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The study presents an analysis of the restriction pattern of rDNA fragments of 95 C. albicans isolates previously classified on the basis of the presence of the intron in rDNA into genotypes A (62 isolates), B (28), and C (5). Most isolates (61) with genotype A were classified as "subtype a" and one as "subtype d" (Karahan and Akar; 2005). No differences were observed in the restriction patterns of the tested genotype B isolates. Similarly, most genotype C strains (4/5) showed the same restriction pattern. The results indicate low subtyping variations of the analyzed isolates, which is in contrast to published data obtained from a Turkish collection of yeasts.
RFLP analysis of mitochondrial DNA was carried out with eight restriction enzymes BamHI, EcoRI, HaeIII, HindIII, MspI, PstI, SalI and XhoI, from which nine mitochondrial gene probes (atp6, atp9, atp1, cox1, nad3, nad6, nad9, pol-r, orf25) were hybridized, by means of digestion products, for seven species of the genus Secale. RFLP EcoRI/pol-r specific markers were determined for all the species of rye. To estimate the relationships among species, genetic pairwise similarities between them were estimated and a UPGMA dendrogram was constructed. The analysis separated the species into two groups. The first comprises the pair Secale sylvestre Host and S. cereale subsp. segetale Zhuk., exhibiting the greatest genetic similarity, that is, closest relationships. The second group is composed of S. strictum/Presl/Presl, S. strictum/Presl/Presl subsp. kuprijanovii/Grossh./ Hammer, S. strictum/Presl/Presl subsp. africanum/Stapf/Hammer, Secale cereale L. and S. vavilovii Grossh., with one clear subgroup comprising Secale strictum/Presl/Presl and S. strictum/Presl/Presl subsp. kuprijanovii/ Grossh./Hammer. The latter two species showed the highest genetic similarity to each other and relatively high genetic similarity to the remaining species in the group.
Epidemiological studies were carried out on 135 isolates of Staphylococcus aureus strains originating from medical staff, patients, and hospital environment. Restriction fragment length polymorphism (RFLP) analysis revealed genetic diversity of S. aureus isolates. Some clones were transmitted among nurses, doctors and patients. Our studies also demonstrate contamination of the hospital environment with S. aureus strains and there is a possibility that the patients acquire staphylococci from the environment. Moreover, we found that many medical staff workers were colonized with S. aureus and the transmission of these strains to patients is possible.
Various viral pathogens infect Cucurbitaceae and cause economic losses. Th e aim of the present study was to detect plant viral pathogens including Cucumber mosaic virus (CMV), Cucumber green mottle mosaic virus (CGMMV), Zucchini yellow mosaic virus (ZYMV), Cucurbit yellow stunting disorder virus (CYSDV) and Cucurbit chlorotic yellows virus (CCYV) in Lorestan province, in western Iran, and also to determine CMV genetic diversity in Iranian populations. A total of 569 symptomatic leaf samples were collected in 2013 and 2014 from cucurbits growing regions in Lorestan province. Th e collected samples were assessed for viral diseases by ELISA. Th e results showed virus incidences in most regions. Th en, the infection of 40 samples to CMV was confi rmed by RT-PCR. Moreover, to distinguish between the two groups (I and II) of CMV, PCR products were digested by two restriction enzymes XhoI and EcoRI. Results of the digestion showed that the isolates of Lorestan belonged to group I. Th e CMV-coat protein gene of eight isolates from diff erent regions and hosts was sequenced and phylogenetic analysis was performed. Subsequent analyses showed even more genetic variation among Lorestan isolates. Th e phylogenetic tree revealed that Lorestan province isolates belonged to two IA and IB subgroups and could be classifi ed together with East Azerbaijan province isolates. Th e results of the present study indicate a wide distribution of CMV, ZYMV, CGMMV, CYSDV and CCYV viruses in cucurbits fi elds of Lorestan province and for the fi rst time subgroup IB of CMV was reported on melon from Iran.
A total of seventeen isolates of Aspergillus flavus from maize were collected from different agro-ecological zones of Tamil Nadu, India. The isolates were tested for their ability to produce aflatoxin B1 (AFB1) in vitro by indirect competitive enzyme-linked immunosorbent assay (ELISA). The amount of AFB1 produced by the isolates of A. flavus ranged from 1.9 to 206.6 ng/ml. Among the various isolates of A. flavus, the isolate AFM46 produced the highest amount of AFB1. DNA was extracted from A. flavus isolates and their molecular variability was investigated by using restriction fragment length polymorphism (RFLP) analysis of the PCR-amplified internal transcribed spacer (ITS) regions of ribosomal DNA. PCR amplification with ITS1 and ITS4 primers resulted in the amplification of a product of approximately 600 bp. Digestion of the PCR products with the restriction enzymes EcoRI, HaeIII and TaqI produced fragments of different sizes. Analysis of the genetic coefficient matrix derived from the scores of RFLP profiles showed that minimum and maximum per cent similarities among the tested A. flavus strains ranged from 0 to 88%. Cluster analysis using the unweighted pair-group method with arithmetic average (UPGMA) clearly separated the isolates into five groups (group I–V) confirming the genetic diversity among the A. flavus isolates from maize.
A rapid PCR-RFLP analysis was optimized to identify the presence of 3 closely related gadoid fish species: Alaska pollack Theragra chalcogramma, Pacific cod Gadus macrocephalus and Atlantic cod Gadus morhua in commercial seafood products. Gadoid universal primers were designed for PCR amplification of a 558-bp fragment encoding the mitochondrial cytochrome b gene. Without purification of the PCR products, double digestion with Eco32l and Eco1051 restriction enzymes generated reproducible species-specific restriction patterns visualizing 3 fragments (106 bp, 161 bp and 291 bp) in Alaska pollack and 2 fragments (106 bp and 452 bp) in Pacific cod, whereas no cleavage was observed in Atlantic cod. This PCR-RFLP analysis is simple, rapid and reliable, and therefore can be routinely applied to discover fraudulent substitution among 3 economically important gadoid species in commercial seafood products.
Picea abies (L.) Karst is one of the most important coniferous species of Europe from both ecological and economical points of view. Traditional methods for the gene pool conservation and biodiversity maintenance in forest ecosystems have been practiced in many countries. For progress in this field using highly polymorphic genetic molecular markers is needed. Our goal was to demonstrate the utility of two polymorphic mitochondrial markers mt15-D02 and nad1 b/c in identification native Norway spruce stands. This molecular markers were tested in 1401 individuals from 59 Polish Norway spruce populations. We detected three alleles, which are called1, 2 and3, for locus mt15-D02 and two alleles , which are called1 and2, for locus nad1 b/c in our material. All five variants of alleles indicate the natural origin of P. abies. Result of this study shows that molecular marker mt15-D02 is easy to use and more informative in compare to marker nad1 b/c.
Polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) analysis was used to identify fish species and to perform their authentication in commercial seafood products. Universal primers were used for PCR amplification of 464-bp long fragments of the mitochondrial cytochrome b gene. The PCR products were digested with restriction enzymes AluI, HinfI, HaeIII, DdeI, NlaIII, HincII, and MboII. Sixty fish samples were obtained from the local markets in the Czech Republic. In 47 samples (78.3%), the results were in agreement with declarations of the producers and 10 samples (16.7%) contained other fish species. There were not great differences between fresh fillets (chilled, frozen etc.) and heat-processed foodstuffs (tinned, smoked, etc). The correct designation was in 72.3% and 81.6% of samples, respectively. Even if in three cases the analysis was unsuccessful the method is useful for the control of the adulteration of food with fish tissue content and in this way it contributes to better consumer awareness.
Chlorazol Black E (CBE) stain has been used for the detection and identification of intestinal parasitic protozoa. In recent years, genotyping of protozoa has been performed to examine pathogenicity and for epidemiologic analysis. In this study, protozoan DNA was amplified from preserved human fecal specimens stained with CBE that were positive for Giardia intestinalis (syn. G. lamblia and G. duodenalis), Chilomastix mesnili, Pentatrichomonas hominis, and Entamoeba histolytica. DNA was amplified from 11 of the 12 (91.6%) samples examined. DNA from CBE-stained smears of G. intestinalis, E. histolytica, and P. hominis was amplified, whereas any amplification product could not be obtained from one of three smears of C. mesnili. Storage term and protozoan number had no association with results of PCR amplification. In genotyping of G. intestinalis, four out of six (66.7%) samples were of genotype AI, while the remaining two (33.3%) samples were of genotype B. The amplified DNA sequences showed high similarity (>99%) with that of G. intestinalis in the GenBank database. These results suggest that DNA remains stable in CBE-stained smears for long term. The present study demonstrates that nuclear extracts from specimens stained with CBE can be amplified by PCR and suggests that specimens stored for extended periods could be applied to genetic and prospective epidemiologic analyses.
Thirty-three type A strains of G. abietina from diseased shoots or needles of P. sylvestris, P. nigra and P. armandii and three strains of Brunchorstia pinea var. cembrae from P. mugo were isolated from four regions of Poland differing with respect to climatic conditions. Genetic polymorphism of the mitochondrial small subunit rRNA (mtSSU rRNA), ribosomal RNA fragment including ITS1, 5.8S and ITS2 and glyceraldehyde phosphate dehydrogenase (GPD) gene was examined by the PCR-RFLP method. Genetic distance was ascertained with respect to B. pinea var. cembrae strains from G. abietina isolated from the examinedpine species (average Nei coefficient 0.137). The smallest genetic distance occurred between the strain groups of G. abietina isolated from P. nigra and P. armandii (0.059) and P. nigra and P. sylvestris (0.061), whereas the highest occurred between the groups of strains deriving from P. armandii and P. sylvestris (0.096). The impact of geographic distance on genetic distance between groups of strains from individual regions has been shown. G. abietina strains originating from mountainous areas were more distanced genetically (on average 0.031) from populations from other regions (Nei genetic distance 0.023). The main factors influencing genetic differences of the pathogen were specificity with respect to the species of the host plant and climate conditions, whereas geographic distance had lesser significance.
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