scholarly journals A Simple PCR Method for Rapid Genotype Analysis ofMycobacterium ulcerans

2000 ◽  
Vol 38 (4) ◽  
pp. 1482-1487 ◽  
Author(s):  
Timothy Stinear ◽  
John K. Davies ◽  
Grant A. Jenkin ◽  
Françoise Portaels ◽  
Bruce C. Ross ◽  
...  

Two high-copy-number insertion sequences, IS2404 and IS2606, were recently identified in Mycobacterium ulcerans and were shown by Southern hybridization to possess restriction fragment length polymorphism between strains from different geographic origins. We have designed a simple genotyping method that captures these differences by PCR amplification of the region between adjacent copies of IS2404 and IS2606. We have called this system 2426 PCR. The method is rapid, reproducible, sensitive, and specific for M. ulcerans, and it has confirmed previous studies suggesting a clonal population structure ofM. ulcerans within a geographic region. M. ulcerans isolates from Australia, Papua New Guinea, Malaysia, Surinam, Mexico, Japan, China, and several countries in Africa were easily differentiated based on an array of 4 to 14 PCR products ranging in size from 200 to 900 bp. Numerical analysis of the banding patterns suggested a close evolutionary link between M. ulceransisolates from Africa and southeast Asia. The application of 2426 PCR to total DNA, extracted directly from M. ulcerans-infected tissue specimens without culture, demonstrated the sensitivity and specificity of this method and confirmed for the first time that both animal and human isolates from areas of endemicity in southeast Australia have the same genotype.

2003 ◽  
Vol 69 (12) ◽  
pp. 7248-7256 ◽  
Author(s):  
J. Schönfeld ◽  
H. Heuer ◽  
J. D. van Elsas ◽  
K. Smalla

ABSTRACT Ralstonia solanacearum is the causative agent of bacterial wilt in many important crops. A specific and sensitive PCR detection method that uses primers targeting the gene coding for the flagella subunit, fliC, was established. Based on the first fliC gene sequence of R. solanacearum strain K60 available at GenBank, the Ral_fliC PCR primer system was designed; this system yielded a single 724-bp product with the DNAs of all of the R. solanacearum strains tested. However, R. pickettii and four environmental Ralstonia isolates also yielded amplicons. The Ral_fliC PCR products obtained with 12 strains (R. solanacearum, R. pickettii, and environmental isolates) were sequenced. By sequence alignment, Rsol_fliC primers specific for R. solanacearum were designed. With this primer system, a specific 400-bp PCR product was obtained from all 82 strains of R. solanacearum tested. Six strains of R. pickettii and several closely related environmental isolates yielded no PCR product; however, a product was obtained with one Pseudomonas syzygii strain. A GC-clamped 400-bp fliC product could be separated in denaturing gradient gels and allowed us to distinguish P. syzygii from R. solanacearum. The Rsol_fliC PCR system was applied to detect R. solanacearum in soil. PCR amplification, followed by Southern blot hybridization, allowed us to detect about one target DNA molecule per PCR, which is equivalent to 103 CFU g of bulk soil−1. The system was applied to survey soils from different geographic origins for the presence of R. solanacearum.


2019 ◽  
Vol 50 (3) ◽  
Author(s):  
Faraj & et al.

 The present study was planned to investigate equine babesiosis in dragging horses in Baghdad city, Iraq by using microscopical and molecular (PCR) techniques. 150 blood samples of horses examined for Theileria equi and Babesia caballi. 16.66% (25/150) were positive by microscopic examination. No significant difference was observed in infection rates between male and female horses and among different age groups. The result showed that PCR method has high rate of infection36% (9/25). Nine positive PCR products were sequenced and deposited in Genebank data base for first time in Iraq, phylogenic analysis demonstrated that 5 sequences belongs to T. equi (MK350319, MK346272, MK346273, MK346274 and MK36275), while 4 sequence (MK346276, MK346277, MK346278 and MK350318) belongs to B. caballi, and mounted a low genetic variation 0.035 and 0.05 respectively, among other comparison isolates. In conclusion PCR technique followed by phylogenic tree analysis a reliable methods for epidemiological, diagnosis and identification of genetic variants studies.


2021 ◽  
Vol 182 (2) ◽  
pp. 114-122
Author(s):  
B. B. Thinh ◽  
R. V. Doudkin ◽  
L. D. Chac ◽  
H. V. Chinh ◽  
Q. V. Hoi ◽  
...  

Background. Tinomiscium petiolare Hook.f. & Thomson is a medicinal species of the family Menispermaceae. This species is currently being intensively exploited for therapeutic purposes. Precise and rapid identification of T. petiolare is critical and essential for the classification, propagation, use and conservation of its genetic resources. In recent years, DNA barcoding has been known to be a fast and sensitive method for identifying species at any stage of development, using short DNA sequences. In this study we have performed the identification of T. petiolare specimens in Vietnam based on the sequence analysis of 4 DNA barcode loci: ITS, matK, rbcL and rpoC.Materials and methods. Total DNA was extracted from leaf samples using DNeasy Plant Mini Kit. PCR amplification of the ITS, matK, rbcL and rpoC regions was carried out on the GeneAmp PCR System 9700 with specific primers. The purified PCR products were sequenced on the ABI 3500 Genetic Analyzer system, using BigDye®Terminator v3.1 Cycle Sequencing Kit. These genetic sequences were analyzed and compared, and a phylogenetic tree was constructed using BioEdit, BLAST, and MEGA 6 programs.Results and conclusion. The success rate of amplification and sequencing was 100% for all 4 DNA barcode loci (ITS, matK, rbcL and rpoC) in the studied specimens. The produced sequence sizes of ITS, matK, rbcL and rpoC in the specimens were 574 bp, 810 bp, 527 bp and 488 bp, respectively. Further, we identified that all studied specimens were genetically related to each other and associated with the same species T. petiolare. Overall, the results of the study generated the most complete DNA barcode database of T. petiolare collected in Vietnam, contributing to the taxonomy and identification of this species. 


Plant Disease ◽  
2002 ◽  
Vol 86 (6) ◽  
pp. 652-660 ◽  
Author(s):  
Sansanalak Rachdawong ◽  
Carole L. Cramer ◽  
Elizabeth A. Grabau ◽  
Verlyn K. Stromberg ◽  
George H. Lacy ◽  
...  

Identifying take-all pathogens, Gaeumannomyces graminis varieties avenae (Gga), graminis (Ggg), and tritici (Ggt), is difficult. Rapid identification is important for development of disease thresholds. We developed a single-tube, polymerase chain reaction (PCR) method differentiating among Gga, Ggg, and Ggt. Nucleotide base sequence analyses of avenacinase-like genes from Gga, Ggg, and Ggt isolates provided the basis for designing variety-specific primers. Sequences from Ggg and Ggt were highly related (99% identity), but Gga sequences were <95% identical to Ggg and Ggt sequences. Three 5′ primers specific for Gga, Ggt, and Ggg and a single 3′ common primer allowed amplification of variety-specific fragments of 617, 870, and 1,086 bp, respectively. Each 5′ primer was specific in mixed populations of primers and templates. No PCR products were amplified from related fungi including Gaeumannomyces cylindrosporus and Phialophora spp. We surveyed 16 putative Ggt isolates using our assay; nine produced Ggt-specific fragments and seven produced Ggg-specific fragments. Five Gga isolates produced Gga-specific fragments. However, Gga- and Ggt-specific fragments were observed from a sixth Gga isolate, RB-W, which indicates a mixed culture or a heterokaryon. Our single-tube, PCR method rapidly differentiates among the important take-all pathogens commonly encountered together in cereal fields.


2021 ◽  
Vol 41 (2) ◽  
Author(s):  
Anton Urfels ◽  
Andrew J. McDonald ◽  
Gerardo van Halsema ◽  
Paul C. Struik ◽  
Pankaj Kumar ◽  
...  

AbstractTimely crop planting is a foundation for climate-resilient rice-wheat systems of the Eastern Gangetic Plains—a global food insecurity and poverty hotspot. We hypothesize that the capacity of individual farmers to plant on time varies considerably, shaped by multifaceted enabling factors and constraints that are poorly understood. To address this knowledge gap, two complementary datasets were used to characterize drivers and decision processes that govern the timing of rice planting in this region. The first dataset was a large agricultural management survey (rice-wheat: n = 15,245; of which rice: n = 7597) from a broad geographic region that was analyzed by machine learning methods. The second dataset was a discussion-based survey (n = 112) from a more limited geography that we analyzed with graph theory tools to elicit nuanced information on planting decisions. By combining insights from these methods, we show for the first time that differences in rice planting times are primarily shaped by ecosystem and climate factors while social factors play a prominent secondary role. Monsoon onset, surface and groundwater availability, and land type determine village-scale mean planting times whereas, for resource-constrained farmers who tend to plant later ceteris paribus, planting is further influenced by access to farm machinery, seed, fertilizer, and labor. Also, a critical threshold for economically efficient pumping appears at a groundwater depth of around 4.5 m; below this depth, farmers do not irrigate and delay planting. Without collective action to spread risk through synchronous timely planting, ecosystem factors such as threats posed by pests and wild animals may further deter early planting by individual farmers. Accordingly, we propose a three-pronged strategy that combines targeted strengthening of agricultural input chains, agroadvisory development, and coordinated rice planting and wildlife conservation to support climate-resilient agricultural development in the Eastern Gangetic Plains.


Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Sohyun Lee ◽  
Nanjoo Park ◽  
Sujung Yun ◽  
Eunseon Hur ◽  
Jiwon Song ◽  
...  

AbstractNon-typhoidal salmonellosis remains a pressing public health problem worldwide. Quinolones, particularly fluoroquinolones, are widely used to treat various infections, including non-typhoidal salmonellosis, which can be a serious illness. The emergence of fluoroquinolone-resistant Salmonella has resulted in treatment failure and high mortality rates. In this study, we estimated the presence of plasmid-mediated quinolone resistance (PMQR) genes in Salmonella enterica isolated from human salmonellosis patients in South Korea from 2016 to 2019. We evaluated the association of these genes with fluoroquinolone susceptibility. Antimicrobial susceptibility tests for Salmonella isolates were performed using the Vitek II system, and the minimum inhibitory concentrations (MIC) of ciprofloxacin and levofloxacin were determined using the E-test method. Plasmid-mediated quinolone resistance (PMQR) genes were detected by PCR amplification and quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes were analyzed following Sanger sequencing of the PCR products. Thirty-four Salmonella strains with reduced susceptibility to fluoroquinolones (ciprofloxacin MIC ≥ 0.125 µg/mL and levofloxacin MIC ≥ 0.25 µg/mL) were selected from 208 human clinical Salmonella isolates. Among them, 22 Salmonella strains harbored one PMQR gene (qnrA, qnrB, or qnrS), and three Salmonella strains carried two PMQR genes (qnrS and aac(6′)-Ib-cr or qnrA and qnrB). qnrS was the most common PMQR gene. Serotyping revealed that Salmonella 4,[5]12:i:- (32.4%, 11/34) and Salmonella Typhimurium (29.4%, 10/34) were the two most predominant serovars, and Multi-locus sequence typing (MLST) showed that ST19 and ST34 were the most frequent sequence types. In conclusion, qnr gene-positive Salmonella 4,[5],12:i:- and Salmonella Typhimurium were the main serovars responsible for reduced susceptibility to fluoroquinolones. Therefore, our findings suggest that PMQR-positive Salmonella strains, which can be isolated from various samples including human, food, and the environment, should be carefully monitored.


Parasitology ◽  
2002 ◽  
Vol 124 (2) ◽  
pp. 177-184 ◽  
Author(s):  
M. B. A. MENDONÇA ◽  
N. S. NEHME ◽  
S. S. SANTOS ◽  
E. CUPOLILLO ◽  
N. VARGAS ◽  
...  

Trypanosoma cruzi is currently classified into 2 major phylogenetic lineages, T. cruzi I and II, that correlate with the formerly described zymodeme 1 and 2, respectively. Another isoenzymic group (zymodeme 3–Z3) was also described. In this study, we analysed the genetic diversity among Z3 isolates of the Brazilian Amazon by restriction fragment length polymorphism of the intergenic transcribed spacers (ITSs) of the ribosomal RNA cistron and the size of the divergent domain D7 of the 24Sα rRNA gene. DNAs from 12 T. cruzi Z3 isolates obtained from humans (2), Panstrongylus geniculatus (1), and Rhodnius brethesi (9) were submitted to PCR amplification of the ITSs plus the 5·8S rDNA. The PCR products were digested with 4 distinct endonucleases and the profiles analysed by a numerical methodology. The phenetic dendrogram revealed a clear dichotomy in the Z3 group, defining 2 groups that were named Z3-A and Z3-B. Dimorphism was also found in the band sizes of the amplified D7 divergent domain of the 24Sα rDNA, which showed a perfect correlation with the ITSs clustering. The organization of the ribosomal cistron was investigated by Southern blotting and shown to be conserved in the genome of the 2 Z3 groups. This study shows that the rDNA cistron allows the definition of 2 distinct subclusters in Z3 isolates.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Silvana Pompéia Val-Moraes ◽  
Eliamar Aparecida Nascimbem Pedrinho ◽  
Eliana Gertrudes Macedo Lemos ◽  
Lucia Maria Carareto-Alves

Fungi constitute an important part of the soil ecosystem, playing key roles in decomposition, cycling processes, and biotic interactions. Molecular methods have been used to assess fungal communities giving a more realistic view of their diversity. For this purpose, total DNA was extracted from bulk soils cultivated with tomato (STC), vegetables (SHC), and native forest (SMS) from three sites of the Taquara Branca river basin in Sumaré County, São Paulo State, Brazil. This metagenomic DNA was used as a template to amplify fungal 18S rDNA sequences, and libraries were constructed inEscherichia coliby cloning PCR products. The plasmid inserts were sequenced and compared to known rDNA sequences in the GenBank database. Of the sequenced clones, 22 were obtained from the SMS sample, 18 from the SHC sample, and 6 from the STC sample. Although most of the clone sequences did not match the sequences present in the database, individual amplified sequences matched with Glomeromycota (SMS), Fungi incertae sedis (SMS), and Neocallimastigomycota (SHC). Most of the sequences from the amplified taxa represent uncultured fungi. The molecular analysis of variance (AMOVA) indicated that fluctuations observed of haplotypes in the composition may be related to herbicide application.


2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Xiaoxiao Zhu ◽  
Hoi-Yan Wu ◽  
Pang-Chui Shaw ◽  
Wei Peng ◽  
Weiwei Su

Abstract Background Pheretima is a minister drug in Naoxintong capsule (NXTC), a well-known traditional Chinese medicine (TCM) formula for the treatment of cardiovascular and cerebrovascular diseases. Owing to the loss of morphological and microscopic characteristics and the lack of recognized chemical marker, it is difficult to identify Pheretima in NXTC. This study aims to evaluate the feasibility of using DNA techniques to authenticate Pheretima, especially when it is processed into NXTC. Methods DNA was extracted from crude drugs of the genuine and adulterant species, as well as nine batches of NXTCs. Based on mitochondrial cytochrome c oxidase subunit I (COI) gene, specific primers were designed for two genera of genuine species, Metaphire and Amynthas, respectively. PCR amplification was performed with the designed primers on crude drugs of Pheretima and NXTCs. The purified PCR products were sequenced and the obtained sequences were identified to species level with top hit of similarity with BLAST against GenBank nucleotide database. Results Primers MF2R2 and AF3R1 could amplify specific DNA fragments with sizes around 230–250 bp, both in crude drugs and NXTC. With sequencing and the BLAST search, identities of the tested samples were found. Conclusion This study indicated that the molecular approach is effective for identifying Pheretima in NXTC. Therefore, DNA identification may contribute to the quality control and assurance of NXTC.


2007 ◽  
Vol 32 (5) ◽  
pp. 373-380 ◽  
Author(s):  
Jorge F. Pereira ◽  
Mariana D.C. Ignacchiti ◽  
Elza F. Araújo ◽  
Sérgio H. Brommonschenkel ◽  
Júlio C.M. Cascardo ◽  
...  

Reverse transcriptase (RT) sequence analysis is an important technique used to detect the presence of transposable elements in a genome. Putative RT sequences were analyzed in the genome of the pathogenic fungus C. perniciosa, the causal agent of witches' broom disease of cocoa. A 394 bp fragment was amplified from genomic DNA of different isolates of C. perniciosa belonging to C-, L-, and S-biotypes and collected from various geographical areas. The cleavage of PCR products with restriction enzymes and the sequencing of various RT fragments indicated the presence of several sequences showing transition events (G:C to A:T). Southern blot analysis revealed high copy numbers of RT signals, forming different patterns among C-, S-, and L-biotype isolates. Sequence comparisons of the predicted RT peptide indicate a close relationship with the RT protein from thegypsy family of LTR-retrotransposons. The possible role of these retrotransposons in generating genetic variability in the homothallic C. perniciosa is discussed.


Sign in / Sign up

Export Citation Format

Share Document