scholarly journals Presence of Francisella tularensis subsp. holarctica DNA in the Aquatic Environment in France

2021 ◽  
Vol 9 (7) ◽  
pp. 1398
Author(s):  
Camille D. Brunet ◽  
Aurélie Hennebique ◽  
Julien Peyroux ◽  
Isabelle Pelloux ◽  
Yvan Caspar ◽  
...  
Keyword(s):  
Francisella Tularensis ◽  
Water Samples ◽  
Real Time Pcr ◽  
Aquatic Environment ◽  
Geographic Area ◽  
The West ◽  
Tularensis Subsp ◽  
High Prevalence ◽  
Sources Of Infection ◽  
Pcr Assays

In 2018, the incidence of tularemia increased twofold in the west of France, with many pneumonic forms, suggesting environmental sources of infection. We investigated the presence of Francisella tularensis subsp. holarctica and other Francisella species DNA in the natural aquatic environment of this geographic area. Two sampling campaigns, in July 2019 and January 2020, allowed the collection of 87 water samples. Using a combination of real-time PCR assays, we tested the presence of either Francisella sp., F. tularensis/F. novicida, and F. tularensis subsp. holarctica, the latter being the only tularemia agent in Europe. Among 57 water samples of the first campaign, 15 (26.3%) were positive for Francisella sp., nine (15.8%) for F. tularensis and/or F. novicida, and four (7.0%) for F. tularensis subsp. holarctica. Ratios were 25/30 (83.3%), 24/30 (80.0%), and 4/30 (13.3%) for the second campaign. Among the thirty sites sampled during the two campaigns, nine were positive both times for Francisella sp., seven for F. tularensis and/or F. novicida, and one for F. tularensis subsp. holarctica. Altogether, our study reveals a high prevalence of Francisella sp. DNA (including the tularemia agent) in the studied aquatic environment. This aquatic environment could therefore participate in the endemicity of tularemia in the west of France.

scholarly journals Novel multiplex real-time PCR assays reveal a high prevalence of diarrhoeagenic Escherichia coli pathotypes in healthy and diarrhoeal children in the South of Vietnam

2020 ◽  
Author(s):  
Vu Thuy Duong ◽  
Le Thi Phuong Tu ◽  
Ha Thanh Tuyen ◽  
Le Thi Quynh Nhi ◽  
James I Campbell ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Real Time Pcr ◽  
Clinical Samples ◽  
Middle Income ◽  
Middle Income Countries ◽  
Virulence Markers ◽  
Low Middle Income Countries ◽  
High Prevalence ◽  
Pcr Assays

Abstract BackgroundDiarrhoeagenic Escherichia coli (DEC) infections are common in children in low-middle income countries (LMICs). However, detecting the various DEC pathotypes is complex as they cannot be differentiated by classical microbiology. We developed four multiplex real-time PCR assays were to detect virulence markers of six DEC pathotypes; specificity was tested using DEC controls and other enteric pathogens. PCR amplicons from the six E. coli pathotypes were purified and amplified to be used to optimize PCR reactions and to calculate reproducibility. After validation, these assays were applied to clinical samples from healthy and diarrhoeal Vietnamese children and associated with clinical data. ResultsThe multiplex real-time PCRs were found to be reproducible, and specific. At least one DEC variant was detected in 34.7% (978/2,815) of the faecal samples from diarrhoeal children; EAEC, EIEC and atypical EPEC were most frequent Notably, 41.2% (205/498) of samples from non-diarrhoeal children was positive with a DEC pathotype. In this population, only EIEC, which was detected in 34.3% (99/289) of diarrhoeal samples vs. 0.8% (4/498) non-diarrhoeal samples (p<0.001), was significantly associated with diarrhoea. Multiplex real-time PCR when applied to clinical samples is an efficient and high-throughput approach to DEC pathotypes. ConclusionsThis approach revealed high carriage rates of DEC pathotypes among Vietnamese children. We describe a novel diagnostic approach for DEC, which provides baseline data for future surveillance studies assessing DEC burden in LMICs.

scholarly journals Real-Time PCR Assays for Quantification ofqnrGenes in Environmental Water Samples and Chicken Feces

2012 ◽  
Vol 79 (5) ◽  
pp. 1743-1745 ◽  
Author(s):  
Elisabet Marti ◽  
José Luis Balcázar
Keyword(s):  
Real Time ◽  
Water Samples ◽  
Real Time Pcr ◽  
Environmental Water ◽  
Quinolone Resistance ◽  
Environmental Water Samples ◽  
Complex Samples ◽  
Chicken Feces ◽  
Pcr Assays

ABSTRACTReal-time PCR assays were developed for the enumeration of plasmid-mediated quinolone resistance (PMQR) determinants, such as theqnrA,qnrB, andqnrSgenes, in different water samples and chicken feces. The results indicate that the developed assays are specific and sensitive for the quantification ofqnrgenes in complex samples.

Development of real-time PCR assays for the specific detection of Francisella tularensis ssp. tularensis, holarctica and mediaasiatica

2010 ◽  
Vol 24 (2) ◽  
pp. 72-76 ◽  
Author(s):  
Jan L. Mitchell ◽  
Nicola Chatwell ◽  
Deanna Christensen ◽  
Helen Diaper ◽  
Timothy D. Minogue ◽  
...  
Keyword(s):  
Real Time ◽  
Francisella Tularensis ◽  
Real Time Pcr ◽  
Specific Detection ◽  
Pcr Assays

scholarly journals Novel multiplex real-time PCR assays reveal a high prevalence of diarrhoeagenic Escherichia coli pathotypes in healthy and diarrhoeal children in the south of Vietnam

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Vu Thuy Duong ◽  
Le Thi Phuong Tu ◽  
Ha Thanh Tuyen ◽  
Le Thi Quynh Nhi ◽  
James I. Campbell ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Real Time Pcr ◽  
The South ◽  
High Prevalence ◽  
Pcr Assays

scholarly journals Genomic Markers for Differentiation of Francisella tularensis subsp. tularensis A.I and A.II Strains

2007 ◽  
Vol 74 (1) ◽  
pp. 336-341 ◽  
Author(s):  
Claudia R. Molins-Schneekloth ◽  
John T. Belisle ◽  
Jeannine M. Petersen
Keyword(s):  
Suppression Subtractive Hybridization ◽  
Francisella Tularensis ◽  
Geographical Location ◽  
Subtractive Hybridization ◽  
Clinical Isolates ◽  
Type B ◽  
Tularensis Subsp ◽  
Genomic Markers ◽  
Pcr Assays ◽  
Genomic Regions

ABSTRACT Tularemia is caused by two subspecies of Francisella tularensis, F. tularensis subsp. tularensis (type A) and F. tularensis subsp. holarctica (type B). F. tularensis subsp. tularensis is further subdivided into two genetically distinct populations (A.I and A.II) that differ with respect to geographical location, anatomical source of recovered isolates, and disease outcome. Using two human clinical isolates, suppression subtractive hybridization was performed to identify 13 genomic regions of difference between A.I and A.II strains. Two PCR assays, one to identify A.I and A.II as well as to discriminate between F. tularensis subsp. holarctica and F. novicida and another specific for A.I, were developed. This is the first report to identify and characterize conserved genomic differences between A.I and A.II.

scholarly journals TaqMan Real-Time PCR Assays for Single-Nucleotide Polymorphisms Which Identify Francisella tularensis and Its Subspecies and Subpopulations

PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e107964 ◽  
Author(s):  
Dawn N. Birdsell ◽  
Amy J. Vogler ◽  
Jordan Buchhagen ◽  
Ashley Clare ◽  
Emily Kaufman ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Real Time ◽  
Francisella Tularensis ◽  
Real Time Pcr ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Pcr Assays

scholarly journals Molecular-Beacon Multiplex Real-Time PCR Assay for Detection of Vibrio cholerae

2006 ◽  
Vol 72 (9) ◽  
pp. 6424-6428 ◽  
Author(s):  
Aneta J. Gubala ◽  
David F. Proll
Keyword(s):  
Vibrio Cholerae ◽  
Real Time ◽  
Water Samples ◽  
Real Time Pcr ◽  
Molecular Beacon ◽  
Environmental Water ◽  
Molecular Beacons ◽  
Pcr Assay ◽  
Specificity And Sensitivity ◽  
Pcr Assays

ABSTRACT A multiplex real-time PCR assay was developed using molecular beacons for the detection of Vibrio cholerae by targeting four important virulence and regulatory genes. The specificity and sensitivity of this assay, when tested with pure culture and spiked environmental water samples, were high, surpassing those of currently published PCR assays for the detection of this organism.

scholarly journals Novel multiplex real-time PCR assays reveal a high prevalence of diarrhoeagenic Escherichia coli pathotypes in healthy and diarrhoeal children in the South of Vietnam

2020 ◽  
Author(s):  
Vu Thuy Duong ◽  
Le Thi Phuong Tu ◽  
Ha Thanh Tuyen ◽  
Le Thi Quynh Nhi ◽  
James I Campbell ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Real Time Pcr ◽  
Clinical Samples ◽  
Middle Income ◽  
Middle Income Countries ◽  
Virulence Markers ◽  
Low Middle Income Countries ◽  
High Prevalence ◽  
Pcr Assays

Abstract Background: Diarrhoeagenic Escherichia coli (DEC) infections are common in children in low-middle income countries (LMICs). However, detecting the various DEC pathotypes is complex as they cannot be differentiated by classical microbiology. We developed four multiplex real-time PCR assays were to detect virulence markers of six DEC pathotypes; specificity was tested using DEC controls and other enteric pathogens. PCR amplicons from the six E. coli pathotypes were purified and amplified to be used to optimize PCR reactions and to calculate reproducibility. After validation, these assays were applied to clinical samples from healthy and diarrhoeal Vietnamese children and associated with clinical data. Results: The multiplex real-time PCRs were found to be reproducible, and specific. At least one DEC variant was detected in 34.7% (978/2,815) of the faecal samples from diarrhoeal children; EAEC, EIEC and atypical EPEC were most frequent Notably, 41.2% (205/498) of samples from non-diarrhoeal children was positive with a DEC pathotype. In this population, only EIEC, which was detected in 34.3% (99/289) of diarrhoeal samples vs. 0.8% (4/498) non-diarrhoeal samples (p<0.001), was significantly associated with diarrhoea. Multiplex real-time PCR when applied to clinical samples is an efficient and high-throughput approach to DEC pathotypes. Conclusions: This approach revealed high carriage rates of DEC pathotypes among Vietnamese children. We describe a novel diagnostic approach for DEC, which provides baseline data for future surveillance studies assessing DEC burden in LMICs.

Enumeration and Identification of Asbestos Fibres in Water

1974 ◽  
Vol 32 ◽  
pp. 526-527 ◽  
Author(s):  
O. Mudroch ◽  
J. R. Kramer
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Drainage Basin ◽  
Lake Superior ◽  
Research Work ◽  
List Type ◽  
The West ◽  
Asbestos Fibre ◽  
Amphibole Asbestos

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

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