P2097 Development of resistance toward macrolides in oropharyngeal streptococci after administration of azithromycin SR or clarithromycin XL in comparison to a control group

2007 ◽  
Vol 29 ◽  
pp. S606
Author(s):  
G. Westphal ◽  
M. Schmidt-Ioanas ◽  
J. Wagner ◽  
H. Lode
Keyword(s):  
Control Group ◽  
Development Of Resistance

scholarly journals Cloning and Functional Verification of CYP408A3 and CYP6CS3 Related to Chlorpyrifos Resistance in the Sogatella furcifera (Horváth) (Hemiptera: Delphacidae)

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 795
Author(s):  
Yanwei Ruan ◽  
Xinxian Liu ◽  
Changwei Gong ◽  
Yuming Zhang ◽  
Litao Shen ◽  
...  
Keyword(s):  
Protein Structures ◽  
Sublethal Dose ◽  
Functional Verification ◽  
Control Group ◽  
Sogatella Furcifera ◽  
Blank Control Group ◽  
P450 Gene ◽  
Development Of Resistance ◽  
Injection Treatment ◽  
P450 Enzyme

The white-back planthopper (WBPH), Sogatella furcifera, mainly harms rice and occurs in most rice regions in China and Asia. With the use of chemical pesticides, S. furcifera has developed varying degrees of resistance to a variety of pesticides. In our study, a chlorpyrifos-resistant population (44.25-fold) was built through six generations of screening with a sublethal dose of chlorpyrifos (LD50) from a field population. The expression levels of ten selected resistance-related P450 genes were analyzed by RT-qPCR and found that CYP408A3 and CYP6CS3 were significantly more expressed in the third instar nymphs of the XY17-G5 and XY17-G6 populations, about 25-fold more than the Sus-Lab strain, respectively (p < 0.01). To elucidate their molecular function in the development of resistance towards chlorpyrifos, we cloned two P450 full lengths and predicted their tertiary protein structures. CYP408A3 and CYP6CS3 were also downregulated after injecting dsCYP408A3, dsCYP6CS3, or their mixture compared to the control group. Moreover, the mortality rates of the dsCYP6CS3 (91.7%) and the mixture injection treatment (93.3%) treated by the LC50 concentration of chlorpyrifos were significantly higher than the blank control group (51.7%) and dsCYP408A3 injection treatment (69.3%) at 72 h (p < 0.01). Meanwhile, the P450 enzyme activities in the dsRNA treatments were lower than that in the control (XY17-G6) (p < 0.01). Therefore, the P450 gene CYP6CS3 may be one of the main genes in the development of chlorpyrifos resistance in S. furcifera.

Resistance by cattle to cattle tick, Boophilus microplus. III. The development of resistance to experimental infestations by purebred Sahiwal and Australian Illawarra Shorthorn cattle

1971 ◽  
Vol 22 (2) ◽  
pp. 331 ◽  
Author(s):  
RW Hewetson
Keyword(s):  
Adult Female ◽  
Acquired Resistance ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Control Group ◽  
The Third ◽  
Development Of Resistance ◽  
Significant Difference ◽  
Sahiwal Cattle ◽  
Males And Females

Purebred Sahiwal cattle acquired resistance to Boophilus microplus in a similar manner to crossbred Sahiwal cattle as previously reported. The purebred entire males and females were more resistant than a control group of crossbred steers because they dropped significantly fewer replete ticks than the crossbreds at the third and fourth, but not at the first and second infestations. Adult female ticks dropped by purebred animals were significantly lighter than those dropped by crossbred animals at the fourth infestation only. There was no significant difference in the numbers of eggs laid and hatched from ticks dropped by purebred and crossbred animals. Australian Illawarra Shorthorn steers developed resistance at a second and third infestation which waned at a fourth infestation, but individual steers displayed developing resistance throughout the four infestations. Day of modal drop of replete female ticks appeared to be affected by breed, and developing resistance or season.

scholarly journals Combating Algae Blooms

2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Ethan Talley ◽  
Whitney Holden
Keyword(s):  
Algal Blooms ◽  
Genetically Engineered ◽  
Plate Count ◽  
Control Group ◽  
Suitable Candidate ◽  
E Coli ◽  
Development Of Resistance ◽  
Algae Blooms ◽  
Cecropin A ◽  
Successive Generations

Microcystis aeruginosa is a common freshwater cyanobacterium that can form toxic algal blooms that harm other species and the environment. This project studied the effects of the antimicrobial peptide Cecropin A on the growth of M. aeruginosa to assess Cecropin A’s effectiveness as a tool to combat algal blooms and limit their environmental impacts. In this study, different concentrations of Cecropin A were tested on M. aeruginosa, the growth of which was then measured using a plate count. Each concentration of Cecropin A tested resulted in a significant decrease in M. aeruginosa growth compared to the control group, indicating the effectiveness of this peptide at inhibiting M. aeruginosa. Because Cecropin A is a peptide, bacteria can be genetically engineered to produce it for anti-algal applications. This study also analyzed the effects of Cecropin A on the non-pathogenic E. coli K12 in order to study development of antibiotic resistance in this bacterium and determine its feasibility for anti-algal applications such as producing or distributing Cecropin A. The effects of Cecropin A were tested on successive generations to determine if this strain of bacterium can build up a resistance to Cecropin A that would make it a suitable candidate to produce large quantities of this peptide. The results over three 24-hour periods of exposure to Cecropin A seem to indicate a development of resistance to Cecropin A by E. coli K12, suggesting that this bacterium may be suitable for production and/or distribution of Cecropin A for anti-bloom control efforts.

scholarly journals Antiplasmodial Property of Glycyrrhiza glabra Traditionally Used for Malaria in Iran: Promising Activity with High Selectivity Index for Malaria

2018 ◽  
pp. 135-140 ◽  
Author(s):  
Ali Ramazani ◽  
Mahdi Tavakolizadeh ◽  
Samira Ramazani ◽  
Hamidreza Kheiri- Manjili ◽  
Mehdi Eskandari
Keyword(s):  
Ethyl Acetate ◽  
Antiplasmodial Activity ◽  
Control Group ◽  
Root Extract ◽  
Methanol Fraction ◽  
Aqueous Fraction ◽  
Percolation Method ◽  
Development Of Resistance

Background: Development of resistance against the frontline anti-malarial drugs has created an alarming situation, which requires intensive drug discovery to develop new, more effective, affordable and accessible anti-malarial agents. The aim of this study was to assess antiplasmodial activity of the different fractions of root extract of Glycyr­rhiza glabra. Methods: Roots of G. glabra were collected from Tarom district of Zanjan Province in 2016 and then dried root ma­terial was chopped and consecutively extracted by the percolation method using solvents of different polarity. Result­ing extracts were assessed for in vitro and in vivo anti-malarial and cell cytotoxicity activities. Results: Among the three different solvent fractions studied, water-methanol and ethyl acetate fractions showed promising in vitro antiplasmodial activity against CQ-sensitive Plasmodium falciparum 3D7 strain (IC50= 9.95 and 13µg/ml, respectively). Further, the selectivity indices (HeLa cells versus P. falciparum) for the promising water-methanol fraction showed selectivity for P. falciparum and potential safer therapy for human. Interestingly, water-methanol and ethyl acetate fractions showed a significant suppression of parasite growth (72.2% and 65%, respec­tively) in comparison with control group in mice infected with P. berghei (P< 0.05). Conclusion: The promising antiplasmodial activity of the aqueous fraction of G. glabra obtained in our study war­rant bioassay-guided fractionation of this fraction to identify active principles responsible for antiplasmodial activity.

Elimination of Nasal Carriage ofStaphylococcus aureusin Hemodialysis Patients

1996 ◽  
Vol 17 (12) ◽  
pp. 793-797 ◽  
Author(s):  
Jan A.J.W. Kluytmans ◽  
Marie-Jose Manders ◽  
Erik van Bommel ◽  
Henri Verbrugh
Keyword(s):  
Nasal Carriage ◽  
Hemodialysis Patients ◽  
University Hospital ◽  
Control Group ◽  
Study Group ◽  
Tertiary Referral Center ◽  
Development Of Resistance ◽  
Hemodialysis Unit ◽  
Historic Control ◽  
The University

AbstractObjective:To study the efficacy of mupirocin for the elimination of nasal carriage ofStaphylococcus aureusin hemodialysis patients.Design:The efficacy of mupirocin was studied in a prospectively followed cohort. The effect of this intervention on the rate ofS aureusbacteremia was evaluated using a historic control group.Setting:Patients on the hemodialysis unit of the University Hospital Rotterdam, a tertiary referral center.Patients:The study group consisted of consecutive patients on hemodialysis from February 1, 1992, until November 1, 1993. They were screened by taking nasal cultures monthly during their time on hemodialysis. IfS aureuswas isolated, treatment with mupirocin nasal ointment was initiated. The control group consisted of patients treated on the same hemodialysis unit from January 1, 1990, until January 1, 1992.Results:The study group consisted of 226 patients, of whom 172 were evaluated to determine the efficacy of mupirocin. Sixty-seven (39%) were identified as nasal carriers. Following the initial treatment, 66 nasal cultures (98.5%) became negative. After 3 months and 6 months, respectively, 63 (94%) and 61 (91%) of the treated carriers had negative cultures. The rate of bacteremia (defined as the number of episodes of5 aureusbacteremia per patient-year on hemodialysis) was significantly lower among the 226 patients in the study group (0.04 per patient-year) than among the 273 patients in the control group (0.25 per patient year;P<.001). Development of resistance and adverse effects were not observed.Conclusions:Mupirocin nasal ointment effectively eliminates nasal carriage of5 aureusin patients on hemodialysis. This was associated with a significant reduction of the incidence of5 aureusbacteremia, as compared to historic controls.

scholarly journals Pharmacokinetic Properties of Artemether, Dihydroartemisinin, Lumefantrine, and Quinine in Pregnant Women with Uncomplicated Plasmodium falciparum Malaria in Uganda

2013 ◽  
Vol 57 (10) ◽  
pp. 5096-5103 ◽  
Author(s):  
Joel Tarning ◽  
Frank Kloprogge ◽  
Mehul Dhorda ◽  
Vincent Jullien ◽  
Francois Nosten ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Plasmodium Falciparum Malaria ◽  
Adverse Outcomes ◽  
Control Group ◽  
Control Groups ◽  
Development Of Resistance ◽  
Pharmacokinetic Properties ◽  
Dosing Regimens ◽  
Lower Drug ◽  
Uncomplicated Plasmodium Falciparum Malaria

ABSTRACTPregnancy alters the pharmacokinetic properties of many drugs used in the treatment of malaria, usually resulting in lower drug exposures. This increases the risks of treatment failure, adverse outcomes for the fetus, and the development of resistance. The pharmacokinetic properties of artemether and its principal metabolite dihydroartemisinin (n= 21), quinine (n= 21), and lumefantrine (n= 26) in pregnant Ugandan women were studied. Lumefantrine pharmacokinetics in a nonpregnant control group (n= 17) were also studied. Frequently sampled patient data were evaluated with noncompartmental analysis. No significant correlation was observed between estimated gestational age and artemether, dihydroartemisinin, lumefantrine, or quinine exposures. Artemether/dihydroartemisinin and quinine exposures were generally low in these pregnant women compared to values reported previously for nonpregnant patients. Median day 7 lumefantrine concentrations were 488 (range, 30.7 to 3,550) ng/ml in pregnant women compared to 720 (339 to 2,150) ng/ml in nonpregnant women (P= 0.128). There was no statistical difference in total lumefantrine exposure or maximum concentration. More studies with appropriate control groups in larger series are needed to characterize the degree to which pregnant women are underdosed with current antimalarial dosing regimens.

scholarly journals Selection of Drug Resistance-Mediating Plasmodium falciparum Genetic Polymorphisms by Seasonal Malaria Chemoprevention in Burkina Faso

2014 ◽  
Vol 58 (7) ◽  
pp. 3660-3665 ◽  
Author(s):  
Anyirékun Fabrice Somé ◽  
Issaka Zongo ◽  
Yves-Daniel Compaoré ◽  
Souleymane Sakandé ◽  
François Nosten ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Burkina Faso ◽  
Control Measure ◽  
Control Group ◽  
Nucleotide Polymorphisms ◽  
Content Type ◽  
Development Of Resistance ◽  
Seasonal Malaria Chemoprevention ◽  
To Receive ◽  
Selection Of

ABSTRACTSeasonal malaria chemoprevention (SMC), with regular use of amodiaquine plus sulfadoxine-pyrimethamine (AQ/SP) during the transmission season, is now a standard malaria control measure in the Sahel subregion of Africa. Another strategy under study is SMC with dihydroartemisinin plus piperaquine (DP).Plasmodium falciparumsingle nucleotide polymorphisms (SNPs) inP. falciparumcrt(pfcrt),pfmdr1,pfdhfr, andpfdhpsare associated with decreased response to aminoquinoline and antifolate antimalarials and are selected by use of these drugs. To characterize selection by SMC of key polymorphisms, we assessed 13 SNPs inP. falciparumisolated from children aged 3 to 59 months living in southwestern Burkina Faso and randomized to receive monthly DP or AQ/SP for 3 months in 2009. We compared SNP prevalence before the onset of SMC and 1 month after the third treatment inP. falciparumPCR-positive samples from 120 randomly selected children from each treatment arm and an additional 120 randomly selected children from a control group that did not receive SMC. The prevalence of relevant mutations was increased after SMC with AQ/SP. Significant selection was seen forpfcrt76T (68.5% to 83.0%,P= 0.04),pfdhfr59R (54.8% to 83.3%,P= 0.0002), andpfdhfr108N (55.0% to 87.2%,P= 0.0001), with trends toward selection ofpfmdr186Y,pfdhfr51I, andpfdhps437G. After SMC with DP, only borderline selection of wild-typepfmdr1D1246 (mutant; 7.7% to 0%,P= 0.05) was seen. In contrast to AQ/SP, SMC with DP did not clearly select for known resistance-mediating polymorphisms. SMC with AQ/SP, but not DP, may hasten the development of resistance to components of this regimen. (This study has been registered at ClinicalTrials.gov under registration no. NCT00941785.)

Hexachlorobenzene toxicity in the monkey ovary: III. Ultrastructure induced by high (10 mg/kg) dose exposure

1991 ◽  
Vol 49 ◽  
pp. 130-131
Author(s):  
A. Singh ◽  
A. Dykeman ◽  
J. Jarrelf ◽  
D. C. Villeneuve
Keyword(s):  
Present Report ◽  
Reproductive Toxicity ◽  
Control Group ◽  
Primate Model ◽  
Human Follicular Fluid ◽  
Thin Sections ◽  
Cynomolgus Monkeys ◽  
Cacodylate Buffer ◽  
Induction Cycle ◽  
Comprehensive Study

Hexachlorobenzene (HCB), a persistent and mobile organochlorine pesticide, occurs in environment. HCB has been shown to be present in human follicular fluid. An objective of the present report, which is part of a comprehensive study on reproductive toxicity of HCB, was to determine the cytologic effects of the compound on ovarian follicles in a primate model.Materials and Methods. Eight Cynomolgus monkeys were housed under controlled conditions at Animal facility of Health and Welfare, Ottawa. Animals were orally administered gelatin capsules containing HCB mixed with glucose in daily dosages of 0.0 or 10 mg/kg b.w. for 90 days; the former was the control group. On the menstrual period following completion of dosing, the monkeys underwent an induction cycle of superovulation. At necropsy, one-half of an ovary from each animal was diced into ca. 2- to 3-mm cubed specimens that were fixed by immersion in 2.5% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.3). Subsequent procedures followed to obtain thin sections that were examined in a Hitachi H-7000 electron microscope have been described earlier.

The effect of bromocriptine on mammary-gland ultrastructure of hyperprolactinemic rats

1984 ◽  
Vol 42 ◽  
pp. 204-205
Author(s):  
I.C. Murray
Keyword(s):  
Mammary Gland ◽  
Dopamine Agonist ◽  
Alveolar Epithelium ◽  
Mammary Glands ◽  
Female Rats ◽  
Control Group ◽  
Cell Hyperplasia ◽  
Once Daily ◽  
Long Evans

In women, hyperprolactinemia is often due to a prolactin (PRL)-secreting adenoma or PRL cell hyperplasia. RRL excess stimulates the mammary glands and causes proliferation of the alveolar epithelium. Bromocriptine, a dopamine agonist, inhibits PRL secretion and is given to women to treat nonpuerperal galactorrhea. Old female rats have been reported to have PRL cell hyperplasia or adenoma leading to PRL hypersecretion and breast stimulation. Herein, we describe the effect of bromocriptine and consequently the reduction in serum PRL levels on the ultrastructure of rat mammary glands.Female Long-Evans rats, 23 months of age, were divided into control and bromocriptine-treated groups. The control animals were injected subcutaneously once daily with a 10% ethanol vehicle and were later divided into a normoprolactinemic control group with serum PRL levels under 30 ng/ml and a hyperprolactinemic control group with serum PRL levels above 30 ng/ml.

Acetaminophen: Neonatal hepatotoxicity due to late pregnancy exposure

1987 ◽  
Vol 45 ◽  
pp. 718-719
Author(s):  
G.A. Miranda ◽  
M.A. Arroyo ◽  
C.A. Lucio ◽  
M. Mongeotti ◽  
S.S. Poolsawat
Keyword(s):  
Low Dose ◽  
Fetal Liver ◽  
Late Pregnancy ◽  
Toxic Chemicals ◽  
Control Group ◽  
High Dose ◽  
Over The Counter ◽  
Liver And Kidney ◽  
Neonatal Liver ◽  
Childbearing Women

Exposure to drugs and toxic chemicals, during late pregnancy, is a common occurrence in childbearing women. Some studies have reported that more than 90% of pregnant women use at least 1 prescription; of this, 60% used more than one. Another study indicated that 80% of the consumed drugs were not prescribed, and of this figure, 95% were “over-the-counter” drugs. Acetaminophen, the safest of all over-the-counter drugs, has been reported to induce fetal liver necrosis in man and animals and to have abortifacient and embryocidal action in mice. This study examines the degree to which acetaminophen affects the neonatal liver and kidney, when a fatty diet is simultaneously fed to the mother during late pregnancy.Timed Swiss Webster female mice were gavaged during late pregnancy (days 16-19) with fat suspended acetaminophen at a high dose, HD = 84.50 mg/kg, and a low dose, LD = 42.25 mg/kg; a control group received fat alone.

Sign in / Sign up

Export Citation Format

Share Document