Molecular characterization of Blastocystis subtypes in symptomatic patients from the southern region of Syria.

Blastocystis sp. is an enteric protist found in humans and a wide range of animal hosts. Genetic variations were established among the 38 different subtypes detected so far, 14 of which are commonly found in human and animal hosts. The aim of the present study is to estimate the prevalence of the common Blastocystis subtypes and evaluate the possible correlation with several variables (gender, age, symptoms, domestic animals…), among patients from the southern region of Syria. Fecal samples were collected from individuals suffering from gastrointestinal complaints. Microscopic examination along with genotype analyses using seven pairs of subtype-specific primers was performed. Our results revealed the presence of Blastocystis sp. in 46 isolates out of the 60 samples microscopically studied (76.7%); single infection was detected in 24 isolates whereas co-infection with other protozoa was identified in 22 ones. Molecular detection targeting the SSU rRNA gene revealed a 100% positive presence of Blastocystis sp. in all the samples. Genotyping results detected the presence of five different subtypes (ST1-ST5) with varying proportions. However, ST1 was the dominant subtype observed (66.7%). Mixed subtype infections were found in 9 isolates (15%). Three samples remained undefined, nonetheless. Our statistical results showed no significant correlation between Blastocystis STs infection and the different studied variables. In conclusion, this study provides the first genetic characterization of Blastocystis subtypes prevalence in patients from the southern region of Syria. ST1 distribution was highly predominant. Further molecular studies are needed to estimate the prevalence of Blastocystis sp. infection in other regions in Syria and to understand the epidemiology and sources of transmission to humans.

Investigation of parasitic contamination of salad vegetables sold by street vendors in city markets in Damascus, Syria.

Monitoring parasitic contamination in raw vegetables used in salads is an important measure in controlling the occurrence of gastroenterological diseases, which may be life-threatening. This study aimed to inspect the parasitological contamination of some raw vegetables used in salads. Eight commonly consumed vegetable types were purchased from street vendors in the city markets. Vegetables were washed and the sediments were obtained for microscopic examination. Genomic DNA was isolated from contaminated samples. Our result showed that 34.4% of the studied samples were contaminated with one or more species of parasites. Lettuce was the most commonly contaminated vegetable type (29.5%), while tarragon leaves showed the lowest level of contamination (2.3%). The risk of contamination was significantly higher in lettuce samples in comparison with the other samples studied. Giardia duodenalis was the most prevalent parasite detected (38.6%) and was abundantly found in lettuce isolates (23.5%). Molecular typing revealed that all Giardia samples found in the contaminated specimens belonged to Assemblage B. Blastocystis spp. were the second most prevalent parasite in samples (29.5%), they were frequently detected in lettuce leaves (30.8%). Other parasites were found in low frequencies. The high level of parasitic contamination found in our study indicates an urgent need to identify the sources of contamination and to monitor irrigation water and ensure its cleanliness.

Molecular and epidemiological characterization of Giardia Intestinalis assemblages detected in Djelfa, Algeria.

Giardia intestinalis is a flagellated protozoan that lives and proliferates in the small intestine of the host causing giardiasis. The route of transmission is the fecal-oral route, either directly or indirectly. Limited genetic information on G. intestinalis is known in Algeria. This study aimed to estimate the prevalence of G. intestinalis assemblages in the city of Djelfa. A total of 355 fecal samples were collected from symptomatic and asymptomatic school children aged ranged between 6 and 11 years old. Genotyping was done to the Giardia positive samples (n = 30) targeting the beta-giardin gene by applying PCR/RFLP assay. Our data showed that most of the cases were asymptomatic (56.7%). Co-infection with other intestinal parasites was found in 16.6% of cases. We obtained 28/30 positive PCR products while two samples only showed false-negative results, and only 20 samples have shown strong PCR products suitable for RFLP analysis. Assemblage A (70%) was more prevalent than assemblage B (30%) and was more expressed by signs than assemblage B. Moreover, only assemblage A was associated with close contacts with domestic animals and birds. In conclusion, this study gave the first molecular data on G. intestinalis isolates in the city of Djelfa. Further expanded studies using more genes and covering other cities in Algeria are mostly needed.

Prevalence of Giardia duodenalis assemblages and sub-assemblages in symptomatic patients from Damascus city and its suburbs.

Giardia duodenalis is one of the most important human enteric parasites worldwide and is endemic throughout the world with a vast range of mammalian hosts. However, there is limited information on the prevalent genetic variability of G. duodenalis in Syria. This study aimed to evaluate the predominance of G. duodenalis assemblages/sub-assemblages causing humans infection in the city of Damascus and its suburbs. 40 symptomatic giardiasis patients were recruited in this study. Fecal samples were genotyped using PCR/RFLP assay targeting the ß-giardin and glutamate dehydrogenase (gdh) genes. HaeIII, BspL1 and RsaI restriction enzymes were used to differentiate between G. duodenalis assemblages/sub-assemblages. Our data showed that 65% of isolates were of assemblage A; 45% belonged to sub-assemblage AII and 20% to sub-assemblage AI. Assemblage B was detected in 27.5% of isolates; 12.5% fit in sub-assemblage BIV, 5% fit in sub-assemblage BIII and 10.5% fit in Discordant genotype BIII/BIV. Mixed genotypes (AII+BIII and AI+BIV) were identified in 3 isolates (7.5%). Significant correlation was found between Giardia AII sub-assemblage and weight loss symptom (P-value=0.05) as well as between contact with domestic animals (cats, P-value=0.027). Moreover, a significant correlation was found between sub-assemblage AI and livestock breeding (P-value=0.000). In conclusion genotyping of human Giardia duodenalis isolates suggests anthroponotic transmission for the route of infection in Damascus and its suburbs. Further studies are needed to screen a wide geographic areas in Syria and to estimate the prevalence of G. duodenalis infection in our population.

Giardia duodenalis in Damascus, Syria: Identification of Giardia genotypes in a sample of human fecal isolates using polymerase chain reaction and restriction fragment length polymorphism analyzing method.

Giardia duodenalis is a common gastrointestinal parasite that infects humans and many other mammals. It is most prevalent in many developing and industrialized countries. G. duodenalis is considered to be a complex species. While no morphological distinction among different assemblages exist, it can be genetically differentiated into eight major assemblages: A to H. The aim of this study was to determine the genetic heterogeneity of G. duodenalis in human isolates (a study conducted for the first time in Syria). 40 fecal samples were collected from three different hospitals during the hot summer season of 2014. Extraction of genomic DNA from all Giardia positive samples (based on a microscopic examination) was performed using QIAamp DNA Stool Mini Kit. ß-giardin gene was used to differentiate between different Giardia assemblages. The 514 bp fragment was amplified using the Polymerase Chain Reaction method, followed by digestion in HaeIII restriction enzyme. Our result showed that genotype A was more frequent than genotype B, 27/40 (67.5%); 4/40 (10%) respectively. A mixed genotype of A+B was only detected in 9 isolates (22.5%). This is the first molecular study performed on G. duodenalis isolates in Syria in order to discriminate among the different genotypes. Further expanded studies using more genes are needed to detect and identify the Giardia parasite at the level of assemblage and sub-assemblage.

Cutaneous leishmaniasis in the central provinces of Hama and Edlib in Syria: Vector identification and parasite typing.

BACKGROUND: Cutaneous leishmaniasis is a disease transmitted by sand fly bites. This disease is highly prevalent in Syria where Leishmania major and Leishmania tropica are the known aetiological agents. In 2011, more than 58,000 cases were reported in the country by the Ministry of Health. The central region of the country harbors 20 % of the reported cases. However, the epidemiology of the disease in this area is not well understood. An epidemiological survey was conducted in 2010 to identity the circulating parasite and the sand fly vector in the central provinces of Edlib and Hama. METHODS: Sand fly specimens were collected using CDC light traps and identified morphologically. Total DNA was extracted from the abdomens of female specimens and from Giemsa-stained skin lesion smears of 80 patients. Leishmania parasites were first identified by sequencing the ITS1 gene amplicons. Then polymorphism analysis was performed using the RFLP technique. RESULTS: A total of 2142 sand flies were collected. They belonged to eight species, among which Phlebotomus sergenti and Phlebotomus papatasi were the most predominant. L. tropica ITS1 gene was amplified from two pools of P. sergenti specimens and from skin smears of cutaneous leishmaniasis patients. This suggests that P. sergenti is the potential vector species in the study area. The digestion profiles of the obtained amplicons by TaqI restriction enzyme were identical for all analysed L. tropica parasites. Moreover, L. infantum ITS1 gene was amplified from two pools of Phlebotomus tobbi in the relatively humid zone of Edlib. CONCLUSIONS: L. tropica is confirmed to be the aetiological agent of cutaneous leishmaniasis cases in the central provinces. RFLP technique failed to show any genetic heterogeneity in the ITS1 gene among the tested parasites. The molecular detection of this parasite in human skin smears and in P. sergenti supports the vector status of this species in the study area. The detection of L. infantum in P. tobbi specimens indicates a potential circulation of this parasite in the humid zone of Edlib. Further epidemiological studies are needed to evaluate the burden of this visceral parasite in the study region.

Characterization of Leishmania Species Isolated from Cutaneous Human Samples from Central Region of Syria by RFLP Analysis.

Cutaneous leishmaniasis (CL) is an endemic disease and a public health problem in Hama governorate located in the central region of Syria. The aim of this study was to characterize Leishmania species isolated from human skin samples. A polymerase chain reaction, restriction fragment length polymorphism (PCR-RFLP) assay, was performed on skin lesion material samples from 32 patients with confirmed CL by direct microscopic examination in order to prove its usefulness and efficiency for identification of Leishmania species. Leishmania tropica (L. tropica) is confirmed as an etiologic agent of CL in this area.

Serodiagnosis of cutaneous leishmaniasis in the Syrian Arab Republic.

OBJECTIVE: To evaluate the validity of western blot (WB) and enzyme linked immunosorbent assay (ELISA) that use antigens from culture promastigote from Leishmania parasites, for laboratory diagnosis of cutaneous leishmaniasis in Syria. METHODS: We utilized 290 serum samples from endemic areas (patients group) and other regions (control samples) in Syria during 2002-2005 and the serological testing was brought to the applied the serological tests at the Department of Animal Biology, Damascus University, Damascus, Syria. RESULTS: Anti-Leishmania antibody was detected in 250 (92.5%) cases using the ELISA and 254 (94%) cases using the WB. It is also noted that this response can change according to the number of lesions. CONCLUSION: Results of this study showed that there was no significant difference between ELISA and WB, which are easy to perform. Thus, they can be used for diagnosing the cutaneous leishmaniasis in Syria.

Assessment of the direct agglutination test, fast agglutination screening test, and rK39 dipstick test for the sero-diagnosis of visceral leishmaniasis in Syria.

OBJECTIVE: To evaluate the performances of 3 serological assays (direct agglutination test [DAT], fast agglutination screening test [FAST], recombinant protein [rK39] dipstick) test for use in primary care, for the diagnosis visceral leishmaniasis (VL) in Syria. METHODS: We utilized 267 serum samples obtained during 2007 from patient groups confirmed and suspected VL, confirmed cutaneous leishmaniasis, toxoplasmosis from endemic areas in Syria and control samples, and applied the 3 serological tests in the Damascus University, Damascus and Health laboratories at the same time, on these samples. RESULTS: Our data show that the tests were very sensitive, where the DAT was the most specific followed by FAST, then rK39 dipstick. CONCLUSION: Our study confirmed that all the tests performed well, and proved to be very important sero-diagnosis tools for visceral leishmaniasis.