Showing 8 results for Anti-Bacterial Agents
Mina Parsa , Malahat Ahmadi , Habib Dastmalchi , Aliasghar Tehrani ,
Volume 11, Issue 6 (11-2017)
Abstract
ABSTRACT
Background and Objectives: Nowadays, the prevalence of multidrug-resistant pathogens such as
Pseudomonas aeruginosa is increasing worldwide. Many studies have been seeking new treatment strategies to treat infections caused by these microorganisms. Silver nanoparticles (AgNPs) along with L-arginine have significant antimicrobial effects and could be used as alternatives for ineffective drugs.
Methods: In this study, the antibacterial activity of AgNPs, L-arginine and various concentrations of AgNPs along with L-arginine (12.5 and 25 mg/ml) were investigated against
P. aeruginosa PAO1 using the broth macrodilution method.
Results: Minimum inhibitory concentration of AgNPs, L-arginine and AgNPs combined with 25 and 12.5 mg/ml L-arginine was 15.6 μg/ml, 25 mg/ml, 1.9 μg/ml and 3.9 μg/ml, respectively. Minimum bactericidal concentration of AgNPs, L-arginine and AgNPs combined with 25 and 12.5 mg/ml L-arginine was 31.2 μg/ml, 50 mg/ml, 3.9 μg/ml and 7.8 μg/ml, respectively.
Conclusion: Our study suggests that AgNPs along with L-arginine can be used as an alternative antibacterial agent against
P. aeruginosa, and might be useful for treatment of wound infections.
Keywords: Nanoparticles, Arginine,
Anti-Bacterial Agents,
Pseudomonas aeruginosa.
Azizollah Ebrahimi , Azimeh Babaaie , Mojtaba Boniadian , Sharareh Lotfalian ,
Volume 13, Issue 3 (5-2019)
Abstract
ABSTRACT
Background and Objectives: Efflux-based systems may play a role in resistance to fluoroquinolones in Gram-negative pathogenic bacteria. Extracts of some medicinal plants contain molecules that can act as efflux pumps inhibitors. In this study, we aimed to evaluate antibacterial activities of ethanolic and chloroform extracts of Cinnamomum zeylanicum and their possible synergistic activity with ciprofloxacin against some Gram-negative pathogenic bacteria. We also analyzed the extracts for presence of efflux pump inhibitors against the examined bacteria.
Methods: Powdered dried leaves and branches of C. zeylanicum were extracted with ethanol (85%) and chloroform by the maceration method. Minimum inhibitory concentrations of the extracts alone or combined with ciprofloxacin and phenylalanine-arginine β-naphthylamide (an efflux pump inhibitor) were determined against Pseudomonas aeruginosa, Acinetobacter bummani, Escherichia coli and Salmonella enteritidis using the double serial microdilution method.
Results: The extracts of C. zeylanicum inhibited the growth of all studied bacteria. Synergistic effects were noted between the extracts and ciprofloxacin against all tested bacteria other than P. aeruginosa. Ciprofloxacin efflux pumps in E. coli, S. enteritiditis and A. baumannii were inhibited by the extracts of C. zeylanicum.
Conclusion: The extracts of C. zeylanicum could be used as ciprofloxacin-potentiating agents against some Gram-negative pathogens.
Keywords: Anti-bacterial agents, Cinnamomum zeylanicum, Bacterial pathogens, Efflux pumps.
Najmeh Jomehpour , Kiarash Ghazvini , Mahshid Jomehpour ,
Volume 13, Issue 3 (5-2019)
Abstract
ABSTRACT
Background and Objectives: Medicinal and aromatic plants are sources of natural antimicrobial compounds that could be useful replacements for antibiotics. The aim of this study was to assess antimicrobial activity of Crocus sativus stigma and Cinnamomum cassia extracts against some Gram-positive and Gram-negative bacteria.
Methods: Antimicrobial activity of methanolic and aqueous extracts of the plants was tested against clinical isolates of Klebsiella pneumonia, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Enterococcus using the microdilution method. Minimal inhibitory concentration (MIC) and minimum bactericidal concentration of each extract against the mentioned bacteria were also determined.
Results: The MIC of the methanolic extract of C. cassia was 80 µg/ml against Enterococcus, K. pneumonia and E. coli. The MIC of the methanolic extract of C. sativus was 160 µg/ml against Enterococcus and S. aureus. The minimum bactericidal concentration of the methanolic extracts of C. sativus and C. cassia was 320 µg/ml against K. pneumonia and 160 µg/ml against Enterococcus.
Conclusion: The extracts of C. sativus and C. cassia exhibit promising antibacterial activities against clinical isolates of the tested bacteria. Our results suggest that the extract of these plants can be further exploited as potential antibacterial agents against multi-drug resistant bacteria.
Keywords: Cinnamomum aromaticum, Crocus, Anti-Bacterial Agents.
Maryam Kouhkan, Miri Mahmoody, Jabbar Khalafy, Sima Pourali, Nasser Samadi,
Volume 14, Issue 2 (3-2020)
Abstract
ABSTRACT
Background and objectives: Antimicrobial resistance is a serious threat to global public health. The overuse and misuse of antibiotics are the most important contributing factors to development of antibiotic resistance. Thus, there is an urgent need to identify and discover new compounds against drug-resistant microorganisms. We have previously synthesized new series of 3-substituted 5H-(1,2,4)triazolo(3',4':2,3) (1,3,4)thiadiazino(5,6-b)quinoxaline derivatives (4a-4f). Here, we evaluate the antimicrobial activity of these derivatives against methicillin-resistant
Staphylococcus aureus, S. aureus, Streptococcus pyogenes,
Pseudomonas aeruginosa,
Escherichia coli,
Candida albicans, Candida tropicalis and
Candida krusei.
Methods: The agar well diffusion and agar dilution methods were used for determining inhibition zone diameter and minimum inhibitory concentration during preliminary evaluation of antimicrobial activity.
Results: All synthesized compounds exhibited antibacterial and antifungal activity against the tested microorganisms
.
Conclusion: Our findings indicate the antimicrobial potential of the six novel synthetic triazolo thiadiazin quinoxaline compounds.
Keywords: Antimicrobial,
Anti-bacterial agents,
Antifungal agents, Triazolo, Thiadiazin, Quinoxaline.
Nakisa Zarrabi Ahrabi, Ali Souldozi, Yasin Sarveahrabi,
Volume 15, Issue 5 (9-2021)
Abstract
Background and objectives: Antibiotic resistance is a major public health challenge. The pervasive antibiotic misuse can lead to increased antibiotic resistance. Thus, there is a need for discovery of new compounds against drug-resistant microorganisms. We synthesized new series of 1, 3, 4-oxadiazole derivatives (4a-4d) and evaluated the antibacterial and antifungal activity of the derivatives against Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii, Klebsiella pneumoniae, Aspergillus fumigatus and Aspergillus flavus.
Methods: The new derivatives of 1, 3, 4-oxadiazole were synthesized using a single-stage, high-yield method. The structure of the new compounds was confirmed by infrared spectroscopy, carbon-nuclear magnetic resonance and hydrogen- nuclear magnetic resonance. Then, antibacterial and antifungal activities of the prepared derivatives (1 mg/ml) were evaluated by determining minimum inhibitory concentration and minimum bactericidal/fungicidal concentration using the agar well diffusion method.
Results: All synthesized compounds, especially (4d) with methoxyphenyl group, exhibited powerful antibacterial activity against the tested bacteria. However, the compounds had no antifungal effect.
Conclusion: Our findings indicate the antibacterial potential of the novel synthetic 1, 3, 4-oxadiazole compounds.
Behnoush Khasheii, Pezhman Mahmoodi, Abdolmajid Mohammadzadeh,
Volume 15, Issue 5 (9-2021)
Abstract
Increasing antibiotic resistance is a global health problem. In recent years, due to the indiscriminate use of antibacterial compounds, many bacterial pathogens, including staphylococci, members of the
Enterobacteriaceae family including
Klebsiella pneumoniae and bacteria such as
Pseudomonas aeruginosa and
Acinetobacter baumannii have become multi-drug resistant. Consequently, it is important to explore alternative approaches for eliminating resistant strains. Bacteria synthesize low-weight molecules called siderophores to chelate iron from the environment as a vital element for their growth and survival. One way to deal with resistant bacterial strains is to utilize siderophore-mediated iron uptake pathways as entrance routes for drug delivery. Therefore, the production of drugs with Trojan horse strategy in the form of conjugated siderophore-antibiotic complexes has recently received much attention
for dealing with resistant isolates.
In this review, we discuss the efficacy of siderophore-antibiotic conjugates as a Trojan horse strategy for eliminating drug-resistant pathogens.
Zahra Kiani, Pouria Mohammad Parast Tabas, Khashayar Khalilpour, Mahjoube Goldani Moghadam, Majid Zare_bidaki,
Volume 15, Issue 5 (9-2021)
Abstract
Background and objectives: Medicinal plants have long been considered as one of the most important pillars of traditional medicine. Existing challenges in the treatment of diseases, particularly infectious diseases, are major drivers for herbal medicine studies. Tribulus terrestris has been widely used in traditional medicine to treat various diseases. This study aimed to investigate in vitro antibacterial effect of the aqueous extract of T. terrestris on several oral bacteria.
Methods: In this experimental study, after preparing the aqueous extract of T. terrestris, minimum inhibitory and bactericidal concentrations (MIC and MBC) of the extract were determined against standard strains of Streptococcus mutans, Staphylococcus aureus, Klebsiella pneumoniae and Streptococcus pyogenes using the broth microdilution method. The experiments were repeated three times and the results were analyzed with SPSS 22 using the one-way analysis of variance (ANOVA) and LSD statistical tests with the significance level set at 0.05.
Results: The aqueous extract of T. terrestris had the highest inhibitory effect on S. pyogenes and S. mutans, and the difference between the MIC and MBC values was significant (P <0.05). However, no such effect was observed against S. aureus and K. pneumonia at concentrations below 50 mg/ml when compared to ampicillin and chlorhexidine.
Conclusion: The aqueous extract of T. terrestris has significant antibacterial effects against S. pyogenes and S. mutans. Therefore, it can be incorporated into topical formulations such as toothpaste and mouthwash products after further in vivo and toxicity experiments.
Manasa Sireesha Devara, Sriushaswini Bhamidipati, Vijaya Bharathi Dondapati , Narasinga Rao Bandaru,
Volume 17, Issue 6 (11-2023)
Abstract
Background: Medicinal plants have played crucial roles in the traditional health care system since the origin of mankind. Among them, cinnamon is used not only as a spice in food but also as a substance with many health-beneficial effects. The aim of the present study was to identify the antibacterial activity of cinnamon bark extract against bacterial isolates from patient pus samples that might help treat infections.
Methods: The antibacterial potential of cinnamon bark extract in both ethanol and methanol against 6 bacterial isolates obtained from pus samples received in the Microbiology Laboratory was identified by agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) using standard techniques.
Results: By agar well diffusion, the highest inhibitory activity of ethanol and methanol extracts of cinnamon was shown by Staphylococcus aureus, followed by coagulase-negative Staphylococci. The lowest inhibitory effect was shown by Proteus mirabilis. The ethanol extract of cinnamon MIC and MBC ranged from 6.25 mg/mL to 12.5 mg/mL and 12.5 mg/mL to 50 mg/mL. The methanol extract of cinnamon MIC showed a value of 12.5 mg/mL, and the methanol extract of MBC ranged from 12.5 mg/mL to 50 mg/mL against all bacterial isolates of the present study.
Conclusion: Staphylococcus aureus is sensitive to the alcoholic extract of cinnamon bark, but its effect is less than that of the selected antibiotic.
