scholarly journals Identification of DNA Unique to the Tomato Fusarium Wilt and Crown Rot Pathogens

1995 ◽  
Author(s):  
Harold Corby Kistler ◽  
Talma Katan
Keyword(s):  
Evolutionary Relationship ◽  
Fungal Species ◽  
Diagnostic Methods ◽  
Crown Rot ◽  
Molecular Diagnostic ◽  
Disease Development ◽  
Optimal Temperature ◽  
Formae Speciales ◽  
Soil Borne Pathogens ◽  
Different Strains

Wilt and crown rot are two important diseases of tomato caused by different strains ("formae speciales") of the fungus, Fusarium oxysporum. While both pathogens are members of the same fungal species, each differs genetically and resistance to the diseases is controlled by different genes in the plant. Additionally, the formae speciales differ in their ecology (e.g. optimal temperature of disease development) and epidemiology. Nevertheless, the distinction between these diseases based on symptoms alone may be unclear due to overlapping symptomatology. We have found in our research that the ambiguity of the pathogens is further confounded because strains causing tomato wilt or crown rot each may belong to several genetically and phylogenetically distinct lineages of F. oxysporum. Furthermore, individual lineages of the pathogen causing wilt or crown rot may themselves be very closely related. The diseases share the characteristic that the pathogen's inoculum may be aerially dispersed. This work has revealed a complex evolutionary relationship among lineages of the pathogens that makes development of molecular diagnostic methods more difficult than originally anticipated. However, the degree of diversity found in these soil-borne pathogens has allowed study of their population genetics and patterns of dispersal in agricultural settings.

scholarly journals Standard and molecular methods in the diagnostics of infections caused by equine herpesviruses 1 and 4

2018 ◽  
Vol 72 (2) ◽  
pp. 68-79
Author(s):  
Nenad Milic ◽  
Andrea Radalj ◽  
Jakov Nisavic
Keyword(s):  
Screening Method ◽  
Rapid Identification ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Equine Herpesvirus ◽  
Viral Kinetics ◽  
Herpesvirus Type ◽  
Equine Herpesvirus Type 1 ◽  
Herpesvirus 4 ◽  
Different Strains

Background. Equine herpesvirus type 1 (EHV-1) is responsible for respiratory disease in young animals, abortion in pregnant mares and neurological disease, whilst equine herpesvirus 4 (EHV-4) is mainly the causative agent of respiratory disorders and rarely causes abortion. These viruses are considered as one of the most clinically and economically important pathogens of horses and can be detected in a range of tissues. Scope and Approach. Serological methods are used to detect the presence and titre of specific antibodies to EHV-1 and EHV-4 in the sera of examined horses and are useful in epizootiological studies. Commercially available ELISA kits are able to differentiate specific EHV-1 and EHV-4 antibodies. EHV-1 and EHV-4 can both be isolated using susceptible cells such as primary horse cell cultures and other non-equine cells with visible cytopathic effect. Since standard diagnostic methods can be time consuming and arduous, the scope of many studies has been to develop and confirm the sensitivity and specificity of molecular diagnostic methods. Key Findings and Conclusions. Polymerase chain reaction (PCR) has proved to be a good screening method for the presence of latent infections of horses caused by these viruses, also making possible the rapid identification and differentiation of EHV-1 and- EHV-4 in the examined samples. Real-time PCR is a sensitive, specific and quantitative method that enables the determination of viral kinetics in infected horses. Genome sequencing can be used to discover mutations in the genomes of EHV-1 and EHV-4 as well as to track the spread of their different strains globally.

scholarly journals SARS-CoV-2 IgG Antibodies Seroprevalence and Sera Neutralizing Activity in MEXICO: A National Cross-Sectional Study during 2020

2021 ◽  
Vol 9 (4) ◽  
pp. 850
Author(s):  
José Esteban Muñoz-Medina ◽  
Concepción Grajales-Muñiz ◽  
Angel Gustavo Salas-Lais ◽  
Larissa Fernandes-Matano ◽  
Constantino López-Macías ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Neutralizing Antibodies ◽  
Herd Immunity ◽  
Cross Sectional Study ◽  
Molecular Techniques ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Neutralizing Activity

Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico’s first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.

scholarly journals High Frequency of Cryptosporidium hominis Infecting Infants Points to A Potential Anthroponotic Transmission in Maputo, Mozambique

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 293
Author(s):  
Idalécia Cossa-Moiane ◽  
Hermínio Cossa ◽  
Adilson Fernando Loforte Bauhofer ◽  
Jorfélia Chilaúle ◽  
Esperança Lourenço Guimarães ◽  
...  
Keyword(s):  
Public Hospitals ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
P Value ◽  
Cryptosporidium Hominis ◽  
Cryptosporidium Spp ◽  
Pcr Rflp ◽  
Maputo City ◽  
Stool Samples ◽  
Polymerase Chain

Cryptosporidium is one of the most important causes of diarrhea in children less than 2 years of age. In this study, we report the frequency, risk factors and species of Cryptosporidium detected by molecular diagnostic methods in children admitted to two public hospitals in Maputo City, Mozambique. We studied 319 patients under the age of five years who were admitted due to diarrhea between April 2015 and February 2016. Single stool samples were examined for the presence of Cryptosporidium spp. oocysts, microscopically by using a Modified Ziehl–Neelsen (mZN) staining method and by using Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) technique using 18S ribosomal RNA gene as a target. Overall, 57.7% (184/319) were males, the median age (Interquartile range, IQR) was 11.0 (7–15) months. Cryptosporidium spp. oocysts were detected in 11.0% (35/319) by microscopy and in 35.4% (68/192) using PCR-RFLP. The most affected age group were children older than two years, [adjusted odds ratio (aOR): 5.861; 95% confidence interval (CI): 1.532–22.417; p-value < 0.05]. Children with illiterate caregivers had higher risk of infection (aOR: 1.688; 95% CI: 1.001–2.845; p-value < 0.05). An anthroponotic species C. hominis was found in 93.0% (27/29) of samples. Our findings demonstrated that cryptosporidiosis in children with diarrhea might be caused by anthroponomic transmission.

Unusual cryptosporidiosis cases in Swedish patients: extended molecular characterization ofCryptosporidium viatorumandCryptosporidiumchipmunk genotype I

Parasitology ◽  
2013 ◽  
Vol 140 (14) ◽  
pp. 1735-1740 ◽  
Author(s):  
MARIANNE LEBBAD ◽  
JESSICA BESER ◽  
MONA INSULANDER ◽  
LILLEMOR KARLSSON ◽  
JENS G. MATTSSON ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Cryptosporidium Parvum ◽  
Geographical Variation ◽  
Indian Subcontinent ◽  
Common Species ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Cryptosporidium Hominis ◽  
Genotype I ◽  
Protein Locus

SUMMARYMost human cases of cryptosporidiosis are caused byCryptosporidium parvumorCryptosporidium hominis, but the use of molecular diagnostic methods has revealed that several other less common species or genotypes can also be involved. Here, we describe two unusual causes of cryptosporidiosis, one being the recently described speciesCryptosporidium viatorumand the otherCryptosporidiumchipmunk genotype I. Two Swedish patients who were infected withC. viatorumhad travelled to Kenya and Guatemala, respectively, and two others had been infected withCryptosporidiumchipmunk genotype I in Sweden. None of these four patients were immunocompromised, and all four showed classical symptoms of cryptosporidiosis. We performed extensive molecular characterization, including analysis of four loci. The twoC. viatorumisolates were found to differ slightly at the 70-kDa heat shock protein locus, which may indicate a local geographical variation in this species that has previously been described exclusively on the Indian subcontinent.

scholarly journals The burden of congenital Chagas disease and implementation of molecular diagnostic tools in Latin America

2018 ◽  
Vol 3 (5) ◽  
pp. e001069 ◽  
Author(s):  
Albert Picado ◽  
Israel Cruz ◽  
Maël Redard-Jacot ◽  
Alejandro G Schijman ◽  
Faustino Torrico ◽  
...  
Keyword(s):  
Latin America ◽  
Chagas Disease ◽  
Diagnostic Algorithm ◽  
Diagnostic Methods ◽  
Diagnosis And Treatment ◽  
Molecular Diagnostic ◽  
Diagnostic Tools ◽  
Molecular Tests ◽  
Epidemiological Impact ◽  
And Performance

It is estimated that between 8000 and 15 000 Trypanosoma cruzi infected babies are born every year to infected mothers in Chagas disease endemic countries. Currently, poor access to and performance of the current diagnostic algorithm, based on microscopy at birth and serology at 8–12 months after delivery, is one of the barriers to congenital Chagas disease (CCD) control. Detection of parasite DNA using molecular diagnostic tools could be an alternative or complement to current diagnostic methods, but its implementation in endemic regions remains limited. Prompt diagnosis and treatment of CCD cases would have a positive clinical and epidemiological impact. In this paper, we analysed the burden of CCD in Latin America, and the potential use of molecular tests to improve access to early diagnosis and treatment of T. cruzi infected newborns.

A point-of-care diagnostic for differentiating Ebola from endemic febrile diseases

2018 ◽  
Vol 10 (471) ◽  
pp. eaat0944 ◽  
Author(s):  
David Sebba ◽  
Alexander G. Lastovich ◽  
Melody Kuroda ◽  
Eric Fallows ◽  
Joshua Johnson ◽  
...  
Keyword(s):  
Ebola Virus ◽  
Clinical Symptoms ◽  
Point Of Care ◽  
Hemorrhagic Fever ◽  
Diagnostic Methods ◽  
Outbreak Detection ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
Live Virus ◽  
And Control

Hemorrhagic fever outbreaks such as Ebola are difficult to detect and control because of the lack of low-cost, easily deployable diagnostics and because initial clinical symptoms mimic other endemic diseases such as malaria. Current molecular diagnostic methods such as polymerase chain reaction require trained personnel and laboratory infrastructure, hindering diagnostics at the point of need. Although rapid tests such as lateral flow can be broadly deployed, they are typically not well-suited for differentiating among multiple diseases presenting with similar symptoms. Early detection and control of Ebola outbreaks require simple, easy-to-use assays that can detect and differentiate infection with Ebola virus from other more common febrile diseases. Here, we developed and tested an immunoassay technology that uses surface-enhanced Raman scattering (SERS) tags to simultaneously detect antigens from Ebola, Lassa, and malaria within a single blood sample. Results are provided in <30 min for individual or batched samples. Using 190 clinical samples collected from the 2014 West African Ebola outbreak, along with 163 malaria positives and 233 negative controls, we demonstrated Ebola detection with 90.0% sensitivity and 97.9% specificity and malaria detection with 100.0% sensitivity and 99.6% specificity. These results, along with corresponding live virus and nonhuman primate testing of an Ebola, Lassa, and malaria 3-plex assay, indicate the potential of the SERS technology as an important tool for outbreak detection and clinical triage in low-resource settings.

scholarly journals Detection of LytA Genes in Streptococcus pneumoniae Isolated from sputum pneumonia patients

Biomedika ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 23-30
Author(s):  
Mustika Sari Hutabarat ◽  
Firdaus Hamid ◽  
Irawaty Djaharuddin ◽  
Alfian Zainuddin ◽  
Rossana Agus ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
False Negative ◽  
Pneumococcal Infection ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
Biochemical Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Streptococcus pneumoniae (pneumococcus) is a Gram-positive facultative anaerobic bacterium that is a major cause of morbidity and mortality worldwide. But the lack of reporting of disease by this bacterium in Indonesia, one of the causes is because the diagnosis of pneumococcal infection is often clinically not typical and conventional methods which are still the standard gold method often give false-negative results. So the purpose of this study was to evaluate the performance of culture and molecular diagnostic methods using the Polymerase Chain Reaction (PCR) technique in detecting Streptococcus pneumoniae in sputum clinical samples using the Autolysin (LytA) gene which is a virulence factor of this bacterium. 57 isolates from 60 samples were confirmed as Streptococcus sp through microscopic identification, culture, and biochemical tests. Then the sensitivity test with an optochin test of 9 (9%) compared the results descriptively with the PCR technique using the Autolysin A (LytA) gene which was obtained more sensitive by 15 (25%).

scholarly journals Validation of Differentially Expressed Immune Biomarkers in Latent and Active Tuberculosis by Real-Time PCR

2021 ◽  
Vol 11 ◽  
Author(s):  
Prem Perumal ◽  
Mohamed Bilal Abdullatif ◽  
Harriet N. Garlant ◽  
Isobella Honeyborne ◽  
Marc Lipman ◽  
...  
Keyword(s):  
Low Cost ◽  
Peripheral Blood Leukocyte ◽  
Primary Diagnosis ◽  
Diagnostic Methods ◽  
World Health ◽  
Molecular Diagnostic ◽  
Roc Curve Analysis ◽  
Simple Arithmetic ◽  
Immune Biomarkers ◽  
The Uk

Tuberculosis (TB) remains a major global threat and diagnosis of active TB ((ATB) both extra-pulmonary (EPTB), pulmonary (PTB)) and latent TB (LTBI) infection remains challenging, particularly in high-burden countries which still rely heavily on conventional methods. Although molecular diagnostic methods are available, e.g., Cepheid GeneXpert, they are not universally available in all high TB burden countries. There is intense focus on immune biomarkers for use in TB diagnosis, which could provide alternative low-cost, rapid diagnostic solutions. In our previous gene expression studies, we identified peripheral blood leukocyte (PBL) mRNA biomarkers in a non-human primate TB aerosol-challenge model. Here, we describe a study to further validate select mRNA biomarkers from this prior study in new cohorts of patients and controls, as a prerequisite for further development. Whole blood mRNA was purified from ATB patients recruited in the UK and India, LTBI and two groups of controls from the UK (i) a low TB incidence region (CNTRLA) and (ii) individuals variably-domiciled in the UK and Asia ((CNTRLB), the latter TB high incidence regions). Seventy-two mRNA biomarker gene targets were analyzed by qPCR using the Roche Lightcycler 480 qPCR platform and data analyzed using GeneSpring™ 14.9 bioinformatics software. Differential expression of fifty-three biomarkers was confirmed between MTB infected, LTBI groups and controls, seventeen of which were significant using analysis of variance (ANOVA): CALCOCO2, CD52, GBP1, GBP2, GBP5, HLA-B, IFIT3, IFITM3, IRF1, LOC400759 (GBP1P1), NCF1C, PF4V1, SAMD9L, S100A11, TAF10, TAPBP, and TRIM25. These were analyzed using receiver operating characteristic (ROC) curve analysis. Single biomarkers and biomarker combinations were further assessed using simple arithmetic algorithms. Minimal combination biomarker panels were delineated for primary diagnosis of ATB (both PTB and EPTB), LTBI and identifying LTBI individuals at high risk of progression which showed good performance characteristics. These were assessed for suitability for progression against the standards for new TB diagnostic tests delineated in the published World Health Organization (WHO) technology product profiles (TPPs).

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