scholarly journals Screening of Neutrophil Activating Factors from a Metagenome Library of Sponge-Associated Bacteria

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 427
Author(s):  
Yoshiko Okamura ◽  
Hirokazu Takahashi ◽  
Atsuyuki Shiida ◽  
Yuto Hirata ◽  
Haruko Takeyama ◽  
...  

Marine sponge-associated bacteria are known as bio-active compound produce. We have constructed metagenome libraries of the bacteria and developed a metagenomic screening approach. Activity-based screening successfully identified novel genes and novel enzymes; however, the efficiency was only in 1 out of 104 clones. Therefore, in this study, we thought that bioinformatics could help to reduce screening efforts, and combined activity-based screening with database search. Neutrophils play an important role for the immune system to recognize excreted bacterial by-products as chemotactic factors and are recruited to infection sites to kill pathogens via phagocytosis. These excreted by-products are considered critical triggers that engage the immune system to mount a defense against infection, and identifying these factors may guide developments in medicine and diagnostics. We focused on genes encoding amino acid ligase and peptide synthetase and selected from an in-house sponge metagenome database. Cell-free culture medium of each was used in a neutrophil chemiluminescence assay in luminol reaction. The clone showing maximum activity had a genomic sequence expected to produce a molecule like a phospho-N-acetylmuramyl pentapeptide by the metagenome fragment analysis.

2009 ◽  
Vol 1 (2) ◽  
Author(s):  
Risa Nofiani ◽  
Siti Nurbetty ◽  
Ajuk Sapar

<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>


2020 ◽  
Vol 16 (9) ◽  
pp. 1273-1280
Author(s):  
Giuseppina Tommonaro ◽  
Ali M. El-Hagrassi ◽  
Walid Fayad ◽  
Carmine Iodice ◽  
Kamel H. Shaker ◽  
...  

Background: Colorectal cancer represents one of the prominent causes of mortality worldwide in men and women. The objective of this study was to search for new potential anticancer compounds, both in prevention and treatment of colorectal cancer. The anticancer potential of marine bacterial extracts against Human colorectal carcinoma cell line (HCT116) was evaluated as well as the partial identification of bioactive metabolites. Methods: All bacterial extracts were tested for their cytotoxicity against HCT116 cell line by means of MTT assay. The highly cytotoxic dichloromethane extracts of marine sponge-associated bacteria Vibrio sp. and Bacillus sp. were analyzed by GC-MS. Results: Two fractions, Vib3 and Bac3, exhibited a very interesting cytotoxicity against human colorectal carcinoma (HCT116) cell line, with a percentage of cytotoxicity of 96.04 % and 29.48 %, respectively. Discussion: The GC-MS analysis revealed the presence of two major fatty acids, palmitic and oleic acids, in Vib3 fraction and fatty acid esters and phenolic compounds in Bac3 fraction. Conclusion: Based on previous literature, it may be hypothesized that the anticancer activity of bacterial extracts could be, at least partially, to the fatty acids fraction.


2018 ◽  
Vol 14 (3) ◽  
pp. 221-229 ◽  
Author(s):  
Aris Tri Wahyudi ◽  
Jepri Agung Priyanto ◽  
Wenang Maharsiwi ◽  
Rika Indri Astuti

2011 ◽  
Vol 77 (20) ◽  
pp. 7207-7216 ◽  
Author(s):  
Naomi F. Montalvo ◽  
Russell T. Hill

ABSTRACTThe giant barrel spongesXestospongiamutaandXestospongiatestudinariaare ubiquitous in tropical reefs of the Atlantic and Pacific Oceans, respectively. They are key species in their respective environments and are hosts to diverse assemblages of bacteria. These two closely related sponges from different oceans provide a unique opportunity to examine the evolution of sponge-associated bacterial communities. Mitochondrial cytochrome oxidase subunit I gene sequences fromX.mutaandX.testudinariashowed little divergence between the two species. A detailed analysis of the bacterial communities associated with these sponges, comprising over 900 full-length 16S rRNA gene sequences, revealed remarkable similarity in the bacterial communities of the two species. Both sponge-associated communities include sequences found only in the twoXestospongiaspecies, as well as sequences found also in other sponge species and are dominated by three bacterial groups,Chloroflexi,Acidobacteria, andActinobacteria. While these groups consistently dominate the bacterial communities revealed by 16S rRNA gene-based analysis of sponge-associated bacteria, the depth of sequencing undertaken in this study revealed clades of bacteria specifically associated with each of the twoXestospongiaspecies, and also with the genusXestospongia, that have not been found associated with other sponge species or other ecosystems. This study, comparing the bacterial communities associated with closely related but geographically distant sponge hosts, gives new insight into the intimate relationships between marine sponges and some of their bacterial symbionts.


Microbiology ◽  
2005 ◽  
Vol 151 (5) ◽  
pp. 1453-1464 ◽  
Author(s):  
M. Gabriela Bowden ◽  
Wei Chen ◽  
Jenny Singvall ◽  
Yi Xu ◽  
Sharon J. Peacock ◽  
...  

Staphylococcus epidermidis is a ubiquitous human skin commensal that has emerged as a major cause of foreign-body infections. Eleven genes encoding putative cell-wall-anchored proteins were identified by computer analysis of the publicly available S. epidermidis unfinished genomic sequence. Four genes encode previously described proteins (Aap, Bhp, SdrF and SdrG), while the remaining seven have not been characterized. Analysis of primary sequences of the Staphylococcus epidermidis surface (Ses) proteins indicates that they have a structural organization similar to the previously described cell-wall-anchored proteins from S. aureus and other Gram-positive cocci. However, not all of the Ses proteins are direct homologues of the S. aureus proteins. Secondary and tertiary structure predictions suggest that most of the Ses proteins are composed of several contiguous subdomains, and that the majority of these predicted subdomains are folded into β-rich structures. PCR analysis indicates that certain genes may be found more frequently in disease isolates compared to strains isolated from healthy skin. Patients recovering from S. epidermidis infections had higher antibody titres against some Ses proteins, implying that these proteins are expressed during human infection. Western blot analyses of early-logarithmic and late-stationary in vitro cultures suggest that different regulatory mechanisms control the expression of the Ses proteins.


2020 ◽  
Vol 287 (1928) ◽  
pp. 20200704
Author(s):  
Rabia Özbek ◽  
Krishnendu Mukherjee ◽  
Fevzi Uçkan ◽  
Andreas Vilcinskas

Parasitoids are insects that use other insects as hosts. They sabotage host cellular and humoral defences to promote the survival of their offspring by injecting viruses and venoms along with their eggs. Many pathogens and parasites disrupt host epigenetic mechanisms to overcome immune system defences, and we hypothesized that parasitoids may use the same strategy. We used the ichneumon wasp Pimpla turionellae as a model idiobiont parasitoid to test this hypothesis, with pupae of the greater wax moth Galleria mellonella as the host. We found that parasitoid infestation involves the suppression of host immunity-related effector genes and the modulation of host genes involved in developmental hormone signalling. The transcriptional reprogramming of host genes following the injection of parasitoid eggs was associated with changes in host epigenetic mechanisms. The introduction of parasitoids resulted in a transient decrease in host global DNA methylation and the modulation of acetylation ratios for specific histones. Genes encoding regulators of histone acetylation and deacetylation were mostly downregulated in the parasitized pupae, suggesting that parasitoids can suppress host transcription. We also detected a strong parasitoid-specific effect on host microRNAs regulating gene expression at the post-transcriptional level. Our data therefore support the hypothesis that parasitoids may favour the survival of their offspring by interfering with host epigenetic mechanisms to suppress the immune system and disrupt development.


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