Estimating Giardia cyst viability using RT-PCR

2002 ◽  
Vol 2 (3) ◽  
pp. 107-115 ◽  
Author(s):  
M. Maux ◽  
I. Bertrand ◽  
C. Gantzer ◽  
J. Schwartzbrod
Keyword(s):  
Nested Pcr ◽  
Target Genes ◽  
Molecular Techniques ◽  
Giardia Cyst ◽  
Health Issues ◽  
Structural Protein ◽  
Gene Encoding ◽  
Response To Stress ◽  
Pcr Method ◽  
Giardia Cysts

The aim of this work was to evaluate the use of molecular techniques for the detection of viable Giardia cysts in the environment to assess public health issues. Three target genes were selected: the heat shock protein gene, HSP70, which is expressed in response to stress; the giardin gene, which encodes a structural protein; and, alcohol dehydrogenase E (ADHE), a novel gene encoding an enzyme involved in the metabolism of energy. We tested the efficiency of five protocols for the extraction of either genomic DNA or total RNA from Giardia cysts: two of these protocols were previously cited in the literature and three consisted of commercial DNA extraction kits. The brands of enzyme were determined according to the primers chosen and the amplification conditions were optimised: 2.5 mM MgCl2, 0.5 mM primers and 60°C for annealing temperature. A semi-nested PCR method and an RT semi-nested PCR procedure were developed to detect mRNA from these three genes and to estimate the viability of Giardia cysts.

scholarly journals Clinical Evaluation of a New PCR Assay for Detection of Coxiella burnetii in Human Serum Samples

1998 ◽  
Vol 36 (1) ◽  
pp. 77-80 ◽  
Author(s):  
G. Q. Zhang ◽  
Sa V. Nguyen ◽  
H. To ◽  
M. Ogawa ◽  
A. Hotta ◽  
...  
Keyword(s):  
Human Serum ◽  
Coxiella Burnetii ◽  
Nested Pcr ◽  
Restriction Enzymes ◽  
Pcr Assay ◽  
Serum Samples ◽  
Gene Encoding ◽  
Human Serum Samples ◽  
Positive Serum ◽  
Pcr Method

A nested PCR method was developed for the detection ofCoxiella burnetii in human serum samples. Two pairs of oligonucleotide primers were designed to amplify a 438-bp fragment of the com1 gene encoding a 27-kDa outer membrane protein ofC. burnetii. The primers amplified the predicted fragments of 21 various strains of C. burnetii but did not react with DNA samples from other microorganisms. The 438-bp amplification products could be digested with restriction enzymes SspI and SalI. The utility of the nested PCR was evaluated by testing human serum samples. The com1 gene fragment was amplified from 135 (87%) of 155 indirect immunofluorescence test (IF)-positive serum samples and from 11 (11%) of 100 IF-negative serum samples. The nested PCR with primers targeted to the com1gene appeared to be a sensitive, specific, and useful method for the detection of C. burnetii in serum samples.

scholarly journals Comparison of Leifsonia xyli subsp. xyli molecular detection in heat-treated sugarcane setts1

2019 ◽  
Vol 49 ◽  
Author(s):  
Vanessa Duarte Dias ◽  
Renato Carrer Filho ◽  
Marcos Gomes da Cunha
Keyword(s):  
Nested Pcr ◽  
Bacterial Population ◽  
Positive Control ◽  
Molecular Techniques ◽  
Conventional Pcr ◽  
Bacterial Dna ◽  
Heat Treated ◽  
Pcr Method ◽  
Management Method ◽  
Primary Management

ABSTRACT The thermotherapy of sugarcane setts is currently the primary management method for Leifsonia xyli subsp. xyli (Lxx), in Brazil. When they are immersed, the enzymes and proteins of the bacterial cell are denatured without harming the setts buds. Due to possible escapes from detection and consequent bacterium survival to thermotherapy, what may result in asymptomatic seedlings, this study aimed to detect the Leifsonia xyli subsp. xyli bacterium in sugarcane setts using molecular techniques and different time and temperature combinations, with or without the addition of antibiotics. The conventional PCR method detected the Lxx bacterial DNA only in the positive control, consisting of a highly susceptible plant with a high bacterial concentration. Using the nested-PCR, the Lxx DNA was detected in all the treatments used. Thus, none of the treatments adopted in the thermotherapy was able to eliminate the Lxx from the setts, and the use of kasugamicin also did not eliminate the bacterium, but reduced the bacterial population in the tested treatments. These results confirm that the nested-PCR is a useful tool to detect the presence of this phytobacterium in setts that will be used as seedlings.

Characterisation of Type 2N von Willebrand Disease Using Phenotypic and Molecular Techniques

1996 ◽  
Vol 75 (06) ◽  
pp. 959-964 ◽  
Author(s):  
I M Nesbitt ◽  
A C Goodeve ◽  
A M Guilliatt ◽  
M Makris ◽  
F E Preston ◽  
...  
Keyword(s):  
Direct Sequencing ◽  
Von Willebrand Disease ◽  
Molecular Techniques ◽  
Haemophilia A ◽  
Binding Region ◽  
Gene Encoding ◽  
Covalently Linked ◽  
Von Willebrand ◽  
Willebrand Factor

Summaryvon Willebrand factor (vWF) is a multimeric glycoprotein found in plasma non covalently linked to factor VIII (FVIII). Type 2N von Willebrand disease (vWD) is caused by a mutation in the vWF gene that results in vWF with a normal multimeric pattern, but with reduced binding to FVIII.We have utilised methods for the phenotypic and genotypic detection of type 2N vWD. The binding of FVIII to vWF in 69 patients, 36 with type 1 vWD, 32 with mild haemophilia A and one possible haemophilia A carrier with low FVIII levels was studied. Of these, six were found to have reduced binding (five type 1 vWD, one possible haemophilia A carrier), DNA was extracted from these patients and exons 18-23 of the vWF gene encoding the FVIII binding region of vWF were analysed. After direct sequencing and chemical cleavage mismatch detection, a Thr28Met mutation was detected in two unrelated individuals, one of whom appears to be a compound heterozygote for the mutation and a null allele. No mutations were found in the region of the vWF gene encoding the FVIII binding region of vWF in the other four patients

scholarly journals Development and validation of a multiplex qPCR assay for detection and relative quantification of HPV16 and HPV18 E6 and E7 oncogenes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexia Bordigoni ◽  
Anne Motte ◽  
Hervé Tissot-Dupont ◽  
Philippe Colson ◽  
Christelle Desnues
Keyword(s):  
Limit Of Detection ◽  
Quantitative Polymerase Chain Reaction ◽  
Human Papillomaviruses ◽  
Molecular Techniques ◽  
Clinical Samples ◽  
Gene Encoding ◽  
Hpv Dna ◽  
E6 And E7 ◽  
High Risk Hpv ◽  
Development And Validation

AbstractHuman papillomaviruses (HPV) play a key role in promoting human anogenital cancers. Current high-risk HPV screening or diagnosis tests involve cytological or molecular techniques mostly based on qualitative HPV DNA detection. Here, we describe the development of a rapid quantitative polymerase chain reaction (qPCR) detection test of HPV16 and HPV18 oncogenes (E6 and E7) normalized on human gene encoding GAPDH. Optimized qPCR parameters were defined, and analytical specificities were validated. The limit of detection was 101 for all genes tested. Assay performances were evaluated on clinical samples (n = 96). Concordance between the Xpert HPV assay and the triplex assay developed here was 93.44% for HPV16 and 73.58% for HPV18. HPV co-infections were detected in 15 samples. The systems developed in the present study can be used in complement to traditional HPV tests for specifically validating the presence of HPV16 and/or HPV18. It can also be used for the follow-up of patients with confirmed infection and at risk of developing lesions, through the quantification of E6 and E7 oncogene expression (mRNA) normalized on the GAPDH expression levels.

scholarly journals Differential activation mechanisms of two isoforms of Gcr1 transcription factor generated from spliced and un-spliced transcripts in Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Seungwoo Cha ◽  
Chang Pyo Hong ◽  
Hyun Ah Kang ◽  
Ji-Sook Hahn
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Target Genes ◽  
Gene Encoding ◽  
Metabolic Switch ◽  
Differential Activation ◽  
N Terminus ◽  
Activation Mechanisms ◽  
In Trans ◽  
Separate Activation

Abstract Gcr1, an important transcription factor for glycolytic genes in Saccharomyces cerevisiae, was recently revealed to have two isoforms, Gcr1U and Gcr1S, produced from un-spliced and spliced transcripts, respectively. In this study, by generating strains expressing only Gcr1U or Gcr1S using the CRISPR/Cas9 system, we elucidate differential activation mechanisms of these two isoforms. The Gcr1U monomer forms an active complex with its coactivator Gcr2 homodimer, whereas Gcr1S acts as a homodimer without Gcr2. The USS domain, 55 residues at the N-terminus existing only in Gcr1U, inhibits dimerization of Gcr1U and even acts in trans to inhibit Gcr1S dimerization. The Gcr1S monomer inhibits the metabolic switch from fermentation to respiration by directly binding to the ALD4 promoter, which can be restored by overexpression of the ALD4 gene, encoding a mitochondrial aldehyde dehydrogenase required for ethanol utilization. Gcr1U and Gcr1S regulate almost the same target genes, but show unique activities depending on growth phase, suggesting that these isoforms play differential roles through separate activation mechanisms depending on environmental conditions.

Autoregulated Expression of Schizosaccharomyces pombe Meiosis-Specific Transcription Factor Mei4 and a Genome-Wide Search for Its Target Genes

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1497-1508 ◽  
Author(s):  
Hiroko Abe ◽  
Chikashi Shimoda
Keyword(s):  
Transcription Factor ◽  
Schizosaccharomyces Pombe ◽  
Target Genes ◽  
Northern Blotting ◽  
Forkhead Transcription Factor ◽  
Gene Encoding ◽  
Putative Promoter Region ◽  
Cis Acting ◽  
A Genome ◽  
Genome Wide Search

Abstract The Schizosaccharomyces pombe mei4+ gene encoding a forkhead transcription factor is necessary for the progression of meiosis and sporulation. We searched for novel meiotic genes, the expression of which is dependent on Mei4p, since only the spo6+ gene has been assigned to its targets. Six known genes responsible for meiotic recombination were examined by Northern blotting, but none were Mei4 dependent for transcription. We determined the important cis-acting element, designated FLEX, to which Mei4p can bind. The S. pombe genome sequence database (The Sanger Centre, UK) was scanned for the central core heptamer and its flanking 3′ sequence of FLEX composed of 17 nucleotides, and 10 candidate targets of Mei4 were selected. These contained a FLEX-like sequence in the 5′ upstream nontranslatable region within 1 kb of the initiation codon. Northern blotting confirmed that 9 of them, named mde1+ to mde9+, were transcriptionally induced during meiosis and were dependent on mei4+. Most mde genes have not been genetically defined yet, except for mde9+, which is identical to spn5+, which encodes one of the septin family of proteins. mde3+ and a related gene pit1+ encode proteins related to Saccharomyces cerevisiae Ime2. The double disruptant frequently produced asci having an abnormal number and size of spores, although it completed meiosis. We also found that the forkhead DNA-binding domain of Mei4p binds to the FLEX-like element in the putative promoter region of mei4 and that the maximum induction level of mei4 mRNA required functional mei4 activity. Furthermore, expression of a reporter gene driven by the authentic mei4 promoter was induced in vegetative cells by ectopic overproduction of Mei4p. These results suggest that mei4 transcription is positively autoregulated.

scholarly journals SfnR2 Regulates Dimethyl Sulfide-Related Utilization inPseudomonas aeruginosaPAO1

2018 ◽  
Vol 201 (4) ◽  
Author(s):  
Benjamin R. Lundgren ◽  
Zaara Sarwar ◽  
Kyle S. Feldman ◽  
Joseph M. Shoytush ◽  
Christopher T. Nomura
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Target Genes ◽  
Dimethyl Sulfide ◽  
Sulfur Compound ◽  
Main Function ◽  
Gene Encoding ◽  
Content Type ◽  
First Results ◽  
Terrestrial Environments ◽  
Initial Activation

ABSTRACTDimethyl sulfide (DMS) is a volatile sulfur compound produced mainly from the degradation of dimethylsulfoniopropionate (DMSP) in marine environments. DMS undergoes oxidation to form dimethyl sulfoxide (DMSO), dimethyl sulfone (DMSO2), and methanesulfonate (MSA), all of which occur in terrestrial environments and are accessible for consumption by various microorganisms. The purpose of the present study was to determine how the enhancer-binding proteins SfnR1 and SfnR2 contribute to the utilization of DMS and its derivatives inPseudomonas aeruginosaPAO1. First, results from cell growth experiments showed that deletion of eithersfnR2orsfnG, a gene encoding a DMSO2-monooxygenase, significantly inhibits the ability ofP. aeruginosaPAO1 to use DMSP, DMS, DMSO, and DMSO2as sulfur sources. Deletion of thesfnR1ormsuEDCgenes, which encode a MSA desulfurization pathway, did not abolish the growth ofP. aeruginosaPAO1 on any sulfur compound tested. Second, data collected from β-galactosidase assays revealed that themsuEDC-sfnR1operon and thesfnGgene are induced in response to sulfur limitation or nonpreferred sulfur sources, such as DMSP, DMS, and DMSO, etc. Importantly, SfnR2 (and not SfnR1) is essential for this induction. Expression ofsfnR2is induced under sulfur limitation but independently of SfnR1 or SfnR2. Finally, the results of this study suggest that the main function of SfnR2 is to direct the initial activation of themsuEDC-sfnR1operon in response to sulfur limitation or nonpreferred sulfur sources. Once expressed, SfnR1 contributes to the expression ofmsuEDC-sfnR1,sfnG, and other target genes involved in DMS-related metabolism inP. aeruginosaPAO1.IMPORTANCEDimethyl sulfide (DMS) is an important environmental source of sulfur, carbon, and/or energy for microorganisms. For various bacteria, includingPseudomonas,Xanthomonas, andAzotobacter, DMS utilization is thought to be controlled by the transcriptional regulator SfnR. Adding more complexity, some bacteria, such asAcinetobacter baumannii,Enterobacter cloacae, andPseudomonas aeruginosa, possess two, nonidentical SfnR proteins. In this study, we demonstrate that SfnR2 and not SfnR1 is the principal regulator of DMS metabolism inP. aeruginosaPAO1. Results suggest that SfnR1 has a supportive but nonessential role in the positive regulation of genes required for DMS utilization. This study not only enhances our understanding of SfnR regulation but, importantly, also provides a framework for addressing gene regulation through dual SfnR proteins in other bacteria.

scholarly journals Detection of Peanut Allergen Traces with a Real Time PCR Assay - The Challenge to Protect Food-Allergic Consumers

2017 ◽  
Vol 7 (1) ◽  
pp. 32 ◽  
Author(s):  
Dimitra Houhoula ◽  
Stamatios Koussissis ◽  
Vladimiros Lougovois ◽  
John Tsaknis ◽  
Dimitra Kassavita ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Rapid Detection ◽  
Food Products ◽  
Molecular Techniques ◽  
Food Allergens ◽  
Pcr Assay ◽  
Peanut Allergen ◽  
Pcr Method ◽  
Detection And Quantification

The aim of the present study was the implementation of molecular techniques in the detection and quantification of allergic substances of peanut in various kinds of food products, e.g., breakfast cereals, chocolates and biscuits that are frequently related to allergies. In some cases, the presence of peanuts can be due to contamination during production and are not declared on the label. A total of 152 samples were collected from supermarkets and were analysed by a Real Time PCR method. The results indicated that 125 samples (83,3%) were found positive in peanut traces but the most important finding is that from the 84 samples that had no allergen declaration for peanuts, 48 (57,1%) of them were found positive. In conclusion, Real Time PCR can be a very important tool for the rapid detection and quantification of food allergens.

scholarly journals Efficient nested-PCR-based method development for detection and genotype identification of Acanthamoeba from a small volume of aquatic environmental sample

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tsui-Kang Hsu ◽  
Jung-Sheng Chen ◽  
Hsin-Chi Tsai ◽  
Chi-Wei Tao ◽  
Yu-Yin Yang ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Nested Pcr ◽  
In Silico ◽  
Environmental Samples ◽  
Method Development ◽  
Small Volume ◽  
Detection Efficiency ◽  
Genotyping Method ◽  
Pcr Method

AbstractAcanthamoeba spp. are opportunistic human pathogens that cause granulomatous amoebic encephalitis and keratitis, and their accurate detection and enumeration in environmental samples is a challenge. In addition, information regarding the genotyping of Acanthamoeba spp. using various PCR methods is equally critical. Therefore, considering the diverse niches of habitats, it is necessary to develop an even more efficient genotyping method for Acanthamoeba spp. detection. This study improved the sensitivity of detection to avoid underestimation of Acanthamoeba spp. occurrence in aquatic environmental samples, and to accurately define the pathogenic risk by developing an efficient PCR method. In this study, a new nested genotyping method was established and compared with various PCR-based methods using in silico, lab, and empirical tests. The in silico test showed that many PCR-based methods could not successfully align specific genotypes of Acanthamoeba, except for the newly designed nested PCR and real-time PCR method. Furthermore, 52 water samples from rivers, reservoirs, and a river basin in Taiwan were analysed by six different PCR methods and compared for genotyping and detection efficiency of Acanthamoeba. The newly developed nested-PCR-based method of genotyping was found to be significantly sensitive as it could effectively detect the occurrence of Acanthamoeba spp., which was underestimated by the JDP-PCR method. Additionally, the present results are consistent with previous studies indicating that the high prevalence of Acanthamoeba in the aquatic environment of Taiwan is attributed to the commonly found T4 genotype. Ultimately, we report the development of a small volume procedure, which is a combination of recent genotyping PCR and conventional real-time PCR for enumeration of aquatic Acanthamoeba and acquirement of biologically meaningful genotyping information. We anticipate that the newly developed detection method will contribute to the precise estimation, evaluation, and reduction of the contamination risk of pathogenic Acanthamoeba spp., which is regularly found in the water resources utilised for domestic purposes.

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