Development of a real-time PCR for detection of the oyster pathogen Nocardia crassostreae based on its homogeneous 16S–23S rRNA intergenic spacer region

2013 ◽  
Vol 114 (2) ◽  
pp. 120-127 ◽  
Author(s):  
Noèlia Carrasco ◽  
Ineke Roozenburg ◽  
Michal Voorbergen-Laarman ◽  
Naoki Itoh ◽  
Marc Y. Engelsma
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Intergenic Spacer ◽  
23S Rrna ◽  
Intergenic Spacer Region

scholarly journals Characterization of a novel Mycoplasma cynos real-time PCR assay

2019 ◽  
Vol 32 (6) ◽  
pp. 793-801 ◽  
Author(s):  
Rebecca L. Tallmadge ◽  
Renee Anderson ◽  
Patrick K. Mitchell ◽  
Zachary C. Forbes ◽  
Brenda Werner ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Intergenic Spacer ◽  
High Specificity ◽  
Mycoplasma Species ◽  
Limit Of Quantification ◽  
Clinical Specimens ◽  
Intergenic Spacer Region ◽  
Tuf Gene ◽  
Gene Assay

Mycoplasma cynos is recognized as an emerging causative pathogen of canine infectious respiratory disease (CIRD) worldwide. We developed a new open-source real-time PCR (rtPCR) assay for M. cynos that performs well under standard rtPCR conditions. Primers and probes were designed to target the M. cynos tuf gene. Reaction efficiencies for the M. cynos tuf gene assay on 2 platforms were based on amplification of standard curves spanning 8 orders of magnitude: ABI 7500 platform, 94.3–97.9% ( r2 ≥ 0.9935); QuantStudio OpenArray platform, 119.1–122.5% ( r2 = 0.9784). The assay performed very well over a range of template input, from 109 copies to the lower limit of quantification at 4 copies of the M. cynos genome on the ABI 7500 platform. Diagnostic performance was estimated by comparison with an in-house legacy assay on clinical specimens as well as testing isolates that were characterized previously by intergenic spacer region (ISR) sequencing. Exclusivity was established by testing 12 other Mycoplasma species. To substantiate the high specificity of the M. cynos tuf gene assay, sequence confirmation was performed on ISR PCR amplicons obtained from clinical specimens. One ISR amplicon sequence revealed M. mucosicanis rather than M. cynos. The complete protocol of the newly developed M. cynos tuf assay is provided to facilitate assay harmonization.

New PCR-based assay for the identification of Pectobacterium carotovorum causing potato soft rot

Plant Disease ◽  
2021 ◽  
Author(s):  
M. Belén Suárez ◽  
Marta Diego ◽  
F. J. Feria ◽  
M J Martín-Robles ◽  
Sergio Moreno ◽  
...  
Keyword(s):  
Real Time ◽  
Dna Sequences ◽  
Real Time Pcr ◽  
Bacterial Species ◽  
Intergenic Spacer ◽  
Soft Rot ◽  
Pcr Analysis ◽  
Rrna Gene ◽  
Accurate Identification ◽  
Intergenic Spacer Region

Soft rot on potato tuber is a destructive disease caused by pathogenic bacterial species of the genera Pectobacterium and Dickeya. Accurate identification of the causal agent is necessary to ensure adequate disease management, since different species may have distinct levels of aggressiveness and host range. One of the most important potato pathogens is P. carotovorum, a highly heterogeneous species capable of infecting multiple hosts. The complexity of this species, until recently divided into several subspecies, has made it difficult to develop precise diagnostic tests. This study proposes a PCR assay based on the new pair of primers Pcar1F/R to facilitate the identification of potato isolates of P. carotovorum according to the most recent taxonomic description of this species. The new primers were designed on a variable segment of the 16S rRNA gene and the intergenic spacer region (ITS) of available DNA sequences from classical and recently established species in the genus Pectobacterium. The results of the PCR analysis of genomic DNA from 32 Pectobacterium and Dickeya strains confirmed that the Pcar1F/R primers have sufficient nucleotide differences to discriminate between P. carotovorum and other Pectobacterium species associated with damage to potato crops, with the exception of P. versatile, which improves the specificity of the currently available primers. The proposed assay was originally developed as a conventional PCR but was later adapted to the real-time PCR format for application in combination with the existing real-time PCR test for the potato-specific pathogen P. parmentieri. This should be useful for the routine diagnosis of potato soft rot.

scholarly journals Application of Real-Time PCR for Quantification of Microcystin Genotypes in a Population of the Toxic Cyanobacterium Microcystis sp

2003 ◽  
Vol 69 (11) ◽  
pp. 6723-6730 ◽  
Author(s):  
Rainer Kurmayer ◽  
Thomas Kutzenberger
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Total Population ◽  
Intergenic Spacer ◽  
Threshold Level ◽  
Logarithmic Scale ◽  
Cycle Number ◽  
Intergenic Spacer Region ◽  
Cell Numbers ◽  
The Mean

ABSTRACT The cyanobacterium Microcystis sp. frequently develops water blooms consisting of organisms with different genotypes that either produce or lack the hepatotoxin microcystin. In order to monitor the development of microcystin (mcy) genotypes during the seasonal cycle of the total population, mcy genotypes were quantified by means of real-time PCR in Lake Wannsee (Berlin, Germany) from June 1999 to October 2000. Standard curves were established by relating cell concentrations to the threshold cycle (the PCR cycle number at which the fluorescence passes a set threshold level) determined by the Taq nuclease assay (TNA) for two gene regions, the intergenic spacer region within the phycocyanin (PC) operon to quantify the total population and the mcyB gene, which is indicative of microcystin synthesis. In laboratory batch cultures, the cell numbers inferred from the standard curve by TNA correlated significantly with the microscopically determined cell numbers on a logarithmic scale. The TNA analysis of 10 strains revealed identical amplification efficiencies for both genes. In the field, the proportion of mcy genotypes made up the smaller part of the PC genotypes, ranging from 1 to 38%. The number of mcyB genotypes was one-to-one related to the number of PC genotypes, and parallel relationships between cell numbers estimated via the inverted microscope technique and TNA were found for both genes. It is concluded that the mean proportion of microcystin genotypes is stable from winter to summer and that Microcystis cell numbers could be used to infer the mean proportion of mcy genotypes in Lake Wannsee.

Conventional and real-time PCR assays for specific detection and quantification of Fusarium oxysporum f. sp. ciceris in plants using intergenic spacer region-based marker

Biologia ◽  
2015 ◽  
Vol 70 (3) ◽  
Author(s):  
Kumari Priyanka ◽  
Sunil C. Dubey ◽  
Arun K. Singh
Keyword(s):  
Fusarium Oxysporum ◽  
Host Plant ◽  
Real Time ◽  
Real Time Pcr ◽  
Infected Plant ◽  
Intergenic Spacer ◽  
Infected Host ◽  
Pcr Assay ◽  
Intergenic Spacer Region ◽  
Plant Samples

AbstractFusarium wilt of chickpea, caused by Fusarium oxysporum f. sp. ciceris (Foc) is one of the most important fungal diseases worldwide. The detection of the pathogen at reasonable time period is of great importance, which requires rapid and sensitive detection methods. The intraspecific divergence sequences found in the intergenic spacer region (IGS) were selected and utilized with the aim to develop a molecular marker specifically to identify the Foc. A marker set, ISR52 F1 and R1 developed, was tested for their specificity as well as sensitivity using conventional as well as real-time polymerase chain reaction (PCR). The specificity of the marker was tested against Foc, other Fusarium species which are closely related to Foc as well as with artificially infected host plant samples. The detection limits of conventional PCR assay was up to 100 pg of infected plant DNA. It proved possible to amplify the IGS region in different portion of a Foc infected host plant by this PCR method. Furthermore, the real-time assay showed more sensitivity and was able to detect the pathogen in infected chickpea plant samples at the DNA concentration of 5 pg. A single melting peak obtained at 87.5°C showed the specificity of the marker towards Foc. Thus, real-time PCR assay proved their potentiality for same-day diagnosis of fungal infection and can be used as a rapid and effective procedure for routine detection and identification of Foc in chickpea samples.

scholarly journals Prevalence and phylogenetic analysis of Mycoplasma synoviae strains isolated from Polish chicken layer flocks

2019 ◽  
Vol 63 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Olimpia Kursa ◽  
Grzegorz Tomczyk ◽  
Anna Sawicka
Keyword(s):  
Phylogenetic Analysis ◽  
Real Time ◽  
Real Time Pcr ◽  
Genetic Material ◽  
Clinical Signs ◽  
Intergenic Spacer ◽  
Lamp Method ◽  
Conventional Pcr ◽  
Mycoplasma Synoviae ◽  
Intergenic Spacer Region

AbstractIntroduction:Mycoplasma synoviae(MS) is a chicken pathogen of major economic importance.Material and Methods:Between 2010 and 2016, 906 commercial layer chicken flocks in Poland were examined for MS, and the phylogenetic relationship among the strains was established. Regionally dispersed samples were collected and tested with the use of real-time PCR to detect the 16S–23S intergenic spacer region. Positive samples were also tested with LAMP and conventional PCR to detect thevlhAgene.Results:MS genetic material was detected in 265 (29%) of the tested flocks by real-time PCR, in 227 by the LAMP method and in 202 (22%) by conventional PCR. The by-year percentage of positive samples began at 34% in 2010, rose to 44% in 2012, and declined to 29% in 2016. A phylogenetic analysis of PolishM. synoviaestrains using a partial sequence of thevlhAgene showed nine genotypes (A–I), the most frequently occurring being F and C. Pathogenic Polish MS field isolates (n = 27) collected from chickens with clinical signs of infection were grouped for their characteristic symptoms: respiratory for genotypes C, E, F, and I (n = 13), EAA and a drop in laying for genotypes F, E, and C (n = 12), and synovitis for genotype A (n = 2).Conclusion:These data showed the country’s isolate diversity. The high prevalence suggests the need to introduce appropriate control programmes. This is the first report of molecular epidemiological data onM. synoviaeinfection in layer chickens in Poland.

Genomic fingerprinting ofFrankiamicrosymbionts fromCeanothuscopopulations using repetitive sequences and polymerase chain reactions

1999 ◽  
Vol 77 (9) ◽  
pp. 1220-1230 ◽  
Author(s):  
Soon-Chun Jeong ◽  
David D Myrold
Keyword(s):  
Dna Sequencing ◽  
Dna Analysis ◽  
Repetitive Sequences ◽  
Intergenic Spacer ◽  
Rrna Genes ◽  
23S Rrna ◽  
Genomic Fingerprinting ◽  
Chain Reactions ◽  
Intergenic Spacer Region ◽  
Polymerase Chain

Specificity between Ceanothus species and their microsymbionts, Frankia, were investigated with nodules collected from three geographically separated copopulations of Ceanothus species. Nodules were analyzed using DNA sequencing and repetitive sequence polymerase chain reaction (rep-PCR) techniques. DNA sequencing of the intergenic spacer region between 16S and 23S rRNA genes suggested that Ceanothus-microsymbiotic Frankia are closely related at the intraspecific level. Diversity of the microsymbionts was further analyzed by genomic fingerprinting using repetitive sequences and PCR. A newly designed direct repeat (DR) sequence and a BOX sequence were used as PCR primers after justification that these primers can generate Frankia-specific fingerprints from nodule DNA. Analysis of the nodules using BOX- and DR-PCR showed that Ceanothus-microsymbiotic Frankia exhibited less diversity within each copopulation than among copopulations. These data suggested that geographic separation plays a more important role for divergence of Ceanothus-microsymbiotic Frankia than host plant.Key words: Frankia, Ceanothus, rep-PCR, diversity.

scholarly journals Molecular Detection and Characterization of Borrelia garinii (Spirochaetales: Borreliaceae) in Ixodes nipponensis (Ixodida: Ixodidae) Parasitizing a Dog in Korea

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 289 ◽  
Author(s):  
Seung-Hun Lee ◽  
Youn-Kyoung Goo ◽  
Paul John L. Geraldino ◽  
Oh-Deog Kwon ◽  
Dongmi Kwak
Keyword(s):  
Molecular Detection ◽  
Single Gene ◽  
Protein A ◽  
Intergenic Spacer ◽  
Surface Protein ◽  
23S Rrna ◽  
Borrelia Garinii ◽  
Intergenic Spacer Region ◽  
Individual Level ◽  
Pcr Targeting

The present study aimed to detect and characterize Borrelia spp. in ticks attached to dogs in Korea. Overall, 562 ticks (276 pools) attached to dogs were collected and tested for Borrelia infection by PCR targeting the 5S-23S rRNA intergenic spacer region (rrf-rrl). One tick larva (pool level, 0.4%; individual level, 0.2%) was confirmed by sequencing Borrelia garinii, a zoonotic pathogen. For molecular characterization, the outer surface protein A (ospA) and flagellin genes were analyzed. Phylogenetic ospA analysis distinguished B. garinii from B. bavariensis, which has been recently identified as a novel Borrelia species. On the other hand, phylogenetic analysis showed that single gene analysis involving rrf-rrl or flagellin was not sufficient to differentiate B. garinii from B. bavariensis. In addition, the B. garinii-infected tick was identified as Ixodes nipponensis by sequencing according to mitochondrial 16S rRNA and the second transcribed spacer region. To our knowledge, this is the first study to report the molecular detection of B. garinii in I. nipponensis parasitizing a dog in Korea. Continuous monitoring of tick-borne pathogens in ticks attached to animals is required to avoid disease distribution and possible transmission to humans.

Differentiation of group VIII Spiroplasma strains with sequences of the 16S–23S rDNA intergenic spacer region

2004 ◽  
Vol 50 (12) ◽  
pp. 1061-1067 ◽  
Author(s):  
Laura B Regassa ◽  
Kimberly M Stewart ◽  
April C Murphy ◽  
Frank E French ◽  
Tao Lin ◽  
...  
Keyword(s):  
Intergenic Spacer ◽  
Analytical Models ◽  
23S Rrna ◽  
Rrna Gene ◽  
Group Viii ◽  
Similarity Coefficients ◽  
Intergenic Spacer Region ◽  
Intergenic Sequences ◽  
The Stability ◽  
The 16S Rrna Gene

Spiroplasma species (Mollicutes: Spiroplasmataceae) are associated with a wide variety of insects, and serology has classified this genus into 34 groups, 3 with subgroups. The 16S rRNA gene has been used for phylogenetic analysis of spiroplasmas, but this approach is uninformative for group VIII because the serologically distinct subgroups generally have similarity coefficients >0.990. Therefore, we investigated the utility of the 16S–23S rRNA spacer region as a means to differentiate closely related subgroups or strains. We generated intergenic sequences and detailed serological profiles for 8 group VIII Spiroplasma strains. Sequence analyses using Maximum Parsimony, Neighbor Joining, and Maximum Likelihood placed the strains into 2 clades. One clade consisted of strains BARC 2649 and GSU5367. The other clade was divided into clusters containing representatives of the 3 designated group VIII subgroups (EA-1, DF-1, and TAAS-1) and 3 previously unclassified strains. The stability of the positions of the strains in various analytical models and the ability to provide robust support for groupings tentatively supported by serology indicates that the 16S–23S intergenic rDNA sequence will prove useful in intragroup analysis of group VIII spiroplasmas.Key words: Mollicutes, Spiroplasma, phylogeny, Tabanidae.

A putative transposase gene in the 16S–23S rRNA intergenic spacer region of Mycoplasma imitans

Microbiology ◽  
2004 ◽  
Vol 150 (4) ◽  
pp. 1023-1029 ◽  
Author(s):  
Ryô Harasawa ◽  
David G. Pitcher ◽  
Ana S. Ramírez ◽  
Janet M. Bradbury
Keyword(s):  
Relative Size ◽  
Intergenic Spacer ◽  
Its Region ◽  
23S Rrna ◽  
Mycoplasma Species ◽  
Insertion Element ◽  
Transposase Gene ◽  
Intergenic Spacer Region ◽  
Pcr Products ◽  
Type Strains

Examination of the nucleotide sequences of the 16S–23S intergenic transcribed spacer (ITS) region of Mycoplasma imitans and Mycoplasma gallisepticum identified a putative transposase gene located only in the ITS of M. imitans, which can be used as a genetic marker to distinguish these two species. The relative size of the PCR products of the ITS region allowed a clear distinction to be made between strains of M. imitans and M. gallisepticum, both of which could be readily discriminated from the type strains of all the other recognized avian Mycoplasma species. In addition, the putative transposase gene assigned in the ITS of M. imitans was shown to include a sequence homologous to that of the P75 gene of M. gallisepticum. This is believed to be the first description of an insertion element in the rRNA operon region of a mycoplasma species.

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