scholarly journals Antibacterial Activity of Grepafloxacin

1998 ◽  
Vol 9 (suppl e) ◽  
pp. 4E-9E
Author(s):  
B Wiedemann ◽  
P Heisig
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Respiratory Tract Infections ◽  
Inhibitory Concentration ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Pharmacodynamic Profile ◽  
Resistant Mutants ◽  
Tract Infections ◽  
Relative Differences

Grepafloxin has an extremely broad spectrum of activity. Its activity against Gram-positive bacteria exceeds that of currently available quinolones. Grepafloxacin-resistant mutants seem to occur less frequently than ciprofloxacin - or ofloxacin-resistant mutants, and the increase in minimum inhibitory concentration (MIC) against the former mutants is less than that of the latter. This applies only to the relative differences (in dilution steps); the absolute values are similar. Grepafloxacin kills Gram-positive bacteria at concentrations little above the MIC. Its pharmacodynamic profile against pneumococci is promising, favouring use of this drug for respiratory tract infections.

scholarly journals Antibacterial Activity of Murrayaquinone A and 6-Methoxy-3,7-dimethyl-2,3-dihydro-1H-carbazole-1,4(9H)-dione

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Biswanath Chakraborty ◽  
Suchandra Chakraborty ◽  
Chandan Saha
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Antibacterial Activities ◽  
Gram Positive ◽  
Gram Negative ◽  
Naturally Occurring

The antibacterial activity of Murrayaquinone A (10), a naturally occurring carbazoloquinone alkaloid, and 6-methoxy-3,7-dimethyl-2,3-dihydro-1H-carbazole-1,4(9H)-dione (11), a synthetic carbazoloquinone, both obtained during the development of the synthesis of Carbazomycin G, having unique quinone moiety, was studied against Gram-positive (Bacillus subtilisandStaphylococcus aureus) and Gram-negative (Escherichia coliandPseudomonassp.) bacteria. Compound10showed antibacterial activities against both ofEscherichia coliandStaphylococcus aureuswhereas compound11indicated the activity againstStaphylococcus aureusonly. Both compounds10and11exhibited minimum inhibitory concentration (MIC) of 50 μg mL−1againstStaphylococcus aureus.

scholarly journals Synthesis and Antibacterial Activity of Cationic Amino Acid-Conjugated Dendrimers Loaded with a Mixture of Two Triterpenoid Acids

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 521
Author(s):  
Anna Maria Schito ◽  
Gian Carlo Schito ◽  
Silvana Alfei
Keyword(s):  
Antibacterial Activity ◽  
Amino Acid ◽  
Bacterial Resistance ◽  
Inhibitory Concentration ◽  
Antimicrobial Effect ◽  
Gram Positive ◽  
Cationic Amino Acid ◽  
Gram Positive Bacteria ◽  
Cationic Compounds ◽  
Conjugated Dendrimers

To counteract the growing bacterial resistance, we previously reported the remarkable antimicrobial activity of amino acid-conjugated cationic dendrimers (CDs) against several Gram-negative species, establishing that the cationic lysine was essential for their potency. In this paper, CDs conjugated with lysine and arginine and encapsulating ursolic and oleanolic acids (UOACDs) were assumed to be excellent candidates for developing new antibacterial agents, possibly active against Gram-positive species. Indeed, both the guanidine group of arginine and the two triterpenoid acids are items known for directing antibacterial effects, particularly against Gram-positive bacteria. The cationic dendrimers were obtained by peripheral conjugation with the selected amino acids and by entrapping a physical mixture of the commercial triterpenoid acids. The cationic compounds were characterized and successfully tested against 15 Gram-positive isolates. Interesting minimum inhibitory concentration (MIC) values were obtained for all the dendrimer-drug agents, establishing that the antibacterial activity observed for the UOACDs strongly depended on the density and on the type of the cationic groups of the cationic amino acid-conjugated dendrimers and not on the presence and the release of UOA. Particularly, lysine was critical for potency, while arginine was critical for redirecting activity against Gram-positive species. Especially, a high cationic character, associated with a balanced content of lysine/arginine, produced a remarkable antimicrobial effect (MIC = 0.5–8.7 µM).

scholarly journals Daya Antibakteri EkstrakMeniran (Phyllanthus niruri linn) Terhadap BakteriEnterococcus faecalis (Antibacterial Activity Of Phyllanthus niruri linn Extract Against Enterococcus faecalis Bacteria)

2016 ◽  
Vol 6 (2) ◽  
pp. 99
Author(s):  
Tri Desiana KH ◽  
Achmad Sudirman ◽  
Devi Eka Juniarti
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Enterococcus Faecalis ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Dilution Method ◽  
Phyllanthus Niruri ◽  
Gram Positive Bacteria ◽  
Nutrient Agar Medium ◽  
Preparation Stage

Background. Enterococcus faecalis is an anaerobic facultative gram-positive bacteria which contribute to the failure of root canal treatment with the number of prevalence 24% to 77%. At the preparation stage, a material for irrigation which has antibacterial activity to Enterococcus faecalis is needed. Phyllantus niruri linn is one of herbal medicament which is potential as antibacterial agent as it contains active antibacterial chemical-compound. Purpose. The purpose of the study is to identify Minimum Inhibitory Concentration and Minimum Bactericidal Concentrationof Phyllantus niruri linn against Enterococcus faecalis.Method. The research method used is laboratory experimental. Enterococcus faecalis ATCC 29212 was suspended into several concentration of Phyllantus niruri linn extract from dilution method on BHIB medium. Each tube was incubated for 24 hours. Then, each tube was subcultured to Nutrient agar medium using spreader in a petridish. Each petridish was incubated for 24 hours and the growth of the colony was manually calculated using CFU/ml unit. Result. At the concentration of 6.25%, Phyllanthus niruri linn was able to inhibit the growth of Enterococcus faecalis as 90% and there was no bacteria at the concentration of 12.5%. Conclusion. 6.25% concentration of Phyllanthus niruri linn extract was Minimum Inhibitory Concentration and 12.5% concentration was Minimum Bactericidal Concentration to Enterococcus faecalis.

SYNTHESIS OF PIPERINE - PIPERAZINE ANALOGUES AND THEIR ANTIBACTERIAL ACTIVITY

INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (06) ◽  
pp. 30-35
Author(s):  
Naveen K. Kottakki ◽  
◽  
Amperayani K. Rao ◽  
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Aromatic Nitro ◽  
Heterocyclic Moiety ◽  
Agar Well Diffusion Method

In the current study, a series of piperine – piperazine analogues (5a to 5f) were designed and synthesized. The piperine was isolated from pepper and used for the conjugation with heterocyclic moiety for better biological activity. The piperazine heterocyclic was chosen for conjugation with piperine. The newly synthesized structures were determined by IR, 1H NMR and 13C NMR spectral data. The compounds were examined for their anti‐microbial activity against gram-positive (Bacillus subtilis) and gram-negative (Vibrio cholerae) bacteria using the agar well diffusion method. The newly synthesized compounds exhibited capable activities against V. cholerae and B. subtilis and it showed minimum inhibitory concentration. Among all the synthesized compounds, 5f has the highest activity (26 mm) against gram-positive bacteria and (29mm) against gram-negative bacteria. The remaining compounds showed appreciable antibacterial activity. The enhanced activity of the synthesized compounds may be due to the presence of conjugated amide linkage with the natural product piperine and piperazine heterocyclic molecule. The substituents present on the aromatic (nitro-substituted) ring also influenced the activity of the compound.

scholarly journals PAMAM-dendrimer Enhanced Antibacterial Effect of Vancomycin Hydrochloride Against Gram-Negative Bacteria

2018 ◽  
Vol 22 ◽  
pp. 10-21 ◽  
Author(s):  
Azadeh Serri ◽  
Arash Mahboubi ◽  
Afshin Zarghi ◽  
Hamid Reza Moghimi
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
In Vitro Release ◽  
Pamam Dendrimers ◽  
Dilution Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Membranes ◽  
Gram Positive Bacteria

Purpose: The antibacterial activity of some antibiotics is specific to either Gram-positive or Gram-negative bacteria.  There are different mechanisms behind such insensitivities like inability of antibiotics to permeate through some bacterial membranes, as is the case for vancomycin in Gram-negative bacteria. The present investigation tries to overcome this problem by dendrimers, in order to make Gram-negative bacteria responsive to vancomycin. Methods: The effects of generations 3 (G3) and 5 (G5) polyamidoamine amine-terminated dendrimers (NH2-PAMAM), on the antibacterial activity of vancomycin, were evaluated. Vancomycin-PAMAM dendrimers complexes were prepared and their antibacterial activities were evaluated by determination of their “minimum inhibitory concentration (MIC)”, “minimum bactericidal concentration” and “fractional inhibitory concentration index” values against two Gram-positive and four Gram-negative bacteria, using broth micro-dilution method. The complexation of vancomycin and dendrimers was also assessed by in vitro release studies across dialysis tubing using a developed HPLC method. Results: Results showed that vancomycin solution was effective against Gram-positive bacteria, but, was not effective in Gram-negative ones. Vancomycin-PAMAM dendrimers exhibited significant antibacterial efficacy against Gram-negative bacteria resulting in a decline of vancomycin MIC values by about 2, 2, 4 and 64 times in E. coli, K. pneumonia, S. typhimurium and P. aeruginosa, respectively. Results also showed that enhanced effect by G5 is more than G3. Dendrimers did not affect antibacterial activity of vancomycin in Gram-positive bacteria, as no permeation problem exists here. Conclusions: The present study revealed that both G3 and G5 cationic PAMAM dendrimers are able to make Gram-negative bacteria sensitive to vancomycin, resulting in decline of MIC values up to 64 times, possibly by increasing its permeation through bacterial membrane. These results look promising for broadening the antibacterial spectrum of vancomycin and such a strategy might be used for increasing the overall life of antibiotics.

scholarly journals Uji Aktivitas Antibakteri Ekstrak Etanol Umbi Batang Tumbuhan Sarang Semut (Myrmecodia Pendens Merr. & L. M. Perry) Terhadap Pseudomonas Aeruginosa Dan Staphylococcus Aureus

2017 ◽  
Author(s):  
Ardianti Febriana
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Phytochemical Screening ◽  
Gram Positive ◽  
Tetracycline Hcl ◽  
And Staphylococcus Aureus

AbstrakTumbuhan sarang semut (Myrmecodia pendens Merr. & L. M. Perry) secara empiris digunakan sebagai obat yang memiliki aktivitas antibakteri. Namun, belum pernah diteliti mengenai aktivitas antibakteri tersebut. Penelitian ini dilakukan untuk mengetahui aktivitas antibakteri umbi batang sarang semut (Myrmecodia pendens Merr. & L. M. Perry) terhadap bakteri Gram negatif dan Gram positif yaitu Pseudomonas aeruginosa dan Staphylococcus aureus, menentukan konsentrasi hambat tumbuh minimum (KHTM), dan nilai banding ak- tivitas antibakterinya terhadap tetrasiklin-HCl. Hasil pengujian aktivitas antibakteri umbi batang sarang semut menunjukkan bahwa ekstrak umbi batang sarang semut memiliki ak- tivitas antibakteri terhadap kedua bakteri tersebut. Konsentrasi hambat tumbuh minimum (KHTM) ekstrak umbi batang sarang semut (Myrmecodia pendens Merr. & L. M. Perry) terhadap Pseudomonas aeruginosa terletak pada konsentrasi 0,83 % , sedangkan pada Staph- ylococcus aureus terletak pada konsentrasi 0,8 %. Hasil uji banding ekstrak umbi batang sarang semut (Myrmecodia pendens Merr. & L. M. Perry) dengan tetrasiklin-HCl terhadap Pseudomonas aeruginosa dan Staphylococcus aureus berturut-turut sebesar 1 : 6,709 x 10-4 dan 1 : 1,038 x 10-5. Penapisan fitokimia menunjukkan bahwa ekstrak umbi batang sarang semut (Myrmecodia pendens Merr. & L. M. Perry) mengandung flavonoid dan polifenol.Kata kunci: Myrmecodia pendens Merr. & L. M. Perry, Aktivitas antibakteri, Pseudomo- nas, StaphylococcusABSTRACTThe ant plant (Myrmecodia pendens Merr. & L. M. Perry) is one of plant applied as tradi- tional medicine. Empirically, the tuber of the ant plant have antibacterial activity. However, the examination of antimicrobial activity from extract of the tuber has never been reported. The research was done to know the activity of antimcrobial againts Gram positive and Gram negatif bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus, to determine Minimum Inhibitory Concentration (MIC) of the tuber, and comparative value antibacterial activity with tetracycline-HCl. The result revealed that the tuber of the ant plant (Myrmeco-dia pendens Merr. & L. M. Perry) has antibacterial activity againts those bacteria. The Min- imum Inhibitory Concentration of extract from the tuber of ant plant to Pseudomonas aeru- ginosa was in range 8,2x103-8,3x103 ppm of concentration, and to Staphylococcus aureus was in range 7,5x103-8x103 ppm of concentration. Comparative value of extract from the tuber of ant plant with tetracycline-HCl againts Pseudomonas aeruginosa and Staphylococ- cus aureus were respective 1:.6.709 x 10-4 and :1.038 x 10-5. Phytochemical screening showed that the extract of the tuber contains flavonoid and polifenol.Keywords: Myrmecodia pendens Merr. & L. M. Perry, Antibacterial activity, Pseudomonas, Staphylococcus

scholarly journals Serious Antimicrobial Resistance Status of Pathogens Causing Hospital-acquired Lower Respiratory Tract Infections in North China

2009 ◽  
Vol 37 (3) ◽  
pp. 899-907 ◽  
Author(s):  
Y Wang ◽  
R Zhang ◽  
W Li ◽  
Y Feng ◽  
T Leng
Keyword(s):  
Antimicrobial Resistance ◽  
Lower Respiratory Tract ◽  
Respiratory Tract Infections ◽  
Gram Negative Bacteria ◽  
Lower Respiratory Tract Infections ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Tract Infections ◽  
Hospital Acquired

Antimicrobial resistance patterns of pathogens causing hospital-acquired lower respiratory tract infections (LRTIs) in Shandong Province, China were investigated using data collected from January 2002 to December 2006. A total of 10337 isolates were characterized in sputum samples from 39 920 LRTI patients: 68.72% were Gram-negative bacteria, 20.65% were Gram-positive bacteria, and 10.62% were fungi. Organisms most frequently isolated were: Pseudomonas aeruginosa (16.88%), Klebsiella pneumoniae (10.80%), Escherichia coli (10.71%), fungi (10.62%), Staphylococcus aureus (9.68%) and Acinetobacter baumannii (9.03%). Imipenem was the most effective antibiotic against Gram-negative bacteria. Most Gram-positive bacteria were susceptible to vancomycin. Susceptibility to cephalosporins was not optimal and resistance to fluoroquinolones was high. Resistance of Gram-negative bacteria showed a rapid increase over the study period, while resistance of Gram-positive bacteria remained relatively stable. The emergence of resistance to commonly prescribed antimicrobial agents used against LRTI pathogens has compounded the problem of using empirical therapy and created selective pressure on physicians to use certain antibiotics.

Diphenhydramine and levofloxacin combination therapy against antimicrobial resistance in respiratory tract infections

2021 ◽  
Vol 16 (6) ◽  
pp. 409-420
Author(s):  
Sadaf Areej ◽  
Adeel Sattar ◽  
Aqeel Javeed ◽  
Sohail Raza
Keyword(s):  
Antibacterial Activity ◽  
Concentration Index ◽  
Respiratory Tract Infections ◽  
Inhibitory Concentration ◽  
Antibacterial Effect ◽  
Gram Negative Bacteria ◽  
H1 Receptor ◽  
In Vitro Antibacterial Activity ◽  
Tract Infections

Background: Antibiotics are in use since decades to treat various infections caused by Gram-positive and Gram-negative bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. Diphenhydramine, an H1 receptor blocker possesses a weak antibiotic action but when combined with other antibiotics may potentiate their antibacterial activity. Materials & methods: This study investigated in vitro antibacterial activity of diphenhydramine when used alone and in combination with levofloxacin against methicillin-resistant S. aureus and P. aeruginosa. Results: The combined antibacterial effect of the drugs against bacteria showed a fractional inhibitory concentration index of ≤0.5, in other words, synergism. No cytotoxicity was observed as percentage cell viability was >50%. Conclusion: The combination of diphenhydramine and levofloxacin exerted antibacterial activity, and was not found to be cytotoxic when given in combination against P. aeruginosa and S. aureus.

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