scholarly journals Biocidal Effect of Leaves of <i>Crataeva religiosa</i> Forst on a Resistant Strain of Groundnut Bean <i>Caryedon serratus</i> (Olivier)

2019 ◽  
Vol 07 (04) ◽  
pp. 81-91
Author(s):  
Aminata Gningue ◽  
Toffène Diome ◽  
Khady Fall ◽  
Mbacké Sembène
Keyword(s):  
Resistant Strain ◽  
Caryedon Serratus

scholarly journals Polygenic and single gene responses to selection for resistance to diazinon in Lucilia cuprina.

Genetics ◽  
1992 ◽  
Vol 130 (3) ◽  
pp. 613-620 ◽  
Author(s):  
J A McKenzie ◽  
A G Parker ◽  
J L Yen
Keyword(s):  
Resistant Strain ◽  
Single Gene ◽  
Natural Populations ◽  
Susceptible Strain ◽  
Selection Line ◽  
Base Population ◽  
Gene Response ◽  
Biochemical Profiles ◽  
Resistant Strains ◽  
Selection For

Abstract Following mutagenesis with ethyl methanesulfonate, selection in a susceptible strain with a concentration of the insecticide diazinon (0.0004%, w/v) above that required to kill 100% of the susceptible strain, the LC100 of that strain, resulted in a single gene response. The resultant four mutant resistant strains have equivalent physiological, genetical and biochemical profiles to a diazinon-resistant strain derived from a natural population and homozygous for the Rop-1 allele. Modification of the microsomal esterase E3 is responsible for resistance in each case. The Rop-1 locus maps approximately 4.4 map units proximal to bu on chromosome IV. Selection within the susceptible distribution, at a concentration of diazinon [0.0001% (w/v)] less than the LC100, resulted in a similar phenotypic response irrespective of whether the base population had been mutagenized. The responses were polygenically based, unique to each selection line and independent of Rop-1. The relevance of the results to selection for insecticide resistance in laboratory and natural populations is discussed.

scholarly journals Methotrexate Binding to Dihydrofolate Reductase from a Methotrexate-resistant Strain of Escherichia coli

1973 ◽  
Vol 248 (18) ◽  
pp. 6375-6379
Author(s):  
Myra N. Williams ◽  
Martin Poe ◽  
Norma J. Greenfield ◽  
Jordan M. Hirshfield ◽  
Karst Hoogsteen
Keyword(s):  
Escherichia Coli ◽  
Dihydrofolate Reductase ◽  
Resistant Strain

Inhibitory Activity of Brown Propolis Extracts on a Norfloxacin-Resistant Strain of Staphylococcus aureus

2021 ◽  
Author(s):  
Vanessa Moreira Frota ◽  
Francisco Matheus F. Dias ◽  
Mariana Ferreira do Nascimento ◽  
Lavosyer da Silva Mendonça ◽  
Emanuella Cristina dos Santos Moita ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Inhibitory Activity ◽  
Resistant Strain

scholarly journals Mechanism of Metronidazole Resistance inHelicobacter pylori: Comparison of the rdxA Gene Sequences in 30 Strains

2000 ◽  
Vol 44 (8) ◽  
pp. 2207-2210 ◽  
Author(s):  
Nadia Maggi Solcà ◽  
Marco Valerio Bernasconi ◽  
Jean-Claude Piffaretti
Keyword(s):  
Phylogenetic Analysis ◽  
Helicobacter Pylori ◽  
Amino Acid ◽  
Resistant Strain ◽  
Point Mutations ◽  
Housekeeping Genes ◽  
Amino Acid Substitutions ◽  
Metronidazole Resistance ◽  
Nucleotide Mutation ◽  
Nucleotide Insertion

ABSTRACT The rdxA gene of 30 independently isolatedHelicobacter pylori strains was sequenced. A comparison of the rdxA sequences revealed a higher percentage of amino acid substitutions in the corresponding protein than in other housekeeping genes. Out of 122 point mutations, 41 were missense and 4 were nonsense. A resistant strain with a nucleotide insertion in therdxA sequence was also found. With the exception of the point mutations and the insertion generating a stop signal, no particular nucleotide mutation or amino acid substitution could be associated to metronidazole resistance. Moreover, phylogenetic analysis of the 30 nucleotide sequences did not demonstrate specific clusters associated with the resistance phenotype.

Stability of spinosad resistance inFrankliniella occidentalis(Pergande) under laboratory conditions

2008 ◽  
Vol 98 (4) ◽  
pp. 355-359 ◽  
Author(s):  
P. Bielza ◽  
V. Quinto ◽  
C. Grávalos ◽  
E. Fernández ◽  
J. Abellán ◽  
...  
Keyword(s):  
Resistant Strain ◽  
Selection Pressure ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Laboratory Conditions ◽  
Flower Thrips ◽  
Factors Influencing ◽  
Stability Of Resistance ◽  
The Stability ◽  
Successive Generations

AbstractThe stability of spinosad resistance in western flower thrips (WFT),Frankliniella occidentalis(Pergande), populations with differing initial frequencies of resistance was studied in laboratory conditions. The stability of resistance was assessed in bimonthly residual bioassays in five populations with initial frequencies of 100, 75, 50, 25 and 0% of resistant individuals. There were no consistent changes in susceptibility of the susceptible strain after eight months without insecticide pressure. In the resistant strain, very highly resistant to spinosad (RF50>23,000-fold), resistance was maintained up to eight months without further exposure to spinosad. In the absence of any immigration of susceptible genes into the population, resistance was stable. In the case of the population with different initial frequency of resistant thrips, spinosad resistance declined significantly two months later in the absence of selection pressure. With successive generations, these strains did not change significantly in sensitivity. Spinosad resistance inF. occidentalisdeclined significantly in the absence of selection pressure and the presence of susceptible WFT. These results suggest that spinosad resistance probably is unstable under field conditions, primarily due to the immigration of susceptible WFT. Factors influencing stability or reversion of spinosad resistance are discussed.

THE DIFFERENTIAL RESPONSE OF STRAINS OF WILD CARROT TO 2,4-D AND RELATED HERBICIDES

1963 ◽  
Vol 43 (3) ◽  
pp. 255-262 ◽  
Author(s):  
C. W. Whitehead ◽  
C. M. Switzer
Keyword(s):  
Resistant Strain ◽  
Differential Response ◽  
Susceptible Strain ◽  
Severe Injury ◽  
Radicle Growth ◽  
Cotyledon Stage ◽  
Wild Carrot

Studies were conducted on the effect of 2,4-D and some related herbicides on a susceptible and a resistant strain of wild carrot (Daucus corota L.). When treated with 2,4-D, 4-(2,4-DB) or 4-(MCPB), plants of the susceptible strain died within a few weeks while those of die resistant strain recovered after showing severe injury symptoms. Treatment with 2,4,5-T or silvex killed both the susceptible and resistant strains.Seeds of the two strains, placed in various concentrations of 2,4-D, showed no differences in germination or radicle growth after 7 days. However, sprays of 2,4-D on seedlings just after emergence produced the differential response. Resistance appeared to develop between germination and the cotyledon stage of growth.There were no differences in the effect of 2,4-D on the respiration of whole tissue of the susceptible and resistant wild carrots.

445. The differentiation of the lactic streptococci and their antibiotics

1951 ◽  
Vol 18 (2) ◽  
pp. 198-204 ◽  
Author(s):  
A. Hirsch ◽  
Elisabeth Grinsted
Keyword(s):  
Lactic Acid ◽  
Resistant Strain ◽  
Streptococcus Cremoris ◽  
Cross Test

Twenty-three strains of lactic acid streptococci were shown to be types ofStreptococcus cremorisorStr. lactisby cultural, biochemical and serological means. The antibiotics produced by thecremorisstrains could be differentiated readily from thelactisantibiotics, of which at least five different varieties are described. A cross-test and a resistant-strain test were used to differentiate the antibiotics.

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