Distribution and phylogenetic analysis of Blastocystis sp. subtypes isolated from IBD patients and healthy individuals in Iran.

Blastocystis is a single-celled intestinal parasite commonly found in humans and a broad range of animals all over the world. In humans, its role in health and disease remains unsettled. The aim of our study was to investigate the distribution of Blastocystis and Blastocystis subtypes (ST) in patients with inflammatory bowel disease (IBD) and control subjects. A total of 71 stool samples were collected from IBD patients, 69 and 2 of whom had ulcerative colitis (UC) and Crohn's Disease (CD), respectively. Moreover, 166 stool samples from healthy subjects were included as control samples. All stool samples were cultivated, and 550-bp fragments of the small subunit ribosomal RNA gene was amplified from Blastocystis-positive cultures. All PCR-positive samples were sequenced. Blastocystis was observed in 9 (12.67%) and 35 (21.1%) IBD patients and healthy controls, respectively. There was no statistically significant correlation between IBD and presence of Blastocystis (P = 0.147). There was a statistically significant correlation between age and Blastocystis colonization in the IBD group (P < 0.05), but not among healthy controls. No significant correlation between gender and colonization was observed. ST1 and ST3 were obtained from 1 (12.5%) and 7 (87.5%) IBD patients, respectively, while in the healthy control group, subtypes 1, 2, and 3 were found in 14 (40%), 12 (34.28%), and 9 (25.72%), respectively. Phylogenetic analysis showed no variation in the distribution of subtypes nor intra-subtype genetic diversity between samples acquired from IBD patients and healthy controls. This study showed a trend towards a lower prevalence of Blastocystis in IBD patients than in control subjects. ST3 sequences isolated from IBD patients and control individuals did not appear to differ genetically.

The first study on opportunistic intestinal microsporidiosis in IBD patients receiving immunosuppressive medications in Iran.

Microsporida are known as opportunistic unicellular organisms and have recently been reclassified as fungi that have been frequently reported from patients with congenital and acquired immunity failure disorders, worldwide. However, use of immunosuppressive medications in inflammatory bowel disease (IBD) patients significantly decreases overall immunity, and increases their susceptibility to opportunistic infections. Totally, 71 stool samples were collected from IBD patients consisted of 69 ulcerative colitis (UC) patients and two Crohn's disease (CD) patients. All patients had taken immunosuppressive and/or immunomodulator drugs for at least 3 weeks. DNA was extracted from all stool samples and Nested PCR was performed using genus-specific primers based on small subunit ribosomal RNA (SSU rRNA) gene. Fisher's Exact Test was applied to evaluate statistical association between microsporidia infection and sex, age and types of IBD. Mean of age ± s.d., women and men percentage of the attended patients were 36·17 ± 11·93, 60·6%, and 39·4%, respectively. A 440-bp fragment of SSU rRNA gene attributed to Enterocytozoon bieneusi was amplified from 12·7% of IBD patients. No Encephalitozoon DNA was detected in the samples. No microsporidia-positive sample was found in CD patients. Fisher's Exact Test showed that there was no statistically significant correlation between intestinal microsporidiosis and age, sex, and IBD types with P values: 0·389, 1·00, and 1·00, respectively. This study has shown IBD patients undergoing immunosuppressive/immunomodulators medications, which may be susceptible to intestinal microsporida infection. E. bieneusi is the commonest intestinal microsporidan reported from IBD patients.

Molecular analysis of isolates of the cestode Rodentolepis nana from the great gerbil, Rhombomys opimus.

Rodentolepis nana (syn. Hymenolepis nana) is a cyclophyllidean zoonotic enteric parasite with worldwide distribution. In humans, it is more prevalent in children, especially in temperate zones. A morphologically similar species of R. nana occurs in different rodents, including gerbils. In the present study molecular characterization of five isolates of R. nana from Rhombomys opimus in the Golestan Province (n= 2) and Razavi Khorasan Province (n= 3), both in north-eastern Iran, were analysed. After DNA extraction, the internal transcribed spacer 2 (ITS2) region of the R. nana isolates was amplified and sequenced, and genetic variation was analysed. Accordingly, two isolates from the Razavi Khorasan Province showed ITS2 signatures that differed from the isolates from the Golestan Province. The third isolate from Razavi Khorasan did not reveal these specific signatures, but exhibited sparse nucleotide polymorphisms in the ITS2 sequence. The ITS gene is conserved, and variation in this fragment could be an interesting subject for further inspection of existing variation in the genome of R. nana, among different domestic and wildlife host species and from different areas.

Trichinella britovi in the jackal Canis aureus from south-west Iran.

Trichinellosis is an important helminthic food-borne zoonosis, which is caused by nematodes of the genus Trichinella. Although, Trichinella spp. has been detected frequently in Iranian wildlife, this parasitic infection is not considered a major public health problem. This is largely because Islamic codes forbid consumption of pork meat in this country. However, knowledge about this zoonotic pathogen is important because human trichinellosis has been documented in countries where most of the population is Muslim. The aims of the present work were to investigate whether Trichinella spp. was still circulating in wildlife of the Khuzestan Province (south-west Iran) about 30 years after the first investigation, to identify the aetiological agent at the species level by molecular analyses, and to review the literature on Trichinella spp. in animals of Iran. During the winter 2009-2010, muscle samples from 32 road-killed animals (14 dogs and 18 jackals, Canis aureus) were collected. Muscle samples were digested and Trichinella sp. larvae were isolated from two jackals. The Trichinella sp. larvae have been identified as Trichinella britovi by molecular analyses. These results confirm that T. britovi is the prevalent species circulating in wild animals of Iran.

Helminth Parasites of Rhombomys opimus from Golestan Province, Northeast Iran.

BACKGROUND: The aim of the study was to determine the helminthic species occurring in great gerbil Rhombomys opimus collected from Maraveh Tappeh, Golestan Province, northeast Iran. METHODS: During 2010-2011, a total of 77 R. opimus were captured from rural areas of Maraveh Tappeh, Golestan Province, using Sherman live traps and examined for infectivity with any larva or adult stages of helminthic parasites. RESULTS: Overall, 63 R. opimus (81.8%) were found infected with different helminthic species. The rate of infectivity with each species was as follows: Trichuris rhombomidis 31.2%, Trichuris muris 32.5%, Trichuris spp. 10.4%, Syphacia muris 2.6%, Dipetalonema viteae (Acanthocheilonema viteae) 37.7%, Skrjabinotaenia lobata 15.6%, Hymenolepis (=Rodentolepis) nana fraterna 5.2%, and Taenia endothoracicus larva 1.3%. CONCLUSION: R. opimus is host for several species of cestodes and nematodes in the study area. The high rate of infectivity with D. viteae indicates the susceptibility of these gerbils to this filarial nematode. Synchronous infections occurred up to four species of helminthes in one host.