Antibacterial Bioactivity of Selected Lactic Acid Bacterial Strains against some Human Pathogenic Bacteria

2015 ◽  
Vol 11 (5) ◽  
pp. 440-447 ◽  
Author(s):  
Islam Nour ◽  
Faiza Fattouh ◽  
Hala El-Adawi
Keyword(s):  
Lactic Acid ◽  
Pathogenic Bacteria ◽  
Bacterial Strains ◽  
Human Pathogenic Bacteria

Antimicrobial Effect of Brazillian Propolis/Polycaprolactone Polymer on some Human Pathogenic Bacteria

2012 ◽  
Vol 506 ◽  
pp. 537-540 ◽  
Author(s):  
S. Sanpa ◽  
Krit Sutjarittangtham ◽  
Tawee Tunkasiri ◽  
Sukum Eitssayeam ◽  
P. Chantawannakul
Keyword(s):  
Pathogenic Bacteria ◽  
Antimicrobial Effect ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Electrospinning Technique ◽  
Propolis Extract ◽  
Human Pathogenic Bacteria ◽  
Polymer Nanofiber ◽  
History Of Use

The antimicrobial activities of propolis against some bacterial strains have been studied. However, there are few reports on biopolymers from propolis. Polycaprolactone (PCL) is a biodegradable polymer that has a long history of use in the biomedical field. In this work, the polymer nanofiber was grown from a Brazillian propolis extract solution on PCL using an electrospinning technique. Antimicrobial activities were investigated by the disc diffusion method. The propolis extract and polymer nanofiber could inhibit some human pathogenic bacteria. In addition, the inhibitory effects on tested microorganism depended on the concentration of propolis extract mixed with the polymer nanofiber. Such properties of the propolis/PCL nanofiners can be further developed for biomedical applications.

scholarly journals Antagonistic action of Lactobacillus spp. against Staphylococcus aureus in cheese from Mompox - Colombia

2015 ◽  
Vol 68 (2) ◽  
pp. 7721-7727
Author(s):  
Piedad M. Montero Castillo ◽  
Antonio Díaz Caballero ◽  
Marlene Durán Lengua
Keyword(s):  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Pathogenic Bacteria ◽  
Antagonistic Activity ◽  
Food Preservation ◽  
Pathogenic Microorganisms ◽  
Bacterial Strains ◽  
Antagonistic Action ◽  
As Species ◽  
Chemical Products

In the food industry, food preservation techniques that do not use chemical products are becoming more common. Therefore, the aim of this research was to evaluate the antagonistic activity (antibiosis) of lactic-acid bacterial strains against pathogenic microorganisms. Lactic-acid bacterial strains were isolated from layered cheese and a commercial product (yogurt); and the same was done with pathogenic bacteria solely from layered cheese. The lactic-acid bacterial strains were identified as species from the Lactobacilli family, while the pathogenic bacteria from layered cheese were identified as Micrococcaceae family species (Staphylococcus aureus). Subsequently, in the same culture medium, bacteria of each species were sowed in order to determine the inhibitory activity ability of the Lactic Acid Bacteria (BAL) As a result, the highly antagonistic activity of the Lactobacilli (inhibition halos were larger than 0.5 centimeters in diameter) against isolated pathogenic microorganisms was demonstrated.

scholarly journals In Vitro Assessment for Antimicrobial Activity of Lactobacillus Helveticus and its Natural Glycopeptides Against Mastitis Causing Pathogens in Dairy Cat

2015 ◽  
Vol 9 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Gundega Gulbe ◽  
Anda Valdovska ◽  
Vaira Saulite ◽  
Jevgenijs Jermolajevs
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Pathogenic Bacteria ◽  
Antimicrobial Effect ◽  
Lactobacillus Helveticus ◽  
Haemolytic Activity ◽  
Pathogenic Microorganisms ◽  
Bacterial Strains ◽  
Coagulase Negative Staphylococci

Probiotic lactic acid bacteria have a great potential to control bovine mastitis as well as they are favourable choice to treat many infectious diseases of human. These bacteria are well known as having many properties which make them beneficial to control pathogenic microorganisms. These include, the ability to adhere to cell, the reduction of pathogenic bacteria adherents, the co–aggregation, the production of organic acids, hydrogen peroxide, bacteriocin and etc., to be safe and non–pathogenic, which antagonize pathogenic microorganisms. However, each strain must be well identified and characterized in vitro before using for disease treatment. The aim of the present study was to screen three kind of test suspensions: TS1, TS2 and TS3, which contains probiotic lactic acid bacterium Lactobacillus helveticus or its natural glycopeptides, and other natural immunomodulators, in order to investigate which content were the most effective in inhibiting several mastitis causing bacteria in dairy cattle: coagulase–positive Staphylococcus aureus, coagulase–negative staphylococci S. haemolyticus, S. saprophyticus, S. simulans, S. vitulinus, and Gram–negative bacteria Citrobacter freundii and Serratia liquefaciens. Test suspensions TS1, TS2 and TS3 were adjusted by pH 6.3, then tested in vitro by well diffusion assay to determine their antimicrobial effect against bacteria. Furthermore haemolytic activity of applied test suspensions were determined. In results TS1 (9-13 mm) and TS2 (10-15 mm) showed the inhibition effect on four of eight tested bacterial strains, whereas TS3 did not displayed any antimicrobial effect. TS2 have a greatest antimicrobial activity as they resulted in the largest inhibition zones.

scholarly journals EVALUATION OF DIFFERENT PROTEIN PRECIPITATES OF A WILD MUSHROOM, GANODERMA LUCIDUM FOR ANTIBACTERIAL ACTIVITIES AGAINST HUMAN PATHOGENIC BACTERIA

2019 ◽  
pp. 303-307
Author(s):  
SUNDARAMOORTHY MARIMUTHU ◽  
SABARIMANIKANDAN MAHENDRAN
Keyword(s):  
Ganoderma Lucidum ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Protein Quantification ◽  
Drug Candidate ◽  
Acid Extract ◽  
Bacterial Strains ◽  
Active Protein ◽  
Human Pathogenic Bacteria ◽  
Test Organisms

Objective: The objective of the present study was to isolate different antibacterial protein precipitates from Ganoderma lucidum against human pathogenic bacteria and to evaluate suitable precipitating agent. Methods: The acid extract was prepared from the aqueous solution of the test mushroom. From separate aliquots of acid extract, antibacterial proteins were precipitated using five different concentrations (10–50%) of ammonium sulfate solutions, 10% trichloroacetic acid (TCA), 80% ethanol and methanol – Chloroform mixture (2:1 ratio). Protein quantification was performed in each stage of purifications. The as-prepared protein precipitates were subjected for antibacterial and hemolytic assays for identification of the active protein precipitate, which in turn was also checked for minimum inhibitory volume (MIV) for all test organisms. Results: The quantity of each protein precipitated by different protein precipitating agents from the acid extract of the test mushroom was found in the range of 2.3–4.8 mg/g wet.wt. Although all the precipitates showed different levels of antibacterial capacities, 10% TCA precipitate was considered as active protein as it yielded the maximum amount of protein (4.8 mg/g.wet.wt) as well as it exhibited burly bactericidal activities at lower volumes of protein solutions subjected (6.3 and 3.2 μl) on all bacterial strains tested with less hemolytic effects. Conclusion: The protein precipitated by 10% TCA from the acid extract of the test mushroom could be developed as a drug candidate for treating infectious diseases caused by pathogenic microbes in human.

scholarly journals Modelling antagonic effect of lactic acid eacteria supernatants on some pathogenic bacteria

2009 ◽  
Vol 52 (spe) ◽  
pp. 29-36 ◽  
Author(s):  
Augustus Caeser Franke Portella ◽  
Susan Karp ◽  
Gessiel Newton Scheidt ◽  
Adenise Lorenci Woiciechwski ◽  
Jose Luis Parada ◽  
...  
Keyword(s):  
Survival Analysis ◽  
Lactic Acid ◽  
Pathogenic Bacteria ◽  
Lactobacillus Rhamnosus ◽  
Growth Failure ◽  
Bacterial Strains ◽  
Predictive Tool ◽  
Lactobacillus Sake ◽  
Kaplan Meier ◽  
Culture Growth

This work presents a statistical model of survival analysis for three pathogenic bacterial strains (Escherichia coli, Listeria monocytogenes and Staphylococcus aureus), when treated with neutralized and non-neutralized filtered supernatants broth from cultures of Lactobacillus acidhophilus, Lactobacillus rhamnosus and Lactobacillus sake. Survival analysis is a method employed to determine the period of time from an initial stage up to the occurrence of a particular event of interest, as death or a particular culture growth failure. In order to evaluate the potential efficacy of the ahead mentioned lactic acid bacteria when used as bioprotective starters in foods, experimental data were statistically treated and expressed by simple representative curves. Following the methodology of Cox and Kaplan-Meier, it was possible to make the selection of the best bioprotective lactic starter, as a predictive tool for evaluation of shelf life and prevention of eventual risks in fresh sausages and other similar food products.

scholarly journals ISOLATION AND CHARACTERIZATION OF UNIQUE FRUCTOPHILIC LACTIC ACID BACTERIA FROM DIFFERENT FLOWER SOURCES.

2020 ◽  
Vol 51 (2) ◽  
pp. 508-518
Author(s):  
G. M. Saleh
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Enterococcus Faecium ◽  
Pathogenic Bacteria ◽  
Lactobacillus Brevis ◽  
Nerium Oleander ◽  
Dual Culture ◽  
Bacterial Strains ◽  
Convolvulus Arvensis ◽  
Isolation And Characterization

This study was aimed to investigate Lactic acid bacteria (LAB) that contain an important group of bacterial strains such as fructophilic lactic acid bacteria that usually isolated from fructose rich niches. These groups of bacteria have been considered as probiotics, especially in animal applications. In this study these bacteria were isolated from 6  Plant sources (flowers) such as: Convolvulus arvensis, Hibiscus rosa-sinensis , Nerium oleander, Rosa rugosa, Tagetes erecta and Zinnia elegans. The bacterial isolates were identified by morphological and molecular methods through the detection of 16SrRNA gene. Carbohydrate fermentation profile as well as their antibacterial activity using the dual culture overlay assay was also detected. The results revealed that 5 types of different lactic acid bacteria were isolated included: Fructobacillus fructosus, Lactobacillus kunkeei, Enterococcus durans, Enterococcus faecium , and  Lactobacillus brevis. These isolates showed variety in fermentation of carbohydrates. Also, all isolates exhibit inhibition effect against pathogenic bacteria (Staphylococcus auresو Pseudomonas aeruginosa) except Enterococcus faecium which showed no effect it.

scholarly journals Dual Transcriptomic Analysis Reveals Metabolic Changes Associated with Differential Persistence of Human Pathogenic Bacteria in Leaves of Arabidopsis and Lettuce

2021 ◽  
Author(s):  
Cristián Jacob ◽  
André C Velásquez ◽  
Nikhil A Josh ◽  
Matthew Settles ◽  
Sheng Yang He ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Bacterial Pathogen ◽  
Disease Outbreaks ◽  
Post Inoculation ◽  
Sequencing Analysis ◽  
Bacterial Strains ◽  
Plant Host ◽  
Human Pathogenic Bacteria ◽  
Serovar Typhimurium ◽  
Model Plant Arabidopsis Thaliana

Abstract Understanding the molecular determinants underlying the interaction between the leaf and human pathogenic bacteria is key to provide the foundation to develop science-based strategies to prevent or decrease the pathogen contamination of leafy greens. In this study, we conducted a dual RNA-sequencing analysis to simultaneously define changes in the transcriptomic profiles of the plant and the bacterium when they come in contact. We used an economically relevant vegetable crop, lettuce (Lactuca sativa L. cultivar Salinas), and a model plant, Arabidopsis thaliana Col-0, as well as two pathogenic bacterial strains that cause disease outbreaks associated with fresh produce, Escherichia coli O157: H7 and Salmonella enterica serovar Typhimurium 14028 s (STm 14028 s). We observed commonalities and specificities in the modulation of biological processes between Arabidopsis and lettuce and between O157: H7 and STm 14028 s during early stages of the interaction. We detected a larger alteration of gene expression at the whole transcriptome level in lettuce and Arabidopsis at 24 hours post inoculation with STm 14028 s compared to that with O157: H7. In addition, bacterial transcriptomic adjustments were substantially larger in Arabidopsis than in lettuce. Bacterial transcriptome was affected at a larger extent in the first 4 hours compared to the subsequent 20 hours after inoculation. Overall, we gained valuable knowledge about the responses and counter-responses of both bacterial pathogen and plant host when these bacteria are residing in the leaf intercellular space. These findings and the public genomic resources generated in this study are valuable for additional data mining.

scholarly journals Expression of Genes Involved in Bacteriocin Production and Self-Resistance inLactobacillus brevis174A Is Mediated by Two Regulatory Proteins

2018 ◽  
Vol 84 (7) ◽  
Author(s):  
Masafumi Noda ◽  
Rumi Miyauchi ◽  
Narandalai Danshiitsoodol ◽  
Yasuyuki Matoba ◽  
Takanori Kumagai ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Gene Cluster ◽  
Cellular Response ◽  
Pathogenic Bacteria ◽  
Response Regulator ◽  
Lactobacillus Brevis ◽  
Regulatory Proteins ◽  
Bacterial Strains ◽  
Content Type ◽  
Transcriptional Regulatory

ABSTRACTWe have previously shown that the lactic acid bacteriumLactobacillus brevis174A, isolated fromCitrus iyofruit, produces a bacteriocin designated brevicin 174A, which is comprised of two antibacterial polypeptides (designated brevicins 174A-β and 174A-γ). We have also found a gene cluster, composed of eight open reading frames (ORFs), that contains genes for the biosynthesis of brevicin 174A, self-resistance to its own bacteriocin, and two transcriptional regulatory proteins. Some lactic acid bacterial strains have a system to start the production of bacteriocin at an adequate stage of growth. Generally, the system consists of a membrane-bound histidine protein kinase (HPK) that senses a specific environmental stimulus and a corresponding response regulator (RR) that mediates the cellular response. We have previously shown that although the HPK- and RR-encoding genes are not found on the brevicin 174A biosynthetic gene cluster in the 174A strain, two putative regulatory genes, designatedbreDandbreG, are in the gene cluster. In the present study, we demonstrate that the expression of brevicin 174A production and self-resistance is positively controlled by two transcriptional regulatory proteins, designated BreD and BreG. BreD is expressed together with BreE as the self-resistance determinant ofL. brevis174A. DNase I footprinting analysis and a promoter assay demonstrated that BreD binds to thebreEDpromoter as a positive autoregulator. The present study also demonstrates that BreG, carrying a transmembrane domain, binds to the common promoter ofbreBandbreC, encoding brevicins 174A-β and 174A-γ, respectively, for positive regulation.IMPORTANCEThe problem of the appearance of bacteria that are resistant to practical antibiotics and the increasing demand for safe foods have increased interest in replacing conventional antibiotics with bacteriocin produced by the lactic acid bacteria. This antibacterial substance can inhibit the growth of pathogenic bacteria without side effects on the human body. The bacteriocin that is produced by aCitrus iyo-derivedLactobacillus brevisstrain inhibits the growth of pathogenic bacteria such asListeria monocytogenes,Staphylococcus aureus, andStreptococcus mutans. In general, lactic acid bacterial strains have a system to start the production of bacteriocin at an adequate stage of growth, which is called a quorum-sensing system. The system consists of a membrane-bound histidine protein kinase that senses a specific environmental stimulus and a corresponding response regulator that mediates the cellular response. The present study demonstrates that the expression of the genes encoding bacteriocin biosynthesis and the self-resistance determinant is positively controlled by two transcriptional regulatory proteins.

scholarly journals Antibiotic resistance patterns of bacterial strains isolated from Periplaneta americana and Musca domestica in Tangier, Morocco

2010 ◽  
Vol 4 (04) ◽  
pp. 194-201 ◽  
Author(s):  
Lamiaa Bouamamaa ◽  
Antonio Sorlozano ◽  
Amin Laglaoui ◽  
Mariam Lebbadi ◽  
Ahmed Aarab ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Musca Domestica ◽  
Pathogenic Bacteria ◽  
Periplaneta Americana ◽  
Human Beings ◽  
Residential Areas ◽  
Bacterial Strains ◽  
Human Pathogenic Bacteria ◽  
Enterococcus Spp ◽  
Staphylococcus Spp

Background:  Flies and cockroaches are two insects in close contact with human beings. They are carriers of human pathogenic bacteria on the external areas of their bodies or in their digestive tracts. This study examines Periplaneta americana and Musca domestica collected from the residential areas of six districts in Tangier, Morocco. Methodology: In total, 251 bacteria were isolated from external areas of the participants' bodies and the antimicrobial susceptibility was calculated. Results: The predominant bacterial species included Escherichia coli (17.9%), Klebsiella spp. (14.7%), Providencia spp. (9.6%), Staphylococcus spp. (15.1%) and Enterococcus spp. (11.6%). The study showed no difference between the species of bacterial strains from American cockroaches and houseflies. Carbapenems and aminoglycosides were active against 100% of the Gram-negative bacilli isolated in this study. Staphylococcus spp. strains were susceptible to linezolid, vancomycin, daptomycin, levofloxacin and cotrimoxazole, and no antibiotic resistance was found in Enterococcus spp. Conclusions: In our setting, although both cockroaches and flies collected from residential areas may be vectors of human pathogenic bacteria, the infections caused by them are easily treatable as a result of the high susceptibility of their bacteria to antibiotics routinely used in the community or in hospitals.

scholarly journals Adhesive and hydrophobic properties of the selected LAB isolated from gastrointestinal tract of farming animals.

2016 ◽  
Vol 63 (2) ◽  
Author(s):  
Katarzyna Grajek ◽  
Anna Sip ◽  
Joanna Foksowicz-Flaczyk ◽  
Anna Dobrowolska ◽  
Agnieszka Wita
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Lactic Acid ◽  
Gastrointestinal Tract ◽  
Lactic Acid Bacteria ◽  
Clostridium Perfringens ◽  
Pathogenic Bacteria ◽  
Bacterial Strains ◽  
Hydrophobic Properties ◽  
Adhesion Ability

The aim of this study was to determine the degree of adhesion and hydrophobicity of some strains of lactic acid bacteria (LAB) with proven antagonistic properties against pathogenic bacteria. Studies were performed using-LAB strains isolated from the gastrointestinal tract of calves and piglets. These strains exhibited an antibacterial activity against pathogenic strains of Clostridium perfringens and Escherichia coli. Cell adhesiveness was examined in relation to the porcine and bovine mucin. Our analyses had shown that the tested microorganisms demonstrated a degree of adhesion in the range of 32.00-40.00% for strains isolated from calves, and 34.00-40.00% for strains isolated from pigs. The hydrophobicity of tested bacteria was in the range of 31.00%-44.00% for strains isolated from pigs, and 26.00%-42.00% for strains obtained from calves. The best mucin adhesion ability was found for bacterial strains belonging to the Enterococcus genus isolated from calves. Taking into account porcine isolates, the best adhesion was observed for the Leuconostoc bacterial strains. Among tested strains, the highest hydrophobicity, measured in relation to hexadecane, was recorded for the bacterial strains belonging to the Leuconostoc sp. isolated from piglets and a of Lactobacillus sp. bacterial strain isolated from calves.

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