IN VITRO SENSITIVITY OF LEPTOSPIRA TO VARIOUS ANTIMICROBIAL AGENTS

1961 ◽  
Vol 7 (5) ◽  
pp. 751-758 ◽  
Author(s):  
J. G. Cousineau ◽  
J. A. McKiel
Keyword(s):  
Liquid Medium ◽  
Antimicrobial Agents ◽  
Culture Media ◽  
Selective Medium ◽  
Antimicrobial Compounds ◽  
In Vitro Sensitivity ◽  
Modified Media

The in vitro sensitivity of Leptospira icterohaemorrhagiae was checked against 14 antimicrobial agents to find which might be added to leptospira culture media to control contamination without seriously depressing growth of leptospires. Estimates of the amounts of leptospira growth resulting in these modified media suggested that five agents were worthy of further study. The determination of leptospira population by microscopic counts showed that three of these compounds produced only slight to moderate inhibition. Two of these three antimicrobial compounds plus a fungicide were tested in combinations. Qualitative tests on these media were also carried out employing L. ballum, L. canicola, L. pyrogenes, and L. sejroe.Based on results of these tests, a new selective medium for growing leptospires is suggested; it consists of a standard leptospira liquid medium to which are added 50 mg/l. sulfathiazole, 5 mg/l. neomycin sulphate, and 0.5 mg/l. actidione.

scholarly journals Reduction in the in vitro sensitivity oF Drechslera tritici-repentis, isolated from wheat, to strobilurin and triazole fungicides

2017 ◽  
Vol 43 (1) ◽  
pp. 20-25
Author(s):  
Rosane Baldiga Tonin ◽  
Erlei Melo Reis ◽  
Aveline Avozani
Keyword(s):  
Inhibitory Concentration ◽  
In Vitro Sensitivity ◽  
Randomized Design ◽  
Inhibition Data ◽  
Ic50 Values ◽  
Control Failure ◽  
Quinone Outside Inhibitors ◽  
Completely Randomized Design

ABSTRACT Reports of failure in the chemical control of wheat yellow leaf spot led to determination of the sensitivity of Drechslera tritici-repentis (Dtr) to the fungicides quinone outside inhibitors (QoIs) and demethylation inhibitors (DMIs). The IC50 was obtained for strobilurins (azoxystrobin, kresoxim-methyl, picoxystrobin and pyraclostrobin) and for triazoles (cyproconazole, epoxiconazole, propiconazole, prothioconazole and tebuconazole), using five Dtr isolates. Seven concentrations of the fungicides were tested in the bioassay: 0.00; 0.01; 0.10; 1.00; 10:00 and 20.00 and 40.00 mg/L active ingredient (a.i.). Assays consisted of completely randomized design and four replicates. Each experiment was performed twice, using the average of the two tests for statistical analysis. The percentage inhibition data for conidial germination (QoIs) and for mycelial growth (DMIs) were subjected to logarithmic regression analysis, calculating the 50% inhibitory concentration (IC50) based on the generated equation. There was a reduction in the sensitivity of Dtr isolates to strobilurins. IC50 values ranged from 0.58 to > 40.00 mg/L. The lowest sensitivity of isolates was detected for azoxystrobin, kresoxim-methyl, picoxystrobin and trifloxystrobin. Pyraclostrobin was most efficient, showing IC50 between 0.58 and 1.03 mg/L. The IC50 ranged from 0.35 to 1.37 mg/L for epoxiconazole, from 0.49 to 1.28 mg/L for propiconazole and from 1.41 to 2.34 mg/L for tebuconazole. Prothioconazole was most potent, showing IC50 between 0.09 and 0.21 mg/L. The hypothesis that the control failure can be attributed to the reduced Dtr sensitivity to the fungicides QoIs and DMIs was confirmed.

scholarly journals Temporary immersion biorreators: efficient technique for the propagation of the ‘Pircinque’ strawberry

2019 ◽  
Vol 41 (1) ◽  
Author(s):  
Samila Silva Camargo ◽  
Leo Rufato ◽  
Maicon Magro ◽  
André Luiz Kulkamp de Souza
Keyword(s):  
Liquid Medium ◽  
Culture Medium ◽  
Culture Media ◽  
Time Factors ◽  
Efficient Technique ◽  
Control Treatment ◽  
Solid Culture ◽  
Temporary Immersion ◽  
Solid Culture Medium

Abstract The in vitro propagation technique via temporary immersion bioreactors is a tool that, through the culture in a liquid medium, allows an increase in the efficiency of seedling production. Several researches with the strawberry crop have shown greater efficiency of the system compared to the conventional process of micropropagation in solid medium. In this sense, the objective herein was to establish a protocol of multiplication and rooting of the ‘Pircinque’ strawberry, in temporary immersion bioreactors. Two distinct and independent studies were carried out, characterized by the multiplication and rooting stages of strawberry explants, newly introduced and registered in Brazil. Two culture media (MS and KNOP) were studied and, as a control treatment, the growth of the explants in solid culture medium was evaluated with the addition of 5 g L-1 of agar. Different immersion times of the culture medium were explored: five or eight times a day, for 15 minutes. The study was composed of the culture medium and immersion time factors, as well as the control (solid) treatment. It was verified that the use of temporary immersion bioreactors system is an efficient technique for the multiplication and rooting of explants of strawberry cv. Pircinque, when compared to the conventional method of micropropagation with the use of solid culture medium, making it possible to optimize the production of seedlings in biofactories. The MS liquid medium, in contact with explants of ‘Pircinque’ strawberry five times a day, increased the growth of the aerial part and the root system.

scholarly journals pfmdr1Amplification Is Related to Increased Plasmodium falciparum In Vitro Sensitivity to the Bisquinoline Piperaquine

2012 ◽  
Vol 56 (7) ◽  
pp. 3615-3619 ◽  
Author(s):  
M. I. Veiga ◽  
P. E. Ferreira ◽  
M. Malmberg ◽  
L. Jörnhagen ◽  
A. Björkman ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Copy Number ◽  
Statistical Significance ◽  
Resistance Locus ◽  
Content Type ◽  
Enhanced Sensitivity ◽  
In Vitro Sensitivity ◽  
Artemisinin Combination Therapies

ABSTRACTThe 4-aminoquinoline bisquinoline piperaquine is an important partner drug in one of the presently recommended artemisinin combination therapies. Recent clinical trials have confirmed its high efficacy in combination with dihydroartemisinin. Resistance to piperaquine alone has, however, been documented. Amplification in copy number of thePlasmodium falciparummultidrug resistance locus on chromosome 5, containing thepfmdr1gene, has been shown to confer resistance to structurally unrelated antimalarials. Through the determination of the 50% inhibitory concentrations (IC50s) and IC90s for piperaquine and chloroquine in a set of 46 adaptedP. falciparumcultures originating from the Thai-Burmese border, we have characterized the regions around thepfmdr1gene and identified a significant association between the presence ofpfmdr1duplications and enhanced sensitivity to piperaquine (P= 0.005 for IC50andP= 0.002 for IC90) and chloroquine, reaching statistical significance at IC90s (P= 0.026). These results substantiate the potential importance ofpfmdr1copy number amplifications in the efficacy of the combination therapy piperaquine-dihydroartemisinin. It supports the rational use of 4-aminoquinolines and artemisinin-based compounds, as they independently select for mutually incompatible combinations of mutations.

scholarly journals In Vitro Antimicrobial Susceptibility Testing of Helicobacter felis, H. bizzozeronii, and H. salomonis

2005 ◽  
Vol 49 (7) ◽  
pp. 2997-3000 ◽  
Author(s):  
K. Van den Bulck ◽  
A. Decostere ◽  
I. Gruntar ◽  
M. Baele ◽  
B. Krt ◽  
...  
Keyword(s):  
Antimicrobial Agent ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Acquired Resistance ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Helicobacter Felis ◽  
Agar Dilution

ABSTRACT The susceptibilities of Helicobacter felis (15 strains), H. bizzozeronii (7 strains), and H. salomonis (3 strains) to 10 antimicrobial agents were investigated by determination of the MIC using the agar dilution method. No consistent differences were noticed between the different Helicobacter species, which were all highly susceptible to ampicillin, clarithromycin, tetracycline, tylosin, enrofloxacin, gentamicin, and neomycin, as demonstrated by low MICs. Higher MICs were obtained for lincomycin (up to 8 μg/ml) and spectinomycin (up to 4 μg/ml). Two H. felis strains showed a MIC of 16 μg/ml for metronidazole, suggesting acquired resistance to this antimicrobial agent.

In vitro culture of tetrathyridia of Mesocestoides corti using a gel based diphasic medium

2002 ◽  
Vol 76 (1) ◽  
pp. 21-25 ◽  
Author(s):  
J. Chernin ◽  
D. Thompson ◽  
D. Swaine
Keyword(s):  
In Vitro Culture ◽  
Liquid Medium ◽  
Asexual Reproduction ◽  
Drug Screening ◽  
Culture Media ◽  
Optimum Conditions ◽  
Survival And Development ◽  
Diphasic Medium

AbstractTetrathyridia of Mesocestoides corti were cultured in vitro in a diphasic medium consisting of a liquid medium (CMRL Sigma) and a thixotropic nutrient gel (Oxoid). Tests demonstrated that a 50% medium/gel mixture produced optimum conditions for the survival and development of tetrathyridia. Established anthelminthic drugs were inoculated into the gel which demonstrated that this system can be used for preliminary anthelminthic drug screening. The development and survival of the tetrathyridia were influenced by the addition of pepsin, trypsin and liver peptone to the culture media. The development and maturation of proglottids were observed in addition to asexual reproduction by the process of budding. Tetrathyridia maintained in vitro and reinfected into both mouse and rat hosts retained their viability.

scholarly journals Resistance of Kansas Sclerotinia homoeocarpa Isolates to Thiophanate-Methyl and Determination of Associated β-Tubulin Mutation

2014 ◽  
Vol 15 (2) ◽  
pp. 80-84 ◽  
Author(s):  
Jesse C. Ostrander ◽  
Richard B. Todd ◽  
Megan M. Kennelly
Keyword(s):  
Golf Course ◽  
Sclerotinia Homoeocarpa ◽  
Fungicide Sensitivity ◽  
Putting Greens ◽  
Thiophanate Methyl ◽  
In Vitro Sensitivity ◽  
Starting Point ◽  
Β Tubulin

Eighty-two isolates of Sclerotinia homoeocarpa from 12 sites in Kansas were evaluated for in vitro sensitivity to the methyl benzimidazole carbamate (MBC) fungicide thiophanate-methyl at the discriminatory dose of 10 μg/ml. Seventeen isolates were sensitive to thiophanate-methyl and the remaining isolates were resistant. Of the 65 isolates from golf course putting greens, two isolates were sensitive and the remaining 63 isolates were resistant. Six resistant and five sensitive isolates were also evaluated in greenhouse assays on fungicide-treated plants. The isolates that were sensitive to thiophanate-methyl in vitro did not cause any disease on thiophanate-methyl-treated plants, and those that were resistant in vitro caused blighting on treated plants equivalent to the nontreated controls. The entire β-tubulin gene was sequenced for four resistant and four sensitive isolates. The resistant isolates all harbored a substitution of alanine for glutamic acid at codon 198 (E198A). These results provide a starting point for further surveys and monitoring of fungicide sensitivity. Accepted 7 April 2014. Published 6 June 2014.

scholarly journals PHYTOCHEMICAL SCREENING AND ANTIAMEBIC STUDIES OF TAMARINDUS INDICA OF LEAVES EXTRACT

2019 ◽  
pp. 507-512
Author(s):  
MANSOUR ABDULNABI H MEHDI ◽  
FADEL YS ALARABI ◽  
MAZAHAR FAROOQUI ◽  
VIDYA PRADHAN
Keyword(s):  
Entamoeba Histolytica ◽  
Culture Media ◽  
Tamarindus Indica ◽  
Phytochemical Screening ◽  
Plant Leaves ◽  
High Concentration ◽  
Amebic Dysentery ◽  
In Vitro Sensitivity ◽  
Ethanolic Extracts

Objective: The present study deals with preliminary phytochemical screening of Tamarindus indica extracts and investigates its antiamebic effect against Entamoeba histolytica in vitro. Methods: E. histolytica was isolated from stools of patients with amebic dysentery and cultivated in lock-egg medium. The leaves extract was added to check its antiamebic activity. Results: The phytochemical screening shows that T. indica contains alkaloids, flavonoids, phenol, and tannins. T. indica extracts (aqueous and ethanolic) were added to culture media E. histolytica. It was observed that E. histolytica count reduced to zero after 72 h and 96 h when 15 mg/ml of aqueous and ethanolic extracts were added, respectively. It is also revealed that there is no cytotoxicity against erythrocytes even when high concentration of plant leaves extract is used. Conclusion: The in vitro sensitivity of T. indica leaves extract against the E. histolytica is established.

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