scholarly journals Characterization of phytoplasmas related to 'Candidatus Phytoplasma asteris' subgroup rpI-L in Iran

2014 ◽  
Vol 54 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Fereshteh Vali-Sichani ◽  
Masoud Bahar ◽  
Leila Zirak
Keyword(s):  
Fragment Length Polymorphism ◽  
Specific Primer ◽  
Sequence Analyses ◽  
Chain Reaction ◽  
Universal Primer ◽  
Disease Symptoms ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Niger Seed

Abstract In two of Iran's central provinces, several herbaceous plants showing phytoplasma disease symptoms were collected to detect 'Canididatus Phytoplasma asteris'-related phytoplasmas. Confirmation of an association of phytoplasmas with diseased plants was done using polymerase chain reaction (PCR) assays having the phytoplasma universal primer pairs P1/P7 followed by R16F2n/ R16R2 in nested PCR. Then, for detection of 'Ca. P. asteris', DNA samples were subjected to amplification of rp and tuf genes using specific primer pairs rp(I)F1A/rp(I)R1A and fTufAy/rTufAy, respectively. Restriction fragment length polymorphism or RFLP analyses of rp gene fragments using Tsp509I restriction enzyme as well as sequence analyses indicated that 'Ca. P. asteris'-related phytoplasmas associated with carrot, niger seed and scallion plants in these regions, belong to the rpI-L subgroup. This research is the first report of carrot, niger seed, and scallion infection with phytoplasmas belonging to the rpI-L subgroup.

scholarly journals Characterization of a Phytoplasma Associated with Frogskin Disease in Cassava

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1139-1145 ◽  
Author(s):  
Elizabeth Alvarez ◽  
Juan F. Mejía ◽  
Germán A. Llano ◽  
John B. Loke ◽  
Alberto Calari ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Manihot Esculenta ◽  
Fragment Length Polymorphism ◽  
Rrna Gene ◽  
South American ◽  
Sequence Analyses ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain

Cassava frogskin disease (CFSD) is an economically important root disease of cassava (Manihot esculenta) in Colombia and other South American countries, including Brazil, Venezuela, Peru, Costa Rica, and Panama. The roots of severely affected plants are thin, making them unsuitable for consumption. In Colombia, phytoplasma infections were confirmed in 35 of 39 genotypes exhibiting mild or severe CFSD symptoms either by direct or nested polymerase chain reaction (PCR) assays employing ribosomal (r)RNA operon primer pairs. The CFSD-associated phytoplasmas were identified as group 16SrIII strains by restriction fragment length polymorphism (RFLP) and sequence analyses of amplified rDNA products, and results were corroborated by PCRs employing group 16SrIII-specific rRNA gene or ribosomal protein (rp) gene primers. Collectively, RFLP analyses indicated that CFSD strains differed from all phytoplasmas described previously in group 16SrIII and, on this basis, the strains were tentatively assigned to new ribosomal and ribosomal protein subgroups 16SrIII-L and rpIII-H, respectively. This is the first molecular identification of a phytoplasma associated with CFSD in cassava in Colombia.

Detection and Quantitation of Enterohemorrhagic Escherichia coli O157, O111, and O26 in Beef and Bovine Feces by Real-Time Polymerase Chain Reaction†

2002 ◽  
Vol 65 (9) ◽  
pp. 1371-1380 ◽  
Author(s):  
VIJAY K. SHARMA
Keyword(s):  
Real Time ◽  
Shiga Toxin ◽  
Enterohemorrhagic Escherichia Coli ◽  
Specific Primer ◽  
Chain Reaction ◽  
Pcr Assay ◽  
E Coli ◽  
Taqman Probes ◽  
Polymerase Chain ◽  
Pcr Assays

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 and certain non-O157 EHEC serotypes (such as O26:H11, O26: NM, O111:H8, and O111:NM) have emerged as significant causes of human disease throughout the world. Important virulence attributes of EHEC are the intimin protein (encoded by the eae gene) and Shiga toxins 1 and 2 (encoded by the stx1 and stx2 genes, respectively). Two sets of real-time polymerase chain reaction (R-PCR) assays were developed for the simultaneous detection and quantitation of EHEC through the monitoring of the presence of the eae and stx genes, and these assays were evaluated. In the eaeR-PCR assay, three sets of primers and TaqMan probes were designed for the amplification and real-time detection of a portion of the eae gene specific to the EHEC O26, O111, and O157 serotypes. In the stxR-PCR assay, two sets of primers and TaqMan probes were used to amplify and detect the stx1 and stx2 genes. DNA prepared from 67 bacterial strains carrying known virulence markers was tested to determine the specificities of the two assays. In the eaeR-PCR assay, eaeO157- and eaeO111-specific primer-probe sets identified only EHEC O157 and O111 strains, respectively. The eaeO26-specific primer-probe set identified all EHEC O26 isolates and some Shiga toxin–negative serotypes of enteropathogenic E. coli and rabbit diarrheagenic E. coli. The stxR-PCR assay was able to identify only those strains carrying either or both of the Shiga toxin–encoding genes. The detection range of both R-PCR assays was linear over DNA concentrations corresponding to 103 to 108 CFU/ml of an EHEC strain. Both assays were able to detect and quantify very low levels (1 to 10 CFU/g of food or feces) of EHEC in feces and ground beef enriched for 16 h in a modified Trypticase soy broth. In conclusion, eae- and stx-based R-PCR assays are reliable and sensitive methods for the rapid screening and specific and quantitative detection of important serotypes of EHEC in cattle and in foods of bovine origin.

scholarly journals Development of a Specific Polymerase Chain Reaction-Based Assay for the Identification of Fusarium oxysporum f. sp. ciceris and Its Pathogenic Races 0, 1A, 5, and 6

2003 ◽  
Vol 93 (2) ◽  
pp. 200-209 ◽  
Author(s):  
María del Mar Jiménez-Gasco ◽  
Rafael M. Jiménez-Díaz
Keyword(s):  
Polymerase Chain Reaction ◽  
Genomic Dna ◽  
Rapd Markers ◽  
Rapd Marker ◽  
Specific Primer ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Pathogenic Races ◽  
Scar Primers

Specific primers and polymerase chain reaction (PCR) assays that identify Fusarium oxysporum f. sp. ciceris and each of the F. oxysporum f. sp. ciceris pathogenic races 0, 1A, 5, and 6 were developed. F. oxysporum f. sp. ciceris- and race-specific random amplified polymorphic DNA (RAPD) markers identified in a previous study were cloned and sequenced, and sequence characterized amplified region (SCAR) primers for specific PCR were developed. Each cloned RAPD marker was characterized by Southern hybridization analysis of Eco RI-digested genomic DNA of a subset of F. oxysporum f. sp. ciceris and nonpathogenic F. oxysporum isolates. All except two cloned RAPD markers consisted of DNA sequences that were found highly repetitive in the genome of all F. oxysporum f. sp. ciceris races. F. oxysporum f. sp. ciceris isolates representing eight reported races from a wide geographic range, nonpathogenic F. oxysporum isolates, isolates of F. oxysporum f. spp. lycopersici, melonis, niveum, phaseoli, and pisi, and isolates of 47 different Fusarium spp. were tested using the SCAR markers developed. The specific primer pairs amplified a single 1,503-bp product from all F. oxysporum f. sp. ciceris isolates; and single 900- and 1,000-bp products were selectively amplified from race 0 and race 6 isolates, respectively. The specificity of these amplifications was confirmed by hybridization analysis of the PCR products. A race 5-specific identification assay was developed using a touchdown-PCR procedure. A joint use of race 0- and race 6-specific SCAR primers in a single-PCR reaction together with a PCR assay using the race 6-specific primer pair correctly identified race 1A isolates for which no RAPD marker had been found previously. All the PCR assays described herein detected up to 0.1 ng of fungal genomic DNA. The specific SCAR primers and PCR assays developed in this study clearly identify and differentiate isolates of F. oxysporum f. sp. ciceris and of each of its pathogenic races 0, 1A, 5, and 6.

scholarly journals Molecular Characterization of Carbapenemase-Producing Escherichia coli and Salmonella in children with diarrhea in rural Burkina Faso

2020 ◽  
Author(s):  
Rene DEMBELE ◽  
Issiaka Soulama ◽  
Wendpoulomdé A. D. Kaboré ◽  
Ali Konaté ◽  
Assèta Kagambèga ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Treatment Options ◽  
Diffusion Method ◽  
Chain Reaction ◽  
Disk Diffusion Method ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Resistance Rates ◽  
Encoding Genes

Abstract Background: In recent years, carbapenemase-producing Enterobacterales (CPE) resistance to antibiotics has dramatically increased leading to limitations of their treatment options. In the present study, we investigated the occurrence of carbapenemase-producing Escherichia coli and Salmonella in rural Burkina Faso. Methods: Salmonella isolates were serotyped according to the Kauffman White scheme. Diarrheagenic Escherichia coli (DEC) strains was identified using 16-plex Polymerase Chain Reaction (PCR), whereas antibiotic susceptibility was realized using the disk diffusion method. Furthermore, multiplex PCR assays were carried out using oligonucleotides to detect the presence of genes of the blaKPC, blaVIM, blaIMP, blaTEM, blaSHV, blaOXA and blaCTX-M types in all E. coli and Salmonella strains.Results: The study highlighted high resistance rates of the identified bacteria to common antibiotics. Likewise, two strains of E. coli were imipenem resistant with carbapenemase-encoding genes. The genes detected were Klebsiella pneumoniae carbapenemase (KPC), Verona integrin-encoded metallo-β-lactamase (VIM) and Imipenemase (IMP-2) reaching a rate of 40% each in E. coli strains. However, no Salmonella carbapenemases blaKPC, blaVIM or blaIMP were detected.Conclusions: This study showed that for a real-time infection control and prompt application of antimicrobial chemotherapy, characterization of carbapenemase-producing Enterobacterales in patients is crucial.

scholarly journals MOLECULAR CHARACTERIZATION OF AMERICAN CUTANEOUS LEISHMANIASIS IN THE TRI‑BORDER AREA OF ASSIS BRASIL, ACRE STATE, BRAZIL

2015 ◽  
Vol 57 (4) ◽  
pp. 343-347 ◽  
Author(s):  
Carolina Bioni Garcia TELES ◽  
Jansen Fernandes MEDEIROS ◽  
Ana Paula de Azevedo dos SANTOS ◽  
Luís Antônio Rodrigues de FREITAS ◽  
Tony Hiroshi KATSURAGAWA ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Rural Areas ◽  
Fragment Length Polymorphism ◽  
Chain Reaction ◽  
Predominant Species ◽  
American Cutaneous Leishmaniasis ◽  
Polymerase Chain ◽  
Urban And Rural Areas ◽  
Rural Work

SUMMARY In this study, Leishmaniaspecies were identified by Polymerase Chain Reaction (PCR). The epidemiology of patients suspected of having American Cutaneous Leishmaniasis in the municipality of Assis Brasil, Acre State, located in the Brazil/Peru/Bolivia triborder was also investigated. By PCR, the DNA of Leishmaniawas detected in 100% of the cases (37 samples) and a PCR-Restriction Fragment Length Polymorphism (RFLP) of the hsp 70gene identified the species in 32 samples: Leishmania (Viannia) braziliensis (65.6%) , L. (V.) shawi (28.1%) , L. (V.) guyanensis (3.1%) and mixed infection L. (V.) guyanensis and L. (Leishmania) amazonensis (3.1%)This is the first report of L. (V.) shawiand L. (L.) amazonensis in Acre. The two predominant species were found in patients living in urban and rural areas. Most cases were found in males living in rural areas for at least three years and involved in rural work. This suggests, in most cases, a possible transmission of the disease from a rural/forest source, although some patients had not engaged in activities associated with permanence in forestall areas, which indicate a possible sandflies adaptation to the periurban setting.

scholarly journals ‘Bois noir’: new phytoplasma disease of grapevine in Iran

2015 ◽  
Vol 55 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Seyed Mehdi Mirchenari ◽  
Amir Massah ◽  
Leila Zirak
Keyword(s):  
Polymerase Chain Reaction ◽  
16S Rrna ◽  
Restriction Enzymes ◽  
Disease Outbreak ◽  
Rrna Gene ◽  
Sequence Analyses ◽  
Chain Reaction ◽  
Universal Primer ◽  
Bois Noir ◽  
Polymerase Chain

Abstract Recently, grapevines showing symptoms suggesting the ‘bois noir’ phytoplasma disease were observed in vineyards located in several central provinces of Iran. Polymerase chain reaction assays using phytoplasma universal primer pair P1A/P7A followed by primer pair R16F2n/R16R2 in nested PCR, confirmed the association of phytoplasmas with symptomatic grapevines. The results of RFLP analyses using HpaII, HinfI, MseI, RsaI, and TaqI restriction enzymes, indicated that grapevine phytoplasma isolates in these regions could be related to the 16SrXII group. Sequence analyses of the partial 16S rRNA gene confirmed that Iranian grapevine phytoplasmas are associated with ‘Candidatus Phytoplasma solani’. This is the first report of the ‘bois noir’ disease outbreak in Iran

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