scholarly journals Antibacterial Effects of Levofloxacin, Erythromycin, and Rifampin in a Human Monocyte System againstLegionella pneumophila

1998 ◽  
Vol 42 (12) ◽  
pp. 3153-3156 ◽  
Author(s):  
Aldona L. Baltch ◽  
Raymond P. Smith ◽  
Mary A. Franke ◽  
Phyllis B. Michelsen
Keyword(s):  
Antibacterial Activity ◽  
Legionella Pneumophila ◽  
Human Monocyte ◽  
Antibacterial Activities ◽  
Human Monocytes ◽  
Antibacterial Effects ◽  
In Vitro System ◽  
Time Period ◽  
Time Periods

ABSTRACT The antibacterial activities of levofloxacin, erythromycin, and rifampin against intracellular Legionella pneumophilaL-1033, serogroup 1, were studied. In an in vitro system utilizing adherent human monocytes, L. pneumophila L-1033, a phagocytosis time period of 1 h, and antibiotic (levofloxacin, erythromycin, and/or rifampin) at 1 to 10 times the MIC, the CFU/ml values for the monocyte lysate were determined during 0- to 4-day time periods. The decrease in CFU/ml with levofloxacin at pH 7.4 was rapid, occurring within 24 h, and was drug concentration dependent (P < 0.01). The decrease in CFU with rifampin was first observed at 48 h (P < 0.01), while only a minimal decrease in CFU/ml was observed with erythromycin. Combination of levofloxacin and rifampin and of levofloxacin and erythromycin at ten times their MICs significantly decreased the CFU/ml value (P < 0.01), to the value attained by levofloxacin alone, while combination of rifampin and erythromycin did not. Removal of levofloxacin after 24 h of incubation resulted in regrowth ofL. pneumophila L-1033, while a continued slow decrease in CFU/ml was seen following rifampin removal; CFU/ml values were unaffected by the removal of erythromycin. At 4 days, and even in assays performed following antibiotic removal, the CFU/ml value continued to be lower in the levofloxacin and rifampin assays than in the assays with erythromycin. Levofloxacin had a significantly higher bactericidal activity against L. pneumophila L-1033 than erythromycin or rifampin. In these assays, the addition of erythromycin or rifampin did not affect the antibacterial activity of levofloxacin.

scholarly journals In vitro effects of quinine on the antibacterial activity of erythromycin against bacteria of clinical relevance

2021 ◽  
Vol 14 (2) ◽  
pp. 077-086
Author(s):  
Oluremi Adejoke Akinwale ◽  
Uyi Oluwatobi Emokpae ◽  
Opeyemi Mariam Adebogun ◽  
Morenike Olutumbi Adeoye-Isijola ◽  
Olufunmiso Olusola Olajuyigbe
Keyword(s):  
Antibacterial Activity ◽  
Synergistic Effect ◽  
Clinical Relevance ◽  
Bacterial Infections ◽  
Antibacterial Activities ◽  
Antibacterial Effects ◽  
Agar Dilution ◽  
Inhibition Zones ◽  
In Vitro Effects

The study investigated the in vitro effects of quinine on the antibacterial activity of erythromycin for possible interactions. The antibacterial activities of each drug and their combinations were investigated by agar diffusion, agar and macrobroth dilution methods. While 100 µl of 1000 µg/ml of erythromycin produced inhibition zones ranging between 13 and 31 ± 1.0 mm in all the isolates except K. pneumoniae and P. aeruginosa ATCC 19582, combining the highest concentration of erythromycin with 35 µg/ml of quinine produced inhibition zones ranging between 14 and 34 ± 1.0 mm with the exception of S. flexneri KZN. Though quinine had no antibacterial effects on the isolates, erythromycin was effective at minimum inhibitory concentrations (MICs) ranging between 25 and 100 µg/ml while their combinations resulted in reduction of MICs of most of the isolates to 12.5 µg/ml except those against A. calcaoceuticus anitratus CSIR, Ps. aeruginosa ATCC 15442, P. shigelloides ATCC 51903, A. hydrophila ATCC 35654, Ps. aeruginosa ATCC 19582 and E. faecalis KZN that remained unchanged in agar dilution. While the MICs of erythromycin ranged between 25 and 50 µg/ml, the MICs of this antibiotic was reduced to concentrations ranging between 12.5 and 50 µg/ml indicating 50% to 75% in the presence of quinine. The combination of erythromycin and quinine, in vitro, resulted in synergistic (50%), additive/indifference (44.44%) and antagonistic (11.11%) interactions while quinine at concentrations lower than plasma quinine concentrations was inhibitory to the antibacterial activity of erythromycin. The synergistic effect may serve as remedy for bacterial infections in which the test bacteria have been implicated.

scholarly journals Flavone-Rich Fractions and Extracts from Oroxylum indicum and Their Antibacterial Activities against Clinically Isolated Zoonotic Bacteria and Free Radical Scavenging Effects

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1773
Author(s):  
Patchima Sithisarn ◽  
Piyanuch Rojsanga ◽  
Pongtip Sithisarn
Keyword(s):  
Antibacterial Activities ◽  
Inhibitory Effect ◽  
Total Flavonoid ◽  
Total Phenolic ◽  
Antibacterial Effects ◽  
E Coli ◽  
Young Fruit ◽  
Oroxylum Indicum ◽  
Zoonotic Bacteria

Oroxylum indicum extracts from the seeds collected from Lampang and Pattani provinces in Thailand, and young fruits and flowers exhibited in vitro display antioxidant and antibacterial activities against clinically isolated zoonotic bacteria including Staphylococcus intermedius, Streptococcus suis, Pseudomonas aeruginosa, β-hemolytic Escherichia coli and Staphylococcus aureus. The orange crystals and yellow precipitates were obtained from the preparation processes of the seed extracts. The orange-red crystals from the seeds collected from Lampang province exhibited strong in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging effects (EC50 value = 25.99 ± 3.30 μg/mL) and antibacterial effects on S. intermedius and β-hemolytic E. coli while the yellow precipitate from the same source exhibited only antioxidant activity. Quantitative analysis of phytochemicals in O. indicum samples by spectrophotometric and HPLC techniques showed that they contained different amounts of total phenolic, total flavonoid and three major flavones; baicalin, baicalein and chrysin contents. Young fruit extract, which contained low amounts of flavone contents, still promoted antibacterial effects against the tested bacteria with IC50 values lower than 1 mg/mL and MIC values between 4 to 10 mg/mL in S. intermedius, S. aureus and S suis while higher IC50 and MIC values against P. aeruginosa and β-hemolytic E. coli were found. From scanning electron microscopy, the extract of the young fruit of O. indicum promoted morphological changes in the bacterial cells by disrupting the bacterial cell walls, inducing leakage of the cellular content, and generating the abnormal accumulation of cells. The mechanism of action of the extract for this antibacterial effect may be the disruption of the cell membrane and abnormal cell aggregations. Regression analysis of the results suggests the correlation between total phenolic and total flavonoid contents and antioxidant and antibacterial effects. Baicalin was found to have a high correlation with an inhibitory effect against β-hemolytic E. coli while three unidentified peaks, which could be flavones, showed high correlations with an inhibitory effect against S. intermedius, S. suis, P. aeruginosa and S. aureus.

scholarly journals In Vitro Anti-Biofilm and Antibacterial Properties of Streptococcus downii sp. nov.

2021 ◽  
Vol 9 (2) ◽  
pp. 450
Author(s):  
Maigualida Cuenca ◽  
María Carmen Sánchez ◽  
Pedro Diz ◽  
Lucía Martínez-Lamas ◽  
Maximiliano Álvarez ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Quantitative Polymerase Chain Reaction ◽  
Bacterial Load ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Oral Bacteria ◽  
Periodontal Pathogens ◽  
Biofilm Model ◽  
Biofilm Development

The aim of this study was to evaluate the potential anti-biofilm and antibacterial activities of Streptococcus downii sp. nov. To test anti-biofilm properties, Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans were grown in a biofilm model in the presence or not of S. downii sp. nov. for up to 120 h. For the potential antibacterial activity, 24 h-biofilms were exposed to S. downii sp. nov for 24 and 48 h. Biofilms structures and bacterial viability were studied by microscopy, and the effect in bacterial load by quantitative polymerase chain reaction. A generalized linear model was constructed, and results were considered as statistically significant at p < 0.05. The presence of S. downii sp. nov. during biofilm development did not affect the structure of the community, but an anti-biofilm effect against S. mutans was observed (p < 0.001, after 96 and 120 h). For antibacterial activity, after 24 h of exposure to S. downii sp. nov., counts of S. mutans (p = 0.019) and A. actinomycetemcomitans (p = 0.020) were significantly reduced in well-structured biofilms. Although moderate, anti-biofilm and antibacterial activities of S. downii sp. nov. against oral bacteria, including some periodontal pathogens, were demonstrated in an in vitro biofilm model.

scholarly journals In VitroActivities of Daptomycin-, Vancomycin-, and Teicoplanin-Loaded Polymethylmethacrylate against Methicillin-Susceptible, Methicillin-Resistant, and Vancomycin-Intermediate Strains of Staphylococcus aureus

2011 ◽  
Vol 55 (12) ◽  
pp. 5480-5484 ◽  
Author(s):  
Yuhan Chang ◽  
Wen-Chien Chen ◽  
Pang-Hsin Hsieh ◽  
Dave W. Chen ◽  
Mel S. Lee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
High Performance ◽  
Low Dose ◽  
Antibacterial Activities ◽  
High Dose ◽  
Bone Cements ◽  
Antibacterial Effects ◽  
Methicillin Resistant ◽  
Content Type

ABSTRACTThe objective of this study was to evaluate the antibacterial effects of polymethylmethacrylate (PMMA) bone cements loaded with daptomycin, vancomycin, and teicoplanin against methicillin-susceptibleStaphylococcus aureus(MSSA), methicillin-resistantStaphylococcus aureus(MRSA), and vancomycin-intermediateStaphylococcus aureus(VISA) strains. Standardized cement specimens made from 40 g PMMA loaded with 1 g (low-dose), 4 g (middle-dose) or 8 g (high-dose) antibiotics were tested for elution characteristics and antibacterial activities. The patterns of release of antibiotics from the cement specimens were evaluated usingin vitrobroth elution assay with high-performance liquid chromatography. The activities of broth elution fluid against differentStaphylococcus aureusstrains (MSSA, MRSA, and VISA) were then determined. The antibacterial activities of all the tested antibiotics were maintained after being mixed with PMMA. The cements loaded with higher dosages of antibiotics showed longer elution periods. Regardless of the antibiotic loading dose, the teicoplanin-loaded cements showed better elution efficacy and provided longer inhibitory periods against MSSA, MRSA, and VISA than cements loaded with the same dose of vancomycin or daptomycin. Regarding the choice of antibiotics for cement loading in the treatment ofStaphylococcus aureusinfection, teicoplanin was superior in terms of antibacterial effects.

scholarly journals Antifungal and Antibacterial Metabolites from a French Poplar Type Propolis

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Séverine Boisard ◽  
Anne-Marie Le Ray ◽  
Anne Landreau ◽  
Marie Kempf ◽  
Viviane Cassisa ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Effect ◽  
Antibacterial Activities ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Gram Positive ◽  
Weak Activity ◽  
Agar Dilution

During this study, thein vitroantifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains:Candida albicans, C. glabrata, andAspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains includingStaphylococcus aureus. Organic extracts showed a significant antifungal activity againstC. albicansandC. glabrata(MIC80between 16 and 31 µg/mL) but only a weak activity towardsA. fumigatus(MIC80= 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially againstS. aureus(SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC10030–97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.

scholarly journals Phytochemical Screening, Polyphenols Content, Antioxidant Power, and Antibacterial Activity of Herniaria hirsuta from Morocco

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Kenza Ammor ◽  
Dalila Bousta ◽  
Sanae Jennan ◽  
Bahia Bennani ◽  
Abdellah Chaqroune ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Antioxidant Power ◽  
Negative Effect ◽  
Hydroethanolic Extract

The aim of this study is to investigate in vitro antioxidant and antibacterial activities of the aqueous and hydroethanolic extracts for aerial parts of Herniaria hirsuta. Extracts were screened for their possible antioxidant activities by three tests: DPPH free radical-scavenging, reducing power, and molybdenum systems. The screening of antibacterial activity of extracts was individually evaluated against sixteen bacteria species using a disc diffusion method. Flavonoids, total phenols, and tannins content were performed for both extracts. It shows higher content in the hydroethanolic extract. The hydroethanolic extract showed a significant antioxidant activity for the three methods studies to the aqueous extract, but nonsignificant results compared to the reference (BHT). However, both extracts have negative effect on the strains studies for the antibacterial activity.

scholarly journals The effect of resorcinol on bovine spermatozoa parameters in vitro

2020 ◽  
pp. 675-686
Author(s):  
M Massányi ◽  
M Halo ◽  
L Strapáková ◽  
T Slanina ◽  
P Ivanič ◽  
...  
Keyword(s):  
Cultivation Temperature ◽  
Negative Effects ◽  
Mtt Test ◽  
Progressive Motility ◽  
Time Period ◽  
Entire Duration ◽  
Bovine Spermatozoa ◽  
Time Periods ◽  
Motility Parameters

The goal of this study was to observe the effect of resorcinol on motility, viability and morphology of bovine spermatozoa. The semen was used from six randomly chosen breeding bulls. Ejaculate was diluted by different solutions of resorcinol in 1:40 ratio. Samples were divided into 7 groups with different concentrations of resorcinol (Control, RES1 – 4 mg/ml, RES2 – 2 mg/ml, RES3 – 1 mg/ml, RES4 – 0.5 mg/ml, RES5 – 0.25 mg/ml and RES6 – 0.125 mg/ml). Motility of spermatozoa was detected using CASA method at temperature of 37 °C in time periods 0, 1, 2, 3, 4 hours from the start of the experiment. Significant motility differences between all groups except control and RES6 with difference of 5.58 %, as well as between RES1 and RES2 groups with difference of 2.17 % were found. Progressive motility had the same significant differences. Spermatozoa viability (MTT test) decreased compared to control in all experimental groups during the entire duration of experiment. Observing morphologically changed spermatozoa, no significant changes were observed and a higher percentage of spermatozoa with separated flagellum in all experimental resorcinol groups compared to control were detected. Also, increased number of spermatozoa with broken flagellum, acrosomal changes and other morphological forms in the group with the highest concentration of resorcinol (RES1) were found. Results of our study clearly show negative effects on motility parameters of spermatozoa which depend on concentration, cultivation temperature and time period.

scholarly journals Chemical Composition, in vitro Cytotoxic, and Antibacterial Activities of Moroccan Medicinal Plants Euphorbia resinifera and Marrubium vulgare

2020 ◽  
Vol 10 (6) ◽  
pp. 7343-7355
Keyword(s):  
Medicinal Plants ◽  
Solid Medium ◽  
Chemical Compounds ◽  
Antibacterial Activities ◽  
Antibacterial Effects ◽  
Animal Cells ◽  
Aerial Parts ◽  
Marrubium Vulgare ◽  
Major Chemical

The purpose of our study was to bring elements of knowledge on the anticancer and antibacterial effects of two plants, widely used in Moroccan traditional pharmacopeia. These plants are: Marrubium vulgare and Euphorbia resinifera. The aerial parts of each plant were extracted successively with Hexane, Dichloromethane, and finally with methanol. The MTT-based method was applied to evaluate the cytotoxicity of the cancer cells: animal cells BSR and Vero and human cell RD. We evidenced an anticancer activity of the extract of the Marrubium vulgare and the dichloromethane extract of Euphorbia resinifera against the studied cells. The antibacterial activity was evaluated for three species of Rhodococcus: Rhodococcus equi, and strains GK1, GK3, grown in a liquid medium, or this medium solidified with agar. In the last test, the method is based on substance diffusion from well throughout the solid medium. The obtained profiles showed that the growth of bacteria is strongly inhibited by the extracts of Marrubium vulgare. However, the extracts of Euphorbia resinifera had no significant effect on bacterial growth. The chemical analysis of the raw extracts of Marrubium vulgare and Euphorbia resinifera by GC-MS analysis showed the presence of several major chemical compounds, mainly: octadecane, 2,6,10,15-tetramethylheptadecane, 2,6,10-trimethyltetradecane, linoleic acid, and deisopropylatrazine. Our observations an encouraging for deepening the studies of the extracts, in order to target better the active molecules, isolate them and to determine their mechanisms of action. The suggested studies would result in the much better valorization of these two medicinal plants.

Synthesis and Antibacterial Activities of Amidine Substituted Monocyclic β-Lactams

2021 ◽  
Vol 17 ◽  
Author(s):  
Lijuan Zhai ◽  
Lili He ◽  
Yuanbai Liu ◽  
Ko Ko Myo ◽  
Zafar Iqbal ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Species ◽  
Antimicrobial Effect ◽  
Antibacterial Activities ◽  
Lead Target ◽  
Bacterial Strains ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Clinical Interest

Background: Mononcyclic β-lactams are regarded as the most resistant class of β-lactams against a series of β-lactamases though possess limited antibacterial activity. Aztreonam being the first clinically approved monobactam needs broad-spectrum efficacy through structural modification. Objective: We strive to synthesize a number of monocyclic β-lactams by varying the substituents at N1, C3 and C4 positions of azetidinone ring and study the antimicrobial effect on variable bacterial strains. Methods: Seven new monobactam derivatives 23a-g, containing substituted-amidine moieties linked to the azetidinone ring via thiazole linker, were synthesized through multistep synthesis. The final compounds were investigated for their in vitro antibacterial activities using broth microdilution method, against ten bacterial strains of clinical interest. The minimum inhibitory concentrations (MICs) of newly synthesized derivatives were compared with aztreonam, ceftazidime and meropenem, existing clinical antibiotics. Results: All compounds 23a-g showed higher antibacterial activities (MIC 0.25 µg/mL to 64 µg/mL) against tested strains as compared to aztreonam (MIC 16 µg/mL to >64 µg/mL) and ceftazidime (MIC >64 µg/mL). However all compounds, except 23d, exhibited lower antibacterial activity against all tested bacterial strains as compared to meropenem. Conclusion: Compound 23d showed comparable or improved antibacterial activity (MIC 0.25 µg/mL to 2 µg/mL) to meropenem (MIC 1 µg/mL to 2 µg/mL) in case of seven bacterial species. Therefore, compound 23d may be valuable lead target for further investigations against multi-drug resistant Gram-negative bacteria.

scholarly journals In vitro antibacterial activity of omeprazole and its selectivity for Helicobacter spp. are dependent on incubation conditions.

1996 ◽  
Vol 40 (3) ◽  
pp. 621-626 ◽  
Author(s):  
J E Sjöström ◽  
J Fryklund ◽  
T Kühler ◽  
H Larsson
Keyword(s):  
Antibacterial Activity ◽  
Proton Pump Inhibitors ◽  
Proton Pump ◽  
Bactericidal Activity ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Antibacterial Activities ◽  
In Vitro Antibacterial Activity ◽  
H Pylori

Factors affecting the in vitro antibacterial activity of omeprazole were studied. Our data show that 3H-labeled omeprazole covalently bound to Helicobacter pylori and to other gram-negative and gram-positive bacteria. The compound was found to bind to a broad range of proteins in H. pylori, and at pH 5, binding was enhanced 15-fold compared with binding at pH 7. The bactericidal activity correlated to the degree of binding, and at pH 5, a pH at which omeprazole readily converts to the active sulfenamide form, beta-mercaptoethanol, a known scavenger of sulfenamide, and fetal calf serum, to which noncovalent protein binding of omeprazole is known to occur, reduced the level of binding and almost entirely abolished the bactericidal activity. At pH 7 the killing activities of omeprazole and structural analogs (e.g., proton pump inhibitors) were dependent on the time-dependent conversion (half-life) to the corresponding sulfenamide. The bactericidal activity exerted by the sulfenamide form at pH 5 was not specific for the genus Helicobacter. However, in brucella broth at pH 7 with 10% fetal calf serum, only Helicobacter spp. were susceptible to omeprazole, with MBCs in the range of 32 to 64 micrograms/ml, and MBCs for more stable proton pump inhibitors were higher. Wild-type H. pylori and its isogenic urease-deficient mutant were equally susceptible to omeprazole. Thus, the urease is not a lethal target for omeprazole action in H. pylori. In conclusion, the antibacterial activities of omeprazole and analogs are dependent on pH and the composition of the medium used. Thus, at a low pH in buffer, these compounds have a nonselective action, whereas in broth at neutral pH, the mechanism of action is selective for Helicobacter spp.

Sign in / Sign up

Export Citation Format

Share Document