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1.
Acta Trop ; 178: 264-275, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29224978

ABSTRACT

The vector Lutzomyia sand flies and reservoir host mammals of the Leishmania parasites, causing the Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador were thoroughly reviewed, performing a survey of literatures including our unpublished data. The Peruvian L. (V.) peruviana, a principal Leishmania species causing Andean-CL in Peru, possessed three Lutzomyia species, Lu. peruensis, Lu. verrucarum and Lu. ayacuchensis as vectors, while the Ecuadorian L. (L.) mexicana parasite possessed only one species Lu. ayacuchensis as the vector. Among these, the Ecuadorian showed a markedly higher rate of natural Leishmania infections. However, the monthly and diurnal biting activities were mostly similar among these vector species was in both countries, and the higher rates of infection (transmission) reported, corresponded to sand fly's higher monthly-activity season (rainy season). The Lu. tejadai sand fly participated as a vector of a hybrid parasite of L. (V.) braziliensis/L. (V.) peruviana in the Peruvian Andes. Dogs were considered to be principal reservoir hosts of the L. (V.) peruviana and L. (L.) mexicana parasites in both countries, followed by other sylvatic mammals such as Phyllotis andium, Didelphis albiventris and Akodon sp. in Peru, and Rattus rattus in Ecuador, but information on the reservoir hosts/mammals was extremely poor in both countries. Thus, the Peruvian disease form demonstrated more complicated transmission dynamics than the Ecuadorian. A brief review was also given to the control of vector and reservoirs in the Andes areas. Such information is crucial for future development of the control strategies of the disease.


Subject(s)
Disease Reservoirs/parasitology , Insect Vectors/parasitology , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/parasitology , Mammals/parasitology , Psychodidae/parasitology , Animals , Ecuador/epidemiology , Humans , Peru/epidemiology , Seasons
2.
Acta Trop ; 177: 135-145, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29017878

ABSTRACT

This study provides comprehensive information on the past and current status of the Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador, mainly focusing on the causative Leishmania parasites and clinico-epidemiological features. Available information and data including our unpublished works were analyzed thoroughly. Endemic regions of the Andean-CL (uta) in Peru run from the north Piura/Cajamarca to the south Ayacucho at a wide range of the Pacific watersheds of the Andes through several departments, while in Ecuador those exist at limited and spotted areas in the country's mid-southwestern two provinces, Azuay and Chimborazo. The principal species of the genus Leishmania are completely different at subgenus level, L. (Viannia) peruviana in Peru, and L. (Leishmania) mexicana and L. (L.) major-like (infrequent occurrence) in Ecuador. The Peruvian uta is now prevalent in different age and sex groups, being not clearly defined as found in the past. The precise reasons are not known and should be elucidated further, though probable factors, such as emergence of other Leishmania parasites, non-immune peoples' migration into the areas, etc., were discussed briefly in the text. The Andean-CL cases in Ecuador are more rural than before, probably because of a rapid development of the Leishmania-positive communities and towns, and the change of life-styles of the inhabitants, including newly constructed houses and roads in the endemic areas. Such information is helpful for future management of the disease, not only for Leishmania-endemic areas in the Andes but also for other endemic areas.


Subject(s)
Leishmania/classification , Leishmania/isolation & purification , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/parasitology , Psychodidae/parasitology , Animals , Ecuador/epidemiology , Female , Geography , Humans , Male , Peru/epidemiology
3.
J Infect Dis ; 216(7): 850-858, 2017 10 17.
Article in English | MEDLINE | ID: mdl-28968717

ABSTRACT

Background: Non-acquired immune deficiency syndrome (AIDS) Kaposi's sarcoma (KS) is extremely rare in Japan but highly endemic in Okinawa, especially in Miyako Islands. We aimed to elucidate the exact incidence and cause of this high prevalence. Methods: Non-AIDS KS cases in Okinawa Prefecture over the past 31 years were reviewed, and human herpesvirus 8 (HHV8) seroprevalence in Miyako Islands was determined. We examined whole-genome sequences of 3 HHV8 strains and performed whole-exome sequencing of 4 male patients from Miyako Islands. Results: Approximately half of the non-AIDS KS cases in Okinawa Prefecture were from Miyako Islands. The age-adjusted incidence rate was 0.87/105 per year for Miyako Islands and 0.056/105 per year for the rest of Okinawa. Human herpesvirus 8 seroprevalence was 15.4% in Miyako Islands. The 3 HHV8 genomes isolated from Miyako islanders formed a phylogenetically branch distinct from those of previously sequenced HHV8 strains and shared specific mutations in 9 proteins. These mutations were verified in Okinawan patients other than those from Miyako Islands. Whole-exome sequencing of the 4 male Miyako Islanders did not reveal shared pathogenic mutations. Conclusions: Miyako Islands are an endemic area of non-AIDS KS. The high rate of a distinct HHV8 may contribute to the high incidence of KS in the region.


Subject(s)
Herpesvirus 8, Human/isolation & purification , Sarcoma, Kaposi/virology , Adolescent , Adult , Aged , Aged, 80 and over , Female , Genome, Viral , Humans , Islands/epidemiology , Japan/epidemiology , Male , Middle Aged , Sarcoma, Kaposi/epidemiology , Young Adult
4.
Am J Dermatopathol ; 39(6): 428-432, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28291135

ABSTRACT

Pellagra is a nutrient deficiency disease caused by insufficient niacin levels. Recent studies have shown that numbers of epidermal Langerhans cells decreased in other diseases caused by nutritional deficiencies, including necrolytic migratory erythema and acrodermatitis enteropathica. Epidermal Langerhans cells are capable of modulating or even halting the inflammatory reaction. The aim of this study was to examine changes in the number of Langerhans cells and other dendritic cells, and maturation of epidermal Langerhans cells in the lesional and adjacent non-lesional skin in pellagra patients. Seven pellagra patients and 10 healthy individuals who served as controls were included. The number and distribution of dendritic cells and other cutaneous cells were examined by immunohistochemistry. Epidermal Langerhans cells decreased considerably in the skin lesions of pellagra patients, whereas other dendritic cells did not change. The decrease in the number of Langerhans cells was positively correlated with the histological severity of skin lesions. As the number of Langerhans cells was not reduced in the undisturbed neighboring skin, the depletion of epidermal Langerhans cells did not precede skin damage but was a cause of prolonged severe inflammation.


Subject(s)
Epidermis/pathology , Langerhans Cells/pathology , Pellagra/pathology , Adult , Aged , Biopsy , Case-Control Studies , Cell Count , Epidermis/chemistry , Female , Humans , Immunohistochemistry , Japan , Langerhans Cells/chemistry , Male , Middle Aged , Severity of Illness Index
5.
PLoS Negl Trop Dis ; 10(7): e0004844, 2016 07.
Article in English | MEDLINE | ID: mdl-27410039

ABSTRACT

A countrywide epidemiological study was performed to elucidate the current geographic distribution of causative species of cutaneous leishmaniasis (CL) in Ecuador by using FTA card-spotted samples and smear slides as DNA sources. Putative Leishmania in 165 samples collected from patients with CL in 16 provinces of Ecuador were examined at the species level based on the cytochrome b gene sequence analysis. Of these, 125 samples were successfully identified as Leishmania (Viannia) guyanensis, L. (V.) braziliensis, L. (V.) naiffi, L. (V.) lainsoni, and L. (Leishmania) mexicana. Two dominant species, L. (V.) guyanensis and L. (V.) braziliensis, were widely distributed in Pacific coast subtropical and Amazonian tropical areas, respectively. Recently reported L. (V.) naiffi and L. (V.) lainsoni were identified in Amazonian areas, and L. (L.) mexicana was identified in an Andean highland area. Importantly, the present study demonstrated that cases of L. (V.) braziliensis infection are increasing in Pacific coast areas.


Subject(s)
Cytochromes b , Leishmania/genetics , Leishmaniasis/epidemiology , Leishmaniasis/parasitology , Ecuador , Gene Expression Regulation , Humans , Phylogeny
6.
Trop Med Health ; 44: 2, 2016.
Article in English | MEDLINE | ID: mdl-27398061

ABSTRACT

BACKGROUND: In Ecuador, cutaneous leishmaniasis (CL) is prevalent countrywide, but only one case of diffuse-CL and two cases of disseminated-CL were experienced during our research activities more than 30 years from 1982 to date. These three patients suffered from multiple lesions distributed at a wide range of the body surface, revealing difficulty to clinically differentiate each other. METHODS: There is a considerable confusion of the use and/or differentiation of the terminologies (terms) between the two disease forms, diffuse-CL and disseminated-CL. One of the aims of the present study is to clarify the difference between the two disease forms, mainly based on the cases experienced in Ecuador. RESULTS: The disseminated-CL case newly reported here was clinically very similar to the diffuse-CL case, but the former showed the following marked differences from the latter: (1) the organisms isolated were identified as the parasites of Leishmania (Viannia) guyanensis/panamensis, which are also known as the causative agents of disseminated-CL in different endemic countries of the New World; (2) the patient was sensitive against antimonials; and (3) mucosal involvement was observed, which is never observed in diffuse-CL. CONCLUSIONS: In the text, three clinical cases, one diffuse-CL and two disseminated-CL, were presented. Furthermore, a bibliographic comparison of the features between the two disease forms was made, and a brief comment was also given.

9.
Acta Trop ; 153: 116-9, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26516109

ABSTRACT

Leishmaniasis remains one of the world's most neglected diseases, and early detection of the infectious agent, especially in developing countries, will require a simple and rapid test. In this study, we established a quick, one-step, single-tube, highly sensitive loop-mediated isothermal amplification (LAMP) assay for rapid detection of Leishmania DNA from tissue materials spotted on an FTA card. An FTA-LAMP with pre-added malachite green was performed at 64°C for 60min using a heating block and/or water bath and DNA amplification was detected immediately after incubation. The LAMP assay had high detection sensitivity down to a level of 0.01 parasites per µl. The field- and clinic-applicability of the colorimetric FTA-LAMP assay was demonstrated with 122 clinical samples collected from patients suspected of having cutaneous leishmaniasis in Peru, from which 71 positives were detected. The LAMP assay in combination with an FTA card described here is rapid and sensitive, as well as simple to perform, and has great potential usefulness for diagnosis and surveillance of leishmaniasis in endemic areas.


Subject(s)
Colorimetry/methods , Leishmania/isolation & purification , Leishmaniasis, Cutaneous/diagnosis , Mass Screening/methods , Rosaniline Dyes/analysis , Adult , Female , Humans , Male , Nucleic Acid Amplification Techniques , Peru , Sensitivity and Specificity
10.
JAMA Dermatol ; 151(12): 1330-1337, 2015 Dec 01.
Article in English | MEDLINE | ID: mdl-26332510

ABSTRACT

IMPORTANCE: Dermatofibrosarcoma protuberans (DFSP) is a rare skin cancer that develops in the deep dermis to subcutaneous adipose tissues. A COL1A1-PDGFB gene fusion, leading to the constitutive expression of PDGFB, is the tumorigenic mechanism in most DFSP cases. OBJECTIVES: To evaluate the specificity of PDGFB expression as a diagnostic marker of DFSP and to determine whether other pathomechanisms (ie, gene fusions) exist in patients with DFSP without the COL1A1-PDGFB fusion gene. DESIGN, SETTING, AND PARTICIPANTS: All patients with DFSP registered in the pathologic database of the University of the Ryukyus from January 1, 1997, through December 31, 2013, and Gunma University from January 1, 1996, through December 31, 2011, were included in this analysis. Samples were obtained from 30 patients presenting with DFSP tumors. We examined the clinicopathologic characteristics and the expression of PDGFB, PDGFRß, PDGFRα, CD34, nestin, factor XIIIa, fibronectin, α-smooth muscle actin, S-100 protein, and Ki-67 in 30 DFSP cases and 48 non-DFSP mesenchymal tumor cases by immunohistochemical analysis. We then analyzed tumor tissues for the presence of the COL1A1-PDGFB fusion gene. We also tested whether other genes enriched in fibroblasts formed fusion products with PDGFB by reverse transcription-polymerase chain reaction analysis, using gene-specific primers. MAIN OUTCOMES AND MEASURES: We aimed to analyze tumor tissues for the presence of the COL1A1-PDGFB fusion gene to investigate expression of PDGFB in DFSP tumors. RESULTS: PDGFB expression was detected in 28 (93%) of 30 patients with DFSP. PDGFB was not homogenously expressed in DFSP tumor cells, whereas CD34 and nestin were often expressed throughout the tumor mass. In 1 DFSP tumor, the COL1A1-PDGFB fusion gene was not detected even though PDGFB was expressed. We identified a novel COL1A2-PDGFB fusion gene in this tumor. CONCLUSIONS AND RELEVANCE: Our findings indicate that PDGFB protein is expressed in most DFSP tumors and may be a useful diagnostic tool when used in conjunction with CD34 and nestin expression analysis. These PDGFB expression data, in addition to our discovery of a novel PDGF fusion gene, strongly support the concept that DFSP is a PDGFB-dependent tumor type.

11.
Biochimie ; 112: 49-56, 2015 May.
Article in English | MEDLINE | ID: mdl-25724270

ABSTRACT

Sequence analysis of the Lutzomyia (Lu.) ayacuchensis salivary gland cDNA library identified a short peptide containing an RGD (Arg-Gly-Asp) sequence flanked by two cysteine residues in the C-terminal end as the most abundant transcript. In the present study, a recombinant protein of the RGD-containing peptide, designated ayadualin, was expressed in Escherichia coli and its activity was characterized. Ayadualin inhibited both collagen and ADP-induced platelet aggregations by interfering with the binding of integrin αIIbß3 to fibrinogen. The RGD sequence and cysteine residues located on both sides of the RGD sequence were essential for the inhibitory action. Moreover, ayadualin efficiently inhibited the intrinsic blood coagulation pathway irrespective of the RGD sequence. Measuring the enzymatic activity of coagulation factors using chromogenic substrates revealed that ayadualin efficiently inhibited factor XIIa (FXIIa) activity in a dose-dependent manner. In addition, pre-incubation of ayadualin with FXII inhibited FXIIa activity, while activated FXIIa was not affected by ayadualin, indicating that ayadualin inhibits the activation of FXII, but not enzymatic activity of FXIIa. These results indicated that ayadualin plays an important role in the blood feeding of Lu. ayacuchensis by inhibiting host hemostasis via dual mechanisms.


Subject(s)
Blood Coagulation/drug effects , Factor XIIa/antagonists & inhibitors , Insect Proteins/pharmacology , Insect Vectors/chemistry , Leishmaniasis, Cutaneous , Oligopeptides/pharmacology , Psychodidae/chemistry , Animals , Dose-Response Relationship, Drug , Humans , Insect Proteins/chemistry , Oligopeptides/chemistry
12.
J Dermatol ; 42(2): 210-4, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25510200

ABSTRACT

Primary cutaneous mucormycosis is a rare but often lethal severe fungal infection, which usually occurs in immunocompromised patients. We report a case of primary cutaneous mucormycosis caused by Mucor irregularis in an elderly patient. Seven months after the surgical dissection of the involved skin, cutaneous mucormycosis recurred at the peripheral edge of the skin graft. Shortly subsequent to the administration of liposomal amphotericin B, the remaining skin lesion was excised again. M. irregularis is rarely but increasingly reported as a cause of mucormycosis in immunocompetent individuals, especially in Asian farmers. M. irregularis may be largely disseminated in the soils of Asia and thus the trivial trauma at the time of farm work may be a trigger for the onset. These cases tend to leave severe cosmetic damage even in healthy individuals, although the vital prognosis is not affected.


Subject(s)
Dermatomycoses/microbiology , Mucor , Mucormycosis/microbiology , Aged , Humans , Male
13.
Acta Trop ; 141(Pt A): 79-87, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25312337

ABSTRACT

Haplotype and gene network analyses were performed on mitochondrial cytochrome oxidase I and cytochrome b gene sequences of Lutzomyia (Lu.) ayacuchensis populations from Andean areas of Ecuador and southern Peru where the sand fly species transmit Leishmania (Leishmania) mexicana and Leishmania (Viannia) peruviana, respectively, and populations from the northern Peruvian Andes, for which transmission of Leishmania by Lu. ayacuchensis has not been reported. The haplotype analyses showed higher intrapopulation genetic divergence in northern Peruvian Andes populations and less divergence in the southern Peru and Ecuador populations, suggesting that a population bottleneck occurred in the latter populations, but not in former ones. Importantly, both haplotype and phylogenetic analyses showed that populations from Ecuador consisted of clearly distinct clusters from southern Peru, and the two populations were separated from those of northern Peru.


Subject(s)
Phylogeny , Psychodidae/genetics , Animals , Base Sequence , Cytochromes b/genetics , Ecuador , Electron Transport Complex IV/genetics , Genetic Variation/genetics , Haplotypes , Humans , Insect Vectors/genetics , Leishmania , Leishmania mexicana , Leishmaniasis, Cutaneous/transmission , Peru , Psychodidae/parasitology
14.
J Dermatol ; 41(10): 926-8, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25228325

ABSTRACT

Leishmaniasis is a major world health problem, and 12 million people are estimated to be infected in 88 countries. There have been few reports of leishmaniasis in Japan and all were of foreign origin; therefore diagnosis is difficult for Japanese physicians. There are 21 different pathogenic Leishmania species, and identification is obtained by polymerase chain reaction (PCR). Here we report an imported case of leishmaniasis by Leishmania (Leishmania) donovani infection from Sri Lanka. L. (L.) donovani usually causes visceral leishmaniasis, but in this case, the patient manifested cutaneous leishmaniasis. The identification of Leishmania species by PCR and investigation of the patient's background such as nationality and disease endemicity are important for diagnosis and treatment. This is the first report of cutaneous leishmaniasis by L. (L.) donovani in Japan.


Subject(s)
Leishmania donovani/isolation & purification , Leishmaniasis, Cutaneous/parasitology , Adult , Humans , Japan , Male
15.
J Dermatol ; 41(8): 739-42, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25041360

ABSTRACT

A 43-year-old Japanese Bolivian male had been suffering from a right leg ulcer after an insect bite during his residence in Bolivia. The ulcer healed after herbal medicine treatment. Ten years later, the patient had symptoms of nasal obstruction, nasal bleeding, and pharyngodynia, which were accompanied by a destructive ulcer with surrounding erythema involving the right nostril apex and columella. Papillary, irregular mucosal lesions were seen on the soft palate. Giemsa staining and polymerase chain reaction (PCR) using biopsy specimens of the papillary mucosal lesions on the soft palate failed to identify Leishmania parasites. However, the IgG antibody test was positive for Leishmania (Leishmania) donovani, and the dot enzyme-linked immunosorbent assay (dot-ELISA) using five Leishmania antigens L. (L.) mexicana, L. (L.) amazonensis, Leishmania (Viannia) guyanensis, L. (V.) braziliensis, and L. (V.) panamensis was positive. Combined, the findings suggested mucocutaneous leishmaniasis. Treatment with liposomal amphotericin B was started but was soon terminated because of palpitation, epigastralgia and facial flushing. It is sometimes difficult to identify the parasites in lesions of mucocutaneous leishmaniasis and serological tests are useful for such occasions.


Subject(s)
Leishmaniasis, Mucocutaneous/diagnosis , Adult , Antibodies, Protozoan/blood , Antigens, Protozoan , Bolivia/ethnology , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin G/blood , Japan , Leishmania/immunology , Leishmaniasis, Mucocutaneous/immunology , Leishmaniasis, Mucocutaneous/pathology , Male , Serologic Tests
16.
Parasit Vectors ; 7: 332, 2014 Jul 16.
Article in English | MEDLINE | ID: mdl-25030377

ABSTRACT

BACKGROUND: Cutaneous leishmaniasis (CL) is a major and fast increasing public health problem, both among the local Pakistani populations and the Afghan refugees in camps. Leishmania (Leishmania) major is one of the etiological agents responsible for CL in Pakistan. Genetic variability and population structure have been investigated for 66 DNA samples of L. (L.) major isolated from skin biopsy of CL patients. METHODS: Multilocus microsatellite typing (MLMT), employing 10 independent genetic markers specific to L. (L.) major, was used to investigate the genetic polymorphisms and population structures of Pakistani L. (L.) major DNA isolated from CL human cases. Their microsatellite profiles were compared to those of 130 previously typed strains of L. (L.) major from various geographical localities. RESULTS: All the markers were polymorphic and fifty-one MLMT profiles were recognized among the 66 L. (L.) major DNA samples. The data displayed significant microsatellite polymorphisms with rare allelic heterozygosities. A Bayesian model-based approach and phylogenetic analysis inferred two L. (L.) major populations in Pakistan. Thirty-four samples belonged to one population and the remaining 32 L. (L.) major samples grouped together into another population. The two Pakistani L. (L.) major populations formed separate clusters, which differ genetically from the populations of L. (L.) major from Central Asia, Iran, Middle East and Africa. CONCLUSIONS: The considerable genetic variability of L. (L.) major might be related to the existence of different species of sand fly and/or rodent reservoir host in Sindh province, Pakistan. A comprehensive study of the epidemiology of CL including the situation or spreading of reservoirs and sand fly vectors in these foci is, therefore, warranted.


Subject(s)
DNA, Protozoan/genetics , Leishmania major/genetics , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/parasitology , Microsatellite Repeats/genetics , Humans , Multilocus Sequence Typing , Pakistan/epidemiology , Phylogeny , Polymorphism, Genetic
17.
Mycopathologia ; 178(1-2): 135-43, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24952716

ABSTRACT

We investigated 793 bird combs [645 chickens and 148 fighting cocks (Shamo)] to determine the prevalence of dermatophytes and their related fungal species. The targeted fungal species were recovered from 195 of the 793 examined birds (24.6 %). Prevalence ratios were compared in temperate (the mainland) and subtropical (Nansei Islands) areas, genders, strains, breeding scale (individual and farm), and housing system (in cage and free ranging). The frequency of the fungal species in the mainland, males, fighting cocks, breeding scale by individual nursing, and free-range housing system exhibited significantly higher positive ratios than that in the other groups. A total of 224 dermatophytes and related species were isolated, including 101 Arthroderma (Ar.) multifidum, 83 Aphanoascus (Ap.) terreus, five Uncinocarpus queenslandicus, two U. reesii, two Ap. pinarensis, one Amauroascus kuehnii, one Ar. simii, one Gymnoascus petalosporus, one Microsporum gallinae, and 28 Chrysosporium-like (Chrysosporium spp.) isolates, which were identified using internal transcribed spacer regions of ribosomal RNA gene sequences. The predominant fungal species in the mainland was Ap. terreus and that in the Nansei Islands was Ar. multifidum. Pathogenic fungal species to humans and animals were limited to M. gallinae and Ar. simii, which corresponded to 0.025 % of the isolates in this study.


Subject(s)
Arthrodermataceae/classification , Arthrodermataceae/isolation & purification , Chickens/microbiology , Comb and Wattles/microbiology , Poultry Diseases/microbiology , Tinea/veterinary , Animals , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Female , Male , Molecular Sequence Data , Prevalence , Sequence Analysis, DNA , Tinea/microbiology
20.
Acta Trop ; 132: 1-6, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24388795

ABSTRACT

Entomological monitoring of Leishmania infection in leishmaniasis endemic areas offers epidemiologic advantages for predicting the risk and expansion of the disease, as well as evaluation of the effectiveness of control programs. In this study, we developed a highly sensitive loop-mediated isothermal amplification (LAMP) method for the mass screening of sand flies for Leishmania infection based on the 18S rRNA gene. The LAMP technique could detect 0.01 parasites, which was more sensitive than classical PCR. The method was robust and could amplify the target DNA within 1h from a crude sand fly template without DNA purification. Amplicon detection could be accomplished by the newly developed colorimetric malachite green (MG)--mediated naked eye visualization. Pre-addition of MG to the LAMP reaction solution did not inhibit amplification efficiency. The field applicability of the colorimetric MG-based LAMP assay was demonstrated with 397 field-caught samples from the endemic areas of Ecuador and eight positive sand flies were detected. The robustness, superior sensitivity, and ability to produce better visual discriminatory reaction products than existing LAMP fluorescence and turbidity assays indicated the field potential usefulness of this new method for surveillance and epidemiological studies of leishmaniasis in developing countries.


Subject(s)
Entomology/methods , Leishmania/isolation & purification , Mass Screening/methods , Nucleic Acid Amplification Techniques/methods , Psychodidae/parasitology , Animals , Colorimetry/methods , Ecuador , Leishmania/genetics , RNA, Ribosomal, 18S/genetics , Rosaniline Dyes/analysis , Sensitivity and Specificity , Time Factors
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