scholarly journals Extract from phyllosphere bacteria with antibiofilm and quorum quenching activity to control several fish pathogenic bacteria

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Olivia Nathalia ◽  
Diana Elizabeth Waturangi

Abstract Objective The objective of this research were to screen quorum quenching activity compound from phyllosphere bacteria as well as antibiofilm activity against several fish pathogen bacteria such as Aeromonas hydrophila, Streptococcus agalactiae, and Vibrio harveyi. Results We found eight phyllosphere bacteria isolates with potential quorum quenching activity to inhibit Chromobacterium violaceum as indicator bacteria. Crude extracts (20 mg/mL) showed various antibiofilm activity against fish pathogenic bacteria used in this study. Isolate JB 17B showed the highest activity to inhibit biofilm formation of A. hydrophila and V. harveyi, meanwhile isolate JB 3B showed the highest activity to inhibit biofilm of S. agalactiae. From destruction assay, isolate JB 8F showed the highest activity to disrupt biofilm of A. hydrophila isolate JB 20B showed the highest activity to disrupt biofilm of V. harveyi, isolate JB 17B also showed the highest activity to disrupt biofilm of S. agalactiae.

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 631
Author(s):  
Mengfan Peng ◽  
Wentao Tong ◽  
Zhen Zhao ◽  
Ling Xiao ◽  
Zhaoyue Wang ◽  
...  

In this experiment, the quorum quenching gene ytnP of Bacillus licheniformis T-1 was cloned and expressed, and the effect against infection of Aeromonas hydrophila ATCC 7966 was evaluated in vitro and vivo. The BLAST results revealed a 99% sequence identity between the ytnP gene of T-1 and its homolog in B.subtilis sub sp. BSP1, and the dendroGram showed that the similarity in the YtnP protein in T-1 was 100% in comparison with B.subtilis 3610, which was categorized as the Aidc cluster of the MBL family. The AHL lactonase activity of the purified YtnP was detected as 1.097 ± 0.7 U/mL with C6-HSL as the substrate. Otherwise, purified YtnP protein could significantly inhibit the biofilm formation of A.hydrophila ATCC 7966 with an inhibition rate of 68%. The MIC of thiamphenicol and doxycycline hydrochloride against A. hydrophila reduced from 4 μg/mL and 0.5 μg/mL to 1 μg/mL and 0.125 μg/mL, respectively, in the presence of YtnP. In addition, YtnP significantly inhibited the expression of five virulence factors hem, ahyB, ast, ep, aerA of A. hydrophila ATCC 7966 as well (p < 0.05). The results of inhibition on virulence showed a time-dependence tendency, while the strongest anti-virulence effects were within 4–24 h. In vivo, when the YtnP protein was co-injected intraperitoneally with A. hydrophila ATCC 7966, it attenuated the pathogenicity of A. hydrophila and the accumulated mortality was 27 ± 4.14% at 96 h, which was significantly lower than the average mortality of 78 ± 2.57% of the Carassius auratus injected with 108 CFU/mL of A. hydrophila ATCC 7966 only (p < 0.001). In conclusion, the AHL lactonase in B. licheniformis T-1 was proven to be YtnP protein and could be developed into an agent against infection of A. hydrophila in aquaculture.


2010 ◽  
Vol 9 (2) ◽  
pp. 127
Author(s):  
. Sunarto ◽  
. Sukenda ◽  
. Widanarni

The ability of probiotic bacteria to control disease infection has been used in aquaculture. This experiment was conducted to isolate and characterize probiotic bacteria; the competition test its ability probiotic bacteria against pathogenic bacteria; and to improve survival rate of Leptobarbus hoeveni. The bacteria were isolated from Leptobarbus hoeveni and its culture environment, and then tested to know its ability to inhibit bacterial fish pathogen in-vitro. Furthermore, the selected probiotic bacteria were tested in vivo to evaluate their ability to inhibit pathogen of Leptobarbus hoeveni.  The result showed that probiotic bacteria inhibit the growth of Streptococcus iniae, Flexibacter columnaris, Mycobacterium fortuitum and Aeromonas hydrophila in vitro.  Isolate DD3 was the best of candidate probiotic because of the ability to inhibit pathogen, especially A. hydrophila, the most virulent bacteria in Leptobarbus hoeveni.<br /><br />Key Words  : probiotic bacteria, Leptobarbus hoeveni, pathogenic bacteria<br /><br />Abstrak<br /><br />Kemampuan bakteri probiotik untuk mengendalikan penyakit infeksi telah digunakan dalam akuakultur. Tujuan penelitian ini adalah mengisolasi dan mengkarakterisasi bakteri probiotik, menguji kemampuan bakteri probiotik terhadap bakteri patogen, sehingga dapat meningkatkan tingkat kelangsungan hidup ikan jelawat. Bakteri diisolasi dari usus ikan jelawat dan lingkungan budaya, kemudian diuji kemampuannya menghambat bakteri patogen secara in-vitro. Selanjutnya bakteri probiotik yang dipilih diuji secara in vivo untuk mengevaluasi kemampuannya dalam menghambat patogen di dalam tubuh ikan jelawat. Dari hasil penelitian diperoleh bakteri probiotik yang diisolasi dari usus dan lingkungan budaya ikan jelawat menunjukkan penghambatan pertumbuhan terhadap Streptococcus iniae, Flexibacter columnaris, Mycobacterium fortuitum dan Aeromonas hydrophila secara in vitro. Isolat DD3 merupakan kandidat probiotik terbaik, karena mempunyai kemampuan untuk menghambat bakteri patogen,  khususnya bakteri  A. hydrophila adalah bakteri yang paling viluren bagi ikan jelawat.<br />    <br />Kata Kunci:   bakteri probiotik, ikan jalawat dan baktri patogen<br />


Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1713
Author(s):  
Fei Shang ◽  
Hui Wang ◽  
Ting Xue

Streptococcus agalactiae (GBS) is a highly contagious pathogen which not only can cause neonatal meningitis, pneumonia, and septicemia but is also considered to be a major cause of bovine mastitis (BM), leading to large economic losses to the dairy industry worldwide. Like many other pathogenic bacteria, GBS also has the capacity to form a biofilm structure in the host to cause persistent infection. Tea saponin (TS), is one of the main active agents extracted from tea ash powder, and it has good antioxidant and antibacterial activities. In this study, we confirmed that TS has a slight antibacterial activity against a Streptococcus agalactiae strain isolated from dairy cow with mastitis and inhibits its biofilm formation. By performing scanning electron microscopy (SEM) experiments, we observed that with addition of TS, the biofilm formed by this GBS strain exhibited looser structure and lower density. In addition, the results of real-time reverse transcription polymerase chain reaction (RT-PCR) experiments showed that TS inhibited biofilm formation by down-regulating the transcription of the biofilm-associated genes including srtA, fbsC, neuA, and cpsE.


2020 ◽  
Vol 367 (15) ◽  
Author(s):  
Ilef Hchaichi ◽  
Francesca Bandini ◽  
Giulia Spini ◽  
Mohamed Banni ◽  
Pier Sandro Cocconcelli ◽  
...  

ABSTRACT Conventional plastics and bioplastics are known to accumulate in aquatic ecosystems, emerging as new surfaces for biofilm formation and gene exchanges. On the other hand, the fate of non-conventional bioplastics in the marine environment is still unclear. In this study we have measured, by means of crystal violet test and scanning electron microscopy (SEM), the ability of two model bacteria, Vibrio harveyi and Enterococcus faecalis, to form biofilms on low-density polyethylene (PE), polylactic acid (PLA) and starch-based bioplastic (SBB) surfaces. Experiments were conducted in artificial sea water, incubating squares of 3 cm2 of the three plastics with the two model microorganisms and sampling overnight, and at 3 and 6 days. The presence of biofilms on plastic surfaces was detected from day one of incubation and SBB was the material with the highest biofilm formation. E. faecalis formed the thickest biofilm after 3 days with PLA and SBB, but did not remain stable, and after 6 days with PE. The maximum biofilm formation of V. harveyi was obtained overnight with SBB and PE, and after 3 days with PLA. Our data indicate that both plastic and bioplastics support the formation of biofilms of model pathogenic bacteria, highlighting potential concerns for human health.


2019 ◽  
Author(s):  
NADINE AMABEL THEODORA ◽  
VANIA DOMINIKA ◽  
Diana Elizabeth Waturangi

Abstract Objective The objectives of this research were to screen anti-quorum sensing activity of phyllosphere bacteria and quantify their antibiofilm activity against biofilm forming bacteria ( Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Salmonella typhimurium, Vibrio cholerae, Pseudomonas aeruginosa). Results We found 11 phyllosphere bacteria isolates with potential anti-quorum sensing activity. Most of the crude extracts from phyllosphere bacteria isolates had anti-quorum sensing activity against Chromobacterium violaceum at certain concentration (20 and 10 mg/mL), but not crude extract from isolate JB 7F. Crude extracts showed various antibiofilm activities against all tested pathogenic bacteria.


Author(s):  
Yaqiu Zhang ◽  
Yiqin Deng ◽  
Juan Feng ◽  
Jianmei Hu ◽  
Haoxiang Chen ◽  
...  

2021 ◽  
Vol 9 (11) ◽  
pp. 2273
Author(s):  
Sarita Soto-Aguilera ◽  
Brenda Modak ◽  
Maialen Aldabaldetrecu ◽  
Carla P. Lozano ◽  
Juan Guerrero ◽  
...  

Biofilm formation in pathogenic bacteria is an important factor of resistance to antimicrobial treatments, allowing them to survive for a long time in their hosts. In the search for new antibiofilm agents, in this work we report the activity of a copper (I) complex, [Cu(NN1)2]ClO4, synthesized with Cu (I) and NN1, an imine ligand 6-((quinolin-2-ylmethylene)amino)-2H-chromen-2-one, a derivate of natural compound coumarin. The antibacterial and antibiofilm capacity was evaluated in Vibrio harveyi BB170 used as model bacteria. Antibacterial activity was measured in vitro by minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and half-maximal inhibitory concentration (IC50) determination. Antibiofilm capacity of copper (I) complex was analyzed by different concentrations of IC50 values. The results showed that the sub-IC50 concentration, 12.6 µg/mL of the copper (I) complex, was able to reduce biofilm formation by more than 75%, and bacterial viability was reduced by 50%. Inverted and confocal laser scanning microscopy showed that the [Cu(NN1)2]ClO4 complex affected the biofilm structure. Therefore, the copper (I) complex is effective as an antibiofilm compound in V. harveyi BB170.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jingyi Yu ◽  
Lulin Rao ◽  
Lingling Zhan ◽  
Yan Zhou ◽  
Yinjuan Guo ◽  
...  

Staphylococcus aureus is the most important pathogenic bacteria in humans. As the resistance of S. aureus to existing antibiotics is increasing, there is an urgent need for new anti-infective drugs. S. aureus biofilms cause persistent infections and resist complete eradication with antibiotic therapy. The present study investigated the inhibitory effect of the novel small-molecule ZY-214-4 (C19H11BrNO4) on S. aureus biofilm formation. At a subinhibitory concentration (4 μg/ml), ZY-214-4 had no effect on the growth of S. aureus strains and also showed no cytotoxicity in human normal bronchial epithelial cells (Bease-2B). The results of a semi-quantitative biofilm test showed that ZY-214-4 prevented S. aureus biofilm formation, which was confirmed by scanning electron microscopy and confocal laser scanning microscopy. ZY-214-4 significantly suppressed the production of polysaccharide intercellular adhesion and prevented cell aggregation, and also inhibited the mRNA expression of icaA and other biofilm-related genes (eno, clfA/B, fnbB, fib, ebpS, psmα, and psmβ) in clinical S. aureus isolates. Thus, at a subinhibitory concentration, ZY-214-4 inhibits biofilm formation by preventing cell aggregation, highlighting its clinical potential for preventing or treating S. aureus infections.


Author(s):  
Marco Wijaya ◽  
Dea Delicia ◽  
Diana Elizabeth Waturangi

Abstract Objectives: The purpose of the study is to screen antiquorum sensing activity compound from actinobacteria using Chromobacterium violaceum as indicator and quantify the antibiofilm activity against several biofilm-forming pathogenic bacteria, such as Staphylococcus aureus ATCC 29213, Bacillus cereus ATCC 14579, Enterococcus faecalis ATCC 33186, Vibrio cholerae , Salmonella typhimurium , Pseudomonas aeruginosa ATCC 27853.Results: Crude extracts from marine actinobacteria isolated from Indonesia were promising for treating biofilm-related diseases. Out of 40 isolates 10 were found to have great quorum quenching activity against C. violaceum. Moreover, these isolates were able to inhibit biofim formation by Gram positive and Gram negative pathogenic bacteria. Quorum quenching agents in extracts of 1AC, 14PM, 16PM, 18PM, and CW17 isolates were predicted as proteins or enzymes.


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