RESUMEN
Zoonotic cutaneous leishmaniasis (ZCL) is a neglected tropical disease caused by Leishmania (L.) major. This zoonosis is characterized by a broad-spectrum clinical polymorphism and may be underestimated and poorly treated since it is a simulator of various dermatoses. The aim of our study was to analyze the clinical polymorphism of patients with ZCL. A total of 142 patients with confirmed CL based on the microscopic examination of skin lesion biopsies were included in this study. Molecular typing of Leishmania species revealed that all patients were infected with L. major. In total, 14 clinical forms were observed. Six were typical and eight were atypical. The typical ZCL forms are grouped as follows: papular (26.76%), ulcero-crusted (26.05%), ulcerated (13.38%), impetiginous (9.86%), nodular (9.15%), and papulo-nodular (5.63%) lesions. In atypical ZCL forms, we described erythematous (2.81%), erysipeloid (1.4%), sporotrichoid, (1.4%), keratotic (0.7%) lupoid (0.7%), lichenoid (0.7%), psoriasiform (0.7%), and zosteriform (0.7%) lesions. Here, the lichenoid and the keratotic forms caused by L. major were reported for the first time in Tunisia. These findings will help physicians to be aware of the unusual lesions of ZCL that could be confused with other dermatological diseases. For this reason, it will be necessary to improve the diagnosis of CL especially in endemic areas. Such large clinical polymorphism caused by L. major may be the result of a complex association between the vector microbiota, the parasite, and the host immune state, and further studies should be carried out in order to reveal the mechanisms involved in clinical polymorphism of ZCL.
Asunto(s)
Leishmaniasis Cutánea , Zoonosis , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/parasitología , Humanos , Masculino , Femenino , Adulto , Zoonosis/parasitología , Zoonosis/diagnóstico , Persona de Mediana Edad , Animales , Adolescente , Adulto Joven , Niño , Leishmania major/genética , Leishmania major/aislamiento & purificación , Anciano , Piel/parasitología , Piel/patología , PreescolarRESUMEN
Phlebotomine sand flies (Diptera: Psychodidae) are the proven vectors of Leishmaniases which are widespread parasitosis in many tropical and subtropical countries. The development of infective metacyclic Leishmania (Kinetoplastida: Trypanosomatidae) promastigotes stage is restricted to the vector midgut. Recently, several studies have assessed the influence of the sand fly midgut fungal microflora on the development of invective Leishmania stage. The aim of this study was to identify the fungal microflora from the cuticle and midgut of wild caught sandflies. A total of 50 sandflies were caught in two different leishmaniasis foci of center Tunisia and analyzed using an in vitro isolation of fungi followed by a morphological and molecular identification of fungal isolates. The morphological identification of sandflies specimens revealed five Species: Phlebotomus (P.) papatasi (n = 25), P. perniciosus (n = 15) P. riouxi (n = 6), P. longicuspis (n = 3) and P. sergenti (n = 1). Forty positive fungal cultures were isolated from 34 sand flies (19 males and 15 females) distributed as following: P. papatasi (n = 16), P. perniciosus (n = 11), P. riouxi (n = 4), P. longicuspis (n = 2) and P. sergenti (n = 1). Thirty-five cultures were isolated from the cuticles and five from the guts. A total of 15 fungi genera belonging to 8 families were identified with the predominance of Aspergillus genus followed by Penicillium genus. Among the 15 fungi genera, five were common between males and females specimens. Lecytophora canina and Leishmania major co-infection was detected in the gut of a female P. papatasi. Our preliminary findings highlight the high diversity of fungal microflora from the sand flies midguts.
Asunto(s)
Leishmaniasis , Phlebotomus , Psychodidae , Femenino , Masculino , Animales , TúnezRESUMEN
Phlebotomine sand flies (Diptera: Phlebotominae) belonging to the genus Phlebotomus are vectors of pathogens such as arboviruses, bacteria, and parasites (Leishmania). Species of the genus Sergentomyia (Se.) transmit Sauroleishmania (Reptile Leishmania) and feed on cold-blooded vertebrates; recently, they have been incriminated in mammalian Leishmania transmission. In addition, they have been reported to feed on warm-blooded vertebrates. This study aimed to (i) screen wild-caught Sergentomyia species for the detection of mammalian Leishmania and (ii) identify the blood meal origin of engorged females. The sand flies were collected using centers for disease control and prevention (CDC) traps, mounted and identified morphologically. Only females of the genus Sergentomyia were screened for Leishmania infection using PCR targeting the 18S ribosomal DNA locus. For positive specimens, Leishmania parasites were typed using nested PCR targeting ribosomal internal transcribed spacer 1 followed by digestion with HaeIII. The PCR-RFLP results were confirmed through sequencing. Blood meal identification was performed through PCR amplification of the vertebrate cytochrome b gene using degenerate primers followed by sequencing. In total, 6026 sand fly specimens were collected between 2009 and 2018. Among these, 511 belonged to five species of Sergentomyia genus: Se. minuta (58.51%), Se. fallax (18.01%), Se. clydei (14.68%), Se. dreyfussi (6.26%), and Se. antennata (2.54%). A total of 256 female Sergentomyia sp. specimens were screened for Leishmania infection. Seventeen (17) were positive (6.64%). Two Leishmania species were identified. Leishmania major DNA was detected in five specimens; this included three Se. fallax, one Se. minuta, and one Se. dreyfussi collected from Tunisia. Leishmania infantum/L. donovani complex was detected in four Se. minuta and three Se. dreyfussi specimens collected from Tunisia. In addition, we identified the blood meal origin of five engorged Se. minuta specimens collected from Tunisia. Sequencing results revealed two blood sources: humans (n = 4) and reptiles (n = 1) indicating possible role of Sergentomyia species in the transmission of human Leishmania. In addition, these species could be involved in the life cycle of L. infantum/L. donovani complex and L. major. The results of the blood meal origin showed that Sergentomyia fed on both cold- and warm-blooded vertebrates. These findings enable a better understanding of the behavior of this sand fly genus. Further studies should focus on the role of Sergentomyia in human Leishmania transmission and possible control of this disease.
Asunto(s)
Leishmania major , Leishmaniasis , Phlebotomus , Psychodidae , Animales , Humanos , Femenino , Psychodidae/parasitología , Túnez , Arabia Saudita , Phlebotomus/parasitología , Leishmaniasis/parasitología , Vertebrados , Leishmania major/genética , ADN Ribosómico , MamíferosRESUMEN
Over the last decade, Malassezia species have emerged as increasingly important pathogens associated with a wide range of dermatological disorders and bloodstream infections. The pathogenesis of Malassezia yeasts is not completely clear, but it seems to be strictly related to Malassezia strains and hosts and needs to be better investigated. This study aimed to assess the enzymatic activities, biofilm formation and in vitro antifungal profiles of Malassezia spp. from pityriasis versicolor (PV) and healthy patients. The potential relationship between virulence attributes, the antifungal profiles and the origin of strains was also assessed. A total of 44 Malassezia strains isolated from patients with (n = 31) and without (n = 13) PV were employed to evaluate phospholipase (Pz), lipase (Lz), and hemolytic (Hz) activities and biofilm formation. In addition, in vitro antifungal susceptibility testing was conducted using the CLSI broth microdilution with some modifications. A high percentage of strains produced Pz, Lz, Hz and biofilm regardless of their clinical origin. The highest number of strains producing high enzymatic activities came from PV patients. A correlation between the intensity of hydrolytic activities (Lz and Pz activities) and the Hz activity was detected. Positive associations between Lz and the low fluconazole susceptibility and Hz and biofilm formation were observed. These results suggest that enzyme patterns and biofilm formation along with antifungal profiles inter-play a role in the pathogenicity of Malassezia spp. and might explain the implication of some Malassezia spp. in invasive fungal infections and in the development of inflammation. LAY SUMMARY: There is still little information on the virulence factors of Malassezia spp., despite their implication in severe diseases. Phospholipase, lipase, and hemolytic activities, biofilm formation and decreased antifungal susceptibility seem to contribute to their virulence in susceptible hosts.
Asunto(s)
Malassezia , Tiña Versicolor , Factores de Virulencia , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Hemólisis , Humanos , Lipasa , Fosfolipasas , Tiña Versicolor/tratamiento farmacológico , Tiña Versicolor/microbiologíaRESUMEN
BACKGROUND: Cutaneous leishmaniasis (CL), a neglected tropical disease, represents a significant public health problem in many endemic countries including Yemen. The ongoing armed conflict that started in March 2015 has had a negative impact on the entire healthcare system as well as on infectious disease control programmes. Therefore, this cross-sectional study aimed to assess knowledge and attitude towards CL among rural endemic communities in southwestern Yemen. METHODS: Five hundred households in five areas of Shara'b district of Taiz governorate were randomly selected to participate in a quantitative survey. A pretested structured questionnaire was used to collect data on the sociodemographic characteristics of the participants, their knowledge and attitude towards CL and their knowledge on the sand fly vector. RESULTS: The analysis was conducted on a final sample of 466 individuals (62.7% males and 37.3% females) aged between 18 and 70 years. Among the participants, 21.5% were non-educated while 39.7 and 20.8% had completed secondary school and tertiary education, respectively. Although the participants were aware of CL, about three quarters (77.7%) of them had poor overall knowledge about disease transmission, clinical presentation, treatment, and prevention. Interestingly, approximately half of the participants (49.1%) were able to differentiate sand flies from other flies and mosquitoes. However, only 14.8% of the participants knew about the role of the phlebotomine sand fly in the transmission of CL. Only 36.6% believed that CL can be prevented and 49.6% had a negative attitude towards the disease. Univariate and multivariate analyses showed that age and gender were the significant determinants of knowledge about CL and the sand fly vector among the studied population. CONCLUSION: A poor level of knowledge about the different epidemiological aspects of CL was found among rural CL-endemic communities in Taiz. This factor, together with the major collapse of the healthcare infrastructure due to the ongoing civil war in Yemen, may be contributing to the continued endemicity of CL in the governorate. It is therefore recommended that health education on CL transmission and prevention should be provided to the targeted communities.
Asunto(s)
Conocimientos, Actitudes y Práctica en Salud , Leishmaniasis Cutánea/epidemiología , Población Rural/estadística & datos numéricos , Adolescente , Adulto , Anciano , Animales , Estudios Transversales , Femenino , Humanos , Insectos Vectores/fisiología , Leishmaniasis Cutánea/prevención & control , Leishmaniasis Cutánea/transmisión , Masculino , Persona de Mediana Edad , Psychodidae/fisiología , Encuestas y Cuestionarios , Yemen/epidemiología , Adulto JovenRESUMEN
Experimental infections of Phlebotomus (L.) perniciosus from a colony established in Madrid (Spain) carried out with the Leishmania (L.) infantum zymodemes MON-1, MON-24, and MON-80 isolated in Tunisia are reported here. Laboratory-reared female sand flies were experimentally fed via membrane feeding device on a suspension of L. infantum promastigotes in defibrinated rabbit blood (107/ml). Engorged females were dissected at progressive time points postfeeding to observe the intravectorial cycle of different L. infantum zymodemes. Development in the sand fly midgut of L. infantum parasites to the infective metacyclic promastigotes and monitoring the forward progression of parasites to finally reach the stomodeal valve (SV) of the sand fly were assessed. All tested L. infantum zymodemes developed properly in P. perniciosus. Experimental feeding with suspensions of promastigotes of all zymodemes led to very heavy late-stage infections. MON-24 and MON-80 zymodemes colonized the (SV) of P. perniciosus earlier than zymodeme MON-1, 2 and 4 days, respectively. Metacyclic promastigotes were observed in all experimental infections. The study shows for the first time that colonized P. perniciosus is able to acquire, retain, and develop in its midgut the zymodemes MON-24 and MON-80 isolated in Tunisia and highlights the putative role of this sand fly species in the transmission of such zymodemes to mammalian hosts in this country. The ability of experimentally infected sand fly species to transmit by bite such zymodemes needs to be assessed.
Asunto(s)
Insectos Vectores/parasitología , Leishmania infantum/crecimiento & desarrollo , Phlebotomus/parasitología , Psychodidae/parasitología , Animales , Femenino , Leishmania infantum/aislamiento & purificación , Leishmaniasis Visceral/parasitología , Leishmaniasis Visceral/transmisión , Conejos , España , TúnezRESUMEN
BACKGROUND/AIMS: The diagnosis of cutaneous leishmaniasis (CL) is based on the microscopic detection of amastigote, isolation of the parasite, or the detection of Leishmania DNA. Nevertheless, since these techniques are time consuming and not usually available in many endemic countries, the diagnosis remains clinical. Consequently, such disease may be overlooked because of its similarity to other skin diseases. The aim of this study is to describe the clinical polymorphism of CL caused by Leishmaniamajor. METHODS: A cross-sectional survey was carried out on 166 patients. Diagnoses were made by both microscopic examination of stained tissue-scraping smears and PCR. The Leishmania species was identified by restriction enzyme analysis of the ribosomal internal transcribed spacer 1 region. The clinical polymorphism was analyzed only for patients with a positive diagnosis for CL and L. major as the identified species. RESULTS AND CONCLUSION: Of the 166 patients, 75 patients fit the inclusion criteria. Twelve different types of CL caused by L. major were defined. The most common type was the ulcero-crusted form followed by the papulonodular form and the impetigenous form. The ulcerated, mucocutaneous, lupoid, and sporotricoid forms were less common. The eczematiform, erysipeloid, verrucous, psoriasiform, and pseudotumoral types were represented by a single case. Zoonotic CL caused by L. major can simulate many other skin diseases, which may lead to a significant spread of this disease and increases in morbidity and drug resistance. This large polymorphism may be the result of a complex association between the genetics of the parasite and the immune response of the host.
Asunto(s)
Leishmania major/aislamiento & purificación , Leishmaniasis Cutánea/diagnóstico , Adolescente , Adulto , Anciano , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Adulto JovenRESUMEN
Phlebotomus perniciosus is the most important vector of Leishmania infantum in the Western part of the Mediterranean basin. Atypical specimens of Ph. perniciosus called (pna) with a parameral sheath simply curved, not bifurcated, have been reported in many locations. In this study, we describe abnormal Ph. perniciosus male specimens. Sand flies were collected in center Tunisia and identified morphologically. Cytochrome b PCR-sequencing was carried out for abnormal Ph. perniciosus male specimens in order to confirm the morphological identification and assess the intraspecific genetic polymorphism. Abnormal Ph. perniciosus specimens were characterized by a multifurcated parameral sheath. A parsimonious haplotype network based on cyt b locus analysis showed that typical and abnormal Ph. perniciosus described in our investigation were grouped together in the same branch. Thus, genetic outcomes confirmed that the new phenotype is only an original morphotype of Ph. perniciosus.
Asunto(s)
Leishmania infantum , Phlebotomus , Psychodidae , Masculino , Animales , Phlebotomus/genética , Phlebotomus/anatomía & histología , Psychodidae/genética , Túnez , Leishmania infantum/genética , Reacción en Cadena de la PolimerasaRESUMEN
BACKGROUND: Despite the marked decline of schistosomiasis in Saudi Arabia in recent years, it is still reported in several regions. This study investigates the epidemiology of schistosomiasis in Saudi Arabia over seven years (2014-2020). METHODOLOGY: A retrospective study was retrieved from the annual reports of the Ministry of Health. A Geographic Information System GIS, Chi-square, and logistic regression were used to analyze the data. RESULTS: Out of the 4,371,481 tested, 680 cases were positive for schistosomiasis, with a cumulative incidence rate of 2.155/100,000 population. This number showed significant variation over the study period (p value < 0.001). The highest number of cases detected in 2015 was almost 2-fold (OR = 1.93; 95%CI: 1.36-2.74) higher than in 2020. Both clinical forms (urinary and intestinal schistosomiasis) exist in Saudi Arabia (79.6% and 20.4% of all schistosomiasis cases, respectively). Schistosomiasis was reported in seven out of thirteen regions. Among them, Mecca has a relatively high number of cases (OR = 5.57; 95%CI: 2.49-12.47). Conversely, the Eastern Province has a low number of cases (OR = 0.09; 95%CI: 0.02-0.39) when compared to the Najran region (p value > 0.001). Regarding the distribution of schistosomiasis cases by gender and nationality, we noticed that most of the positive cases were found among males (70.6%) and expatriates (83.6%). CONCLUSIONS: The persistence of schistosomiasis and the disparity in the demographic factors underscores the imperative for intensified and integrative One Health interventions to combat this disease in Saudi Arabia.
RESUMEN
Malassezia yeasts have recently gained medical importance as emerging pathogens associated with a wide range of dermatological and systemic infections. Since standardized methods for in vitro antifungal susceptibility testing have not yet been established for Malassezia spp., related diseases are always treated empirically. As a result, a high rate of recurrence and decreased antifungal susceptibility have appeared. Thus, the aims of the study were to assess and analyze the in vitro susceptibility of Malassezia isolated from pityriasis versicolor (PV) lesions and healthy controls. A total of 58 Malassezia strains isolated from PV patients and healthy controls were tested. In vitro antifungal susceptibility testing was conducted using the CLSI broth microdilution with some modifications. Candida spp. criteria established in accordance with CLSI guidelines were used for data interpretation. Ketoconazole and posaconazole seemed to be the most effective molecules against Malassezia species. However, considerable percentages of itraconazole, fluconazole, and amphotericin B ''resistant'' strains (27.6%, 29.3%, and 43.1%, respectively) were revealed in this study. Malassezia furfur, M. sympodialis, and M. globosa showed different susceptibility profiles to the drugs tested. These results emphasize the importance of accurately identifying and evaluating the antifungal susceptibility of Malassezia species in order to guide a specific and effective treatment regimen.
RESUMEN
Malassezia (M.) genus includes commensal yeasts of increasing medical importance, as they result in many diseases, ranging from pityriasis versicolor (PV) to systemic infections. Previous studies reported geographical variations in distribution of Malassezia species in PV lesions. The aims of the current study were to define the clinico-demographic features of PV in Tunisia, to characterize Malassezia isolates using phenotypic and molecular techniques and to find out any association between species and clinico-demographic parameters. In total, 120 PV patients were enrolled in this study. Skin scrapings were collected and inoculated on Sabouraud agar and modified Dixon medium. Malassezia species were identified using conventional phenotypic methods and 26 s rDNA PCR-RFLP. The highest prevalence of PV was observed among young adults' group. The most affected body areas were the back and neck. In overall, 50.8% and 35% of PV cases had pruritus and history of recurrence respectively. The overall concordance between phenotypic and molecular methods was high (80.95%). The discordant results are rather due to the presence of multiple species in a single culture than true misidentification. Using PCR-RFLP, M. furfur was the most isolated species (38.7%) followed by M. globosa (37.7%), M. restricta and M. sympodialis. No statistically significant association was noted between Malassezia spp. and clinico-demographic characteristics. Unlike many reports from temperate climate countries, M. furfur and M. globosa along together were the most frequently isolated species in Tunisian PV patients. Although phenotypic methods remain simple and cost-effective, molecular techniques are considered as fast and accurate methods for diagnosis purposes.
Asunto(s)
Malassezia , Tiña Versicolor , Medios de Cultivo , Humanos , Prevalencia , Piel , Tiña Versicolor/diagnóstico , Tiña Versicolor/epidemiología , Túnez/epidemiología , Adulto JovenRESUMEN
Owing to Saudi Arabia's high-income economy many Saudi families hire foreign housemaids. However, since the housemaids are potential carriers of intestinal parasites, hiring them increases the risk of transmission to the Saudi community. In this context, this study aimed to evaluate the prevalence of intestinal parasitic infections in foreign housemaids in northwestern Saudi Arabia. Using direct wet mount and concentration by flotation, the stool samples of 169 housemaids were examined, and eleven parasite species, six helminths and five protozoans, were detected. The overall prevalence of intestinal parasitic infection was 20.11% (34/169). Twelve cases were infected with one intestinal helminth, 12 were infected with one intestinal protozoan, and 10 had polyparasitism. The most common intestinal parasites were Cryptosporidium spp. (n = 10), hookworms (n = 7), and T. Trichiura (n = 7). The findings highlight that intestinal parasites present an important public health concern for foreign housemaids in Saudi Arabia. More vigilance is thus required, and periodic follow-up should be exercised throughout foreign housemaids' stay in the country.
Asunto(s)
Emigrantes e Inmigrantes/estadística & datos numéricos , Parasitosis Intestinales/epidemiología , Adulto , África , Asia , Estudios Transversales , Femenino , Humanos , Parasitosis Intestinales/parasitología , Persona de Mediana Edad , Prevalencia , Arabia Saudita/epidemiología , Adulto JovenRESUMEN
The COVID-19 pandemic has affected many societies' life aspects and activities including social and Islamic practices; more attention should be given to investigate the interaction between Islamic worships and the spread of the disease. Here, we performed a cross-sectional study using an online questionnaire to assess the preventive Islamic attitudes and practices during the COVID-19 lockdown period from the Saudi publics' perspectives. Mann-Whitney, Kruskal and logistic regression tests were used to analyze the data. The results revealed that most participants had positive Islamic attitudes and practices. However, elders and males were less obeyed to preventive measures during performing worship (p < 0.05). While younger, females and not married were less obeyed when dealing with COVID-19 related death (p < 0.05). Even though, elders were less likely to have poor social and Islamic practices concerning adherence to preventive measures during the pandemic (OR = 0.38; 95% CI: 0.176-0.816) than younger. Furthermore, males, Saudi participants, lower education level, lower Islamic attitudes scores were more likely to have poor social and Islamic practices concerning adherence to preventive measures during the pandemic (OR = 1.65; 95% CI: 1.126-2.421; OR = 1.57; 95% CI: 1.067-2.322; OR = 3.09; 95% CI: 1.721-5.563; and OR = 1.89; 95% CI: 1.309-2.753, respectively), than their corresponding targeted counterparts. Thus, despite the high preventative perceptions of Islamic attitudes and practices of the Saudi community, our study highlighted some risk groups with less preventative practices. Thus, targeted health education interventions are highly recommended for these risk groups to enhance the commitment to government instructions.
Asunto(s)
COVID-19 , Pandemias , Adaptación Psicológica , Anciano , Control de Enfermedades Transmisibles , Estudios Transversales , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , SARS-CoV-2 , Arabia Saudita/epidemiología , Encuestas y CuestionariosRESUMEN
The present study reports on the in vitro antileishmanial activity of two Ircinidae (Dictyoceratida, Demospongiae, Porifera) Ircinia spinosula and Sarcotragus sp. Sampled from the east coast of Tunisia. The ethyl acetate, dichloromethane, and aqueous extracts were tested against Leishmania major promastigotes. The anti-proliferative activity was checked using different extracts concentration during 72 h. We found that the IC50 (sub-inhibitory concentration) values ranged from 1.39 to 264.67 mug/ml. The most active extract was that from sarcotragus sp dichloromethane extract. Microscopic observations showed that the extracts promoted cellular alterations and induce enlargement of the nucleus and modification of the parasite shape. These promising results in relation with in vitro antileishmanial activity open the way for complementary investigation in order to purify and identify active molecules.
Asunto(s)
Antiprotozoarios/aislamiento & purificación , Antiprotozoarios/farmacología , Leishmania major/efectos de los fármacos , Poríferos/química , Animales , Evaluación Preclínica de Medicamentos , Concentración 50 Inhibidora , Leishmania major/citología , Microscopía , Pruebas de Sensibilidad Parasitaria , TúnezRESUMEN
BACKGROUND: Phlebotomus (Larroussius) perniciosus and Canis familiaris are respectively the only confirmed vector and reservoir for the transmission of Leishmania (L.) infantum MON-1 in Tunisia. However, the vector and reservoir hosts of the two other zymodemes, MON-24 and MON-80, are still unknown. The aim of this study was to analyze the L. infantum life cycle in a Tunisian leishmaniasis focus. For this purpose, we have focused on: i) the detection, quantification and identification of Leishmania among this sand fly population, and ii) the analysis of the blood meal preferences of Larroussius (Lar.) subgenus sand flies to identify the potential reservoirs. METHODOLOGY AND FINDINGS: A total of 3,831 sand flies were collected in seven locations from the center of Tunisia affected by human visceral leishmaniasis. The collected sand flies belonged to two genus Phlebotomus (Ph.) (five species) and Sergentomyia (four species). From the collected 1,029 Lar. subgenus female sand flies, 8.26% was positive to Leishmania by ITS1 nested PCR. Three Leishmania spp. were identified: L. infantum 28% (24/85), L. killicki 13% (11/85), and L. major 22% (19/85). To identify the blood meal sources in Ph. Lar. subgenus sand flies, engorged females were analyzed by PCR-sequencing targeting the vertebrate cytochrome b gene. Among the 177 analyzed blood-fed females, 169 samples were positive. Sequencing results showed seven blood sources: cattle, human, sheep, chicken, goat, donkey, and turkey. In addition, mixed blood meals were detected in twelve cases. Leishmania DNA was found in 21 engorged females, with a wide range of blood meal sources: cattle, chicken, goat, chicken/cattle, chicken/sheep, chicken/turkey and human/cattle. The parasite load was quantified in fed and unfed infected sand flies using a real time PCR targeting kinetoplast DNA. The average parasite load was 1,174 parasites/reaction and 90 parasites/reaction in unfed and fed flies, respectively. CONCLUSION: Our results support the role of Ph. longicuspis, Ph. perfiliewi, and Ph. perniciosus in L. infantum transmission. Furthermore, these species could be involved in L. major and L. killicki life cycles. The combination of the parasite detection and the blood meal analysis in this study highlights the incrimination of the identified vertebrate in Leishmania transmission. In addition, we quantify for the first time the parasite load in naturally infected sand flies caught in Tunisia. These findings are relevant for a better understanding of L. infantum transmission cycle in the country. Further investigations and control measures are needed to manage L. infantum transmission and its spreading.
Asunto(s)
ADN/análisis , Conducta Alimentaria , Contenido Digestivo/química , Contenido Digestivo/parasitología , Especificidad del Huésped , Leishmania infantum/aislamiento & purificación , Phlebotomus/fisiología , Animales , ADN/genética , Dermatoglifia del ADN , ADN Espaciador Ribosómico/genética , Transmisión de Enfermedad Infecciosa , Femenino , Humanos , Leishmania infantum/genética , Masculino , Phlebotomus/parasitología , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , TúnezRESUMEN
An entomological study was conducted in a Leishmania infantum focus, including the identification of the sand fly species, the detection and the characterization of Leishmania DNA in female sand flies, and blood meal origins in engorged sand flies. A total of 643 sand flies (31% female, 69% male) was identified based on their morphological features or molecular markers. Ten different species were identified, with Phlebotomus perniciosus, the confirmed vector of L. infantum, being the most abundant (56%), P. papatasi in 25% of sand flies, the unique vector species of L. major, and P. longicuspis in 7% of cases, the suspected second vector of L. infantum. Moreover, the infection rate was 3.4% in P. perniciousus, P. papatasi, P. longicuspis, and Sergentomya minuta. Also, L. infantum was identified in five unfed P. perniciosus and two P. longicuspis. Our results suggest the vector role of P. perniciosus and P. longicuspis in the transmission cycle of L. infantum. The DNA of four mammalian species (human, rabbit, horse, and cow) was identified in the blood meals of sand flies, suggesting that these species are potential reservoirs of leishmaniasis, though it is not yet fully elucidated (especially for MON-24 and MON-80). We suggest the existence of different transmission cycles of L. infantum involving different species of sand flies and hosts.
Asunto(s)
Reservorios de Enfermedades/parasitología , Insectos Vectores/clasificación , Leishmania infantum/fisiología , Leishmaniasis Visceral/transmisión , Psychodidae/clasificación , Animales , Bovinos , Femenino , Caballos , Especificidad del Huésped , Humanos , Insectos Vectores/parasitología , Leishmaniasis Visceral/parasitología , Masculino , Phlebotomus/clasificación , Phlebotomus/parasitología , Psychodidae/parasitología , ConejosRESUMEN
The transmission of parasites of the genus Leishmania involves a large diversity of mammalian reservoir hosts. However, many of these are yet to be identified, mainly in isolated biotopes such as the Amazonian rain forest. Furthermore, the trophic preferences of insect vectors have major epidemiologic implications. In this study, we developed a molecular tool for the identification of blood meals of phlebotomine sand flies. This assay is based on specific amplification and sequencing of the blood meal-derived single copy prepronociceptin (PNOC) gene, which is used as a target in phylogenetic studies of mammals. Sand flies were identified simultaneously with the blood-meal identification, using molecular analysis of a ribosomal locus. After a systematic assessment of the sensitivity and specificity of polymerase chain reaction amplification of the PNOC gene using human fed sand flies, the assay was tested on wild-caught sand flies. This work has important implications for the discovery of new Leishmania reservoir hosts and for a better understanding of complex parasite life cycles.
Asunto(s)
Reservorios de Enfermedades/clasificación , Insectos Vectores/parasitología , Leishmania/fisiología , Phlebotomus/parasitología , Precursores de Proteínas/genética , Receptores Opioides/genética , Animales , Secuencia de Bases , Fenómenos Fisiológicos Sanguíneos , Bovinos , Cartilla de ADN/química , Reservorios de Enfermedades/parasitología , Femenino , Caballos , Humanos , Leishmania/química , Leishmania/genética , Masculino , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico/genética , Sensibilidad y Especificidad , Especificidad de la Especie , Factores de TiempoRESUMEN
BACKGROUND: Cutaneous leishmaniasis (CL) is a vector-borne disease transmitted by the bite of an infected sand fly. This disease is highly prevalent in Saudi Arabia where Leishmania major and L. tropica are the etiological agents. In the region of Hail, northwestern of Saudi Arabia, the incidence is about 183 cases/year. However, the epidemiology of the disease in this area is not well understood. Thus, an epidemiological survey was conducted in 2015-2016 to identify the circulating parasite and the sand fly fauna in the region of Hail. Skin lesion scrapings were collected from suspected patients with CL. METHODS: The diagnosis was made by microscopic examination of Giemsa-stained smear and PCR. The parasite was identified by PCR and sequencing of the single copy putative translation initiation factor alpha subunit gene. Sand fly specimens were collected and identified morphologically. Total DNA was extracted from the abdomen of female specimens and Leishmania DNA was detected by PCR. RESULTS: Among the 57 examined patients, 37 were positive for CL. The identification of the parasite has revealed the single species Leishmania major. The 384 sand flies were collected belonged to two genera (Phlebotomus and Sergentomyia), six sub-genera and six species. Phlebotomus papatasi, Ph. kazeruni and Sergentomyia clydei were the dominant species. Leishmania DNA was detected in two females of Ph. papatasi two of Ph. kazeruni and one specimen of Sergentomyia clydei. CONCLUSIONS: Leishmania major is confirmed to be the etiological agent of cutaneous leishmaniasis in northwestern Saudi Arabia. The molecular detection of Leishmania DNA in Ph. papatasi and Ph. kazeruni supports the potential role of these two species in the transmission of Leishmania. Further epidemiological studies are needed to prove their role and to evaluate the burden of CL in the study region.
Asunto(s)
Insectos Vectores/parasitología , Leishmania major/aislamiento & purificación , Leishmaniasis Cutánea/epidemiología , Psychodidae/parasitología , Adolescente , Adulto , Anciano , Animales , Antígenos de Protozoos/genética , Niño , Preescolar , Femenino , Humanos , Lactante , Leishmania major/genética , Leishmania major/fisiología , Leishmaniasis Cutánea/parasitología , Leishmaniasis Cutánea/transmisión , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Arabia Saudita/epidemiología , Piel/parasitología , Piel/patología , Encuestas y Cuestionarios , Adulto JovenRESUMEN
OBJECTIVE: To evaluate the prevalence of intestinal parasites among patients in Hail, Northwestern Saudi Arabia. METHODS: Stool samples were collected from 130 patients (69 females and 61 males) in Hail General Hospital. Each sample was examined by direct wet mount microscopic examination using both normal saline and Lugol's iodine preparation and concentration techniques using salt and formol-ether solutions. Permanent stained smears were performed for intestinal coccidian using modified Ziehl-Neelsen technique. RESULTS: The overall prevalence of intestinal parasitic infection was 45.38% (59 cases). Forty-four (33.84%) were found to be infected with one or more intestinal protozoa, 5 (3.84%) were infected with helminthes and 10 (7.69%) had mixed infection with both helminthes and protozoa. The most common intestinal helminth detected was Ancylostoma duodenale (n = 5, 3.84%), followed by Ascaris lumbricoides, Taenia sp. and Trichuris trichiura (n = 2 for each species, 1.5%). For intestinal protozoa, the coccidian Cryptosporidium parvum (n = 25, 19.23%) was the most common followed by Entamoeba histolytica/dispar (n = 21, 16.15%), Giardia lamblia (n = 15, 11.54%), Entamoeba coli (n = 5, 3.85%) and Blastocystis hominis (n = 3, 2.30%). The prevalence of intestinal parasitic infections in females was significantly higher than in males (P < 0.05). CONCLUSIONS: This is the first study highlighting that intestinal parasites are still an important public health problem in Northwestern Saudi Arabia. Therefore, health education would be the best way to prevent from intestinal parasite infections which are mainly food borne diseases.