may be incriminated in circulation of detected Trypanosoma spp.
- Keywords
- Phlebotomus, Sergentomyia, Trypanosoma sp., blood meal source, sand flies,
- Publication type
- Journal Article MeSH
BACKGROUND: Identification of blood sources of hematophagous arthropods is crucial for understanding the transmission cycles of vector-borne diseases. Many different approaches towards host determination were proposed, including precipitin test, ELISA, DNA- and mass spectrometry-based methods; yet all face certain complications and limitations, mostly related to blood degradation. This study presents a novel method for blood meal identification, peptide mass mapping (PMM) analysis of host-specific hemoglobin peptides using MALDI-TOF mass spectrometry. METHODOLOGY/PRINCIPAL FINDINGS: To identify blood meal source, proteins from abdomens of engorged sand fly females were extracted, cleaved by trypsin and peptide fragments of host hemoglobin were sequenced using MALDI-TOF MS. The method provided correct host identification of 100% experimentally fed sand flies until 36h post blood meal (PBM) and for 80% samples even 48h PBM. In females fed on two hosts, both blood meal sources were correctly assigned for 60% of specimens until 36h PBM. In a validation study on field-collected females, the method yielded unambiguous host determination for 96% of specimens. The suitability of PMM-based MALDI-TOF MS was proven experimentally also on lab-reared Culex mosquitoes. CONCLUSIONS/SIGNIFICANCE: PMM-based MALDI-TOF MS analysis targeting host specific hemoglobin peptides represents a sensitive and cost-effective method with a fast and simple preparation protocol. As demonstrated here on phlebotomine sand flies and mosquitoes, it allows reliable and rapid blood source determination even 48h PBM with minimal material input and provides more robust and specific results than other currently used methods. This approach was also successfully tested on field-caught engorged females and proved to be a promising useful tool for large-scale screening of host preferences studies. Unlike other methods including MALDI-TOF protein profiling, it allows correct identification of mixed blood meals as was demonstrated on both experimentally fed and field-collected sand flies.
- MeSH
- Blood Chemical Analysis methods MeSH
- Species Specificity MeSH
- Hemoglobins chemistry MeSH
- Humans MeSH
- Proof of Concept Study MeSH
- Peptides chemistry MeSH
- Psychodidae chemistry physiology MeSH
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization MeSH
- Feeding Behavior MeSH
- Tandem Mass Spectrometry MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Evaluation Study MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Hemoglobins MeSH
- Peptides MeSH
BACKGROUND: Leishmania infantum is the most widespread etiological agent of visceral leishmaniasis (VL) in the world, with significant mortality rates in human cases. In Latin America, this parasite is primarily transmitted by Lutzomyia longipalpis, but the role of Lutzomyia migonei as a potential vector for this protozoan has been discussed. Laboratory and field investigations have contributed to this hypothesis; however, proof of the vector competence of L. migonei has not yet been provided. In this study, we evaluate for the first time the susceptibility of L. migonei to L. infantum. METHODS: Females of laboratory-reared L. migonei were fed through a chick-skin membrane on rabbit blood containing L. infantum promastigotes, dissected at 1, 5 and 8 days post-infection (PI) and checked microscopically for the presence, intensity and localisation of Leishmania infections. In addition, morphometric analysis of L. infantum promastigotes was performed. RESULTS: High infection rates of both L. infantum strains tested were observed in L. migonei, with colonisation of the stomodeal valve already on day 5 PI. At the late-stage infection, most L. migonei females had their cardia and stomodeal valve colonised by high numbers of parasites, and no significant differences were found compared to the development in L. longipalpis. Metacyclic forms were found in all parasite-vector combinations since day 5 PI. CONCLUSIONS: We propose that Lutzomyia migonei belongs to sand fly species permissive to various Leishmania spp. Here we demonstrate that L. migonei is highly susceptible to the development of L. infantum. This, together with its known anthropophily, abundance in VL foci and natural infection by L. infantum, constitute important evidence that L. migonei is another vector of this parasite in Latin America.
- Keywords
- Leishmania infantum, Lutzomyia migonei, Vector competence,
- MeSH
- Insect Vectors * MeSH
- Leishmania infantum cytology isolation & purification MeSH
- Microscopy MeSH
- Psychodidae growth & development parasitology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
BACKGROUND: The recent geographical expansion of phlebotomine vectors of Leishmania infantum in the Mediterranean subregion has been attributed to ongoing climate changes. At these latitudes, the activity of sand flies is typically seasonal; because seasonal phenomena are also sensitive to general variations in climate, current phenological data sets can provide a baseline for continuing investigations on sand fly population dynamics that may impact on future scenarios of leishmaniasis transmission. With this aim, in 2011-2013 a consortium of partners from eight Mediterranean countries carried out entomological investigations in sites where L. infantum transmission was recently reported. METHODS/PRINCIPAL FINDINGS: A common protocol for sand fly collection included monthly captures by CDC light traps, complemented by sticky traps in most of the sites. Collections were replicated for more than one season in order to reduce the effects of local weather events. In each site, the trapping effort was left unchanged throughout the survey to legitimate inter-seasonal comparisons. Data from 99,000 collected specimens were analyzed, resulting in the description of seasonal dynamics of 56,000 sand flies belonging to L. infantum vector species throughout a wide geographical area, namely P. perniciosus (Portugal, Spain and Italy), P. ariasi (France), P. neglectus (Greece), P. tobbi (Cyprus and Turkey), P. balcanicus and P. kandelakii (Georgia). Time of sand fly appearance/disappearance in collections differed between sites, and seasonal densities showed variations in each site. Significant correlations were found between latitude/mean annual temperature of sites and i) the first month of sand fly appearance, that ranged from early April to the first half of June; ii) the type of density trend, varying from a single peak in July/August to multiple peaks increasing in magnitude from May through September. A 3-modal trend, recorded for P. tobbi in Cyprus, represents a novel finding for a L. infantum vector. Adults ended the activity starting from mid September through November, without significant correlation with latitude/mean annual temperature of sites. The period of potential exposure to L.infantum in the Mediterranean subregion, as inferred by adult densities calculated from 3 years, 37 sites and 6 competent vector species, was associated to a regular bell-shaped density curve having a wide peak center encompassing the July-September period, and falling between early May to late October for more than 99% of values. Apparently no risk for leishmaniasis transmission took place from December through March in the years considered. We found a common pattern of nocturnal females activity, whose density peaked between 11 pm and 2 am. CONCLUSIONS: Despite annual variations, multiple collections performed over consecutive years provided homogeneous patterns of the potential behavior of leishmaniasis vectors in selected sites, which we propose may represent sentinel areas for future monitoring. In the investigated years, higher potential risk for L. infantum transmission in the Mediterranean was identified in the June-October period (97% relative vector density), however such risk was not equally distributed throughout the region, since density waves of adults occurred earlier and were more frequent in southern territories.
- MeSH
- Insect Vectors parasitology physiology MeSH
- Leishmania infantum physiology MeSH
- Leishmaniasis epidemiology parasitology transmission MeSH
- Humans MeSH
- Climate MeSH
- Population Dynamics MeSH
- Psychodidae parasitology physiology MeSH
- Seasons MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Mediterranean Region epidemiology MeSH
BACKGROUND: Infection caused by parasites from L. donovani complex can manifest as a serious visceral disease or a self-healing milder cutaneous form. The different tropism and pathology in humans is caused by the interaction between parasites, host and vector determinants but the mechanisms are not well understood. In Cukurova region in Turkey we previously identified a major focus of cutaneous leishmaniasis caused by L. donovani/infantum hybrids (CUK strain) and isolated this parasite from the locally abundant sand fly, Phlebotomus tobbi. Here, we present the first experimental study with P. tobbi. We tested the susceptibility of this species to various Leishmania under laboratory conditions, characterized glycoproteins in the P. tobbi midgut putatively involved in parasite-vector interaction and compared the development of the CUK strain in the sand fly with one other dermotropic and three viscerotropic strains belonging to the L. donovani complex. METHODS: Females of laboratory reared P. tobbi, P. perniciosus and Lutzomyia longipalpis were infected using membrane feeding on rabbit blood containing promastigotes of various Leishmania species with different tropisms. The individual guts were checked microscopically for presence and localization of Leishmania parasites; the number of parasites was assessed more precisely by qPCR. In addition, glycosylation of midgut proteins of P. tobbi was studied by lectin blotting of midgut lysate with lectins specific for terminal sugars of N-type and O-type glycans. RESULTS: High infection rates, heavy parasite loads and late-stage infection with colonization of the stomodeal valve were observed in P. tobbi infected by Leishmania major or L. infantum CUK hybrid. In parallel, lectin blotting revealed the presence of O-glycosylated proteins in the P. tobbi midgut. In P. perniciosus and L. longipalpis all five Leishmania strains tested developed well. In both vectors, significantly higher parasite numbers were detected by qPCR for dermotropic L. donovani from Cyprus, however, in all other parameters studied, including localization of infection and colonization of stomodeal valve, dermotropic and viscerotropic strains were not significantly different. CONCLUSIONS: We showed high susceptibility of P. tobbi to various Leishmania spp. This, together with the presence of O-glycosylated midgut proteins in their midguts demonstrate that P. tobbi is a permissive vector. Two dermotropic and three viscerotropic strains from the L. donovani complex developed late-stage infections in natural L. infantum vectors, P. perniciosus and L. longipalpis and none of the parameters studied seem to be linked with different tropism of parasites in the vertebrate host.
- MeSH
- Gastrointestinal Tract parasitology MeSH
- Insect Vectors parasitology MeSH
- Rabbits MeSH
- Leishmania infantum genetics growth & development isolation & purification MeSH
- Leishmania major genetics growth & development isolation & purification MeSH
- Leishmaniasis, Cutaneous epidemiology parasitology MeSH
- Humans MeSH
- Phlebotomus parasitology MeSH
- Psychodidae parasitology MeSH
- Tropism MeSH
- Animals MeSH
- Check Tag
- Rabbits MeSH
- Humans MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
- Geographicals
- Turkey MeSH
UNLABELLED: A new phlebovirus, Adana virus, was isolated from a pool of Phlebotomus spp. (Diptera; Psychodidae) in the province of Adana, in the Mediterranean region of Turkey. Genetic analysis based on complete coding of genomic sequences indicated that Adana virus belongs to the Salehabad virus species of the genus Phlebovirus in the family Bunyaviridae. Adana virus is the third virus of the Salehabad virus species for which the complete sequence has been determined. To understand the epidemiology of Adana virus, a seroprevalence study using microneutralization assay was performed to detect the presence of specific antibodies in human and domestic animal sera collected in Adana as well as Mersin province, located 147 km west of Adana. The results demonstrate that the virus is present in both provinces. High seroprevalence rates in goats, sheep, and dogs support intensive exposure to Adana virus in the region, which has not been previously reported for any virus included in the Salehabad serocomplex; however, low seroprevalence rates in humans suggest that Adana virus is not likely to constitute an important public health problem in exposed human populations, but this deserves further studies. IMPORTANCE: Until recently, in the genus Phlebovirus, the Salehabad virus species consisted of two viruses: Salehabad virus, isolated from sand flies in Iran, and Arbia virus, isolated from sand flies in Italy. Here we present the isolation and complete genome characterization of the Adana virus, which we propose to be included in the Salehabad virus species. To our knowledge, this is the first report of the isolation and complete genome characterization, from sand flies in Turkey, of a Salehabad virus-related phlebovirus with supporting seropositivity in the Mediterranean, Aegean, and Central Anatolia regions, where phleboviruses have been circulating and causing outbreaks. Salehabad species viruses have generally been considered to be a group of viruses with little medical or veterinary interest. This view deserves to be revisited according to our results, which indicate a high animal infection rate of Adana virus and recent evidence of human infection with Adria virus in Greece.
- MeSH
- Microscopy, Electron veterinary MeSH
- Phylogeny MeSH
- Insect Vectors virology MeSH
- Bunyaviridae Infections epidemiology veterinary virology MeSH
- Goats virology MeSH
- Humans MeSH
- Molecular Sequence Data MeSH
- Neutralization Tests veterinary MeSH
- Sheep virology MeSH
- Phlebotomus virology MeSH
- Phlebovirus classification genetics isolation & purification ultrastructure MeSH
- Dogs virology MeSH
- Base Sequence MeSH
- Sequence Analysis, DNA veterinary MeSH
- Seroepidemiologic Studies MeSH
- Cluster Analysis MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Dogs virology MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Turkey epidemiology MeSH
BACKGROUND: In East Africa, Phlebotomus orientalis serves as the main vector of Leishmania donovani, the causative agent of visceral leishmaniasis (VL). Phlebotomus orientalis is present at two distant localities in Ethiopia; Addis Zemen where VL is endemic and Melka Werer where transmission of VL does not occur. To find out whether the difference in epidemiology of VL is due to distant compositions of P. orientalis saliva we established colonies from Addis Zemen and Melka Werer, analyzed and compared the transcriptomes, proteomes and enzymatic activity of the salivary glands. METHODOLOGY/PRINCIPAL FINDINGS: Two cDNA libraries were constructed from the female salivary glands of P. orientalis from Addis Zemen and Melka Werer. Clones of each P. orientalis library were randomly selected, sequenced and analyzed. In P. orientalis transcriptomes, we identified members of 13 main protein families. Phylogenetic analysis and multiple sequence alignments were performed to evaluate differences between the P. orientalis colonies and to show the relationship with other sand fly species from the subgenus Larroussius. To further compare both colonies, we investigated the humoral antigenicity and cross-reactivity of the salivary proteins and the activity of salivary apyrase and hyaluronidase. CONCLUSIONS: This is the first report of the salivary components of P. orientalis, an important vector sand fly. Our study expanded the knowledge of salivary gland compounds of sand fly species in the subgenus Larroussius. Based on the phylogenetic analysis, we showed that P. orientalis is closely related to Phlebotomus tobbi and Phlebotomus perniciosus, whereas Phlebotomus ariasi is evolutionarily more distinct species. We also demonstrated that there is no significant difference between the transcriptomes, proteomes or enzymatic properties of the salivary components of Addis Zemen (endemic area) and Melka Werer (non-endemic area) P. orientalis colonies. Thus, the different epidemiology of VL in these Ethiopian foci cannot be attributed to the salivary gland composition.
- MeSH
- Enzymes chemistry classification genetics MeSH
- Insect Vectors genetics MeSH
- Leishmaniasis, Visceral immunology MeSH
- Molecular Sequence Data MeSH
- Mice, Inbred BALB C MeSH
- Mice MeSH
- Phlebotomus genetics MeSH
- Amino Acid Sequence MeSH
- Sequence Alignment MeSH
- Salivary Proteins and Peptides chemistry classification genetics immunology MeSH
- Salivary Glands chemistry enzymology MeSH
- Transcriptome genetics MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Intramural MeSH
- Geographicals
- Ethiopia MeSH
- Names of Substances
- Enzymes MeSH
- Salivary Proteins and Peptides MeSH