Molecular epidemiology of cryptosporidiosis in Iranian children, Tehran, Iran

Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determination of subtypes of Cryptosporidium among children with diarrhea in Tehran by sequence analysis of the highly polymorphic 60-kDa glycoprotein [GP60] gene. Fecal samples were collected from 794 diarrheic children. Initial identification of Cryptosporidium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly. Out of 794 collected samples, 19 [2.40%] were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 [89.47%] of the positive isolates were Cryptosporidium parvum and 2 [10.52%] were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa [6/17] and IId [11/17]. The most common allele in all 17 isolates belonged to IId A20G1a [41.18%]. A22G1 [IF] subtype was detected in two C. hominis isolates of the children. The predominancy of C. parvum species [specially, IId A20G1a subtype] in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran

[Consideration sensitivity of PCR-Ribotyping method in identification Salmonella spp isolates from patients with diarrhea]

Background: Salmonella is the most important diarrheagenic pathogens, which can cause food borne disease where the main route of transmission among human is through contaminated meat and poultry foods. Its symptoms can be diarrhea, fever, vomiting and sometimes bloody diarrhea. For it's importance, it is essential to be identified and characterized by more precise methods such as molecular techniques. The aim of this study was to consider sensitivity of PCR-Ribotyping method for identification of Salmonella spp

Materials and methods: in this study our samples were Salmonella strains, which were isolated from patients with diarrhea. Their DNA was extracted by phenol/ Chloroform method. We did PCR-Ribotyping method with P1, P2 primers for 16S-23SrRNA gene. At last PCR-products run on 1.8% agarose gel in 120V for 90 min. the analysis was done after Ethidium bromide staining

Results: all the 40 strains containing paratyphi A, B, C and D serotypes also, serotype typhi contained 5 bands ranging 700 to 2500 bp

Conclusions: according to the results we can say that PCR-Ribotyping method has the highest sensitivity for identification of genus Salmonella but it is not suitable for Serotyping of Salmonella strains