Showing 9 results for Lactobacillus
M Bonyadi, M Rahimi, M Nahai, M Akbari Dibavar, F Mirzaee,
Volume 4, Issue 2 (10-2010)
Abstract
Abstract
Bachground and objectives:
micro-organisms, usually made from strains of the genera
Probiotics are nonpathogenic and beneficialLactobacillus and
Bifidobacterium. The probiotics are known as dietary supplements withLactobacillus and
Bifidobacterium , in sufficient quantities and specific compound, are used for
Material and Methods:
obtained from dairy products, yogurt, grains cheese, saffron flower, fresh
pinto beans, red beans, fresh green beans . All samples were incubated in
MRS Agar cultures at 42, 37, and 25
isolated, concentrated, and lyophilized. Finally the differential recognition
was performed in deferential cultures.
In this cross-sectional study 100 Samples were°c for two days, and then bacteria were
Results
isolated. Lactobacillus delbrueki and L.bulgaris(each 10 cases)
(8 cases) and L .casei (5 cases) are the most prevalent Lactobacillus strains.
Lactococcus themrophilus the most frequent Lactococcus where isolated in
this study.
: Of 100 food samples 19 Lactobacillus and Lactococcus strains were، L.salivarius
Conclusion:
especially Lactobacillus strains are presented in foods. It is recommended that
these probiotics be isolated and proliferated and used in industry and also for
therapeutic purposes.
Based on the results of this study, many kinds of probiotics
Key words:
probiotic, Lactobacillus, foods
therapeutic purposes and food industry. The aim of this study was to evaluate
the frequency of Lactobacillus and Lactococcus strains in food stuffs cities in
Eastern Azerbaijan, Iran.
beneficial effects on consumer health. In some countries,
K Dorri, N Namdar, V Hemayatkhahjahromi,
Volume 7, Issue 1 (4-2013)
Abstract
Abstract
Background and objective: The effects of lactobacillus Species and their metabolites on dairy products were proved as probiotics on pathogenic bacteria. The aim of this study was to isolate the lactobacillus from dairy product (Yogurt, cheese, milk and whey …) and to determine the antimicrobial activity against some pathogenic bacteria (Salmonella typhimurium, E.coli, Helicobacter pylori.
Material and methods: Samples of dairy products were collected and were serially diluted in peptone medium. To isolate lactobacillus, diluted sample were plated on MRS Agar medium and incubated at 37ºc for 48-72h in anaerobic condition. Identification of the lactobacilli was performed according to their morphological, cultural, physiological and biochemical characteristics. The inhibitory effect of isolated lactobacillus strains were performed against pathogenic bacteria by Agar Well Diffusion Assay and Disc method.
Results: of 50 samples of isolated Lactobacillus from dairy products (including 11 identified Lactobacillus), 19 samples have inhibitory effect on pathogenic bacteria such as Salmonella typhimurium, Escherichia coli and Helicobacter pylori. The most identified strains areLactobacillusbulgaris, Lactobacillus Salivarius and Lactobacillus delbrueki.
Conclusion: According to this study, some lactobacillus strains isolated from dairy products are useful in the management of diarrhea and other gastrointestinal diseases, and the use of these strains can be useful for prevention and treatment.
Keywords:Lactobacillus, Dairyproducts, SalmonellaTyphimurium, E.coli, Helicobacter pylori
Mohammad Mohammaddoost Chakoosari, Mohammad Faezi Ghasemi, Alireza Masiha, Reza Kazemi Darsanaki, Abolfazl Amini,
Volume 9, Issue 5 (11-2015)
Abstract
Abstract
Background and Objective: Probiotics are living microorganisms that have beneficial effects on the health of digestive system. The aim of this study was to evaluate the antimicrobial ability of acidic and neutral supernatants (culture supernatant) of lactic acid bacteria against common bacterial pathogens.
Methods: Four species of lactic acid bacteria (Lactobacillus plantarum PTCC1745, Lactobacillus PTCC1608, Lactobacillus Saki PTCC1712 and Lactobacillus Lactis PTCC1336) were obtained from the microbial collection of Iranian Research Organization for Science and Technology in Lyophilized form. The antimicrobial activity of neutral and acidic supernatants against bacterial pathogens was investigated using the Disk and Well Diffusion Agar methods.
Results: Lactic acid bacteria showed good antimicrobial ability against six pathogenic bacteria with the highest inhibitory effect observed in Lactococcus lactis against E. coli PTCC1399 through well method with an average diameter of 14 mm inhibition zone. In this study, the well diffusion method was far more sensitive compared to the disk method and acidic supernatants showed higher antimicrobial efficiency compared to neutral types.
Conclusion: the Metabolites produced by lactic acid bacteria are able to inhibit the growth of pathogenic bacteria that can be an important and practical solution for the prevention and treatment of infections and ultimately improve human health.
Leila Goudarzi, Rouha Kasra Kermanshahi, Zahra Moosavi-Nejad,
Volume 10, Issue 2 (3-2016)
Abstract
ABSTRACT
Background and Objective: Lactic acid bacteria are Gram-positive, catalase-negative, nonsporulating, either rod- or coccus-shaped bacteria that have beneficial effects on their hosts by producing antimicrobial substances such as lactic acid, hydrogen peroxide, bacteriocins and biosurfactants. Bacteriocins are antimicrobial peptides that are produced by bacteria and can inhibit the growth of other bacteria.
Methods: In this experimental study, bacteriocin production by Lactobacilli as known probiotic strains was evaluated in different physicochemical conditions. Antagonistic activity was evaluated using quantitative method of Microscale Optical Density Assay (MODA). After neutralization of acid and treatment with various enzymes, temperature, pH and NaCl conditions, the antimicrobial activity of culture supernatant fluid of Lactobacillus acidophilus and L. plantarum was investigated against pathogenic Proteus.
Results: The culture supernatant fluid of Lactobacilli was sensitive to proteolytic enzymes with relatively good stability to temperature. The antimicrobial activity was also present due to production of bacteriocin under different NaCl conditions (1 to 4% NaCl) and pH range of 5 to 8.
Conclusion: It seems that the antimicrobial liquid of Lactobacillus strains contains bacteriocin, which shows antimicrobial effects against pathogenic strains of Proteus. To investigate further this effect, some complementary studies should be performed.
Hossein Naghili, Hossein Tajik, Mojtaba Raeisi, Hadi Ghasem Mahdi , Mehran Moradi, Majid Amin Zare, Touraj Mehdizadeh, Hasan Hasanzadazar , Fardin Hariri,
Volume 10, Issue 6 (11-2016)
Abstract
ABSTRACT
Background and Objective: Several studies have
shown the antimicrobial activity of lactobacilli against Salmonella enterica (serotype typhimurium). The aim of this study was to evaluate the inhibitory potential of metabolites produced by probiotic culture of Lactobacillus casei against S. typhimurium and its impact on S. typhimurium motility and biofilm formation.
Methods: In order to evaluate the impact of the metabolites, L. casei cell-free culture supernatant (CFCS) was collected by centrifugation of L. casei secondary cultures. Effectiveness of the CFCS against Salmonella was evaluated by the well-diffusion method. In addition, in vitro effect of this treatment on motility in Swarm agar and biofilm formation by the bacteria was investigated.
Results: Inhibition zone diameters of S. typhimurium were 0.83 and 12.1 mm at concentrations of 50 and 100 μl of Lactobacillus CFCS against the log4 of S. typhimurium, respectively. Moreover, CFCS treatment inhibited the motility and biofilm formation by Salmonella. Concentrations of 5% and 10% were determined as the minimum inhibitory concentrations for motility and biofilm formation by S. typhimurium. Furthermore, effectiveness of the CFCS against Salmonella was dose-dependent (P<0.05).
Conclusion: L. casei CFCS is able to inhibit the growth, motility and biofilm formation in S. typhimurium.
Keywords: Anti-Bacterial, Lactobacillus Casei Metabolites, Phenotypic Characteristics of S. typhimurium
Kazem Maftuni , Peyman Zare ,
Volume 11, Issue 5 (9-2017)
Abstract
ABSTRACT
Background and objective: Considering the toxic side effects of chemotherapy in treatment of cancer, anticancer drugs of natural origin including probiotic Lactobacillus strains have recently attracted a lot of attention.
Methods: After culturing chronic myeloid leukemia cell line K562 in 96-well plates, effects of different concentrations of culture supernatant from Lactobacillus casei on differentiation of the cells were investigated after 48 and 72 hours under an inverted microscope. Number of live cells and percentage of viable cells were determined by trypan blue exclusion test of cell viability. Cytotoxicity was assessed by MTT assay. Data analysis was performed by SPSS (version) 22 using one-way analysis of variance and Tukey's test at significance level of 0.05.
Results: Secondary metabolites from the probiotic bacteria L. casei induced cellular differentiation, exerted anti-cancer effects and inhibited growth in K562 cells. Apoptotic cell death was confirmed by MTT and DNA fragmentation assays in a way that increasing the dilution from 1.2 to 1.32 significantly increased the viability of cells (P=0.001). In addition, increasing the dilution significantly increased the number of live cells in the first 48 hours (P=0.001).
Conclusion: Culture supernatant of L. casei reduces the number of live cells, and induces apoptosis and monocytic differentiation in K562 cells in a dose- and time-dependent manner. Therefore, combined chemotherapy and differentiation therapy using such supernatants could be useful for treatment of cancer.
Keywords: Cell differentiation, K562 cell line, Probiotic, Lactobacillus casei.
Hamidreza Ebrahimnezhad, Leila Barzegar, Davoud Esmaeili,
Volume 14, Issue 1 (1-2020)
Abstract
ABSTRACT
Background and Objectives: Probiotics are live microorganisms that function through various mechanisms and affect the alteration of the commensal microbiota against pathogens. Nowadays, given the problems associated with antibiotics use, probiotic strains offer a novel and appropriate alternative for the treatment of diseases such as diarrhea. The aim of this study was to investigate the antibacterial synergism of Lactobacillus spp., Bifidobacterium spp. and Escherichia coli strain Nissle 1917 (ECN) on the clinical sample of diarrheagenic E.coli and Campylobacter jejuni.
Methods: A paper disk-diffusion technique was used to evaluate the antibacterial activity. Sterile 6 mm paper disks were saturated with probiotic suspensions made by settling probiotic medications into distilled water. Three kinds of disk were prepared. One disk was prepared for Lactobacillus spp. and Bifidobacterium spp., another for ECN, and the third was made by combined probiotics. Clinical samples of diarrheagenic E.coli and Campylobacter jejuni were cultivated on Muller Hinton agars, and disks were placed on the inoculated Muller Hinton agars. All plates were incubated under microaerophilic and appropriate conditions.
Results: The zone of inhibition (ZOI) of the bacterial growth was measured. All pathogenic microorganisms showed sensitivity to the probiotic disks. The combined disks had better effects against pathogens compared with single disks.
Conclusion: A considerable synergistic effect was observed in the results of combined probiotics; therefore, combined strains can be more efficient against intestinal pathogens in comparison with single probiotics.
Keywords: Probiotic, Lactobacillus, Bifidobacterium, Escherichia coli Nissle, Diarrhea, Campylobacter jejun.i.
Saba Bahrevar, Amir Abbas Barzegari, Shiva Khezri, Vahid Nejati,
Volume 15, Issue 5 (9-2021)
Abstract
Background and objectives: Safety is a key criterion for assessment of probiotics. The objective of this study was to evaluate safety of a new Iranian Lactobacillus paracasei IBRC-M 11110 strain as a candidate probiotic.
Methods: Eighteen male and 18 female Wistar rats were divided into two experimental and a control group. The experimental groups received the bacterium at two doses of 6 × 108 CFU/day and 6× 109 CFU/day for 28 days through oral gavage. The control groups received normal saline. On day 29, blood, serum and tissue samples were taken for analysis.
Results: Administration of the bacterium did not affect the general health and body weight of the rats during the study period. No significant change was observed in the blood parameters of rats in the experimental groups except for a significant decrease in mean corpuscular volume and mean corpuscular hemoglobin of male rats. Serum analysis showed a significant increase in the alanine transaminase and a significant decrease in aspartate transaminase in the experimental groups of male and female rats, respectively. In both male and female rats, a significant decrease in urea and a significant increase in creatinine were observed in the experimental groups. However, the above parameters were all within the normal range. Histopathological analysis of liver and kidney tissues also showed no abnormality.
Conclusion: The results confirm that L. paracasei IBRC-M 11110 was safe in the subacute toxicity test in Wistar rats.
Mahnoosh Fatemi, Fereshte Ghandehari , Danial Salehi, Parastoo Torabian,
Volume 17, Issue 6 (11-2023)
Abstract
Background: Discovering new cytotoxic compounds has received significant attention due to the rise in drug resistance and the adverse effects associated with chemotherapy drugs. In this study, the cytoplasmic extract of Lactobacillus casei was used to produce iron oxide nanoparticles (Fe2o3 NPs), and the cytotoxic effects of NPs were investigated on MCF-7 and human embryonic kidney 293 (HEK-293) cells.
Methods: The cytoplasmic extract of L. casei was mixed with 103M iron sulfate solution and incubated for 3 weeks at 37 °C and 5% CO2. The coprecipitation method was used to synthesize chemical Fe2o3 NPs. The synthesis of NPs was studied by electron microscopy and X-ray diffraction (XRD) analysis, and the cytotoxic effects were evaluated with dilutions (10, 100, and 1000 µg/mL) on MCF-7 and HEK cells.
Results: X-ray diffraction analysis and scanning electron microscopy presented the mean of NPs synthesized by the green method to be about 15 nm and their shape to be spherical, as well as the average of chemically synthesized NPs to be about 20 nm with cubic structure. Chemical and green synthesized NPs only at a concentration of 1000 µg/mL were able to significantly reduce the survival rate of normal HEK-293 cells; chemically synthesized NPs decreased MCF-7 cell survival only at 1000 µg/mL and green synthesis at 100 µg/mL and 1000 µg/mL.
Conclusion: Generating Fe2o3 NPs is biologically safe using the green synthesis method and the cytoplasmic extract of L. casei, which may be a suitable candidate for the treatment of cancer cells.
