Isolation and identification of halophilic and halotolerant bacteria from the sediments of the Qeshm Island mangrove forest

Due to specific environmental and ecological conditions, mangrove forests are known as marine transitional zones between sea and land, and, as such, they host organisms with high ecological plasticity. The mangrove forests of Qeshm Island (Iran) are relatively pristine habitats and represent an ideal target for investigating patterns of either aquatic or benthic biodiversity. To provide insights on microbial diversity in this area, nineteen halophilic and halotolerant bacteria were isolated from the sediments in 2017 during low tide. The extracted bacterial strains were studied morphologically by streaking, initial observation of colonies and bacterial staining, and characterized using a battery of biochemical tests including KOH, MR, VP, urease, TSI, S/I/M, Mac, LIA, ODC, ADH, oxidase, catalase, and tryptophan deaminase. The optimum growth of halophilic bacteria was observed in salt concentrations from 5 to 20% NaCl, whereas the extreme halophilic Gram-positive strain grew in salt concentration of up to 30% NaCl. Molecular analyses were also carried out on four halophilic strains and one extreme halophilic gram-positive bacteria. Phylogenetic taxonomy analysis, after 16S rDNA gene Sanger sequencing, revealed that the halophilic bacteria were closely related to the strain types of the genus Bacillus including Bacillus licheniformis, Bacillus velezensis, Bacillus Paralicheniformis and Bacillus sp. with 99% bootstrap value. The extreme halophilic strain was associated to strains of Planococcus plakortidis with 100% bootstrap value.

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Antibacterial activity of Baccharis trimera (Less.) DC. (carqueja) against bacteria of medical interest

Revista CERES ◽

10.1590/s0034-737x2013000500019 ◽

2013 ◽

Vol 60 (5) ◽

pp. 731-734 ◽

Cited By ~ 4

Author(s):

Álan Alex Aleixo ◽

Karina Marjorie Silva Herrera ◽

Rosy Iara Maciel de Azambuja Ribeiro ◽

Luciana Alves Rodrigues dos Santos Lima ◽

Jaqueline Maria Siqueira Ferreira

Keyword(s):

Antibacterial Activity ◽

Folk Medicine ◽

Salmonella Typhi ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Clinical Interest ◽

Antibacterial Susceptibility ◽

Baccharis Trimera ◽

Medical Interest

Baccharis trimera (Less.) (Asteraceae), popularly know as "carqueja", is a species commonly used in folk medicine for the treatment or prevention of diseases. In this context, the purpose of this work was to study the antibacterial activity of crude hydroalcoholic extract from Baccharis trimera against Gram-positive bacterial strains (Staphylococcus aureus ATCC 29213, Staphylococcus saprophyticus ATCC 15305, Staphylococcus epidermidis ATCC 12228, Enterococcus faecalis ATCC 19433) and Gram-negative bacteria (Escherichia coli EHEC ATCC 43895, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 27736, Salmonella typhi ATCC 19430) of clinical interest. Antibacterial susceptibility was evaluated by broth microdilution assay following the CLSI (formerly the NCCLS) guidelines. The extract from B. trimera showed antibacterial activity against Gram-positive bacteria and the most interesting result was obtained against S. epidermidis that presented Minimal Inhibitory Concentration of 250μg/mL. These results indicate that B. trimera have bacterisostatic potential against Gram-positive bacterial strains of medical interest and could serve as a base for further studies on the use of isolated compounds from this species as future antimicrobials.

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Purification of Bioactive Peptide with Antimicrobial Properties Produced by Saccharomyces cerevisiae

Foods ◽

10.3390/foods9030324 ◽

2020 ◽

Vol 9 (3) ◽

pp. 324 ◽

Cited By ~ 2

Author(s):

Shayma Thyab Gddoa Al-sahlany ◽

Ammar Altemimi ◽

Alaa Al-Manhel ◽

Alaa Niamah ◽

Naoufal Lakhssassi ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Antimicrobial Properties ◽

Antibacterial Peptide ◽

Inhibition Activity ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Viable Cells ◽

Ph Range

A variety of organisms produce bioactive peptides that express inhibition activity against other organisms. Saccharomyces cerevisiae is considered the best example of a unicellular organism that is useful for studying peptide production. In this study, an antibacterial peptide was produced and isolated from Saccharomyces cerevisiae (Baker’s yeast) by an ultrafiltration process (two membranes with cut-offs of 2 and 10 kDa) and purified using the ÄKTA Pure 25 system. Antibacterial peptide activity was characterized and examined against four bacterial strains including Gram-positive and Gram-negative bacteria. The optimum condition for yeast growth and antibacterial peptide production against both Escherichia. coli and Klebsiella aerogenes was 25–30 °C within a 48 h period. The isolated peptide had a molecular weight of 9770 Da, was thermostable at 50–90 °C for 30 min, and tolerated a pH range of 5–7 at 4 °C and 25 °C during the first 24 h, making this isolated antibacterial peptides suitable for use in sterilization and thermal processes, which are very important aspect in food production. The isolated antibacterial peptide caused a rapid and steady decline in the number of viable cells from 2 to 2.3 log units of gram-negative strains and from 1.5 to 1.8 log units of gram-positive strains during 24 h of incubation. The isolated antibacterial peptide from Saccharomyces cerevisiae may present a potential biopreservative compound in the food industry exhibiting inhibition activity against gram-negative and gram-positive bacteria.

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Innate Immune Responses of Human Neonatal Cells to Bacteria from the Normal Gastrointestinal Flora

Infection and Immunity ◽

10.1128/iai.70.12.6688-6696.2002 ◽

2002 ◽

Vol 70 (12) ◽

pp. 6688-6696 ◽

Cited By ~ 145

Author(s):

Helen Karlsson ◽

Christina Hessle ◽

Anna Rudin

Keyword(s):

Immune System ◽

Mononuclear Cells ◽

Innate Immune ◽

Enzyme Linked Immunosorbent Assay ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Tnf Α ◽

Adult Cells

ABSTRACT The hygiene hypothesis postulates that the prevalence of allergy has increased due to decreased microbial stimulation early in life, leading to delayed maturation of the immune system. The aim of this study was to examine the cytokine pattern produced from cord blood mononuclear cells relative to adult cells after stimulation with bacterial strains from the normal flora. Mononuclear cells from cord and adult blood samples were stimulated with the following bacteria: Bifidobacterium adolescentis, Enterococcus faecalis, Lactobacillus plantarum, Streptococcus mitis, Corynebacterium minutissimum, Clostridium perfringens, Bacteroides vulgatus, Escherichia coli, Pseudomonas aeruginosa, Veillonella parvula, and Neisseria sicca. The levels of interleukin 12 (IL-12), tumor necrosis factor alpha (TNF-α), IL-10, and IL-6 were measured by enzyme-linked immunosorbent assay. The TNF-α production was also analyzed after blocking CD14, Toll-like receptor 2 (TLR-2), and TLR-4 prior to stimulation with bacteria. The levels of IL-12 and TNF-α were similar in cord and adult cells. Gram-positive bacteria induced considerably higher levels of IL-12 and TNF-α than gram-negative bacteria in both cord and adult cells. The levels of IL-6 were significantly higher in newborns than in adults, whereas the levels of IL-10 were similar in newborns and adults. Gram-negative and gram-positive bacteria induced similar levels of IL-6 and IL-10 in cord cells. L. plantarum bound or signaled through CD14, TLR-2, and TLR-4, whereas E. coli acted mainly through CD14 and TLR-4. These results indicate that the innate immune response in newborns to commensal bacteria is strong and also suggest that different bacterial strains may have differential effects on the maturation of the immune system of infants.

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Isolation and identification of membrane vesicle-associated proteins in Gram-positive bacteria and mycobacteria

MethodsX ◽

10.1016/j.mex.2014.08.001 ◽

2014 ◽

Vol 1 ◽

pp. 124-129 ◽

Cited By ~ 18

Author(s):

Rafael Prados-Rosales ◽

Lisa Brown ◽

Arturo Casadevall ◽

Sandra Montalvo-Quirós ◽

Jose L. Luque-Garcia

Keyword(s):

Membrane Vesicle ◽

Isolation And Identification ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Associated Proteins

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Contribution of Toll-like receptors to the innate immune response to Gram-negative and Gram-positive bacteria

Blood ◽

10.1182/blood-2006-06-032961 ◽

2006 ◽

Vol 109 (4) ◽

pp. 1574-1583 ◽

Cited By ~ 126

Author(s):

Greg Elson ◽

Irène Dunn-Siegrist ◽

Bruno Daubeuf ◽

Jérome Pugin

Keyword(s):

Cell Activation ◽

Dependent Manner ◽

Toll Like Receptors ◽

Bacterial Strains ◽

Gram Positive ◽

Independent Manner ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Molecular Pattern ◽

High Concentrations

Abstract Innate recognition of bacteria is a key step in the activation of inflammation and coagulation, and it is dependent on pathogen-associated molecular pattern (PAMP) ligation to Toll-like receptors (TLRs) and CD14. The dominant receptors activated when cells encounter a whole bacterium, which express several PAMPs, are poorly defined. Herein, we have stimulated various human cells with prototypic Gram-negative and Gram-positive bacteria. Receptor-dependent responses to whole bacteria were assessed using both TLR-transfected cells and specific monoclonal antibodies against TLRs, MD-2, and CD14. Enterobacteria-activated leukocytes and endothelial cells in a TLR4/MD-2–dependent manner, most likely via lipopolysaccharide (LPS). TLR2 activation was observed with a high bacterial inoculum, and in epithelial cells expressing TLR2 but not TLR4. Pseudomonas aeruginosa stimulated cells by both TLR2 and TLR4/MD-2. Gram-positive bacteria activated cells only at high concentrations, in a partially TLR2-dependent but TLR4/MD-2–independent manner. Either TLR or CD14 neutralization blocked activation to all bacterial strains tested with the exception of some Gram-positive strains in whole blood in which partial inhibition was noted. This study identifies dominant TLRs involved in responses to whole bacteria. It also validates the concept that host cell activation by bacterial pathogens can be therapeutically reduced by anti-TLR4, -TLR2, and -CD14 mAbs.

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Isolation and Identification of Bacteria from Marine Biofilms

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.277-279.612 ◽

2005 ◽

Vol 277-279 ◽

pp. 612-617 ◽

Cited By ~ 3

Author(s):

Yoo Kyung Lee ◽

Kae Kyoung Kwon ◽

Kyeung Hee Cho ◽

Jae Hyun Park ◽

Hong Kum Lee

Keyword(s):

Culturable Bacteria ◽

Bacterial Isolates ◽

Isolation And Identification ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Rdna Sequences ◽

Marine Biofilms ◽

Antifouling Agent ◽

Identification Of Bacteria ◽

Invertebrate Larvae

In the marine environment, biofilms cover most of the subtidal and intertidal solid surfaces. Culturable bacteria forming marine biofilms were isolated on artificial substrate called acrylic coupons. The bacterial isolates were identified through a comparison of 16S rDNA sequences. A total of 115 strains were cultured and identified, 45 of which showed the same sequences with other strains. Therefore, 70 strains were finally identified. The bacterial isolates belonged to a–Proteobacteria (32 isolates), g–Proteobacteria (12 isolates), CFB group bacteria (4 isolates), high GC Gram-positive bacteria (9 isolates), and low GC Gram-positive bacteria (13 isolates). The bacterial isolates may be used as standard bacteria to test new antifouling agent. They may also be utilized as useful bacteria to enhance the settlement of commercial algae and invertebrate larvae for aquaculture.

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The antimicrobial potentialities of (Nk-lysin peptides of chicken, bovine, and human) against bacteria and rotavirus

10.21203/rs.3.rs-409635/v1 ◽

2021 ◽

Author(s):

Maged. M Mahmoud ◽

Ahmed M. Al-Hejin ◽

Turki S Abujaml ◽

S Abd-Elmaksoud ◽

Salem M. El-Hamidy ◽

...

Keyword(s):

Antiviral Activity ◽

Klebsiella Oxytoca ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Negative ◽

Beta Lactamases ◽

Gram Positive Bacteria ◽

The Past ◽

Antiviral Activities ◽

First Time

Abstract For the first time, this study was carried out to investigate and evaluate the relative antibacterial activity of three different Nk-lysin peptides from human, chicken, and bovine activity compared to Gram-negative and Gram-positive bacteria as well as antiviral activity against rotavirus (strain SA-11) and finally mechanisms of action optionality. This report is the first of its kind that investigates the increased antimicrobial ability of (Nk-lysin + AgNPs) and (Nk-lysin + human IL-2) combinations against S. typhi activity by carrying out direct comparison under similar experimental settings. Our results showed that gram-negative and gram-positive microorganisms, including Streptococcus pyogenes, Streptococcus mutans, Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca, Shigella sonnei, Klebsiella pneumoniae and Salmonella typhimurium, are susceptible to NK-lysin treatment. It was shown in our findings that there was equal potentiality in mixture (Nk-lysin + AgNPs) and (Nk-lysin + human IL-2) for preventing the growth of S. typhi, however, when added together, there was minor increase in the level of action. In our study, the TOHO-1 gene was absent in treated bacteria. Following treatment with Nk-lysin peptides, the beta-lactamases genes (CTX-M-1, M-8, and M-9) were not found in any bacterial strains. The examination did not find any of the plasmid mediated quinolone resistance genes in the bacterial strains as a response to NK-lysin treatment. Nonetheless, no study has been carried out in the past that characterized the antiviral activity of bovine, human and chicken Nk-lysin peptides. Hence, this is the foremost study on the enhanced antimicrobial activity of human, bovine and chicken Nk-lysin peptides against Rotavirus (strain SA-11). The findings of the study demonstrated that the powerful antiviral activities were exhibited by Nk-lysin peptides against Rotavirus (strain SA-11). Based on the comparison between these peptides, it can be concluded that there is an evident potent antiviral activity of bovine Nk-lysin against Rotavirus (strain SA-11) as it restrains infection by up to 90%. However, growth was restricted by 80% by chicken Nk-lysin and by 50% by the human peptide.

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IDENTIFIKASI BAKTERI AEROB GRAM NEGATIF DAN GRAM POSITIF MENGGUNAKAN METODE KONVENSIONAL DAN OTOMATIK

INDONESIAN JOURNAL OF CLINICAL PATHOLOGY AND MEDICAL LABORATORY ◽

10.24293/ijcpml.v19i2.1065 ◽

2018 ◽

Vol 19 (2) ◽

pp. 105

Author(s):

Patricia M. Tauran ◽

Irda Handayani ◽

Nurhayana Sennang

Keyword(s):

Aerobic Bacteria ◽

Gram Negative Bacteria ◽

Bacterial Taxonomy ◽

Biochemical Tests ◽

Gram Positive ◽

Gram Negative ◽

Gram Positive Bacteria ◽

Automated Method ◽

Automatic Methods ◽

Automated Methods

Choosing the method of bacteria identification is crucial to obtain accurate and quick results. This study will analyze the identificationresults of Gram negative and Gram positive from aerobic bacteria by examination using conventional and automatic methods at Dr.Wahidin Sudirohusodo Hospital Laboratory. A total of 85 samples consisting of 66 Gram negative bacteria and 19 Gram positive bacteriawere identified using conventional and automated methods. In this study, there was some correspondent identification result betweenthe conventional as well as the automated methods, namely 31.5% for Gram negative bacteria and 30.8% for Gram positive bacteria.However, the non-correspondent identification result between conventional and automated methods was found greater, namely, 68.5%for Gram negative bacteria and 69.2% for Gram positive bacteria. The non-correspondent identification result was due to the developmentof bacterial taxonomy and the differences of numbers and types of the biochemical tests between conventional and automatic methods.Bacteria identification using automated method is more accurate and faster than the conventional method, so it is recommended usingthis particularly for the laboratory and educational referral center.

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Phytochemical analyses and antibacterial activities of Erodium, Euphorbia, Logoecia and Tamarix species

The Journal of Infection in Developing Countries ◽

10.3855/jidc.11776 ◽

2019 ◽

Vol 13 (11) ◽

pp. 1013-1020

Author(s):

Khaldoun J Al-Hadid ◽

Nehaya Al-Karablieh ◽

Ahmad Sharab ◽

Ihsan Mutlak

Keyword(s):

Antibacterial Agents ◽

Antibacterial Activities ◽

Microtiter Plate ◽

Phytochemical Analysis ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Phytochemical Components ◽

Promising Source ◽

Group D

Introduction: Resistance against commonly used antibacterial agents has become a globally recognized threat to human health. Therefore, the development of new and effective antibacterial agents is necessary to treat infections caused by resistant bacterial strains; plants are a promising source of new agents to be tested. Methodology: The minimum inhibitory concentrations (MIC) of ethanolic extracts of Erodium gruinum, Euphorbia hierosolymitana, Logoecia cuminoides, and Tamarix tetragyna against 10 Gram-negative and 5 Gram-positive bacteria were determined using agar well diffusion and microtiter plate dilution methods, respectively. The phytochemical composition of the crude extracts of the plants was determined using HPLC. Results: Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae, Proteus mirabilis, and Acinetobacter baumannii were sensitive to E. gruinum and E. hierosolymitana extracts. P. aeruginosa ATCC 27853 and M. catarrhalis were sensitive to L. cuminoides extract. P. aeruginosa ATCC 27853, P. mirabilis, and K. pneumoniae were sensitive to T. tetragyna extracts. For Gram-positive bacteria, Staphylococcus aureus ATCC 33591 and ATCC 43300 were sensitive to E. gruinum and E. hierosolymitana extracts. S. aureus ATCC 43300 and ATCC 33591 and Group D Streptococcus were sensitive to T. tetragyna extract. All Gram-positive bacteria were completely resistant to the extract of L. cuminoides. The major phytochemical components of the plant extracts belonged to flavonoids, tannins, terpenes, quinones, phytosterols, phytoestrogens, carbohydrates, fatty acids, and coumarin. Conclusion: The study showed the potential of the development of antibacterial agents from these plants. Phytochemical analysis revealed compounds that are candidates for new antibacterial drugs.

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Mixtures of Scutellaria baicalensis and Glycyrrhiza L. Extracts as Antibacterial and Antiviral Agents in Active Coatings

Coatings ◽

10.3390/coatings11121438 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1438

Author(s):

Magdalena Ordon ◽

Paweł Nawrotek ◽

Xymena Stachurska ◽

Anna Schmidt ◽

Małgorzata Mizielińska

Keyword(s):

Synergistic Effect ◽

Pseudomonas Syringae ◽

Plant Extracts ◽

Antimicrobial Agents ◽

Antiviral Agents ◽

Scutellaria Baicalensis ◽

Bacterial Strains ◽

Gram Positive ◽

Gram Positive Bacteria ◽

Highly Active

The aim of this study was to develop active packaging materials covered in active coatings (offering antibacterial and antiviral properties) that contain selected plant extracts. In addition, the synergistic effect of the active substances in these extracts was also analysed. The results of the study demonstrated that Scutellaria baicalensis and Glycyrrhiza L. extracts (two of six analysed plant extracts) were the most active agents against selected Gram-positive and Gram-negative bacterial strains. Additionally, the synergistic effect of S. baicalensis and Glycyrrhiza L. extracts was noted, meaning that the effect of these two plant extract mixtures on Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas syringae growth was higher than the activity of individual pure extracts. Mixtures of the extracts were introduced into the coating carrier. A polyethylene (PE) foil was then coated with active layers containing mixtures of S. baicalensis and Glycyrrhiza L. extracts as antimicrobial agents. The results of this research showed that all of the active coatings had a bacteriolytic effect on B. subtilis and a bacteriostatic effect on S. aureus cells. The coatings were found to be inactive against E. coli and P. syringae cells. This means that the coatings could be used as internal coatings to preserve food products against Gram-positive bacteria that may be responsible for food spoilage. The results of this study also demonstrated that the coatings were highly active against phage phi 6 phage particles, used as SARS-CoV-2 surrogate. This means that the coatings could be used as external coatings to limit the spread of SARS-CoV-2 and pathogenic Gram-positive bacteria via human hands.

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