جستجوی مقالات مرتبط با کلیدواژه « Nested » در نشریات گروه « پزشکی »

The diagnosis of ocular toxoplasmosis is mainly based on clinical features. However, ocular fluid testing by PCR may be very helpful for approval or rejection of this etiology. In this study, we utilized a nested-PCR technique, targeting the B1 partial sequence to analyze the aqueous and vitreous samples for evaluating the presence of the Toxoplasma DNA.
Fifty aqueous or vitreous humor samples were obtained from patients with clinical features of ocular toxoplasmosis admitted to ophthalmology hospitals and clinics in Iran, within 2014. The samples were subsequently subjected to DNA extraction and purification. For nested amplification of the Toxoplasma B1 gene, two primer pairs were used. The outer and inner primers are expected to produce a 193 bp and a 96 bp fragments, respectively.
The first-round PCR resulted in the detection of T. gondii in 58% of samples by amplification of the expected 193bp DNA fragment. The nested-PCR using the inner primers, detected 15 additional samples from those with negative amplicons in the first round PCR (overall positivity of 88%). In addition, vitreous samples showed relatively more positive cases than aqueous humor in detection of the infection.
The nested-PCR protocol using the B1 gene, with the high detection power, could be a useful complimentary method to clinical diagnose of ocular toxoplasmosis.

Invasive fungal infection (IFIs) is a major infectious complication in immunocompromised patients. Early diagnosis and initiation of antifungal therapy is important to achieve the best outcome..
The current study aimed to investigate the incidence of IFIs and evaluate the diagnostic performance of non-invasive laboratory tests: serologic (β-D-glucan, galactomannan) and molecular (nested polymerase chain reaction) tests to diagnose fungal infections in hematologic pediatric patients..
Patients and In a cross-sectional study from October 2014 to January 2015, 321 blood samples of 62 pediatric patients with hematologic disorders and at high risk for fungal infections were analyzed. Non-invasive tests including the Platelia Aspergillus enzyme immunoassay (EIA) to detect galactomannan antigen, Glucatell for β–D–glucan and nested PCR to detect Candida and Aspergillus species-specific DNA were used in a weekly screening strategy..
Twenty six patients (42%) were considered as proven and probable IFIs, including 3 (5%) proven and 23 (37%) probable cases. Eighteen patients (29%) were considered as possible cases. The sensitivity, specificity, positive and negative predictive values for galactomannan test in 26 patients with proven and probable fungal infections were 94.4%, 100%, 100% and 94.7%; for β-D-glucan test 92.3%, 77.7%, 85%, 87.5% and for nested-PCR were 84.6%, 88.8%, 91.7% and 80%, respectively..
The rate of IFIs in pediatric patients with hematologic disorders is high, and sample collection from the sterile sites cannot be performed in immunocompromised patients. Detection of circulating fungal cell wall components and DNA in the blood using non-invasive methods can offer diagnostic help in patients with suspected IFIs. Their results should be interpreted in combination with clinical, radiological and microbiological findings..

A. bovis and A. phagocytophilium are leukocytotropic agents of bovine anaplasmosis. They are obligate intracellular bacteria that can infect and cause Anaplasmosis in human and animals. Therefore, this study was carried out to detect A. bovis and A. phagocytophilum in naturally infected dairy cattle in Isfahan using molecular techniques.
In this study a total of 209 blood samples were collected from cattle in central part of Iran (Isfahan). The presence of A. bovis and A. phagocytophilium were examined by species-specific nested polymerase chain reaction (nPCR) based on 16S rRNA gene.
Out of the 209 cattle examined, 4 (1.99%) and 2 (1%) were found positive for A. bovis and A. phagocytophilium by nPCR, respectively.
These data showed a relatively low prevalence of leukocytic Anaplasma infection in cattle in central part of Iran.

Toxoplasma gondii is an obligate intracellular protozoan parasite that exists worldwide. Various techniques have been developed for T. gondii detection.

The aim of this study was the detection of T. gondii in diabetic patients with RE and B1 genes and the comparison of these two genes for diagnosis using the nested-PCR assay method.
Patients and

DNA samples from 205 diabetic patients who had been referred to the diabetes center of Ali Asghar hospital in Zahedan, Iran, were collected and analyzed using the nested-PCR assay method. Toxoplasma antibody data gathered using the enzyme-linked immunosorbent assay (ELISA) method from a previous study was used to group patients. The data were analyzed using SPSS 18. The chi-square test was used for comparison.

Of the diabetic patients selected, the following results were obtained: 53 (IgG, IgM); 20 (IgG-, IgM); 72 (IgG, IgM-); and 60 (IgG-, IgM-). The nested-PCR detected the following: in the acute group, 21/53 (39.63%), 30/53 (56.60%) (IgM, IgG); in the chronic group, 40/72 (55.56%), 51/72 (70.83%), (IgG, IgM-); in the false positive group, 18/20 (90%), 17/20 (85%) (IgM, IgG-); and sero-negative samples of 38/60 (63.33%) and 60/ 41 (77.35%) for RE and B1 genes, respectively. The prevalence of toxoplasmosis showed positive in patients with diabetes in the B1 gene 139 (67.8%) and RE gene 117 (57.1%).

Our study demonstrated that the B1 gene, more so than the RE gene, showed positive samples and can be used to detect toxoplasmosis, although the B1 gene, in comparison to the RE gene, did not show any superiority of molecular diagnosing capability. Results also showed that toxoplasma molecular detection methods can be used instead of routine serological detection methods in a clinical laboratory testing.

Wolbachia are common intracellular bacteria that infect different groups of arthropods including mos­quitoes. These bacteria modify host biology and may induce feminization, parthenogenesis, male killing and cyto­plasmic incompatibility (CI). Recently Wolbachia is being nominated as a bio-agent and paratransgenic candidate to control mosquito borne diseases. Here we report the results of a survey for presence, frequency, and phylogenetic congruence of these en­dosymbiont bacteria in Culex pipiens populations in Northern, Central, and Southern parts of Iran using nested-PCR amplification of wsp gene. Wolbachia DNA were found in 227 (87.3%) out of 260 wild-caught mosquitoes. The rate of infection in adult females ranged from 61.5% to 100%, while in males were from 80% to 100%. The Blast search and phyloge­netic analysis of the wsp gene sequence revealed that the Wolbachia strain from Iranian Cx. pipiens was identical to the Wolbachia strains of supergroup B previously reported in members of the Cx. pipiens complex. They had also identical sequence homology with the Wolbachia strains from a group of distinct arthropods including lepidopteran, wasps, flies, damselfly, thrips, and mites from remote geographical areas of the world. It is suggested that Wolbachia strains horizontally transfer between unrelated host organisms over evo­lutionary time. Also results of this study indicates that Wolbachia infections were highly prevalent infecting all Cx. pipiens populations throughout the country, however further study needs to define Wolbachia inter-population repro­ductive incompatibility pattern and its usefulness as a bio-agent control measure.

The aim of this study was to detect low parasite and asymptomatic malaria infections by means of three malaria diagnostic tests, in a low transmission region of Minab district, Hormozgan Province, southern Iran. Blood samples of 200 healthy volunteers from Bagh-e-Malek area were evaluated using microscopic, rapid diagnostic tests (RDT) and nested-PCR to in­spect malaria parasite. The results showed no Plasmodium parasite in subjects by means of micros­copy and RDT. However, 3 P. vivax positive samples (1.5%) were discov­ered by Nested-PCR while microscopy and RDT missed the cases. Microscopy as the gold standard method and RDT correctly identi­fied 98.5% of cases, and molecular analysis is sensitive and reliable, especially in the detection of "asymptomatic" infections for active case surveillance. Regarding the existence of asymptomatic malaria in endemic area of Hormozgan, Iran, nested-PCR could be considered as a sensitive tool to interrupt malaria transmis­sion in the country, beside the microscopic and RDT methods.

Toxoplasmosis is a worldwide spread disease. The present study examined the prevalence of Toxoplasma gondii infection among animals of edible meat (cattle and sheep) in Chaharmahal va Bakhtiari Province (Southwest of Iran) in 2012. Furthermore, we attempted for the first time to identify this parasite from the meat products in the province. The tongue, brain, femur muscle and liver of 50 sheep and 70 cattle as well as 50 samples of meat products were selected and collected to perform molecu­lar survey using Nested-PCR method. Of the studied sheep, 38% were infected. The infection rate in the age groups under 1 year, 1-2 years, and more than 2 years was 25%, 35.29% and 52.94%, respectively. The infection rate in femur muscle, brain, liver and tongue was 28%, 32%, 30% and 16%, respectively. Of the studied cattle, 8.57% were in­fected. The infection rate in the age groups 1-2 years, 2-4 years, and more than 4 years was 3.7%, 9.09% and 14.28%, respectively. Sheep was infected 6 times more than cattle (OR = 6.53 CI = 2.374-18.005).The infection rate among samples of meat products was 12% (6 samples out of 50 samples). Due to the high rate of this parasitic infection among the slaughtered animals as well as meat products in this region, the use of infected material can be one of the main risk factors of transmission of the parasite to humans.

Species of Microsporidia have been known as opportunistic obli­gate intracellular parasites particularly in immunocompromised patients. Enterocyto­zoon bieneusi is one of most prevalent intestinal microsporida parasites in HIV+/AIDS patients. In this study, intestinal microsporidia infection was deter­mined in HIV+/AIDS patients using microscopic and molecular methods. Stool samples were collected from HIV+/AIDS patients during 12 months. All of the stool specimens washed with PBS (pH: 7.5). Slim slides were prepared from each sample and were examined using light microscope with 1000X magnification. DNA extraction carried out in microscopic positive samples. DNA amplification and genus/species identification also performed by Nested-PCR and sequencing techniques. From 81 stool samples, 25 were infected with microsporidia species and E. bieneusi were identified in all of positive samples. No Encephalitozoon spp. was identified in 81 collected samples using specific primers. E. bieneusi is the most prevalent intestinal microsporidia in immunocompromised patients of Iran. On the other hand, Nested-PCR using spe­cific primers for ssu rRNA gene is an appropriate molecular method for identifica­tion of E. bieneusi.

Epstein-Barr virus (EBV) is a DNA virus which belongs to the Herpesviridae family and in γ-herpesvirus subfamily, has been infected about 95% of the world’s population. EBV is transmitted through saliva and associated with different disease such as Infectious Mononucleosis, Nasopharyngeal Carcinoma, Burkitt`s Lymphoma, Hodgkin and Non-Hodgkin`s Lymphoma. The study proposed to determine the frequency of Epstein-Barr virus expression in histological tissue of non-Hodgkin''s Lymphoma in Ahwaz, Iran. In this study 29 samples of Non-Hodgkin`s Lymphoma were examined from Ahwaz Imam Khomeini Hospital, using Nested-PCR technique on EBNA-1 region in order to determine the presence of EBV genome in tumoral tissues. Among 29 cases of Non-Hodgkin''s Lymphoma, 14 (48%) cases were positive for EBV. Out of 14 samples of Non-Hodgkin`s Lymphoma, 4(28.57%) were female and 10 (71.42%) were male. A number of 8 (57%) cases belonged to the adults age group which proves association between age and EBV positive Non-Hodgkin`s Lymphoma according to Fisher`s exact test (P=0.03). However, in the current study there was no significant difference between EBV positive cases and sex subject (P=0.626). The result of the this study revealed that Epstein-Barr virus played a possible important role in Non-Hodgkin`s Lymphoma especially on adults.

Anaplasma phagocytophilum is a zoonotic, tick borne rickettsial pathogen. A. phagocytophilum has been detected in North America, Europe, Africa and Asia by molecular methods. In Iran we have little information about the distribution of this agent in human and animals. From March 2007 to July 2007, one hundred and fifty blood samples and corresponding blood smears of cattle without any signs of disease were prepared from a region in Isfahan, Iran with previous history of tick borne disease outbreak.The blood smears were first stained with Giemsa and analyzed for the presence of A. phagocytophilum in the neutrophils. The extracted DNA from blood cells were analyzed by A. phagocytophilum specific nested PCR using primers derived from the 16S rRNA gene. All blood smears were negative for A. phagocytophilum like structures by Giemsa staining, but 2 out of 150 blood samples (1.33%) were positive for A. phagocytophilum specific nested PCR using specific primers derived from 16S rRNA gene. This study is the first detection of A. phagocytophilum in carrier cattle in Iran. The present study showed that A. Phagocytophilum is detectable in cattle without any sign of infection but maintained a persistant sub-clinical state in the cattle reservoir, which can be inferred as possible risk for management of public health.