scholarly journals Random Mutagenesis of theAspergillus oryzaeGenome Results in Fungal Antibacterial Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Cory A. Leonard ◽  
Stacy D. Brown ◽  
J. Russell Hayman
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Random Mutagenesis ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Resistant Bacteria ◽  
Klebsiella Pneumonia ◽  
Antibacterial Compounds ◽  
Severe Infections

Multidrug-resistant bacteria cause severe infections in hospitals and communities. Development of new drugs to combat resistant microorganisms is needed. Natural products of microbial origin are the source of most currently available antibiotics. We hypothesized that random mutagenesis ofAspergillus oryzaewould result in secretion of antibacterial compounds. To address this hypothesis, we developed a screen to identify individualA. oryzaemutants that inhibit the growth of Methicillin-resistantStaphylococcus aureus(MRSA)in vitro. To randomly generateA. oryzaemutant strains, spores were treated with ethyl methanesulfonate (EMS). Over 3000 EMS-treatedA. oryzaecultures were tested in the screen, and one isolate, CAL220, exhibited altered morphology and antibacterial activity. Culture supernatant from this isolate showed antibacterial activity against Methicillin-sensitiveStaphylococcus aureus, MRSA, andPseudomonas aeruginosa, but notKlebsiella pneumoniaorProteus vulgaris. The results of this study support our hypothesis and suggest that the screen used is sufficient and appropriate to detect secreted antibacterial fungal compounds resulting from mutagenesis ofA. oryzae. Because the genome ofA. oryzaehas been sequenced and systems are available for genetic transformation of this organism, targeted as well as random mutations may be introduced to facilitate the discovery of novel antibacterial compounds using this system.

scholarly journals In Vitro and In Vivo Antibacterial Activity of Gliotoxin Alone and in Combination with Antibiotics against Staphylococcus aureus

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 85
Author(s):  
Patricia Esteban ◽  
Sergio Redrado ◽  
Laura Comas ◽  
M. Pilar Domingo ◽  
M. Isabel Millán-Lou ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Resistant Bacteria ◽  
Infection Model ◽  
Antimicrobial Drugs ◽  
Hospital Acquired ◽  
Antibiotic Efficacy

Multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causes of hospital-acquired and community infections and pose a challenge to the human health care system. Therefore, it is important to find new drugs that show activity against these bacteria, both in monotherapy and in combination with other antimicrobial drugs. Gliotoxin (GT) is a mycotoxin produced by Aspergillus fumigatus and other fungi of the Aspergillus genus. Some evidence suggests that GT shows antimicrobial activity against S. aureus in vitro, albeit its efficacy against multidrug-resistant strains such as MRSA or vancomycin-intermediate S. aureus (VISA) strainsis not known. This work aimed to evaluate the antibiotic efficacy of GT as monotherapy or in combination with other therapeutics against MRSA in vitro and in vivo using a Caenorhabditis elegans infection model.

scholarly journals Assessment of Microbial Load of Un-pasteurized Fruit Juices and in vitro Antibacterial Potential of Honey Against Bacterial Isolates

2015 ◽  
Vol 9 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Muhammad Naeem Iqbal ◽  
Aftab Ahmad Anjum ◽  
Muhammad Asad Ali ◽  
Firasat Hussain ◽  
Shahzad Ali ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Viable Count ◽  
Fruit Juices ◽  
Microbial Load ◽  
Resistant Bacteria ◽  
Klebsiella Pneumonia ◽  
Street Vendors ◽  
Permissible Limits ◽  
Development Of Resistance

The development of resistance in bacteria against commonly used antibiotics/drugs is of considerable medical significance. Aim of this study was to determine the microbial load of un-pasteurized packed fruit juices sold in Lahore city and to determine antibacterial activity of five different honey samples against isolated bacteria. Unpasteurized fruit juice samples (n=60) were collected from street vendors. All the samples were subjected to Total viable count (TVC), Staphylococcal count (SC) and Coliform count (CC). One hundred and ten strains of bacteria were isolated from various fruit juices and identified on the basis of cultural characters, morphology and biochemical characters. Mean TVCs, SCs and CCs of juices (6.80±1.91, 5.45±1.06 and 3.25±1.25 log10 CFU/ml respectively) were non-significant with standard permissible limits (p<0.05). Among all the fruit juices, 66.66% of samples had TVC more than 4 log10 CFU/ml, 51.66% of samples had SC more than 3 log10 CFU/ml and 46.66% of samples had CC more than 2 log10 CFU/ml. Among the bacillus isolates purified, were Bacillus alvei, Bacillus subtilis, Bacillus polymyxa, Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli and Enterobecter. All five different types of honey samples used in this study showed antibacterial activity against B. alvei, B. polymyxa, B. subtilis and S. aureus and no activity against P. aeruginosa, K. pneumonia, Enterobecter and E. coli. It is concluded that microbial load in unpasteurized fruit juices is significantly higher than standard permissible limits which insinuates its possible role in spoilage and food borne illnesses. Periodic monitoring of packed fruit juices should be carried out to make them safe for consumption. Honey can be used as an alternative for treatment of various infections, especially those caused by antibiotic resistant bacteria.

Design, synthesis and antibacterial evaluation of ocotillol derivatives with polycyclic nitrogen-containing groups

2021 ◽  
Author(s):  
Yucheng Cao ◽  
Kaiyi Wang ◽  
Jiali Wang ◽  
Haoran Cheng ◽  
Mengxin Ma ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Resistant Bacteria ◽  
Design Synthesis ◽  
In Vitro Antibacterial Activity ◽  
Strong Inhibitory Effect ◽  
Hospital Acquired ◽  
Derivatives Of

Aim: With the increasing abuse of antibacterial drugs, multidrug-resistant bacteria have become a burden on human health and the healthcare system. To find alternative compounds effective against hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA), novel derivatives of ocotillol were synthesized. Methods & Results: Ocotillol derivatives with polycyclic nitrogen-containing groups were synthesized and evaluated for in vitro antibacterial activity. Compounds 36–39 exhibited potent antibacterial activity against hospital-acquired MRSA, with MIC = 8–64 μg/ml. Additionally, a combination of compound 37 and the commercially available antibiotic kanamycin showed synergistic inhibitory effects, with a fractional inhibitory concentration index of ≤0.375. Conclusion: Compound 37 has a strong inhibitory effect, and this derivative has potential for use as a pharmacological tool to explore antibacterial mechanisms.

scholarly journals Molecular Composition and Antibacterial Effect of Five Essential Oils Extracted from Nigella sativa L. Seeds against Multidrug-Resistant Bacteria: A Comparative Study

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mohammed Dalli ◽  
Salah-eddine Azizi ◽  
Hind Benouda ◽  
Ali Azghar ◽  
Maroua Tahri ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oils ◽  
Nigella Sativa ◽  
Multidrug Resistant ◽  
Climatic Conditions ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Microdilution Method

Nigella sativa L. (NS) and its volatile compounds are well known for their broad spectrum of effects. This study aimed to investigate the variability of the chemical composition and the in vitro antibacterial activity of five essential oils (Eos) originated from Morocco, Saudi Arabia, Syria, India, and France. These five samples were grown under different edaphic and climatic conditions. The agar diffusion method and microdilution method in 96-well plates were used to test the sensitivity of multidrug-resistant strains clinically isolated from patients (methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii), for the determination of the minimum inhibitory concentration and bactericidal concentration. Among all the investigated Eos, the monoterpenes were highly present in the chemical composition. Moroccan, Saudi Arabian, and Syrian seeds were characterized by the presence α-phellandrene (20.03–30.54%), β-cymene (12.31–23.82 %), and 4−caranol (9.77–14.27%). The Indian seeds were rich with 4-caranol (18.81%), β-cymene (14.22%), α-phellandrene (10.58%), and β-chamigrene (9.54%), while France NS was rich with estragole (20.22%) and D-limonene (14.63%). The minimum inhibitory (MIC) and bactericidal concentration (MBC) obtained for the four Eos (with the exception of France because of the low yield) tested were ranging from 3 to 40 μl/ml. Gram-positive (+) bacteria were slightly sensitive to the Eos tested than the Gram-negative (−) bacteria. The results of this study showed that the Eos of NS seeds show interesting antibacterial activity which could be associated to the existence of different bioactive compounds. Indeed, these compounds can be used for preventive or curative purposes in the face of the noncontrolled emergence of resistance to antibiotics.

scholarly journals Evaluation of Antibacterial Activity of Essential Oils and Their Combination against Multidrug-Resistant Bacteria Isolated from Skin Ulcer

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Eshetu Gadisa ◽  
Hydar Usman
Keyword(s):  
Antibacterial Activity ◽  
Essential Oils ◽  
Antibacterial Effect ◽  
Wound Care ◽  
In Vitro Study ◽  
Inhibition Zone ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria

Background. Emerging of multidrug-resistant bacteria can compromise the effectiveness of antibiotics used to treat skin infections. Those bacteria imposed public health problems and questioning medical care in the 21st century. In this circumstance, essential oils of medicinal plants origin are supreme sources of structural and functionally divergent compounds, which inhibited the growth of common wound colonizing MRSA and ESBL producing P. aeruginosa. The aim of this study was to evaluate the combined antibacterial activity of essential oils extracted from Rumex abyssinicus, Cucumis pustulatus, and Discopodium penninervium against multidrug-resistant (MDR) isolates of skin ulcers. Methods. Essential oils (EOs) were extracted from aerial parts of R. abyssinicus, C. pustulatus, and D. penninervium with steam distillation. A mixture of each oil (1 : 1) was adsorbed to a disc and placed on Mueller Hinton Agar. Then, minimum zone of inhibition and bactericidal concentration of EOs was measured after incubeted for 18–24 hours at 37 °C. Their combined antibacterial effect was determined by the fractional inhibitory concentration index. Results. The antibacterial activity of mixed oil varied in their doses and bacteria species, of which a mixture of essential oil of R. abyssinicus and D. penninervium had inhibition zone (32 mm); its MIC and MBC values range from 1-2 μl/ml against MRSA. It had an inhibition zone (36 mm), MIC value 4 μl/ml, and MBC (8 μl/ml) against ESBL producing P. aeruginosa, whereas combined effects of R. abyssinicus and C. pustulatus had MIC values ranging from 2–8 μl/ml for E. coli and K. pneumoniae and 2 μl/ml for MRSA. There was a strong synergistic effect between R. abyssinicus and D. penninervium and promising antibacterial effect more specifically on MRSA and P. aeruginosa. Conclusion. This in vitro study of the combined effect of EOs has significant antibacterial activity on wound colonizing bacteria and reduces delaying wound healing as that of modern drugs tested in parallel. Hence, further structural elucidation of active compounds helps us to properly design or synthesis of topical antibiotics for wound care.

scholarly journals Design, synthesis, and discovery of novel oxindoles bearing 3-heterocycles as species-specific and combinatorial agents in eradicating Staphylococcus species

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jonghoon Shin ◽  
Krishna Bahadur Somai Magar ◽  
Jungwoon Lee ◽  
Kwang-sun Kim ◽  
Yong Rok Lee
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Cellular Level ◽  
One Pot ◽  
Design Synthesis ◽  
Reference Drug ◽  
As Species ◽  
Species Specific

Abstract A series of new functionalized 3-indolylindolin-2-ones, 3-(1-methylpyrrol-2-yl)indolin-2-ones, and 3-(thiophen-2-yl)indolin-2-ones were synthesized by using novel indium (III)-catalysed reaction of various 3-diazoindolin-2-ones with indoles, 1-methylpyrrole, or thiophene via one-pot procedure. The newly synthesized compounds were characterized and screened for their in vitro antibacterial activity against various Staphylococcus species, including methicillin-resistant Staphylococcus aureus. results revealed that five compounds KS15, KS16, KS17, KS19, and KS20 exhibited potent and specific antibacterial activity against Staphylococcus species albeit inactive against Gram-negative bacteria. Especially, compounds exhibited superior antibacterial potency against Staphylococcus epidermidis compared to the reference drug streptomycin. The most potential compound KS16 also increased the susceptibility of Staphylococcus aureus to ciprofloxacin, gentamicin, kanamycin, and streptomycin. Among them, KS16 was found to be a synergistic compound with gentamicin and kanamycin. Furthermore, the cellular level of autolysin protein was increased from the KS16-treated Staphylococcus aureus cells. Finally, in vitro CCK-8 assays showed that KS16 exhibited no cytotoxicity at the minimum inhibitory concentrations used for killing Staphylococcus species. From all our results, novel oxindole compounds directly have lethal action or boost existing antibiotic power with the reduction of doses and toxicity in the treatment of multidrug-resistant Staphylococcus species.

scholarly journals Fluorocycline TP-271 Is Potent against Complicated Community-Acquired Bacterial Pneumonia Pathogens

mSphere ◽  
2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Trudy H. Grossman ◽  
Corey Fyfe ◽  
William O’Brien ◽  
Meredith Hackel ◽  
Mary Beth Minyard ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Bacterial Pneumonia ◽  
The Elderly ◽  
Multidrug Resistant ◽  
New Antibiotics ◽  
Severe Infections ◽  
Intravenous And Oral Administration ◽  
Resistance Rates

ABSTRACT Rising resistance rates for macrolides, fluoroquinolones, and β-lactams in the most common pathogens associated with community-acquired bacterial pneumonia (CABP) are of concern, especially for cases of moderate to severe infections in vulnerable populations such as the very young and the elderly. New antibiotics that are active against multidrug-resistant Streptococcus pneumoniae and Staphylococcus aureus are needed for use in the empirical treatment of the most severe forms of this disease. TP-271 is a promising new fluorocycline antibiotic demonstrating in vitro potency and nonclinical efficacy by intravenous and oral administration against the major pathogens associated with moderate to severe CABP. TP-271 is a novel, fully synthetic fluorocycline antibiotic in clinical development for the treatment of respiratory infections caused by susceptible and multidrug-resistant pathogens. TP-271 was active in MIC assays against key community respiratory Gram-positive and Gram-negative pathogens, including Streptococcus pneumoniae (MIC90 = 0.03 µg/ml), methicillin-sensitive Staphylococcus aureus (MSSA; MIC90 = 0.25 µg/ml), methicillin-resistant S. aureus (MRSA; MIC90 = 0.12 µg/ml), Streptococcus pyogenes (MIC90 = 0.03 µg/ml), Haemophilus influenzae (MIC90 = 0.12 µg/ml), and Moraxella catarrhalis (MIC90 ≤0.016 µg/ml). TP-271 showed activity (MIC90 = 0.12 µg/ml) against community-acquired MRSA expressing Panton-Valentine leukocidin (PVL). MIC90 values against Mycoplasma pneumoniae, Legionella pneumophila, and Chlamydia pneumoniae were 0.004, 1, and 4 µg/ml, respectively. TP-271 was efficacious in neutropenic and immunocompetent animal pneumonia models, generally showing, compared to the burden at the start of dosing, ~2 to 5 log10 CFU reductions against MRSA, S. pneumoniae, and H. influenzae infections when given intravenously (i.v.) and ~1 to 4 log10 CFU reductions when given orally (p.o.). TP-271 was potent against key community-acquired bacterial pneumonia (CABP) pathogens and was minimally affected, or unaffected, by tetracycline-specific resistance mechanisms and fluoroquinolone or macrolide drug resistance phenotypes. IMPORTANCE Rising resistance rates for macrolides, fluoroquinolones, and β-lactams in the most common pathogens associated with community-acquired bacterial pneumonia (CABP) are of concern, especially for cases of moderate to severe infections in vulnerable populations such as the very young and the elderly. New antibiotics that are active against multidrug-resistant Streptococcus pneumoniae and Staphylococcus aureus are needed for use in the empirical treatment of the most severe forms of this disease. TP-271 is a promising new fluorocycline antibiotic demonstrating in vitro potency and nonclinical efficacy by intravenous and oral administration against the major pathogens associated with moderate to severe CABP.

scholarly journals Identification of Pyruvate Kinase in Methicillin-Resistant Staphylococcus aureus as a Novel Antimicrobial Drug Target

2011 ◽  
Vol 55 (5) ◽  
pp. 2042-2053 ◽  
Author(s):  
Roya Zoraghi ◽  
Raymond H. See ◽  
Peter Axerio-Cilies ◽  
Nag S. Kumar ◽  
Huansheng Gong ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pyruvate Kinase ◽  
Drug Target ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibacterial Drug ◽  
Methicillin Resistant ◽  
Content Type ◽  
Antistaphylococcal Activity

ABSTRACTNovel classes of antimicrobials are needed to address the challenge of multidrug-resistant bacteria such as methicillin-resistantStaphylococcus aureus(MRSA). Using the architecture of the MRSA interactome, we identified pyruvate kinase (PK) as a potential novel drug target based upon it being a highly connected, essential hub in the MRSA interactome. Structural modeling, including X-ray crystallography, revealed discrete features of PK in MRSA, which appeared suitable for the selective targeting of the bacterial enzyme.In silicolibrary screening combined with functional enzymatic assays identified an acyl hydrazone-based compound (IS-130) as a potent MRSA PK inhibitor (50% inhibitory concentration [IC50] of 0.1 μM) with >1,000-fold selectivity over human PK isoforms. Medicinal chemistry around the IS-130 scaffold identified analogs that more potently and selectively inhibited MRSA PK enzymatic activity andS. aureusgrowthin vitro(MIC of 1 to 5 μg/ml). These novel anti-PK compounds were found to possess antistaphylococcal activity, including both MRSA and multidrug-resistantS. aureus(MDRSA) strains. These compounds also exhibited exceptional antibacterial activities against other Gram-positive genera, including enterococci and streptococci. PK lead compounds were found to be noncompetitive inhibitors and were bactericidal. In addition, mutants with significant increases in MICs were not isolated after 25 bacterial passages in culture, indicating that resistance may be slow to emerge. These findings validate the principles of network science as a powerful approach to identify novel antibacterial drug targets. They also provide a proof of principle, based upon PK in MRSA, for a research platform aimed at discovering and optimizing selective inhibitors of novel bacterial targets where human orthologs exist, as leads for anti-infective drug development.

scholarly journals Antibacterial Activity of Cinnamon Extract (Cinnamomum burmannii) against Staphylococcus aureus and Escherichia coli In Vitro

2019 ◽  
Vol 3 (2) ◽  
pp. 19-28
Author(s):  
Nita Parisa ◽  
Rahma Nur Islami ◽  
Ella Amalia ◽  
Mariana Mariana ◽  
Riana Sari Puspita Rasyid
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Ethanol Extract ◽  
Inhibition Zone ◽  
Control Group ◽  
Antibacterial Compounds ◽  
Cinnamon Extract ◽  
Cinnamomum Burmannii

Abstract   Infectious disease is one of the most common diseases in the world. Staphylococcus aureus and Escherichia coli are two common causes of infection and are resistant to many antibiotics, so the new agents are needed to overcome antibiotic resistance. Cinnamon is often used as a preservative because it has antibacterial activity. Cinnamomum burmannii is kind of native cinnamon from Indonesia. The antimicrobial active compounds cinnamaldehyde and eugenol are the main reasons for its antibacterial activity. This study observed the efficacy of the cinnamon extract (Cinnamomum burmannii) as antibacterial against Staphylococcus aureus and Escherichia coli. An experimental study, in vitro using Post-test Only Control Group Designed, has been done in Microbiology and Biotechnology Laboratory of Medical Faculty of Sriwijaya University. Cinnamon was extracted, then tested for its antibacterial activity using well diffusion and serial dilution to determine diameter of inhibition zone and minimum bactericidal concentration. Phytochemical tests were also conducted to determine the antibacterial compounds of cinnamon extract. Ethanol extract of cinnamon was able to inhibit the growth of Staphylococcus aureus with MBC 5% and inihibitory zone 6,84±0,68 mm and Escherichia coli with MBC 10% and inhibitory zone 5,69±0,69 mm. Cinnamon extract which has the greatest effectiveness is concentration of 40% with inhibition zone 15,69±0,80 mm (Staphylococcus aureus) and 9,63±0,59 mm (Escherichia coli). This ability is due to the antibacterial compounds as evidenced by positive results in various phytochemical tests. Cinnamon extract is effective as antibacterial against Staphylococcus aureus and Escherichia coli in vitro.   Keywords: efficacy, antibacterial, Cinnamomum burmannii, Staphylococcus aureus, Escherichia coli

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