scholarly journals Paenibacillus alvei MP1 as a Producer of the Proteinaceous Compound with Activity against Important Human Pathogens, Including Staphylococcus aureus and Listeria monocytogenes

Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 319
Author(s):  
Magdalena Pajor ◽  
Zirui Ray Xiong ◽  
Randy W. Worobo ◽  
Piotr Szweda
Keyword(s):  
Antimicrobial Activity ◽  
Ammonium Sulfate ◽  
Pathogenic Bacteria ◽  
De Novo ◽  
Wide Spectrum ◽  
Honey Sample ◽  
Human Pathogens ◽  
Heat Stable ◽  
Ammonium Sulfate Precipitate ◽  
The One

An emerging need for new classes of antibiotics is, on the one hand, evident as antimicrobial resistance continues to rise. On the other hand, the awareness of the pros and cons of chemically synthesized compounds’ extensive use leads to a search for new metabolites in already known reservoirs. Previous research showed that Paenibacillus strain (P. alvei MP1) recovered from a buckwheat honey sample presented a wide spectrum of antimicrobial activity against both Gram-positive and Gram-negative pathogens. Recent investigation has confirmed that P. alvei MP1 (deposited at DDBJ/ENA/GenBank under the accession WSQB00000000) produces a proteinaceous, heat-stable compound(s) with the maximum antimicrobial production obtained after 18 h of P. alvei MP1 growth in LB medium at 37 °C with continuous shaking at 200 RPM. The highest activity was found in the 40% ammonium sulfate precipitate, with high activity also remaining in the 50% and 60% ammonium sulfate precipitates. Moderate to high antimicrobial activity that is insensitive to proteases or heat treatment, was confirmed against pathogenic bacteria that included L. monocytogenes FSL – X1-0001 (strain 10403S), S. aureus L1 – 0030 and E. coli O157: H7. Further studies, including de novo sequencing of peptides by mass spectrometry, are in progress.

Antimicrobial activity of Commercial essential oils on human pathogens

2021 ◽  
pp. 4440-4444
Author(s):  
B. R. Malathy ◽  
Sweetlin Ajitha P ◽  
Sangeetha K. S ◽  
Swetha Thampy ◽  
Kamala G
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oils ◽  
Pathogenic Bacteria ◽  
Steam Distillation ◽  
Diffusion Method ◽  
Human Pathogens ◽  
Aromatic Plants ◽  
Zone Of Inhibition ◽  
E Coli ◽  
Development Of Resistance

Essential oils (EOs) are natural extracts from the seeds, stems, roots, flowers, bark and other parts of the plant prepared by steam distillation. They are complex, volatile, natural compounds formed by aromatic plants as secondary metabolites. They are known for their bactericidal, virucidal, fungicidal, sedative, anti-inflammatory, analgesic, spasmolytic and locally anesthetic properties. They are generally composed of a combination of substances like terpenes, phenolics, aldehydes or alcohols. The complex composition and different mechanisms of action of EOs may be an advantage over other antimicrobials to prevent the development of resistance of pathogenic bacteria. With this background, the aim of this study was to evaluate the antimicrobial activity of five essential oils like basil, lime, rosemary, thyme and canada balsam against 14 microbes. The effects of essential oil on the selected microbes were determined by agar well diffusion method. The zone of inhibition was observed and measured in millimeter. Essential oils which showed inhibitory diameter >15 mm were further tested to determine the minimum inhibitory concentration (MIC). S. aureus, E. coli, S. mutans, S. sanguinis, C. albicans and M. furfur were inhibited by all essential oils. K. pneumoniae, P. aeruginosa and E .faecalis were inhibited only by thyme and not by other essential oils. The MIC values ranged from 50% to 0.10%. The least MIC value of 0.10% was shown by thyme and basil to S. aureus, thyme to E.coli and all essential oils against C. albicans except lime.

scholarly journals Antibacterial Activity of Pediocin and Pediocin-Producing Bacteria Against Listeria monocytogenes in Meat Products

2021 ◽  
Vol 12 ◽  
Author(s):  
Nasim Khorshidian ◽  
Elham Khanniri ◽  
Mehrdad Mohammadi ◽  
Amir M. Mortazavian ◽  
Mojtaba Yousefi
Keyword(s):  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Meat Products ◽  
Low Molecular Weight ◽  
Potential Health ◽  
Gram Positive Bacteria ◽  
Chemical Preservatives ◽  
Safe Food ◽  
The One

One of the most important challenges in the food industry is to produce healthy and safe food products, and this could be achieved through various processes as well as the use of different additives, especially chemical preservatives. However, consumer awareness and concern about chemical preservatives have led researchers to focus on the use of natural antimicrobial compounds such as bacteriocins. Pediocins, which belong to subclass IIa of bacteriocin characterized as small unmodified peptides with a low molecular weight (2.7–17 kDa), are produced by some of the Pediococcus bacteria. Pediocin and pediocin-like bacteriocins exert a broad spectrum of antimicrobial activity against Gram-positive bacteria, especially against pathogenic bacteria, such as Listeria monocytogenes through formation of pores in the cytoplasmic membrane and cell membrane dysfunction. Pediocins are sensitive to most protease enzymes such as papain, pepsin, and trypsin; however, they keep their antimicrobial activity during heat treatment, at low temperatures even at −80°C, and after treatment with lipase, lysozyme, phospholipase C, DNase, or RNase. Due to the anti-listeria activity of pediocin on the one hand and the potential health hazards associated with consumption of meat products on the other hand, this review aimed to investigate the possible application of pediocin in preservation of meat and meat products against L. monocytogenes.

scholarly journals Highly Efficient Antimicrobial Activity of CuxFeyOz Nanoparticles against Important Human Pathogens

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2294
Author(s):  
Lu Zhu ◽  
David W. Pearson ◽  
Stéphane L. Benoit ◽  
Jing Xie ◽  
Jitendra Pant ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Synthesis Process ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Human Pathogens ◽  
Log Reduction ◽  
Highly Efficient ◽  
Short Period ◽  
Antimicrobial Material

The development of innovative antimicrobial materials is crucial in thwarting infectious diseases caused by microbes, as drug-resistant pathogens are increasing in both number and capacity to detoxify the antimicrobial drugs used today. An ideal antimicrobial material should inhibit a wide variety of bacteria in a short period of time, be less or not toxic to normal cells, and the fabrication or synthesis process should be cheap and easy. We report a one-step microwave-assisted hydrothermal synthesis of mixed composite CuxFeyOz (Fe2O3/Cu2O/CuO/CuFe2O) nanoparticles (NPs) as an excellent antimicrobial material. The 1 mg/mL CuxFeyOz NPs with the composition 36% CuFeO2, 28% Cu2O and 36% Fe2O3 have a general antimicrobial activity greater than 5 log reduction within 4 h against nine important human pathogenic bacteria (including drug-resistant bacteria as well as Gram-positive and Gram-negative strains). For example, they induced a >9 log reduction in Escherichia coli B viability after 15 min of incubation, and an ~8 log reduction in multidrug-resistant Klebsiella pneumoniae after 4 h incubation. Cytotoxicity tests against mouse fibroblast cells showed about 74% viability when exposed to 1 mg/mL CuxFeyOz NPs for 24 h, compared to the 20% viability for 1 mg/mL pure Cu2O NPs synthesized by the same method. These results show that the CuxFeyOz composite NPs are a highly efficient, low-toxicity and cheap antimicrobial material that has promising potential for applications in medical and food safety.

scholarly journals Antimicrobial Activity ofCroton macrostachyusStem Bark Extracts against Several Human Pathogenic Bacteria

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Jackie K. Obey ◽  
Atte von Wright ◽  
Jimmy Orjala ◽  
Jussi Kauhanen ◽  
Carina Tikkanen-Kaukanen
Keyword(s):  
Antimicrobial Activity ◽  
Ethyl Acetate ◽  
Pathogenic Bacteria ◽  
Ethyl Acetate Extract ◽  
Scientific Evidence ◽  
Enterobacter Aerogenes ◽  
Stem Bark ◽  
Human Pathogens ◽  
Zone Of Inhibition ◽  
Traditional Use

In Kenya, leaves and roots fromCroton macrostachyusare used as a traditional medicine for infectious diseases such as typhoid and measles, but reports on possible antimicrobial activity of stem bark do not exist. In this study, the antibacterial and antifungal effects of methanol, ethyl acetate and butanol extracts, and purified lupeol ofC. macrostachyusstem bark were determined against important human gram-negative pathogensEscherichia coli,Salmonella typhi,Klebsiella pneumoniae, andEnterobacter aerogenes, gram-positiveListeria monocytogenes,and a fungusCandida albicans. The most promising broad scale antimicrobial activity against all the studied pathogens was shown by the ethyl acetate extract. The ethyl acetate extract induced the zone of inhibition between10.1±0.6 mm and16.0±1.2 mm againstS. typhi,E. coli,K. pneumoniae,E. aerogenes,andL. monocytogeneswith weaker antimicrobial activity againstC. albicans(zone of inhibition:5.6±1.0 mm). The antibiotic controls (amoxicillin, ciprofloxacin, ampicillin, benzylpenicillin, clotrimazole, and cefotaxime) showed antimicrobial activity with zones of inhibition within13.4±0.7–22.1±0.9 mm. The ethyl acetate extract had MIC in the range of 125–250 mg/mL against all the studied bacteria and againstC. albicansMIC was 500 mg/mL. The present results give scientific evidence and support the traditional use ofC. macrostachyusstem bark as a source for antimicrobials. We show thatC. macrostachyusstem bark lupeol is a promising antimicrobial agent against several important human pathogens.

scholarly journals A Sequential Statistical Approach towards an Optimized Production of a Broad Spectrum Bacteriocin Substance from a Soil BacteriumBacillussp. YAS 1 Strain

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Amira M. Embaby ◽  
Yasmin Heshmat ◽  
Ahmed Hussein ◽  
Heba S. Marey
Keyword(s):  
Antimicrobial Activity ◽  
Staphylococcus Epidermidis ◽  
Statistical Approach ◽  
Wide Spectrum ◽  
Enterobacter Aerogenes ◽  
Lactobacillus Bulgaricus ◽  
Human Pathogens ◽  
Wide Range ◽  
Potential Applications

Bacteriocins, ribosomally synthesized antimicrobial peptides, display potential applications in agriculture, medicine, and industry. The present study highlights integral statistical optimization and partial characterization of a bacteriocin substance from a soil bacterium taxonomically affiliated asBacillussp. YAS 1 after biochemical and molecular identifications. A sequential statistical approach (Plackett-Burman and Box-Behnken) was employed to optimize bacteriocin (BAC YAS 1) production. Using optimal levels of three key determinants (yeast extract (0.48% (w/v), incubation time (62 hrs), and agitation speed (207 rpm)) in peptone yeast beef based production medium resulted in 1.6-fold enhancement in BAC YAS 1 level (470 AU/mL arbitrary units againstErwinia amylovora). BAC YAS 1 showed activity over a wide range of pH (1–13) and temperature (45–80°C). A wide spectrum antimicrobial activity of BAC YAS 1 against the human pathogens (Clostridium perfringens,Staphylococcus epidermidis,Campylobacter jejuni,Enterobacter aerogenes,Enterococcussp.,Proteussp.,Klebsiellasp., andSalmonella typhimurium), the plant pathogen (E. amylovora), and the food spoiler (Listeria innocua) was demonstrated. On top and above, BAC YAS 1 showed no antimicrobial activity towards lactic acid bacteria (Lactobacillus bulgaricus,L. casei,L. lactis, andL. reuteri). Promising characteristics of BAC YAS 1 prompt its commercialization for efficient utilization in several industries.

scholarly journals Antimicrobial Activity of Crude Extracts of Oldenlandia auricularia against Some Selected Human Pathogens

2019 ◽  
pp. 1-9
Author(s):  
W. M. D. Thisera ◽  
A. G. K. Neranja ◽  
R. M. P. S. Thilakarathne ◽  
K. D. K. P. Kumari
Keyword(s):  
Antimicrobial Activity ◽  
Microbial Activity ◽  
Pathogenic Bacteria ◽  
Negative Control ◽  
Maximum Activity ◽  
Shigella Dysenteriae ◽  
Diffusion Method ◽  
Dilution Method ◽  
Human Pathogens ◽  
Mic Value

Aims: Currently there is a high demand on novel anti-microbial agents derived from natural sources due to low cost and less adverse effects. The present study was designed to screen the anti-microbial activity of different extracts of Oldenlandia auricularia against common pathogenic bacteria and fungi.  Study Design: Experimental study. Place and Duration of Study: Department of Basic Sciences at Faculty of Allied Health Sciences and Research Laboratory at Faculty of Medicine, General Sir John Kotelawala Defence University, Ratmalana, Sri Lanka, between July 2018 and November 2018. Methodology: The aqueous, methanol, acetone and hexane extracts were prepared with the leaves, roots and stem of the plant Oldenlandia auricularia separately. The agar well diffusion method and broth macro dilution method were applied in order to screen the anti -microbial activity of each test extract against the Escherichia coli, Salmonella enterica, Shigella dysenteriae, Candida albicans and Staphylococcus aureus. Results: The zone of inhibition of most of the test extracts showed a significant (P =.05) difference, when compared with the negative control. The lowest MIC value for test extracts was 31.25 mg/ml, while the highest was 250 mg/ml. The acetone extract of the stem showed the lowest MIC value against E. coil. The highest anti-bacterial activity against S. enterica exerted by the root of the plant. All three tested parts of the plant were active against S. aureus and the maximum activity against C. albicans was shown by the leave extracts. The lowest MIC value against S. dysenteriae was 62.5 mg/ml, which indicated that the plants materials are less sensitive to the S. dysenteriae than the other tested pathogens. The results of the quantitative assay confirmed the results obtained from the qualitative assay. Conclusion: The different parts of Oldenlandia auricularia plant displayed potential antimicrobial activity against different pathogens.

Noticing and analysis of pedagogical practices in mathematics

2019 ◽  
Author(s):  
Yuri Morales López ◽  
Marianela Alpízar Vargas ◽  
Ana Lucía Alfaro Arce ◽  
Vicenç Font-Moll
Keyword(s):  
Classroom Management ◽  
Wide Spectrum ◽  
Math Education ◽  
Pedagogical Practices ◽  
Math Teachers ◽  
Education Activity ◽  
The One ◽  
Analysis Models ◽  
Teacher's Knowledge ◽  
Math Teacher

The purpose of this presentation is to show elements associated to the study and analysis of pedagogical practices used by mathematics teachers, taking into consideration different approaches and conceptions derived from theories related to the role of the math teacher. The project highlights the need to use different strategies to analyze the processes occurring in the activities and tasks organized and implemented by the teacher. One of the main tasks in teacher training is to promote the capacity to noticing on the pedagogical activity, where noticing is understood as an inherent process to improve the quality of classroom management. In addition, different analysis models should be compared using examples and experiential practices and the different theories and research projects developed in this field related to this type of analysis. Knowing what happens in the classroom is a task inherent to the math teacher. For sure, if the teacher does not understand or is even able to perceive what is happening in the class, improvement actions are very difficult to implement. Consequently, math teachers must develop the capability of analyzing their pedagogical activity and the related elements. It is not about isolating variables and looking for causal relationships, but rather about understanding the teacher’s activity as the center of the multiple situations occurring in the classroom, which may be known more in depth, if the attention is focused on the organization, ordering, and execution of the tasks planned by the teacher. It must also be understood that the competence of analyzing mentioned here is not an isolated activity without an effect. Such analysis must be approached from an active perspective where scenarios are generated to mitigate complex situations or to value an approach different than the one happening in the classroom. Being aware that there are many aspects to analyze (most likely almost everything that happens is analyzable), we must take a stand on which situations are highly related to what happens in our classroom and which could eventually happen. With such a wide spectrum, some questions that need to be addressed are: What is important in the math education activity and who defines what is important? What elements are of interest to math teachers? How does the analysis conducted relate to the different models of the teacher's knowledge? How does our previous experience influence the assessments we make? How do we distinguish elements of interest to analysis? What is the relationship between reflecting and analyzing? At what stages of the teacher’s activity is an analysis required? What is the ultimate purpose of analyzing teaching activities? What competencies or skills are related to the analysis? What types of analysis are appropriate (content, cognitive, media, among others)? How can we balance the actions derived from the analyses we conduct? From all these questions the most important one that can guide the study of this reflection would be: What should be assessed in pedagogical activities and what is the objective of analyzing such pedagogical activities in math education?

ANTIMICROBIAL ACTIVITIES OF METHANOL EXTRACT FROM UNIDENTIFIED SPONGE ASSOCIATED BACTERIA IN LEMUKUTAN ISLAND, KALIMANTAN BARAT

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar
Keyword(s):  
Antimicrobial Activity ◽  
Bacillus Subtilis ◽  
Pathogenic Bacteria ◽  
Methanol Extract ◽  
Agar Medium ◽  
Antimicrobial Activities ◽  
Antimicrobial Compounds ◽  
Associated Bacteria ◽  
Minimum Inhibitory Concentrations ◽  
Sponge Associated Bacteria

<p>The increase of issues on the antibiotics resistant pathogenic bacteria has triggered high exploration for new antimicrobial compounds. One of the potential sources is sponge-associated bacteria. The aim of this study was to get sponge-associated bacteria extract containing antimicrobial activities. On the basis screening of antimicrobial activity using by streaking on agar medium, there were two potential isolates with antimicrobial activities namely LCS1 and LCS2. The two isolates were cultivated,then secondary metabolite product were extracted using methanol as a solvent. Minimum inhibitory concentrations (MICs) of extract LCS 1 were 1,000 μg/well for S. aureus, 950 μg/well for Salmonella sp.and 800 μg/well for Bacillus subtilis. Minimum inhibitory concentrations of extract LCS 2 were 500 μg/well for S. aureus, 1,050 μg/well for Salmonella sp., 750 μg/well for Bacillus subtilis, 350 μg/well for P. aeruginosa, 750 μg/sumur terhadap B. subtilis. Based on the MIC values, the two assay extracts have a relatively low antimicrobial activity.</p> <p>Keywords:Antimicrobial,Sponges associated bacteria,MICs</p>

Study of Phosphocalcic Glasses from SiO2-CaO-P2O5 System with and Without Silver II. The bioactivity analysis by FTIR, SEM methods and microbiological study of silver-doped glasses

2017 ◽  
Vol 68 (6) ◽  
pp. 1188-1192
Author(s):  
Daniela Avram ◽  
Nicolae Angelescu ◽  
Dan Nicolae Ungureanu ◽  
Ionica Ionita ◽  
Iulian Bancuta ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Body Fluid ◽  
Pathogenic Bacteria ◽  
De Novo ◽  
Microbiological Examination ◽  
Doped Glasses ◽  
P2o5 System ◽  
Scanning Electron

The study in vitro of the glass powders bioactivity was performed by soaking them in simulated body fluid for 3 to 21 days at a temperature of 37�C and pH = 7.20. The synthesis de novo of hydroxyapatite, post soaking was confirmed by Fourier Transform Infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The study of the antimicrobial activity was performed by microbiological examination on two strains of pathogenic bacteria involved in postoperative nosocomial infections.

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