Variation of the Chloroquine Resistance Transporter (Crt) Gene in Chloroquine-Resistant and Chloroquine-Sensitive Plasmodium berghei

Background: The emergence and spread of chloroquine resistant Plasmodium falciparum in the world stimulated some investigators to consider different aspects of chloroquine resistance in human and rodent Plasmodia. Using animal Plasmo­dia, particularly primate and rodent Plasmodia can be useful model for human Plasmodia studies. In this study we have tried to consider and compare the sequence of chloroquine resistance transporter (crt) gene among chloroquine-resistant and chloroquine-sensitive strains of Plasmodium berghei. Methods: This experimental study was performed at the Malaria Laboratory of School of public health. DNA was ex­tracted from two strains of P. berghei which their resistance and sensitivity had been demonstrated in mice with treatment by chloroquine. By using specific primer for crt gene some parts of this gene were amplified by PCR, and obtained frag­ments were then sequenced and compared. Results: There were considerable differences in crt gene between two strains. Sequenced 1212 bp of crt gene fragment in the two strains showed 43 differences at nucleotides level and 16 differences in presumed coding amino acids. Conclusion: crt can be addressed as a considerable gene which involves in induction of resistance to chloroquine in P. berghei, as P. falciparum. The results increased such a promise that considering crt gene in chloroquine-sensitive and chlo­roquine-resistant P. berghei can prepare suitable and helpful fields for more understanding the molecular aspects of chloro­quine-resistance in Plasmodia and reversing the effectiveness of 4-aminoquinolines particularly chloroquine for treatment of drug resistant Plasmodia

Identifying differentially expressed genes in trophozoites and cysts of Acanthamoeba T4 genotype: Implications for developing new treatments for Acanthamoeba keratitis

Acanthamoeba T4 genotype is the most prevalent genotype associated with amoebic keratitis. Acanthamoeba keratitis therapy is difficult due to transformation of trophozoite to cyst stage, which hinders the treatment of the disease. Although encystation assists the organism to survive against the chemotherapeutic compounds, the precise mechanism of encystation remains poorly understood. The purpose of this work was to identify differentially expressed genes in Acanthamoeba T4 genotype which might be useful for understanding of the encystment process and may thus help develop more efficient treatment. The mRNA profile of trophozoite and cyst of Acanthamoeba T4 genotype isolated from a soft contact lens wearer were analyzed using a cDNA amplified fragment length polymorphism (cDNA-AFLP) technique. Subsequently, a real time reverse transcriptase-PCR was performed to validate the cDNA-AFLP results. Three genes, heat shock protein70 (hsp70), actin-I and elongation factor-1alpha (EF-1α) were differentially expressed during Acanthamoeba differentiation. An in silico result predicted that transformation of trophozoite to cyst could be mediated through their cooperation with the protein partners interaction. Taken together, our experimental and bioinformatics findings suggested potential functions of hsp70, EF-1α and actin-I in differentiation of Acanthamoeba T4 genotype which may be useful in the design of an efficient therapeutic strategy in AK. © 2014 Elsevier GmbH

Identification of antimony resistance markers in Leishmania tropica field isolates through a cDNA-AFLP approach

Pentavalent antimonial compounds have been the first line therapy for leishmaniasis; unfortunately the rate of treatment failure of anthroponotic cutaneous leishmaniasis (ACL) is increasing due to emerging of drug resistance. Elucidation of the molecular mechanisms operating in antimony resistance is critical for development of new strategies for treatment. Here, we used a cDNA-AFLP approach to identify gene(s) which are differentially expressed in resistant and sensitive Leishmania tropica field isolates. We identified five genes, aquaglyceroporin (AQP1) acts in drug uptake, ATP-binding cassette (ABC) transporter (MRPA) involved in sequestration of drug, phosphoglycerate kinase (PGK) implicated in glycolysis metabolism, mitogen activated protein kinase (MAPK) and protein tyrosine phosphatase (PTP) responsible for phosphorylation pathway. The results were confirmed using real time RT-PCR which revealed an upregulation of MRPA, PTP and PGK genes and downregulation of AQP1 and MAPK genes in resistant isolate. To our knowledge, this is the first report of identification of PTP and PGK genes potentially implicated in resistance to antimonials. Our findings support the idea that distinct biomolecules might be involved in antimony resistance in L. tropica field isolates. © 2013 Elsevier Inc

The Increasing Importance of Vermamoeba

Vermamoeba vermiformis are one of the most prevalent free-living amoebae. These amoebae are ubiquitous and also thermotolerant. Of concern, V. vermiformis have been found in hospital water networks. Furthermore, associations between V. vermiformis and pathogenic bacteria have been reported, such as Legionella pneumophila. Moreover, V. vermiformis are well known to host viruses, bacteria, and other microorganisms and cases of keratitis due to V. vermiformis in conjunction with other amoebae have been reported. Despite the preceding, the medical importance of V. vermiformis is still an ongoing discussion and its genome has been only recently sequenced. Herein, we present a review of the current understanding of the biology and pathogenesis pertaining to V. vermiformis, as well as its’ role as an etiological agent and trojan horse. An approach known as theranostics which combines both diagnosis and therapy could be utilized to eradicate and diagnose keratitis cases caused by such amoebae. Given the rise in global warming, it is imperative to investigate these rarely studied amoebae and to understand their importance in human health