scholarly journals In Vitro Evaluation of Antimicrobial Activity and Cytotoxicity of Different Nanobiotics Targeting Multidrug Resistant and Biofilm Forming Staphylococci

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Mennatallah A. Mohamed ◽  
Maha Nasr ◽  
Walid F. Elkhatib ◽  
Wafaa N. Eltayeb
Keyword(s):  
Antimicrobial Activity ◽  
Rat Hepatocytes ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Antibiotic Resistant ◽  
Diphenyltetrazolium Bromide ◽  
New Antibiotics ◽  
Conventional Antibiotics

Antibiotic-resistant and biofilm-forming bacteria have surprisingly increased over recent years. On the contrary, the rate of development of new antibiotics to treat these emerging superbugs is very slow. Therefore, the aim of this study was to prepare novel nanobiotic formulations to improve the antimicrobial activity of three antibiotics (linezolid, doxycycline, and clindamycin) against Staphylococci. Antibiotics were formulated as nanoemulsions and evaluated for their antimicrobial activities and cytotoxicities. Cytotoxicity of the conventional antibiotics and nanobiotics was analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on rat hepatocytes. Half-maximal inhibitory concentration (IC50) was estimated from an experimentally derived dose-response curve for each concentration using GraphPad Prism software. Upon quantitative assessment of Staphylococcus biofilm formation, eighty-four isolates (66.14 %) were biofilm forming. Linezolid and doxycycline nanobiotics exhibited promising antibacterial activities. On the contrary, clindamycin nanobiotic exhibited poor antibacterial activity. Minimum biofilm inhibitory concentrations showed that 73.68 %, 45.6%, and 5.2% of isolates were sensitive to linezolid, doxycycline, and clindamycin nanobiotics, respectively. Results of this study revealed that antibiotics loaded in nanosystems had a higher antimicrobial activity and lower cytotoxicities as compared to those of conventional free antibiotics, indicating their potential therapeutic values.

scholarly journals The Pomegranate: Effects on Bacteria and Viruses That Influence Human Health

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Amy B. Howell ◽  
Doris H. D'Souza
Keyword(s):  
Antimicrobial Activity ◽  
Foodborne Pathogens ◽  
Clinical Results ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Oral Bacteria ◽  
Resistant Bacteria ◽  
Wide Range

Pomegranates have been known for hundreds of years for their multiple health benefits, including antimicrobial activity. The recent surge in multidrug-resistant bacteria and the possibility of widespread global virus pandemics necessitate the need for additional preventative and therapeutic options to conventional drugs. Research indicates that pomegranates and their extracts may serve as natural alternatives due to their potency against a wide range of bacterial and viral pathogens. Nearly every part of the pomegranate plant has been tested for antimicrobial activities, including the fruit juice, peel, arils, flowers, and bark. Many studies have utilized pomegranate peel with success. There are various phytochemical compounds in pomegranate that have demonstrated antimicrobial activity, but most of the studies have found that ellagic acid and larger hydrolyzable tannins, such as punicalagin, have the highest activities. In some cases the combination of the pomegranate constituents offers the most benefit. The positive clinical results on pomegranate and suppression of oral bacteria are intriguing and worthy of further study. Much of the evidence for pomegranates’ antibacterial and antiviral activities against foodborne pathogens and other infectious disease organisms comes fromin vitrocell-based assays, necessitating further confirmation ofin vivoefficacy through human clinical trials.

scholarly journals A Study of Ethno-Veterinary Medicinal Plants and In Vitro Antimicrobial Activities Against Bovine Mastitis Isolated Bacterial Pathogens in Algeria

2019 ◽  
Vol 76 (2) ◽  
pp. 154
Author(s):  
Radhwane SAIDI ◽  
Nora MIMOUNE ◽  
Ratiba BAAZIZI ◽  
Mohamed Hocine BENAISSA ◽  
Djamel KHELEF ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Bovine Mastitis ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Economic Losses ◽  
Resistant Bacteria ◽  
Mentha Pulegium ◽  
Antibiotic Resistant ◽  
Marrubium Vulgare

Bovine mastitis is the most serious dairy problem in terms of economic losses to the dairy industry. In Algeria, dominates as one of the most prevalent diseases in dairy cattle among the dairy farms. Mastitis treatment with antibiotics leads to the development of antibiotic resistant strains and consumer health problem. Multidrug-resistant bacteria have become a major health issue. With new generations of virulence and resistant bacteria, we need to improve our understanding and produce novel techniques to control these pathogenic strains. In our study, the activity of several extracts from seven medicinal plants, namely Mentha pulegium, Lavandula dentate, Origanium sp, Marrubium vulgare, Salvia bicolor, Blackstonia perfoliata, and Phlomis crinita, traditionally used in Algeria was investigated against 26 methicillin resistant staphylococci and multi-resistant Escherichia coli. (E.coli) isolated from animals with mastitis manifestation by the disc diffusion method.Results revealed the potential of extracts of Salvia bicolor, Marrubium vulgare and Phlomis crinita as antibacterial agents against strains isolated from bovine mastitis and support the possible use of these phytotherapic agents in the clinical management of the disease. Further studies into their toxicity and phytochemistry are advocated.

scholarly journals In vitro activity of hybrid lavender essential oils against multidrug resistant strains of Pseudomonas aeruginosa

2018 ◽  
Vol 12 (01) ◽  
pp. 009-014 ◽  
Author(s):  
Matthew Donadu ◽  
Donatella Usai ◽  
Antonio Pinna ◽  
Tiziana Porcu ◽  
Vittorio Mazzarello ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Cell Model ◽  
Antimicrobial Properties ◽  
The United States ◽  
Multidrug Resistant ◽  
New Antibiotics ◽  
Mediterranean Regions ◽  
A Cell

Introduction: Lavender is an evergreen shrub native to Northern Africa and other mountainous Mediterranean regions. It grows throughout Southern Europe, the United States, and Australia. Lavender essential oil has been used since ancient times and is known for its anti-inflammatory, antidepressant, antiseptic, antifungal and antimicrobial properties. Methodology: in this study, the antimicrobial activity of two Lavender essential oils (Lavanda sumian and Lavanda grosso) against 16 multidrug-resistant P. aeruginosa strains from clinical ocular samples taken from migrant patients has been investigated. The in vitro cytotoxic activity on human Wong-Kilbourne derivative (WKD) conjunctiva cells from healthy patients and nitric oxide synthase (NOS) activity on murine macrophage (J774.1A) were also evaluated. Results: L. sumian showed lower antimicrobial activity when compared to L. grosso. Both lavender oils tested had no cytotoxic effect at very low concentrations, mostly L. grosso. The essential oils extracted from L. sumian and L. grosso significantly reduced NOS in a cell model. Conclusion: Increase in drug resistance and lack of new antibiotics may encourage the development of natural antimicrobial treatments.

scholarly journals Imcroporin, a New Cationic Antimicrobial Peptide from the Venom of the Scorpion Isometrus maculates

2009 ◽  
Vol 53 (8) ◽  
pp. 3472-3477 ◽  
Author(s):  
Zhenhuan Zhao ◽  
Yibao Ma ◽  
Chao Dai ◽  
Ruiming Zhao ◽  
SongRyong Li ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptide ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Lead Compound ◽  
Cationic Antimicrobial Peptide ◽  
Antibiotic Resistant ◽  
Multidrug Resistant Pathogens ◽  
Conventional Antibiotics

ABSTRACT The pace of resistance against antibiotics almost exceeds that of the development of new drugs. As many bacteria have become resistant to conventional antibiotics, new drugs or drug resources are badly needed to combat antibiotic-resistant pathogens, like methicillin-resistant Staphylococcus aureus (MRSA). Antimicrobial peptides, rich sources existing in nature, are able to effectively kill multidrug-resistant pathogens. Here, imcroporin, a new antimicrobial peptide, was screened and isolated from the cDNA library of the venomous gland of Isometrus maculates. The MIC of imcroporin against MRSA was 50 μg/ml, 8-fold lower than that of cefotaxime and 40-fold lower than that of penicillin. Imcroporin killed bacteria rapidly in vitro, inhibited bacterial growth, and cured infected mice. These results revealed that imcroporin could be considered a potential anti-infective drug or lead compound, especially for treating antibiotic-resistant pathogens.

scholarly journals Fosfomycin

2016 ◽  
Vol 29 (2) ◽  
pp. 321-347 ◽  
Author(s):  
Matthew E. Falagas ◽  
Evridiki K. Vouloumanou ◽  
George Samonis ◽  
Konstantinos Z. Vardakas
Keyword(s):  
Bacterial Infections ◽  
Clinical Effectiveness ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Development Of Resistance ◽  
Extensively Drug Resistant ◽  
New Antibiotics

SUMMARYThe treatment of bacterial infections suffers from two major problems: spread of multidrug-resistant (MDR) or extensively drug-resistant (XDR) pathogens and lack of development of new antibiotics active against such MDR and XDR bacteria. As a result, physicians have turned to older antibiotics, such as polymyxins, tetracyclines, and aminoglycosides. Lately, due to development of resistance to these agents, fosfomycin has gained attention, as it has remained active against both Gram-positive and Gram-negative MDR and XDR bacteria. New data of higher quality have become available, and several issues were clarified further. In this review, we summarize the available fosfomycin data regarding pharmacokinetic and pharmacodynamic properties, thein vitroactivity against susceptible and antibiotic-resistant bacteria, mechanisms of resistance and development of resistance during treatment, synergy and antagonism with other antibiotics, clinical effectiveness, and adverse events. Issues that need to be studied further are also discussed.

scholarly journals In vitro activity of essential oils against Pseudomonas aeruginosa isolated from infected hip implants

2018 ◽  
Vol 12 (11) ◽  
pp. 996-1001 ◽  
Author(s):  
Veronica Amorese ◽  
Matthew Donadu ◽  
Donatella Usai ◽  
Angelino Sanna ◽  
Fabio Milia ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Antimicrobial Properties ◽  
Multidrug Resistant ◽  
Thymus Vulgaris ◽  
Hip Implants ◽  
Melaleuca Alternifolia ◽  
New Antibiotics ◽  
Normal Human

Introduction: Essential oils have been used since ancient times and are known for their anti-inflammatory, anti-depressive, antiseptic, antifungal and antimicrobial properties. Methodology: in this study the antimicrobial activity of two essential oils from Melaleuca alternifolia and Thymus vulgaris–red thyme geraniol was tested against 16 multidrug-resistant P. aeruginosa strains from infected hip implants as well as the “in vitro” cytotoxic activity on normal human Wong-Kilbourne derivative (WKD) cells. Results: Thymus vulgaris–red thyme geraniol showed lower antimicrobial activity when compared to Melaleuca alternifolia. All tested oils were cytotoxic at concentrations lower than 0.12%. Conclusion: Increase in drug resistance and lack of new antibiotics may encourage the development of natural treatments together with higher concern on environmental issues and natural lifestyle.

Synthesis and Antimicrobial Activities of Novel Rutin Derivatives Carrying Quinoline Moiety

2020 ◽  
Vol 71 (6) ◽  
pp. 401-407
Author(s):  
Dan Lupascu ◽  
Lenuta Profire ◽  
Maria Apotrosoaei ◽  
Cristina Tuchilus ◽  
Ioana Mirela Vasincu ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Antimicrobial Agents ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Biological Properties ◽  
Research Directions ◽  
Good Antibacterial Activity ◽  
Vegetal Species

Antimicrobial resistance constitutes a topical subject and it is one of the major threats to public health. According to statistics, the incidence of multidrug-resistant microorganisms, such as bacteria, fungi and protozoa has increased in the last decades and it continues to spread. Therefore, the development of novel antimicrobial agents to combat drug-resistant infections is very important, among other research directions in this field. Quinoline ring is a very interesting structure for researchers because of its diverse biological properties (antimicrobial, anticancer, anticonvulsant, antiinflamatory and cardiovascular). On the other hand several studies showed good antibacterial activity (including anti-Pseudomonas effects) and antifungal properties of rutin or vegetal species with a high flavonoids (especially rutin) concentration. Based on the above considerations, eight novel rutin derivatives carrying 4- and 8-aminoquinoline moiety were designed, synthesized and characterized by FTIR, 1H NMR and elemental analysis. All compounds were evaluated for their in vitro antimicrobial activities against representative Gram-positive, Gram-negative and fungal pathogens. The results indicated that all rutin derivatives exhibited good antibacterial activities, similar to ciprofloxacin.

scholarly journals Antimicrobial Activity of Nanoemulsion in Combination with Cetylpyridinium Chloride in Multidrug-Resistant Acinetobacter baumannii

2013 ◽  
Vol 57 (8) ◽  
pp. 3568-3575 ◽  
Author(s):  
Yoon Y. Hwang ◽  
Karthikeyan Ramalingam ◽  
Diane R. Bienek ◽  
Valerie Lee ◽  
Tao You ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Acinetobacter Baumannii ◽  
Cetylpyridinium Chloride ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Antibiofilm Activity ◽  
Antibiotic Resistant ◽  
Content Type ◽  
A Cell ◽  
Triton X

ABSTRACTAcinetobacter baumanniihas emerged as a serious problematic pathogen due to the ever-increasing presence of antibiotic resistance, demonstrating a need for novel, broad-spectrum antimicrobial therapeutic options. Antimicrobial nanoemulsions are emulsified mixtures of detergent, oil, and water (droplet size, 100 to 800 nm) which have broad antimicrobial activity against bacteria, enveloped viruses, and fungi. Here, we screened the antimicrobial activities of five nanoemulsion preparations against fourAcinetobacter baumanniiisolates to identify the most suitable preparation for further evaluation. Among them, N5, which contains 10% (vol/vol) Triton X-100, 25% (vol/vol) soybean oil, and 1% (wt/vol) cetylpyridinium chloride (CPC), showed the best efficacy againstA. baumanniiin both its planktonic and biofilm forms and was selected for further study. Our data demonstrate that, while the killing of planktonic forms ofA. baumanniiwas due to the 1% CPC component of our nanoemulsions, the breakdown of biofilms was achieved via the emulsified oil and detergent fractions. Furthermore, we documented the effect of ethanol and NaCl in combination with N5 on planktonicA. baumannii. In killing curves of N5 combined with other agents (ethanol or NaCl), a synergistic effect of a ≥2-log decrease in CFU/ml was observed. The antibiofilm activity of N5 was confirmed via a cell proliferation test and scanning electron microscopy. The effects of exposure to severe environmental conditions, which simulates the field conditions in Iraq and Afghanistan, were evaluated, and this exposure did not affect the overall antimicrobial activity of N5. These studies lay a solid foundation for the utilization of nanoemulsions against the antibiotic-resistant forms ofA. baumannii.

scholarly journals In Vitro Antimicrobial Activity and Mutant Prevention Concentration of Colistin against Acinetobacter baumannii

2010 ◽  
Vol 54 (9) ◽  
pp. 3998-3999 ◽  
Author(s):  
Yun Cai ◽  
Ran Li ◽  
Beibei Liang ◽  
Nan Bai ◽  
Youning Liu ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Plasma Concentration ◽  
Combination Therapy ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Recommended Dosage ◽  
Mutant Prevention Concentration ◽  
Emergence Of Resistance

ABSTRACT The antimicrobial activities of colistin and other antibiotics against clinical Acinetobacter baumannii and the mutant prevention concentration (MPC) of colistin against multidrug-resistant A. baumannii were studied. All 70 stains tested were sensitive to colistin. The MPC range of colistin against 30 multidrug-resistant A. baumannii stains was approximately 32 to >128 μg/ml, and the MPC at which 90% of the isolates tested were prevented (MPC90) exceeded 128 μg/ml, which was much higher than the plasma concentration of colistin at the current recommended dosage. So, combination therapy for colistin treatment of A. baumannii would be prudent to slow the emergence of resistance.

Mechanisms involved in effects of antimicrobial peptides, bactenectins ChBac3.4, ChBac5, and mini-ChBac7.5Nb, on bacterial cells

2017 ◽  
pp. 43-50
Author(s):  
О.В. Шамова ◽  
М.С. Жаркова ◽  
П.М. Копейкин ◽  
Д.С. Орлов ◽  
Е.А. Корнева
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Innate Immunity ◽  
Infectious Diseases ◽  
Metabolic Activity ◽  
Capra Hircus ◽  
Bacterial Cells ◽  
Antibiotic Resistant ◽  
Resistant Strains

Антимикробные пептиды (АМП) системы врожденного иммунитета - соединения, играющие важную роль в патогенезе инфекционных заболеваний, так как обладают свойством инактивировать широкий спектр патогенных бактерий, обеспечивая противомикробную защиту живых организмов. В настоящее время АМП рассматриваются как потенциальные соединения-корректоры инфекционной патологии, вызываемой антибиотикорезистентными бактериями (АБР). Цель данной работы состояла в изученим механизмов антибактериального действия трех пептидов, принадлежащих к семейству бактенецинов - ChBac3.4, ChBac5 и mini-ChBac7.5Nb. Эти химически синтезированные пептиды являются аналогами природных пролин-богатых АМП, обнаруженных в лейкоцитах домашней козы Capra hircus и проявляющих высокую антимикробную активность, в том числе и в отношении грамотрицательных АБР. Методы. Минимальные ингибирующие и минимальные бактерицидные концентрации пептидов (МИК и МБК) определяли методом серийных разведений в жидкой питательной среде с последующим высевом на плотную питательную среду. Эффекты пептидов на проницаемость цитоплазматической мембраны бактерий для хромогенного маркера исследовали с использованием генетически модифицированного штамма Escherichia coli ML35p. Действие бактенецинов на метаболическую активность бактерий изучали с применением маркера резазурина. Результаты. Показано, что все исследованные пептиды проявляют высокую антимикробную активность в отношении Escherichia coli ML35p и антибиотикоустойчивых штаммов Escherichia coli ESBL и Acinetobacter baumannii in vitro, но их действие на бактериальные клетки разное. Использован комплекс методик, позволяющих наблюдать в режиме реального времени динамику действия бактенецинов в различных концентрациях (включая их МИК и МБК) на барьерную функцию цитоплазматической мембраны и на интенсивность метаболизма бактериальных клеток, что дало возможность выявить различия в характере воздействия бактенецинов, отличающихся по структуре молекулы, на исследуемые микроорганизмы. Установлено, что действие каждого из трех исследованных бактенецинов в бактерицидных концентрациях отличается по эффективности нарушения целостности бактериальных мембран и в скорости подавления метаболизма клеток. Заключение. Полученная информация дополнит существующие фундаментальные представления о механизмах действия пролин-богатых пептидов врожденного иммунитета, а также послужит основой для биотехнологических исследований, направленных на разработку на базе этих соединений новых антибиотических препаратов для коррекции инфекционных заболеваний, вызываемых АБР и являющимися причинами тяжелых внутрибольничных инфекций. Antimicrobial peptides (AMPs) of the innate immunity are compounds that play an important role in pathogenesis of infectious diseases due to their ability to inactivate a broad array of pathogenic bacteria, thereby providing anti-microbial host defense. AMPs are currently considered promising compounds for treatment of infectious diseases caused by antibiotic-resistant bacteria. The aim of this study was to investigate molecular mechanisms of the antibacterial action of three peptides from the bactenecin family, ChBac3.4, ChBac5, and mini-ChBac7.5Nb. These chemically synthesized peptides are analogues of natural proline-rich AMPs previously discovered by the authors of the present study in leukocytes of the domestic goat, Capra hircus. These peptides exhibit a high antimicrobial activity, in particular, against antibiotic-resistant gram-negative bacteria. Methods. Minimum inhibitory and minimum bactericidal concentrations of the peptides (MIC and MBC) were determined using the broth microdilution assay followed by subculturing on agar plates. Effects of the AMPs on bacterial cytoplasmic membrane permeability for a chromogenic marker were explored using a genetically modified strain, Escherichia coli ML35p. The effect of bactenecins on bacterial metabolic activity was studied using a resazurin marker. Results. All the studied peptides showed a high in vitro antimicrobial activity against Escherichia coli ML35p and antibiotic-resistant strains, Escherichia coli ESBL and Acinetobacter baumannii, but differed in features of their action on bacterial cells. The used combination of techniques allowed the real-time monitoring of effects of bactenecin at different concentrations (including their MIC and MBC) on the cell membrane barrier function and metabolic activity of bacteria. The differences in effects of these three structurally different bactenecins on the studied microorganisms implied that these peptides at bactericidal concentrations differed in their capability for disintegrating bacterial cell membranes and rate of inhibiting bacterial metabolism. Conclusion. The obtained information will supplement the existing basic concepts on mechanisms involved in effects of proline-rich peptides of the innate immunity. This information will also stimulate biotechnological research aimed at development of new antibiotics for treatment of infectious diseases, such as severe in-hospital infections, caused by antibiotic-resistant strains.

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