Diffusible factors involved in early interactions of actinorhizal symbiosis are modulated by the host plant but are not enough to break the host range barrier

2011 ◽  
Vol 38 (9) ◽  
pp. 671 ◽  
Author(s):  
Luciano Andrés Gabbarini ◽  
Luis Gabriel Wall
Keyword(s):  
Root Exudates ◽  
Fragment Length Polymorphism ◽  
Pcr Analysis ◽  
Plant Origin ◽  
Actinorhizal Symbiosis ◽  
Negative Results ◽  
Alnus Acuminata ◽  
Infection Pathway ◽  
Full Activation ◽  
Discaria Trinervis

Nodulation kinetics were analysed in two nitrogen-fixing actinorhizal symbioses that show different pathways for infection: Alnus acuminata H. B. K., which is infected by Frankia ArI3, and Discaria trinervis (Hooker et Arnot) Reiche, which is infected by Frankia BCU110501. Both pairs are incompatible in cross-inoculation experiments. The dose–response effects in nodulation were studied in A. acuminata seedlings using different concentrations of compatible and incompatible bacteria in co-inoculation experiments. Restriction fragment length polymorphism PCR analysis and plant-trapping analysis showed no co-occupation in A. acuminata nodules when plants were co-inoculated with Frankia BCU110501 and Frankia ArI3. Despite the lack of co-occupation, the noninfective BCU110501 could modify the nodulation parameters of the non-host A. acuminata when infective ArI3 was present in the inoculum. The results suggest that although BCU110501 was not able to induce nodulation in A. acuminata, its interaction with the plant could induce autoregulation as if some level of infection or partial recognition could be achieved. We explored the possibility that physiological complementation of the heterologous Frankia BCU110501 for nodulation of A. acuminata originated in the homologous Frankia ArI3 in the presence of compatible root exudates. Despite the possibility of full activation between bacteria and the host, there was no co-infection of Frankia BCU110501 in Alnus or of Frankia ArI3 in Discaria either. These negative results suggest a physical recognition barrier in actinorhizal symbiosis that operates after early interactions, involving something other than root exudates and diffusible factors of bacterial or plant origin, regardless of the infection pathway.

scholarly journals Suitability of different tissue fixatives for subsequent PCR analysis of Cysticercus ovis

2012 ◽  
Vol 49 (2) ◽  
pp. 67-70 ◽  
Author(s):  
M. Kolesárová ◽  
R. Herich ◽  
M. Levkut ◽  
J. Čurlík ◽  
M. Levkut
Keyword(s):  
Retrospective Studies ◽  
Pcr Amplification ◽  
Pcr Analysis ◽  
Chain Reaction ◽  
Fresh Tissue ◽  
Carnoy’S Solution ◽  
Negative Results ◽  
Pcr Product ◽  
Polymerase Chain ◽  
Cysticercus Ovis

AbstractPCR amplification of specific DNA regions is a powerful tool for retrospective studies, but not all preservation or fixation methods render DNA that is suitable for subsequent amplification. Several factors affect sensitivity of polymerase chain reaction (PCR) amplification. There were reported the effects of commonly used fixation solutions — 10 % neutral buffered formalin, 20 % neutral buffered formalin and Carnoy’s solution and the efficiency of PCR amplification in fresh tissue and paraffin (or wax) embedded samples of Cysticercus ovis. DNA from samples was isolated and PCR product of 1300 bp was amplified. Results indicated that the samples fixed in Carnoy’s solution produced reliable amplification of desired fragments. The samples that were fixed in 10 % and 20 % neutral buffered formalin brought negative results.

Diffusible factors from Frankia modify nodulation kinetics in Discaria trinervis, an intercellular root-infected actinorhizal symbiosis

2011 ◽  
Vol 38 (9) ◽  
pp. 662 ◽  
Author(s):  
Luciano Andrés Gabbarini ◽  
Luis Gabriel Wall
Keyword(s):  
Root Hair ◽  
Root Nodules ◽  
Root Hairs ◽  
Basic Structure ◽  
Peptide Bond ◽  
Nodule Development ◽  
Actinorhizal Symbiosis ◽  
Biochemical Characterisation ◽  
Clade 1 ◽  
Discaria Trinervis

Frankia BCU110501 induces nitrogen-fixing root nodules in Discaria trinervis (Gillies ex Hook. & Arn.) Reiche (Rhamnaceae) via intercellular colonisation, without root hair deformation. It produces diffusible factors (DFs) that might be involved in early interactions with the D. trinervis roots, playing a role in the nodulation process. The induction of root nodule development in actinorhizal symbiosis would depend on the concentration of factors produced by the bacteria and the plant. A detailed analysis of nodulation kinetics revealed that these DFs produce changes at the level of initial rate of nodulation and also in nodulation profile. Diluted Frankia BCU110501 inoculum could be activated in less than 96 h by DFs produced by Frankia BCU110501 cells that had been previously washed. Biochemical characterisation showed that Frankia BCU110501 DFs have a molecular weight of <12 kDa, are negatively charged at pH 7.0 and seem to contain a peptide bond necessary for their activity. Frankia BCU110501, belonging to Frankia Clade 3, does not induce nodules in Alnus acuminata H.B.K. ssp. acuminata but is able to deform root hairs, as do Frankia strains from Clade 1. The root hair deforming activity of Frankia BCU110501 DFs show the same biochemical characteristics of the DFs involved in nodulation of D. trinervis. These results suggest that Frankia symbiotic factors have a basic structure regardless of the infection pathway of the host plant.

scholarly journals Diagnostic Performance of Hrp2 Based Diagnostic Test Kits and Frequency of Pfhrp2 Gene Deletion in Plasmodium falciparum Isolates of Osogbo, Southwestern Nigeria

2021 ◽  
pp. 20-25
Author(s):  
A. S. Nassar ◽  
A. S. Bakarey ◽  
A. A. Abdulazeez ◽  
O. O. Fayemi
Keyword(s):  
Plasmodium Falciparum ◽  
Diagnostic Test ◽  
Gene Deletion ◽  
False Negative ◽  
University Teaching ◽  
Pcr Analysis ◽  
Southwestern Nigeria ◽  
Blood Samples ◽  
Negative Results ◽  
Test Kit

Introduction: The introduction of P. falciparum encoded HRP-2 based malaria Rapid Diagnostic Test (RDT) kits is widely accepted in Nigeria and worldwide as a simplified form of diagnosis and a cheaper alternative to the microscopy technique (gold standard). However, deletion of Pfhrp2 gene contributes to false negative results and large number of such deletions has been reported in advanced countries thereby highlighting the importance of surveillance to detect such deletions in our local environment. Methodology: Microscopy as well as RDT techniques (using Rapid malaria test kit: SD BIOLINE Malaria Ag P.f/Pv, South Korea) were carried out on the blood samples of three hundred and twenty-three (323) febrile subjects attending Ladoke Akintola University Teaching Hospital, Osogbo, Osun State Nigeria. PCR analysis was also conducted on 50 blood samples that were positive for microscopy but negative for RDT. Results: The results from the study revealed that microscopy had a sensitivity of 99% and specificity of 99.2%. The RDT however had a sensitivity of 100% and a specificity of 60.1%. Fifty (50) samples that were positive for microscopy but negative for RDT were subjected to further PCR examination to detect the possible deletion of the Pfhrp-2 gene and the result revealed that the gene was present in 39 (78%) of the blood samples while remaining 11 (22%) samples lacked the gene which could possibly be the reason for the negative results obtained using the RDT kits. Conclusion: This study provides evidence of low level of presence of Pfhrp-2 gene deletion of Plasmodium falciparum parasites in our healthcare facility setting in Osogbo, Nigeria.

scholarly journals Rapid Detection of the CYP2D6*3, CYP2D6*4, and CYP2D6*6 Alleles by Tetra-Primer PCR and of the CYP2D6*5 Allele by Multiplex Long PCR

2000 ◽  
Vol 46 (8) ◽  
pp. 1072-1077 ◽  
Author(s):  
Martin Hersberger ◽  
Jacqueline Marti-Jaun ◽  
Katharina Rentsch ◽  
Edgar Hänseler
Keyword(s):  
Fragment Length Polymorphism ◽  
Poor Metabolizers ◽  
Pcr Analysis ◽  
Sequencing Analysis ◽  
Cyp2d6 Gene ◽  
Cyp2d6 Activity ◽  
Single Tube ◽  
Long Pcr ◽  
Allele Specific ◽  
Specific Amplification

Abstract Background: Interindividual differences in CYP2D6 activity range from total absence of metabolism of certain drugs to ultrafast metabolism and can produce adverse effects or lack of therapeutic effect under standard therapy. Several mutations have been described in the CYP2D6 gene that abolish CYP2D6 activity. However, four mutations explain the majority of the poor metabolizers. We describe four single-tube assays to detect these mutations. Methods: Three tetra-primer PCR assays were developed to detect the mutations in the CYP2D6*3, *4, and *6 alleles. In these single-tube assays, the CYP2D6 locus is amplified directly, followed by the allele-specific amplification on this new template. In addition, a multiplex long PCR was developed to genotype the CYP2D6*5 allele. Two long PCR amplifications for detection of the deletion of CYP2D6 (*5) and for detection of the CYP2D6 gene region were combined in one tube. Results: Analysis of 114 alleles showed no CYP2D6*3 allele, and allele frequencies of 28.1% for CYP2D6*4, 2.6% for CYP2D6*5, and 0.9% for CYP2D6*6. Re-analysis of the DNA samples by restriction fragment length polymorphism and sequencing analysis confirmed these results. Furthermore, re-analysis of sequenced genomic DNA by tetra-primer PCR analysis (7–11 times) always showed identical results. Conclusions: Our set of single-tube assays allows rapid and reproducible genotyping of the majority of CYP2D6 poor metabolizers.

scholarly journals CYP2C9 polymorphism in patients with epilepsy: genotypic frequency analyzes andphenytoin adverse reactions correlation

2011 ◽  
Vol 69 (2a) ◽  
pp. 153-158 ◽  
Author(s):  
Carlos Alexandre Twardowschy ◽  
Lineu César Werneck ◽  
Rosana Herminia Scola ◽  
Luciano De Paola ◽  
Carlos Eduardo Silvado
Keyword(s):  
Adverse Reactions ◽  
Pcr Analysis ◽  
Similar Distribution ◽  
Genotypic Frequency ◽  
Negative Results ◽  
Specific Pcr ◽  
Cyp2c9 Polymorphism ◽  
Literature Evidence ◽  
Allele Type ◽  
The Mean

OBJECTIVE: CYP2C9 is a major enzyme in human drug metabolism and the polymorphism observed in the corresponding gene may affect therapeutic outcome during treatment. The distribution of variant CYP2C9 alleles and prevalence of phenytoin adverse reactions were hereby investigated in a population of patients diagnosed with epilepsy. METHOD: Allele-specific PCR analysis was carried out in order to determine frequencies of the two most common variant alleles, CYP2C9*2 and CYP2C9*3 in genomic DNA isolated from 100 epileptic patients. We also analyzed the frequency of phenytoin adverse reactions among those different genotypes groups. The data was presented as mean±standard deviation. RESULTS: The mean age at enrollment was 39.6±10.3 years (range, 17-72 years) and duration of epilepsy was 26.5±11.9 years (range 3-48 years). The mean age at epilepsy onset was 13.1±12.4 years (range, 1 month-62 years). Frequencies of CYP2C9*1 (84%), CYP2C9*2 (9%) and CYP2C9*3 (7%) were similar to other published reports. Phenytoin adverse reactions were usually mild and occurred in 15% patients, without correlation with the CYP2C9 polymorphism (p=0.34). CONCLUSION: Our findings indicate an overall similar distribution of the CYP2C9 alleles in a population of patients diagnosed with epilepsy in the South of Brazil, compared to other samples. This sample of phenytoin users showed no drug related adverse reactions and CYP2C9 allele type correlation. The role of CYP2C9 polymorphism influence on phenytoin adverse reaction remains to be determined since some literature evidence and our data found negative results.

scholarly journals Genetic relationships among biotypes of Bemisia tabaci (Hemiptera: Aleyrodidae) based on AFLP analysis

2000 ◽  
Vol 90 (5) ◽  
pp. 391-396 ◽  
Author(s):  
M.T. Cervera ◽  
J.A. Cabezas ◽  
B. Simón ◽  
J.M. Martínez-Zapater ◽  
F. Beitia ◽  
...  
Keyword(s):  
Bemisia Tabaci ◽  
New World ◽  
Fragment Length Polymorphism ◽  
Indian Subcontinent ◽  
Genetic Relationships ◽  
Similarity Coefficient ◽  
Pcr Analysis ◽  
Aflp Analysis ◽  
Rapd Pcr ◽  
Nigerian Population

AbstractGenetic similarities between 13 samples belonging to nine reference biotypes and two field populations of Bemisia tabaci (Gennadius), one field population of B. medinae Gómez-Menor and another of B. afer Priesner &Hosny, were evaluated using amplified fragment length polymorphism (AFLP) markers. The results indicate that B. tabaci biotypes can be grouped together with a minimum similarity coefficient of 0.32 and separated from the two other species with a similarity coefficient of 0.07. Bemisia tabaci biotypes were grouped in four clusters which comprised: (i) Near East and Indian subcontinent biotypes; (ii) B and Q biotypes plus a Nigerian population from cowpea; (iii) New World A biotype; and (iv) S biotype and a Nigerian population from cassava. These results were consistent with a previous grouping of biotypes based on RAPD-PCR analysis. The AFLP assay allowed the scoring of a total of 354 polymorphic bands in two reaction events with the use of two primer combinations.

scholarly journals Ocular findings and retinal involvement in COVID-19 pneumonia patients: A cross-sectional study in an Italian referral centre

2020 ◽  
Author(s):  
Maria Pia Pirraglia ◽  
Giancarlo Ceccarelli ◽  
Alberto Cerini ◽  
Giacomo Visioli ◽  
Gabriella d'Ettorre ◽  
...  
Keyword(s):  
Cross Sectional Study ◽  
Pcr Analysis ◽  
Sectional Study ◽  
Corneal Sensitivity ◽  
Cross Sectional ◽  
Viral Spread ◽  
Negative Results ◽  
Ocular Findings ◽  
Sensitivity Assessment ◽  
Eye Screening

Abstract Background: changes in immune and coagulation systems and possible viral spread through blood-brain barrier have been described in SARS-CoV-2 infection. In this study, we evaluate the possible retinal involvement and ocular findings in severe COVID-19 pneumonia patients. Methods: a cross sectional study was conducted on 46 patients affected by severe COVID-19 who were hospitalized in one Intensive Care Unit (ICU) and in two Infectious Diseases wards, including a bedside eye screening, corneal sensitivity assessment and retinography. Results: a total of 43 SARS-CoV-2 positive pneumonia patients affected with COVID-19 pneumonia were included, 25 males and 18 females, with a median age of 70 [IQR 59-78]. Except for one patient with unilateral posterior chorioretinitis of opportunistic origin, of whom aqueous tap was negative for SARS-CoV-2, no further retinal manifestation related to COVID-19 infection was found in our cohort. We found 3 patients (7%) with bilateral conjunctivitis in whom PCR analysis on conjunctival swab provided negative results for SARS-CoV-2. No alterations of corneal sensitivity were found.Conclusion: we demonstrated the absence of retinal involvement in SARS-CoV-2 pneumonia patients. Ophthalmologic evaluation in COVID-19, particularly in patients hospitalized in an ICU setting, may be useful to reveal systemic co-infections by opportunistic pathogens.

scholarly journals Retinal involvement and ocular findings in COVID‐19 pneumonia patients 

2020 ◽  
Author(s):  
Maria Pia Pirraglia ◽  
Giancarlo Ceccarelli ◽  
Alberto Cerini ◽  
Giacomo Visioli ◽  
Gabriella d'Ettorre ◽  
...  
Keyword(s):  
Cross Sectional Study ◽  
Pcr Analysis ◽  
Opportunistic Pathogens ◽  
Corneal Sensitivity ◽  
Cross Sectional ◽  
Viral Spread ◽  
Negative Results ◽  
Ocular Findings ◽  
Sensitivity Assessment ◽  
Eye Screening

Abstract Background: changes in immune and coagulation systems and possible viral spread through blood-brain barrier have been described in SARS-CoV-2 infection. In this study, we evaluate the possible retinal involvement and ocular findings in severe COVID-19 pneumonia patients. Methods: a cross sectional study was conducted on 46 patients affected by severe COVID-19 who were hospitalized in one Intensive Care Unit (ICU) and in two Infectious Diseases wards, including a bedside eye screening, corneal sensitivity assessment and retinography. Results: a total of 43 SARS-CoV-2 positive pneumonia patients affected with COVID-19 pneumonia were included, 25 males and 18 females, with a median age of 70 [IQR 59-78]. Except for one patient with unilateral posterior chorioretinitis of opportunistic origin, of whom aqueous tap was negative for SARS-CoV-2, no further retinal manifestation related to COVID-19 infection was found in our cohort. We found 3 patients (7%) with bilateral conjunctivitis in whom PCR analysis on conjunctival swab provided negative results for SARS-CoV-2. No alterations of corneal sensitivity were found.Conclusion: we demonstrated the absence of retinal involvement in SARS-CoV-2 pneumonia patients. Ophthalmologic evaluation in COVID-19, particularly in patients hospitalized in an ICU setting, may be useful to reveal systemic co-infections by opportunistic pathogens.

scholarly journals Detection of Phytoplasmas in Declining Pears in Southern Australia

Plant Disease ◽  
1997 ◽  
Vol 81 (3) ◽  
pp. 254-258 ◽  
Author(s):  
B. Schneider ◽  
K. S. Gibb
Keyword(s):  
Nested Pcr ◽  
Fragment Length Polymorphism ◽  
Rflp Analysis ◽  
Restriction Enzymes ◽  
Pcr Analysis ◽  
Pcr Assay ◽  
Specific Primers ◽  
Pear Tree ◽  
Pear Trees ◽  
Polymerase Chain

Forty-nine pear tree samples collected in Victoria, most of them showing decline symptoms, were tested by polymerase chain reaction (PCR) analysis to detect phytoplasmas. Two universal phytoplasma-specific primer pairs, fP1/rP7 and fU5/rU3, were tested, but only fU5/rU3 amplified the phytoplasma DNA adequately. Nested PCR with universal and group-specific primers, however, proved more effective. Thirty pear trees reacted positively in a nested PCR assay. Restriction fragment length polymorphism (RFLP) analysis with the restriction enzymes MseI and AluI of the PCR fragment amplified with the primer pair fU5/rU3 revealed patterns identical to those from the sweet potato little leaf phytoplasma. This is the first report of a phytoplasma in pear in Australia.

Sign in / Sign up

Export Citation Format

Share Document