scholarly journals Antibacterial Activity of Ulva fasciata against Multidrug Resistant Bacterial Strains

2014 ◽  
Vol 19 ◽  
pp. 40-51 ◽  
Author(s):  
M. Chandrasekaran ◽  
Venugopalan Venkatesalu ◽  
G. Adaikala Raj ◽  
S. Krishnamoorthy

The present study was conducted to evaluate the antibacterial activity of different organic solvent increasing polarity viz., hexane, chloroform, ethyl acetate, acetone and methanol extracts of Ulva fasciata (Chlorophyceae) were collected from Kanniyakummari, Gulf of Mannar biosphere Reserve, Tamilnadu, India. Marine green algae extracts of U. fasciata against multi-drug resistant standard and clinical bacterial strains viz., Bacillus subtilis, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhimurium, Vibrio cholerae, Shigella flexneri, Proteus mirabilis and P. vulgaris. The ethyl acetate extracts of U. fasciata showed highest antibacterial activity against all the bacterial strains tested. The mean zone of inhibition produced by the extracts in disc diffusion assays were ranged from 7.1 mm to 15.0 mm. The Minimum Inhibitory Concentrations (MIC) were between 125 μg/ml and 500 μg/ml, while the Minimum Bactericidal Concentrations (MBC) were between 250 μg/ml and 1000 μg/ml. The highest mean of zone inhibition (15.0 mm) and lowest MIC (125 μg/ml) and MBC (250 μg/ml) values were observed in ethyl acetate extract of U. fasciata against B. subtilis. The ethyl acetate extract of the U. fasciata showed the presence of phytochemicals, terpenoids, tannins and phenolic compounds in U. fasciata than the other solvents extracts. The present results of the ethyl acetate extract of U. fasciata can be used as an antibacterial substance for the treatment of multi drug resistant bacterial infections

Author(s):  
Patel N ◽  
Mohan J S S

The n- Hexane, ethyl acetate, methanol and distilled water Leaf, Stem, Flower and Fruit extracts of Moringa oleifera were evaluated for their antibacterial activity against six Gram-Negative and Gram-Positive bacteria and antifungal activity against seven fungal strains using Ciprofloxacin, Doxycycline, Fluconazole and Ketacozole as positive control. The activity was analyzed by well diffusion and two-fold serial broth dilution method of different extract. The study revealed that all the extracts irrespective of their types, in different concentrations inhibited growth of the test pathogens to varying degrees. Ethyl acetate extract showed maximum activity against all the bacterial strains followed in descending order by methanol, n-.Hexane and distilled water extracts. Ethyl acetate extract showed high antibacterial activity against Serratia marcescens (22mm) Methanol and n-Hexane extract were effective against Enterococcus faecalis and Bacillus subtilis (10mm) respectively. Aqueous extract showed maximum number of inhibition against Staphylococcus aureus (27mm) and Micrococcus luteus (18mm). Ethyl acetate extract showed maximum inhibition against Trichoderma harzianum (16mm) than other extracts were ineffective against selected fungus. MIC values were recorded as 0.125 to 4mg/ml. The phytochemical screening revealed the presence of phenols and flavonoids. Expression to these results it may be concluded that M. oleifera may be a potential source for the curing of various infectious diseases caused by the resistant microbes


2018 ◽  
Vol 18 (9) ◽  
pp. 787-796 ◽  
Author(s):  
Fawzi Mahomoodally ◽  
Simla Ramcharun ◽  
Gokhan Zengin

Introduction: Onion (Allium cepa L.) and garlic (Allium sativum L.) extracts are traditionally used in many cultures as antimicrobial agents. Nonetheless, there is still a dearth of scientific validation pertaining to the antibacterial and possible antibiotic potentiating activity of these plants. Methods: Decoction as traditionally used and methanol, ethanol, ethyl acetate, and acetone extracts of onion and garlic were evaluated for their antibacterial activity against 15 bacterial strains (6 ATCC strains and 9 clinical isolates) using the broth microdilution method to establish the minimum inhibitory concentration. The bacteriostatic and bactericidal actions were determined as compared to conventional antibiotics (streptomycin and chloramphenicol). Fractional Inhibitory Concentration (FIC) was determined to establish any synergistic interaction between the extracts and antibiotics using a modified checkerboard assay. Results: The ethyl acetate extract of garlic showed bactericidal effect against 1 ATCC (E. coli) and 2 clinical isolates. Streptomycin produced only indifferent effect (FIC 1< and ≤ 4) when combined with ethyl acetate extract of onion. Chloramphenicol showed synergism with ethyl acetate extract of onion against ATCC S. aureus (FIC 0.27-0.30) and Micrococci species (FIC 0.27-0.32). Streptomycin showed mostly antagonism whereas chloramphenicol showed synergism effects with the ethyl acetate extract of garlic. The observed antibacterial activity might be justified due to the presence of high concentration of phenolic compounds in the extracts. Conclusion: This study has provided an opportunity to establish valuable baseline information on the antibiotic potentiating activity of onion and garlic which can be further exploited for the treatment and/or management of infectious diseases.


2021 ◽  
Author(s):  
Iris K Lee ◽  
Daniel A Jacome ◽  
Joshua K Cho ◽  
Vincent Tu ◽  
Anthony Young ◽  
...  

Recently, several molecular imaging strategies have developed to image bacterial infections in humans. Nuclear approaches, specifically positron emission tomography (PET), affords sensitive detection and the ability to non-invasively locate infections deep within the body. Two key radiotracer classes have arisen: metabolic approaches targeting bacterial specific biochemical transformations, and antibiotic-based approaches that have inherent selectivity for bacteria over mammalian cells. A critical question for clinical application of antibiotic radiotracers is whether resistance to the template antibiotic abrogates specific uptake, thus diminishing the predictive value of the diagnostic test. We recently developed small-molecule PET radiotracers based on the antibiotic trimethoprim (TMP), including [11C]-TMP, and have shown their selectivity for imaging bacteria in preclinical models. Here, we measure the in vitro uptake of [11C]-TMP in pathogenic susceptible and drug-resistant bacterial strains. Both resistant and susceptible bacteria showed similar in vitro uptake, which led us to perform whole genome sequencing of these isolates to identify the mechanisms of TMP resistance that permit retained radiotracer binding. By interrogating these isolate genomes and a broad panel of previously sequenced strains, we reveal mechanisms where uptake or binding of TMP radiotracers can potentially be maintained despite the annotation of genes conferring antimicrobial resistance. Finally, we present several examples of patients with both TMP-sensitive and drug-resistant infections in our first-in-human experience with [11C]-TMP. This work underscores the ability of an antibiotic radiotracer to image bacterial infection in patients, which may allow insights into human bacterial pathogenesis, infection diagnosis, and antimicrobial response monitoring.


Author(s):  
R. Cabrera-Contreras ◽  
R. Morelos-Ramírez ◽  
J. P. Quiróz-Ríos ◽  
D. Muñoz-Quiróz

Essential oils (EOs) are commonly used in food industry, due that they possess antioxidative and antimicrobial properties. There are few essential oils that have been used in medicine, due to its potent antibacterial activity against intrahospital pathogens. OEO has experimentally shown potent antibacterial effect on nosocomial Gram-positive bacteria, therefore it can be very useful in hospital environments, where there are many bacterial pathogens, which are the etiological agents of nosocomial infections and most of them are resistant to several antibiotics. Objective: The aim of this study was to determine antimicrobial effect of OEO on most frequent bacterial intrahospital pathogens: MRSA, MRSE comparatively to selected ATCC bacterial reference strains. Methods: This experimental study investigates the antibacterial action of oregano (Origanum vulgare) essential oil (OvEO) on two human pathogens: Staphylococcus aureus (SA) and Staphylococcus epidermidis (SE) Here, we used OEO against one of the most prominent antibiotic-resistant bacterial strains: methicillin-resistant SA (MRSAmecA+ = Meticillin Resistant SA and mecA- = Meticillin Resistance SA ), methicillin-resistant SE (MRSEmecA+ = Meticillin Resistance Staphylococcus epidermidis mecA+) and reference strains: S. aureus ATCC 700699, S. epidermidis ATCC 359845 and E. coli ATCC 25922. Bactericidal effects of the OEO on these bacteria were mainly evaluated using undiluted and four serial dilutions in coconut oil (CCO) l: 1:10, 1:100, 1:200, 1:400. Results: OEO, undiluted and 4 serial dilutions showed potent antibacterial activity against all strains tested. In conclusion, this OEO could be used as an alternative in medicine. The ability of OEO to inhibit and kill clinical Multi-Drug-Resistant (MDR): MRSA and MRSE strains, highlights it´s potential for use in the management of drug-resistant MDR infections in hospitals wards.


2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Courtney M. Starks ◽  
Vanessa L. Norman ◽  
Russell B. Williams ◽  
Matt G. Goering ◽  
Stephanie M. Rice ◽  
...  

One new and seven known diterpenes were identified from an antibacterial chromatographic fraction of Taxodium ascendens. Of these, demethylcryptojaponol (2), 6-hydroxysalvinolone (3), hydroxyferruginol (4), and hinokiol (5) demonstrated potent activity against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). These compounds represent a class of synthetically accessible compounds that could be further developed for treatment of drug-resistant bacterial infections.


2016 ◽  
Vol 11 (9) ◽  
pp. 1934578X1601100
Author(s):  
Sakon Monggoot ◽  
Jariya Burawat ◽  
Patcharee Pripdeevech

A total of 17 endophytic fungal isolates were obtained from the leaves of Mentha cordifolia Opiz (Lamiaceae). Seven isolates were identified to the level of genus by using taxonomically relevant morphological traits. Colletotrichum and Phomopsis species were dominant among these strains. All strains were separated from M. cordifolia leaf for the first time. The ethyl acetate extracts of all endophytic fungi were tested for antibacterial activity against Salmonella typhimurium TISTR1166 and Pseudomonas aeruginosa TISTR781. Most endophytes exhibited antibacterial activity. Ustilago sp. MFLUCC15-1024 presented the highest inhibition zone diameter with a MIC of 31.25 μg/mL against the tested pathogens. The chemical composition of the ethyl acetate extract of this strain was investigated using gas chromatography-mass spectrometry. Twenty-one components were identified. 2-Phenylethanol (38.7%), E-ligustilide (12.4%), α-eudesmol (10.2%), β-vetivone (4.6%), β-ylangene (3.7%) and verbanol (3.4%) were the major components of the extract. The strong antibacterial activity of Ustilago sp. MFLUCC15-1024 ethyl acetate extract may be attributed to the presence of a high concentration of bioactive compounds including phenyl ethyl alcohol, E-ligustilide and α-eudesmol. The results indicate that there is high diversity of endophytic fungi in M. cordifolia leaf, and that Ustilago sp. MFLUCC15-1024 strain could be an excellent resource of natural antibacterial compounds.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
M. Atif ◽  
Seemab Iqbal ◽  
M. Fakhar-E-Alam ◽  
M. Ismail ◽  
Qaisar Mansoor ◽  
...  

In this experimental approach, we explored the structures, morphologies, phototoxicities, and antibacterial activities of undoped and Mn-doped ceria nanocomposite materials, MnxCe1−xO2. The MnxCe1−xO2 nanocomposites were synthesized by employing a soft chemical route. Our prime focus was on the influence of different factors, both physical and chemical, i.e., the concentration of manganese in the product, size of the nanocomposite, drug dose, and incubation time, on the bacterial strains. Different bacterial strains were selected as experimental biological models of the antibacterial activity of the manganese-doped cerium oxide nanocomposite. In addition to the photodynamic response, the adenocarcinoma cell line (MCF-7) was also studied. Based on cell viability losses and bacterial inhibition analyses, the precise mechanisms of apoptosis or necrosis of 5-ALA/PpIX-exposed MCF-7 cells under 630 nm red lights and under dark conditions were elucidated. It was observed that the undoped nanocomposites had lower cytotoxicities and inhibitions compared with those of the doped nanocomposites towards pathogens. The antibacterial activity and effectiveness for photodynamic therapy were enhanced in the presence of the manganese-doped ceria nanocomposite, which could be attributed to the correlation of the maximum reactive oxygen species generation for targeted toxicity and maximum antioxidant property in bacteria growth inhibition. The optimized cell viability dose and doping concentration will be beneficial for treating cancer and bacterial infections in the future.


2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Yohannes Kelifa Emiru ◽  
Ebrahim Abdela Siraj ◽  
Tekleab Teka Teklehaimanot ◽  
Gedefaw Getnet Amare

Objective. To evaluate the antibacterial effects of the leaf latex of Aloe weloensis against infectious bacterial strains. Methods. The leaf latex of A. weloensis at different concentrations (400, 500, and 600 mg/ml) was evaluated for antibacterial activities using the disc diffusion method against some Gram-negative species such as Escherichia coli (ATCC 14700) and Pseudomonas aeruginosa (ATCC 35619) and Gram-positive such as Staphylococcus aureus (ATCC 50080) and Enterococcus fecalis (ATCC 4623). Results. The tested concentrations of the latex ranging between 400 and 600 mg·mL−1 showed significant antibacterial activity against bacterial strain. The highest dose (600 mg/ml) of A. weloensis leaf latex revealed the maximum activity (25.93 ± 0.066 inhibition zone) followed by the dose 500 mg/ml against S. aureus. The lowest antibacterial activity was observed by the concentration 400 mg/ml (5.03 ± 0.03) against E. coli. Conclusion. The results of the present investigation suggest that the leaf latex of A. weloensis can be used as potential leads to discover new drugs to control some bacterial infections.


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