Molecular Subtyping of Blastocystis from Diverse Animals in the United Arab Emirates.

The contribution of Blastocystis from non-human hosts to zoonotic transmission is only partly known. The objective of this study was to determine the distribution of Blastocystis genetic subtypes in different animal species in United Arab Emirates. A total of 114 stool samples were tested using PCR of the small subunit (SSU) rRNA gene and sequence analysis. Twenty-three Blastocystis-positive samples were identified. The following detection rates were observed: cattle, 22.7%; sheep, 63.6%; rabbits, 33.3%; rodents, 37.5%; reptiles, 21.2%. Four subtypes were identified in this study; ST4, ST10, ST14, and ST17; ST10 was isolated from sheep and cattle, corroborating previous data indicating that these are natural hosts for this subtype. Cases of mixed subtype colonization were also detected. Conspicuously, we found ST14 in rabbits. The discovery of ST17 in a squirrel indicates a novel host for this subtype. Furthermore, the discovery of ST4 in rodents suggests that these may serve as reservoir for human Blastocystis ST4 colonization. Six tortoises and one iguana were positive for Blastocystis. In conclusion, this is the first report of Blastocystis infection in various animals in the UAE. Apart from ST4, no potentially zoonotic subtypes were detected.

PREVALENCE OF CRYPTOSPORIDIUM SPP. AMONG ASYMPTOMATIC HEALTHY EXPATRIATE WORKERS IN SHARJAH, UNITED ARAB EMIRATES.

BACKGROUND: Epidemiological data on Cryptosporidium infections in the United Arab Emirates (UAE) is scarce. Therefore, the main objective of this study was to determine the prevalence of Cryptosporidium species among a community of expatriates in Sharjah, UAE working in different sectors, including the food industry, house maids and other domestic occupations. MATERIALS AND METHODS: One hundred and thirty four stool samples were collected from asymptomatic individuals presenting to the Sharjah Municipality Public Health Clinic (SMPHC) for screening of intestinal parasites for work permission purposes between 2009 and 2011. Demographic information such as age, sex, and country of origin was collected. Genomic DNA extracted from the stool samples were tested for Cryptosporidium species using real-time PCR (qPCR). RESULTS: Twenty-six individuals (19.4%) were positive for Cryptosporidium sp. by PCR. The infection rate was found to be highest in Afghan nationals (33%; 3/9) compared with the rest of the study population; yet, no significant association existed between nationality and infection rate. Moreover, no association was observed between infection rate and gender (χ2 = 2.439; P = 0.118), nor infection rate and age group (χ2 = 1.219; P = 0.544). CONCLUSION: Infection by Cryptosporidium sp. was common in the study group, and further studies are needed within the native Emirati population before any conclusions can be made about foreigners potentially transmitting the parasite. Furthermore, data provided in this study could help determine its public and veterinary significance particularly in outbreaks in the country.

Prevalence and subtype distribution of Blastocystis in healthy individuals in Sharjah, United Arab Emirates.

Blastocystis is estimated to be one of the most common parasites of the intestinal tract of humans, comprising multiple subtypes (ST). Meanwhile, the distribution of Blastocystis ST in many communities and countries remains unknown. In the present work, we aimed to identify the prevalence of Blastocystis and the ST distribution in human stool samples collected from healthy expatriates from different geographical regions and residing in Sharjah, United Arabian Emirates (UAE). A total of 133 samples were screened and subtyped using partial small subunit ribosomal RNA gene sequencing. Fifty-nine (44.4%) samples were identified as positive. Among these, 39 were successfully sequenced and subtyped. The ST distribution was as follows: ST3, 58.9% (23/39); ST1, 28.2% (11/39); and ST2, 7.6% (3/39). No correlation between geographic origin and infection (χ(2)=11.006; P=0.528) nor gender and infection (χ(2)=1.264; P=0.261) was observed. The data were compared with those available for other Middle Eastern and North African neighboring countries. This study is the first to provide data concerning the prevalence of Blastocystis and the frequency of various STs in the UAE, confirming the absence of ST4 and the commonness of ST1, ST2, and ST3 in this geographical region.

Genetic variability of the serine-rich Entamoeba histolytica protein gene in clinical isolates from the United Arab Emirates.

The genetic diversity of 20 Entamoeba histolytica isolates from asymptomatic individuals from the UAE was investigated by analyzing polymorphism in the serine-rich E. histolytica gene (SREHP) by nested polymerase chain reaction (PCR) amplification followed by restriction fragment length polymorphism (RFLP) on DNA extracted directly from stool samples. The SREHP gene was successfully amplified in 15 out of 20 E. histolytica-positive samples. Four out of the remaining five isolates did not amplify for the SREHP gene. Despite successful amplification of the SREHP gene in the fifth isolate, AluI digestion of the amplified PCR product revealed no bands. As a result, all five samples were excluded from the study. Twelve different profiles were obtained from the 15 successfully amplified isolates. Thus, demonstrating extensive genetic variability and reinforcing the argument that E. histolytica has an extremely polymorphic genetic structure. Despite the sample size limitation, a finding in the study was the occurrence of one profile common to one Indian isolate while another profile common to one Pakistani isolate; indicating the possibility of clonal infection. Furthermore, we found one isolate from a Bangladeshi expatriate identical to 2 asymptomatic Bangladeshi isolates reported in an earlier study. No clear association between the different genotypes and the study population demographics was noted. The results also indicated the possibility of strains clustering by region.

Differential detection of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii in fecal samples by nested PCR in the United Arab Emirates (UAE).

Amoebiasis is one of the most important infectious diseases afflicting mainly tropical and subtropical countries. This study was carried out in the Sharjah Emirate, UAE in order to accurately detect and differentiate Entamoeba histolytica, Entamoeba dispar and E. moshkovskii in fecal samples collected from the Sharjah municipality public health clinic by ELISA and nested polymerase chain reaction (PCR). One hundred and twenty specimens were examined and the PCR was positive for E. histolytica, E. dispar and E. moshkovskii (collectively referred to as Entamoeba complex) in 19.2% (23 out of 120). Of those, 10% (12/120) were mono - infection with E. histolytica; 2.5% (3/120) with E. dispar; and 2.5% (3/120) E. moshkovskii. The nested PCR also detected mixed infections by both E. histolytica and E. dispar in 3.3% (4/120) and E. dispar and E. moshkovskii in 0.8% (1/120). The TechLab ELISA kit failed to detect E. histolytica in any of the E. histolytica PCR positive samples. Overall, the percentage of E. histolytica including those found in mixed infections was 13.3% (16/120). Compared to nested PCR, microscopy was found to have an overall sensitivity of 52.2% and a specificity of 75.2% for detection of Entamoeba complex. The present study indicates that E. histolytica is present in the UAE with an average incidence rate of 13.3%. However, larger studies need to be conducted in order to confirm these findings. We propose the use of PCR in both the routine diagnosis of amoebiasis and epidemiological survey in the UAE.