Molecular Identification of Giardia duodenalis Isolates from Fars Province, Iran

Background: Giardia duodenalis is one of the most common human intestinal protozoan parasites worldwide and is endemic throughout the world with a vast range of mammalian hosts. The present study aimed to identify the prevalence of G. duodenalis isolates and determine the most common of its assemblages in the patients referring to health centers and hospitals in Fars province, Iran that will be subjected to further molecular investigation. Methods: We collected 1000 human fecal samples from health centers and hospitals in Shiraz, Iran in a one year period from September 2009 to August 2010. Microscopic examination for the presence of G. duodenalis cysts and trophozoites was performed by direct wet mount before and after the concentration techniques. Extraction of DNA was performed by Phenol-Chloroform-Isoamylalcohol (PCI). G. duodenalis-positive specimens were analyzed by PCR. A fragment of the SSU-rDNA (292 bp) gene was amplified by PCR using the forward primer RH11 and the reverse primer RH4. Genotyping was performed using sequence analysis of G. duodenalis glutamate dehydrogenase gene using primers GDHeF, GDHiF, and GDHiR. Results: The prevalence of Giardia infection was 10.7% (107/1000) examined based on microscopic examination. PCR identified 80% (40/50) of the samples as positive for G. duodenalis based on SSU-rDNA amplification on sucrose gradient samples. Besides, genotyping results indicated 32 isolates (80%) as assemblage AII and 8 isolates (20%) as assemblage BIII and BIV based on the DNA sequence analysis of the glutamate dehydrogenase locus of G. duodenalis. Conclusion: The findings of this study emphasize that Iran (Fars Province) is a favorable area for giardiasis with an anthroponotic infection route

Paramecium learning: New insights

application/pdfLearning is a fundamental process that involves complex neural systems. However, microorganisms without a nervous system have also been shown to have learning abilities. Specifically, Paramecium caudatum has been reported to form associations between lighting conditions and cathodal shocks in its swimming medium. We replicated previous reports on this phenomenon and tested predictions of a molecular pathway hypothesis of paramecium learning.　In contrast to previous reports, our results indicated that paramecia can only associate higher light intensities with cathodal stimulation and cannot associate lower light intensities with cathodal stimulation. These results support the predictions of the previously proposed model of the molecular mechanisms of learning in paramecia, which depends on the effects of cathodal shocks on the interplay between cyclic adenosine monophosphate levels and phototactic　behavior in paramecia.journal articl

Molecular and Microscopic-Based Characterization of Plasmodium

Despite malaria control programs in recent years, malaria transmission has not been eliminated in Iran. Molecular techniques including PCR, which has proved more sensitive and specific than microscopic examination methods, help to detect infection in low levels of parasitemia and mixed infections. Main our objectives were setting up nested PCR for detection of malaria and evaluating PCR based on plasmodia DNA from blood smears in Fars province, the comparison of this method with traditional microscopy and also evaluate the data in comparison with its neighboring province, Hormozgan. A total of 149 malaria positive samples including 116, 19, and 14 samples from Shiraz, Jask, and Lengeh ports were utilized in this study, respectively. Blood slides were prepared for microscopic observation. DNA from thin smears was extracted and nested PCR was analyzed using rPLU5 and rPLU6 for genus specification, rFAL1, rFAL2, and rVIV1, rVIV2 for P. falciparum and P. vivax detection, respectively. The results showed that 126 (84.6%), 16 (10.7%), and 7 (4.7%) out of 149 cases were positive for P. vivax, P. falciparum, and mixed infections, respectively, by microscopy. The PCR indicated that 95 (63.7%), 15 (10.1%), and 22 (14.8%) cases were infected with P. vivax, P. falciparum, and mixed mentioned species, respectively, and 17 (11.4%) cases were uninfected. Our results confirmed the considerable sensitivity of nested PCR for detection of the mixed infections. Simultaneous application of PCR even based on microscopy slides can facilitate access to the highest level of confidence in malaria researches

Occurrence of Dioctophyme renale (Goeze, 1782) in road-killed canids of Iran and its public health implication

Dioctophyme renale, is the largest of parasitic nematodes, which infects different species of fish-eating carnivores worldwide. The northern provinces of Iran (Guilan and Mazandaran) located in south of the Caspian Sea are suitable for parasitic infections due to the mild and humid climatic conditions. From separate surveys of road-killed canids in various parts of the Caspian Sea littoral area in Iran, 70 carcasses were collected along the roads of Guilan and Mazandaran from 2015 to 2017. Dioctophyme renale detected by direct observation and molecular methods based on Cytochrome c oxidase subunit 1 (COX1 gene) sequencing analysis. Molecular investigation was also performed to validate prevalence and reduce false negative concerns. Dioctophyme renale was found in eight of 70 carnivores, mostly in the right kidneys, as well as two cases in the abdominal cavity of a dog and a golden jackal. More carcasses on the roads were seen with lacerated internal organs. Given the frequent number of giant kidney worms in canids in the region, the transmission of this zoonotic helminth to humans seems possible, since the area is a tourism hub in the country. The infection burden of this helminth should be investigated using DNA analysis of kidney tissue of road-killed carnivores in Iran. Keywords: Giant kidney worm, COX1, gene Carnivores, Conventional PCR, One healt

Vaccines for Canine Leishmaniasis

Leishmania infantum is the obligatory intracellular parasite of mammalian macrophages and causes zoonotic visceral leishmaniasis (ZVL). The presence of infected dogs as the main reservoir host of ZVL is regarded as the most important potential risk for human infection. Thus the prevention of canine visceral leishmaniasis (CVL) is essential to stop the current increase of the Mediterranean visceral leishmaniasis. Recently considerable advances in achieving protective immunization of dogs and several important attempts for achieving an effective vaccine against CVL lead to attracting the scientists trust in its important role for eradication of ZVL. This paper highlights the recent advances in vaccination against canine visceral leishmaniasis from 2007 until now

Leishmanial selenoproteins and the host immune system: towards new therapeutic strategies?

AbstractOptimum levels of selenoproteins are essential for starting and managing the host immune responses against pathogens. According to the expression of selenoproteins in Leishmania parasites, and since high levels of selenoproteins lead to adverse effects on immune cells and their functions, Leishmania parasites might then express selenoproteins such as selenomethionine in their structure and/or secretions able to challenge the host immune system. Finally, this adaptation may lead to evasion of the parasite from the host immune system. The expression of selenoproteins in Leishmania parasites might then induce the development of infection. We therefore suggest these molecules as new therapeutic candidates for the treatment of leishmaniasis.</jats:p