ABSTRACT
A family of reticulocyte-binding proteins of Plasmodium vivax (PvRBP) is localised at the apical pole of the merozoites and appears to bind to reticulocytes specifically and has also been involved in identifying host cells. Protein component produced by the Pvrbp2c gene is highly antigenic. The aim of this study was to detect the genetic diversity in the Pvrbp2c gene of Iranian P. vivax field isolates using the polymerase chain reaction- restricted fragment length polymorphism (PCR-RFLP) technique. A total of 79 P. vivax malaria patients with fever participated in the study. Alu1 and Apo1 restriction enzymes were independently used to identify allelic variants of the Pvrbp2c gene. All of the samples exhibited a single band of about 2 Kb in nested PCR. Among 79 P. vivax field isolates in the RFLP with Apo1 and Alu1 restriction enzymes, 15 and nine patterns were observed, respectively. In total, 24 various patterns were detected from the combined findings of both Alu1 and Apo1 fragments in RFLP. This study revealed that Pvrbp2c has genetic diversity in southeast Iran. Genotyping of Pvrbp2c not only shows the heterogeneity of P. vivax but also provides important information that could be used to control vivax malaria.
ABSTRACT
A family of reticulocyte-binding proteins of Plasmodium vivax (PvRBP) is localised at the apical pole of the merozoites and appears to bind to reticulocytes specifically and has also been involved in identifying host cells. Protein component produced by the Pvrbp2c gene is highly antigenic. The aim of this study was to detect the genetic diversity in the Pvrbp2c gene of Iranian P. vivax field isolates using the polymerase chain reaction- restricted fragment length polymorphism (PCR-RFLP) technique. A total of 79 P. vivax malaria patients with fever participated in the study. Alu1 and Apo1 restriction enzymes were independently used to identify allelic variants of the Pvrbp2c gene. All of the samples exhibited a single band of about 2 Kb in nested PCR. Among 79 P. vivax field isolates in the RFLP with Apo1 and Alu1 restriction enzymes, 15 and nine patterns were observed, respectively. In total, 24 various patterns were detected from the combined findings of both Alu1 and Apo1 fragments in RFLP. This study revealed that Pvrbp2c has genetic diversity in southeast Iran. Genotyping of Pvrbp2c not only shows the heterogeneity of P. vivax but also provides important information that could be used to control vivax malaria.
ABSTRACT
Balamuthia mandrillaris is an opportunistic free-living amoeba that has been reported to cause cutaneous lesions and Balamuthia amoebic encephalitis. The biology and environmental distribution of B. mandrillaris is still poorly understood and isolation of this pathogen from the environment is a rare event. Previous studies have reported that the presence of B. mandrillaris in the environment in Iran may be common. However, no clinical cases have been reported so far in this country. In the present study, a survey was conducted in order to evaluate the presence of B. mandrillaris in hot-spring samples of northern Iran. A total of 66 water samples were analysed using morphological and molecular tools. Positive samples by microscopy were confirmed by performing PCR amplification of the 16S rRNA gene of B. mandrillaris. Sequencing of the positive amplicons was also performed to confirm morphological data. Two of the 66 collected water samples were positive for B. mandrillaris after morphological and molecular identification. Interestingly, both positive hot springs had low pH values and temperatures ranging from 32 °C to 42 °C. Many locals and tourists use both hot springs due to their medicinal properties and thus contact with water bodies containing the organism increases the likelihood of infection. To the best of our knowledge, this is the first report on the isolation of B. mandrillaris from hot-spring sources related to human activity. Therefore, B. mandrillaris should be considered as a possible causative agent if cases of encephalitis are suspected following immersion in hot springs in addition to Acanthamoeba and Naegleria.
Subject(s)
Balamuthia mandrillaris/isolation & purification , Hot Springs/microbiology , Iran , Polymerase Chain Reaction , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
Early, accurate and effective diagnosis of toxoplasmosis can make an important contribution to the prevention and control of disease, especially in people who are at risk. In this study, two commonly used genomic repeats of Toxoplasma gondii, RE (GenBank accession number AF146527) and B1, were compared to each other in nested-PCR assay. Five hundred and thirty-five blood samples from children with leukemia were tested for the presence of T. gondii antibodies using enzyme immunoassays. One hundred and ten DNA samples of these patients (50 IgM+, IgG+, 10 IgM-, IgG+, and 50 IgM-, IgG-) were analyzed by nested-PCR. The specificity of two nested PCR assays was determined using the DNA samples of other parasites and human chromosomal DNA. As a result, 82% (41/50) and 68% (34/50) of the IgM+, IgG+ samples were positive on duplicate RE and B1-nested PCR analyses, respectively. None of the 10 IgM-, IgG+ seropositive samples was detected positive after testing RE and B1-nested PCR assays in duplicate. One (2%) of the 50 seronegative samples was positive by duplicate RE-nested PCR but none of them were positive by duplicate B1-nested PCR. The detection limit of the RE-nested PCR assay was 640 fg of T. gondii DNA whereas this rate for B1-nested PCR was 5.12 pg of the DNA template. No cross-reactivity with the DNA of other parasites and human chromosomal DNA was found. The results indicate that an RE-based nested PCR assay is more sensitive than B1 genomic target, of those tested, for detection of T. gondii. It is noteworthy that in comparison with B1-nested PCR, RE-nested PCR could detect the T. gondii DNA in seronegative samples too.
