sensitive and specific PCR based method for identification of cryptosporidium sp. using new primers from 18S ribosomal RNA

The main goal of the present study was to develop a new sensitive and specific PCR based method for Identification of Cryptosporidium sp. using novel primers from 18S ribosomal RNA. Cryptosporidiosis in high-risk host groups particularly in neonates and immuno-compromised individuals may result in death. To the best of our knowledge this is the first study regarding develop a new PCR based method to diagnose the cryptosporidiosis in Iran. A total of 850 human fecal samples from patients clinically suspected to cryptosporidiosis and 100 healthy and diarrheic cattle stool specimens were collected. The simplified formol-ether concentration method was carried out for all samples. They were then examined microscopically by modified Ziehl-Neelsen staining method. Total DNA was extracted by QIA amp DNA stool mini kit. PCR and nested-PCR was carried out by using designed primers. Twenty nine cases of cryptosporidiosis infection in human and 30 samples from cattle microscopically were positive. The described primary and nested PCR method could detect all Cryptosporidium positive samples from human and cattle. Regards to suspected negative samples in primary PCR examination, the Nested PCR could approve two more positive results. Furthermore, Nested PCR analysis was able to detect one more case which was negative in both microscopically examination and primary PCR. Specificity of the test was 100%. Sensitivity of Nested PCR in comparison to our gold standard; microscopy after Ridley concentration modified ziehl-Neelsen, was 100%. Our developed PCR based method by using new primers devised from 18S ribosomal RNA revealed the ability for identification of the Cryptosporidium species such as C. parvum and C. huminis with high specificity and sensitivity

Mini-Exon genotyping of leishmania species in khuzestan province, southwest Iran

Leishmaniasis is a protozoan disease cause by Leishmania genus. Anthroponotic and zoonotic cutaneous leishmaniasis are endemic in Iran. The aim of this study was to identify the causative agent of cutaneous leishmaniasis by mini-exon gene in five regions of Khuzestan Province, southwest of Iran. From 2007 to 2008 in this cross-sectional study, cutaneous samples were collected from patients referred to Health Centers and Hospitals of the Khuzestan Province for cutaneous leishmaniasis diagnosis and cultured in Novy-MacNeal-Nicolle [NNN] and RPMI 1640. The propagated promastigotes were harvested and Leishmania species of cutaneous leishmaniasis were identified by RFLP and DNA sequencing of the PCR generated fragments. L. major and L. tropica were the causative agents of cutaneous leishmaniasis by predominantly of L. major species. The alignment of the mini-exon sequencing isolates with reported sequencing of L. major and L. tropica revealed 92%-99% identity. Our study showed that mini-exon PCR-RFLP was useful method to identify the causative species of cutaneous leishmaniasis

Frequency of intestinal parasites in Tehran

For a long time, intestinal parasite infections are among the major problems of public health in Iran. Our aim was epidemiological studies on the frequency of intestinal parasites in patients referred to three hospitals in Tehran during 2007-2008. During 2007-2008, by simple random selection, 1000 stool samples were collected from Milad, Hazrat-e-Rasoul and Shahid Fahmideh hospitals in Tehran, Iran. We examined the samples using direct smear, formol-ethyl acetate concentration, Agar-plate culture and Ziehl-Neelsen staining technique. The frequency of intestinal parasites were: Blastocystis hominis 12.8%, Giardia lamblia 2.5%, Entamoeba coli 4.8%, lodamoeba butschlli 0.9%, unknown 4 nuclei cysts 0.4%, Endolimax nana 3.2%, Chilomastix mesnili 0.4%, Strongyloides stercoralis 0.1%, Hymenolepis nana 0.2% and Taenia saginata 0.2%. Coccidian parasites were not found. Results show that infection with intestinal parasites does not statistically significant according to sex and age. The intestinal parasites, especially helminthic infections have been decreased during recent years