scholarly journals Contrasting plant ecological benefits endowed by naturally occurring EPSPS resistance mutations under glyphosate selection

2021 ◽  
Author(s):  
Martin M. Vila‐Aiub ◽  
Heping Han ◽  
Qin Yu ◽  
Federico García ◽  
Stephen B. Powles
Keyword(s):  
Resistance Mutations ◽  
Ecological Benefits ◽  
Naturally Occurring ◽  
Plant Ecological

scholarly journals Naturally occurring dominant drug resistance mutations occur infrequently in the setting of recently acquired hepatitis C

2014 ◽  
Vol 20 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Tanya L Applegate ◽  
Silvana Gaudieri ◽  
Anne Plauzolles ◽  
Abha Chopra ◽  
Jason Grebely ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Hepatitis C ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Naturally Occurring

scholarly journals Engineered Large Wood Structures in Stream Restoration Projects in Switzerland: Practice-Based Experiences

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2520
Author(s):  
Vasco Neuhaus ◽  
Matthias Mende
Keyword(s):  
Stream Restoration ◽  
Point Of View ◽  
Large Wood ◽  
Ecological Benefits ◽  
Wood Structures ◽  
The Public ◽  
Naturally Occurring ◽  
Different Dimensions ◽  
Swiss Plateau ◽  
Insight Into

The effects of large wood (LW) presence in streams on river ecology and morphology are becoming widely researched and nowadays their ecological benefits are undisputed. Yet LW presence in most Swiss plateau streams is poor mainly due to anthropological pressure on river ecosystems. The use of anchored, engineered LW structures under various forms in stream restoration projects is now state of the art. However, binding benchmarks for the equivalent naturally occurring instream LW quantities and complex LW structures do not yet exist. Therefore, hydraulic engineers often find themselves in a conflict between acceptable instream LW quantities for flood protection, quantities desirable from an ecological point of view and, last but not least, quantities accepted by the public based on the current ideologies of landscape design. In the first section, this paper treats the complexity of defining benchmarks for LW quantities in restoration projects. In the second section, we provide a qualitative practical insight into relevant questions when planning engineered LW structures, such as placement, anchoring, naturalness, and effectiveness from a hydraulic engineer’s point of view. The third part presents three examples of restoration projects with different dimensions where various engineered LW structures with different outcomes were built and introduced into active streams. Finally, the conclusion provides further possible measures to retain LW in streams and to restore more natural LW dynamics in rivers.

scholarly journals Distribution of naturally -occurring NS5B resistance-associated substitutions in Egyptian patients with chronic Hepatitis C

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249770
Author(s):  
Hala Rady Ahmed ◽  
Nancy G. F. M. Waly ◽  
Rehab Mahmoud Abd El-Baky ◽  
Ramadan Yahia ◽  
Helal F. Hetta ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hepatitis C ◽  
Resistance Mutation ◽  
Resistance Mutations ◽  
Resistance Level ◽  
Direct Acting Antiviral ◽  
Naturally Occurring ◽  
Treatment Naïve ◽  
Substitution Mutations ◽  
Direct Acting

Background NS5B polymerase inhibitors represent the cornerstone of the present treatment of Hepatitis C virus infection (HCV). Naturally occurring substitution mutations to NS5B inhibitors have been recorded. The current study intended to demonstrate possible natural direct acting antiviral (DAA)—mutations of the HCV NS5B region in HCV patients in Minia governorate, Egypt. Methods Samples were collected from 27 treatment-naïve HCV patients and 8 non-responders. Out of 27 treatment-naïve patients, 17 NS5B sequences (amino acids 221–345) from treatment-naïve patients and one sample of non-responders were successfully amplified. Nucleotide sequences have been aligned, translated into amino acids, and compared to drug resistance mutations reported in the literature. Results NS5B amino acid sequence analysis ensures several novel NS5B mutations existence (more than 40 substitution mutations) that have not been previously documented to be correlated with a resistant phenotype. It was found that K304R (82.4%), E327D and P300T (76.5% each) substitutions were the most distributed in the tested samples, respectively. S282T, the major resistance mutation that induces high sofosbuvir-resistance level in addition to other reported mutations (L320F/C) and (C316Y/N) were not recognized. Q309R mutation is a ribavirin-associated resistance, which was recognized in one strain (5.9%) of genotype 1g sequences. Besides, one substitution mutation (E237G) was identified in the successfully amplified non-responder sample. Conclusion Our study showed various combinations of mutations in the analyzed NS5B genes which could enhance the possibility of therapy failure in patients administered regimens including multiple DAA.

scholarly journals Naturally occurring resistance mutations within the core and NS5B regions in hepatitis C genotypes, particularly genotype 5a, in South Africa

2016 ◽  
Vol 127 ◽  
pp. 90-98 ◽  
Author(s):  
N. Prabdial-Sing ◽  
J.T. Blackard ◽  
A.J. Puren ◽  
A. Mahomed ◽  
W. Abuelhassan ◽  
...  
Keyword(s):  
South Africa ◽  
Hepatitis C ◽  
Resistance Mutations ◽  
The Core ◽  
Naturally Occurring

scholarly journals Pandemic fluoroquinolone resistant Escherichia coli clone ST1193 emerged via simultaneous homologous recombinations in 11 gene loci

2019 ◽  
Vol 116 (29) ◽  
pp. 14740-14748 ◽  
Author(s):  
Veronika Tchesnokova ◽  
Matthew Radey ◽  
Sujay Chattopadhyay ◽  
Lydia Larson ◽  
Jamie Lee Weaver ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Homologous Recombination ◽  
Multidrug Resistant ◽  
Fluoroquinolone Resistance ◽  
Resistance Mutations ◽  
Chromosomal Dna ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Naturally Occurring ◽  
High Level

Global growth in antibiotic resistance is a major social problem. A high level of resistance to fluoroquinolones requires the concurrent presence of at least 3 mutations in the target proteins—2 in DNA gyrase (GyrA) and 1 in topoisomerase IV (ParC), which occur in a stepwise manner. In the Escherichia coli chromosome, the gyrA and parC loci are positioned about 1 Mb away from each other. Here we show that the 3 fluoroquinolone resistance mutations are tightly associated genetically in naturally occurring strains. In the latest pandemic uropathogenic and multidrug-resistant E. coli clonal group ST1193, the mutant variants of gyrA and parC were acquired not by a typical gradual, stepwise evolution but all at once. This happened as part of 11 simultaneous homologous recombination events involving 2 phylogenetically distant strains of E. coli, from an uropathogenic clonal complex ST14 and fluoroquinolone-resistant ST10. The gene exchanges swapped regions between 0.5 and 139 Kb in length (183 Kb total) spread along 976 Kb of chromosomal DNA around and between gyrA and parC loci. As a result, all 3 fluoroquinolone resistance mutations in GyrA and ParC have simultaneously appeared in ST1193. Based on molecular clock estimates, this potentially happened as recently as <12 y ago. Thus, naturally occurring homologous recombination events between 2 strains can involve numerous chromosomal gene locations simultaneously, resulting in the transfer of distant but tightly associated genetic mutations and emergence of a both highly pathogenic and antibiotic-resistant strain with a rapid global spread capability.

Naturally occurring resistance mutations to HIV-1 entry inhibitors in subtypes B, C, and CRF31_BC

2012 ◽  
Vol 54 (1) ◽  
pp. 6-10 ◽  
Author(s):  
Leonardo Augusto Luvison Araújo ◽  
Dennis Maletich Junqueira ◽  
Rubia Marília de Medeiros ◽  
Maria Cristina Cotta Matte ◽  
Sabrina Esteves de Matos Almeida
Keyword(s):  
Resistance Mutations ◽  
Entry Inhibitors ◽  
Naturally Occurring ◽  
Hiv 1
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