scholarly journals MagnaExtract, a novel magnetic bead-based extraction method for the molecular detection of antimicrobial resistance genes in fresh water

2021 ◽  
Author(s):  
Rachel L. Byrne ◽  
Derek Cocker ◽  
Ghaith Alyayyoussi ◽  
Madalitso Mphasa ◽  
Mary Charles ◽  
...  

ABSTRACTBackgroundEnvironmental water samples are increasingly recognised as an important reservoir of antimicrobial resistance (AMR) genes. Polymerase chain reaction (PCR) and next generation sequencing (NGS) offer a potentially inclusive surveillance platform for a wide range of AMR genes. However, molecular methods are dependent upon the extraction of DNA of high yield and quality. Current options for DNA extraction from complex environmental matrices for downstream molecular applications are either expensive or low yielding. We present here a novel magnetic bead-based DNA extraction method, for the detection of antimicrobial resistance genes (ARGs) from river water in Malawi, named MagnaExtract.MethodsMagnaExtract involves initial filtration of 250ml freshwater, followed by an overnight incubation of the filter in 15ml buffered peptone water (BPW), common procedure in microbiology laboratories. 200µl is then taken for a boil (95°C) and spin step and mixed with magnetic beads to bind DNA. Following washes with ethanol, the DNA is eluted in nuclease-free water. To determine the effectiveness of this method, 98 freshwater samples were collected from two rivers in Southern Malawi, and DNA was isolated using the MagnaExtract method, two commercial Qiagen (Germany) kits; PowerWater and DNeasy Blood and tissue, alongside a boil and spin of BPW, and a boil and spin from bacterial isolate grown on agar media. All samples were screened with a high-resolution melt (HRM) PCR panel previously validated for the detection of third generation cephalosporin and carbapenem ARGs. We compared the DNA yield obtained using all extraction methods, as well as the identification of each ARG.ResultsDNA yield using MagnaExtract was statistically greater than both boil and spin methods and DNeasy Blood & Tissue (Qiagen, Germany). DNA yield was slightly lower than using PowerWater (Qiagen) but the difference was not statistically significant. MagnaExtract was the only method to identify ARGs in all 98 water samples compared with PowerWater (n=82), DNeasy (n=95) boilate of BPW (n=75) and boilate of bacterial isolate (n=87). The most commonly detected ARG was OXA-48 (n=93). In addition, we found overnight incubation in non-selective enrichment broth (BPW) to promote the growth of bacteria harbouring extended spectrum beta lactamase (ESBL) genes and reduction in the detection of carbapenemase genes.ConclusionThe MagnaExtract approach offers a simple, affordable, high yielding DNA extraction method for the detection of ARGs isolated from river water samples.

2019 ◽  
Vol 39 (2) ◽  
Author(s):  
Yimiao Xia ◽  
Fusheng Chen ◽  
Yan Du ◽  
Chen Liu ◽  
Guanhao Bu ◽  
...  

Abstract Soybean is the most important genetically modified (GM) oilseed worldwide. Regulations relating to the approval of biotech soybean varieties and product labeling demand accurate and reliable detection techniques to screen for GM soya. High-quality extracted DNA is essential for DNA-based monitoring methods. Thus, four widely used protocols (SDS, CTAB, DP305, and DNeasy Plant Mini Kit) were compared in the present study to explore the most efficient DNA extraction method for raw soya matrix. The SDS-based method showed the highest applicability. Then crucial factors influencing DNA yield and purity, such as SDS lysis buffer component concentrations and organic compounds used to isolate DNA, were further investigated to improve the DNA obtained from raw soybean seeds, which accounts for the innovation of this work. As a result, lysis buffer (2% SDS (w/v), 150 mM NaCl, 50 mM Tris/HCl, 50 mM EDTA, pH 8.0) and organic reagents including chloroform/isoamyl alcohol (24:1, v/v) (C: I), isopropanol, and ethanol corresponding to the extraction and first and second precipitation procedures, respectively, were used in the optimized SDS method. The optimized method was verified by extracting approximately 2020–2444 ng DNA/mg soybean with A260/280 ratios of 1.862–1.954 from five biotech and non-biotech soybean varieties. Only 0.5 mg of soya was required to obtain enough DNA for PCR amplification using the optimized SDS-based method. These results indicate that the screening protocol in the present study achieves the highest suitability and efficiency for DNA isolation from raw soya seed flour.


Author(s):  
Hornel Koudokpon ◽  
Victorien Dougnon ◽  
Christelle Lougbegnon ◽  
Esther Deguenon ◽  
Wassiyath Mousse ◽  
...  

Background: The environment plays an important role in the dissemination of multidrug resistant bacteria, especially through the aquatic ecosystem, including hospital effluents, rivers, but also spring water and drinking water. This study aims to determine selected antimicrobial resistance genes in some aquatic matrices in southern Benin. Methods: Collected water samples were filtered through a membrane 0.22 µm thick. After filtration, the membrane was deposited on Muëller Hinton agar. Then the colonies resulting from this subculture were subjected to a microbiological examination by the conventional method. The antibiotic sensitivity test was carried out by the Kirby Bauer method according to the recommendations of the French Society of Microbiology. Resistance genes were looked for by PCR. Results: Of the 222 water samples collected, 265 bacterial strains were isolated, the majority of which were strains of Coagulase Negative Staphylococcus (CNS) with 37.74% (n = 100), followed by strains of Klebsiella pneumoniae (21.89%; n = 58), Escherichia coli (10.57%; n = 28). All isolated gram-negative bacilli strains are multidrug resistant with resistance of all strains to amoxicillin, ampicillin and amoxicillin + clavulanic acid. Of the 15 resistance genes searched in the genome of Gram-negative bacilli strains, 8 were detected, namely the TEM, SHV, CTX-M15, VIM, NDM, SUL1, SUL2 and AADA genes. Resistance of CNS strains to amoxicillin, oxacillin and cefoxitin was observed. The meca gene was detected in all CNS strains. The vanA and VanB genes were only detected in strains isolated from drinking water in sachets collected from producers and street sellers. Conclusion: These results show the dissemination of resistance genes in Benin and once again confirms the urgency of a global fight against antimicrobial resistance.


2018 ◽  
Vol 2 ◽  
Author(s):  
Markus Majaneva ◽  
Ola H. Diserud ◽  
Shannon H.C. Eagle ◽  
Mehrdad Hajibabaei ◽  
Torbjørn Ekrem

Characterisation of freshwater benthic biodiversity using DNA metabarcoding may allow more cost-effective environmental assessments than the current morphological-based assessment methods. DNA metabarcoding methods where sorting or pre-sorting of samples are avoided altogether are especially interesting, since the time between sampling and taxonomic identification is reduced. Due to the presence of non-target material like plants and sediments in crude samples, DNA extraction protocols become important for maximising DNA recovery and sample replicability. We sampled freshwater invertebrates from six river and lake sites and extracted DNA from homogenised bulk samples in quadruplicate subsamples, using a published method and two commercially available kits: HotSHOT approach, Qiagen DNeasy Blood & Tissue Kit and Qiagen DNeasy PowerPlant Pro Kit. The performance of the selected extraction methods was evaluated by measuring DNA yield and applying DNA metabarcoding to see if the choice of DNA extraction method affects DNA yield and metazoan diversity results. The PowerPlant Kit extractions resulted in the highest DNA yield and a strong significant correlation between sample weight and DNA yield, while the DNA yields of the Blood & Tissue Kit and HotSHOT method did not correlate with the sample weights. Metazoan diversity measures were more repeatable in samples extracted with the PowerPlant Kit compared to those extracted with the HotSHOT method or the Blood & Tissue Kit. Subsampling using Blood & Tissue Kit and HotSHOT extraction failed to describe the same community in the lake samples. Our study exemplifies that the choice of DNA extraction protocol influences the DNA yield as well as the subsequent community analysis. Based on our results, low specimen abundance samples will likely provide more stable results if specimens are sorted prior to DNA extraction and DNA metabarcoding, but the repeatability of the DNA extraction and DNA metabarcoding results was close to ideal in high specimen abundance samples.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charmaine Lloyd ◽  
Kai Heng Tan ◽  
Kar Leong Lim ◽  
Vimala Gana Valu ◽  
Sarah Mei Ying Fun ◽  
...  

AbstractThis study aimed at exploring microalgal heterogeneity from fresh water samples collected from inland water bodies in the heavily built city of Singapore. Culturable pure isolates (n = 94) were subject to an in-house microalgal DNA extraction method and LSU rDNA sequencing. Isolates were analysed for their predominance and distribution. A total of 17 different algal genera were identified (H = 2.8, EH = 0.6), of whichScenedesmusspp. andChlorellaspp. constituted 27.5% and 21.3% of isolates respectively, followed byMicractiniumspp. (18.8%) andChlamydomonasspp. (12.5%). We also report 16 new microalgal strains from this region. The data is important from an ecological and biotechnological perspective.


2018 ◽  
Vol 24 (1) ◽  
Author(s):  
DIVYA SHARMA ◽  
DALIP KUMAR ◽  
RHITOBAN RAY CHOUDHURY

PCR-based markers have been widely used for the analysis of genetic diversity and to avoid ambiguity, molecular characterization is very effective tool for accurate discrimination and identification of a species in insects. Because these studies require analysis of large number of samples, a DNA extraction method that is fast, inexpensive and yields high quality DNA from the preserved samples, needs to be evaluated. A comparative analysis of four methods for DNA extraction from a single specimen of rice weevil, Sitophilus oryzae preserved in 90% alcohol has been communicated. Significantly higher DNA yields were obtained by using SDS-Potassium acetate method followed by CTAB, DNA XPress and Bioline Isolate II genomic DNA kit. Maximum purity (A260/A280- 1.8) was obtained with Bioline Isolate II genomic DNA kit method. The Absorbance ratio was appreciably low with DNA Xpress kit showing the presence of proteins. Bioline Isolate II genomic DNA kit was time efficient and yielded good quality DNA but at a high cost. Based on DNA yield and quality, these evaluations provide a guide for choosing Bioline Isolate II genomic DNA kit method of DNA extraction for rice weevils and optimizing the extraction conditions for rice weevils.


2003 ◽  
Vol 25 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Hans Jürgen Grote ◽  
Viola Schmiemann ◽  
Mario Sarbia ◽  
Alfred Böcking

Objective: To date, there are only few systematic reports on the quality of DNA extracted from routine diagnostic cytologic specimens. It was the aim of the present study to evaluate the ability of 50% ethanol/2% carbowax (Saccomanno fixative) to preserve bronchial secretions with high quality genomic DNA as well as to compare different DNA extraction methods.Methods: DNA was extracted from 45 bronchial aspirates by four different extraction protocols. Beside DNA yield, DNA quality with regard to purity, integrity, and PCR success rate were investigated.Results: No fragmentation of sample DNA due to the fixative was detected. It was preserved as high molecular weight DNA. DNA yield, purity, and integrity were dependent on the DNA extraction method to some extend. Irrespective of the DNA extraction method the PCR success rate for amplification of β‐globin gene fragments (268, 536, and 989 bp) was 100%. Conclusions: A fixative containing 50% ethanol/2% carbowax preserves high quality DNA which is well suited for PCR‐based assays regardless of the extraction protocol used. The selection of the DNA extraction protocol has to be adjusted to the circumstances of application.


Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1416
Author(s):  
Vanessa Silva ◽  
Eugénia Ferreira ◽  
Vera Manageiro ◽  
Lígia Reis ◽  
María Teresa Tejedor-Junco ◽  
...  

Natural aquatic environments represent one of the most important vehicles of bacterial dissemination. Therefore, we aimed to isolate staphylococci from surface waters and to investigate the presence of antimicrobial resistance genes and virulence factors as well as the genetic lineages of all Staphylococcus aureus isolates. Staphylococci were recovered from water samples collected from 78 surface waters, including rivers, streams, irrigation ditches, dams, lakes, and fountains. The presence of antimicrobial resistance genes and virulence factors was investigated by PCR. Multilocus sequence typing and spa-typing were performed in all S. aureus isolates. From the 78 water samples, 33 S. aureus, one S. pseudintermedius, and 51 coagulase-negative staphylococci (CoNS) were identified. Among the S. aureus isolates, four MRSA were identified, and all harbored the mecC gene. Fourteen S. aureus were susceptible to all antimicrobials tested and the remaining showed resistance to penicillin, erythromycin and/or tetracycline encoded by the blaZ, ermT, msr(A/B), tetL, and vgaA genes. Regarding the clonal lineages, one mecC-MRSA isolate belonged to spa-type t843 and sequence type (ST) 130 and the other three to t742 and ST425. The remaining S. aureus were ascribed 14 spa-types and 17 sequence types. Eleven species of CoNS were isolated: S. sciuri, S. lentus, S. xylosus, S. epidermidis, S. cohnii spp. urealyticus, S. vitulinus, S. caprae, S. carnosus spp. Carnosus, S. equorum, S. simulans, and S. succinus. Thirteen CoNS isolates had a multidrug resistance profile and carried the following genes: mecA, msr(A/B), mph(C), aph(3′)-IIIa, aac(6′)-Ie–aph(2′’)-Ia, dfrA, fusB, catpC221, and tetK. A high diversity of staphylococci was isolated from surface waters including mecCMRSA strains and isolates presenting multidrug-resistance profiles. Studies on the prevalence of antibiotic-resistant staphylococci in surface waters are still very scarce but extremely important to estimate the contribution of the aquatic environment in the spread of these bacteria.


2016 ◽  
Vol 5 (08) ◽  
pp. 4754
Author(s):  
Tanushree Mitra* ◽  
Shivshankar Kumdale ◽  
Sameer Chowdhary ◽  
Amol D. Raut

The main objective of this study was to make sure whether randomly taken 12 samples were sensitive to abacavir. The genomic DNA from 12 blood sample were extracted by phenol chloroform DNA extraction method, extracted genomic DNA were amplified and sequenced, thereafter SNPs were detected. Every sample had shown the presence of normal base at SNP position. This study indicated, those randomly taken 12 patients were sensitive to abacavir, so they can consume abacavir if they get infected with HIV.


2021 ◽  
Vol 9 (4) ◽  
pp. 707
Author(s):  
J. Christopher Noone ◽  
Fabienne Antunes Ferreira ◽  
Hege Vangstein Aamot

Our culture-independent nanopore shotgun metagenomic sequencing protocol on biopsies has the potential for same-day diagnostics of orthopaedic implant-associated infections (OIAI). As OIAI are frequently caused by Staphylococcus aureus, we included S. aureus genotyping and virulence gene detection to exploit the protocol to its fullest. The aim was to evaluate S. aureus genotyping, virulence and antimicrobial resistance genes detection using the shotgun metagenomic sequencing protocol. This proof of concept study included six patients with S. aureus-associated OIAI at Akershus University Hospital, Norway. Five tissue biopsies from each patient were divided in two: (1) conventional microbiological diagnostics and genotyping, and whole genome sequencing (WGS) of S. aureus isolates; (2) shotgun metagenomic sequencing of DNA from the biopsies. Consensus sequences were analysed using spaTyper, MLST, VirulenceFinder, and ResFinder from the Center for Genomic Epidemiology (CGE). MLST was also compared using krocus. All spa-types, one CGE and four krocus MLST results matched Sanger sequencing results. Virulence gene detection matched between WGS and shotgun metagenomic sequencing. ResFinder results corresponded to resistance phenotype. S. aureus spa-typing, and identification of virulence and antimicrobial resistance genes are possible using our shotgun metagenomics protocol. MLST requires further optimization. The protocol has potential application to other species and infection types.


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