Effect of quorum quenching bacteria on growth, virulence factors and biofilm formation ofYersinia ruckeri in vitroand anin vivoevaluation of their probiotic effect in rainbow trout

2018 ◽  
Vol 41 (9) ◽  
pp. 1429-1438 ◽  
Author(s):  
Somayeh Torabi Delshad ◽  
Siyavash Soltanian ◽  
Hassan Sharifiyazdi ◽  
Peter Bossier
Keyword(s):  
Rainbow Trout ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Quorum Quenching ◽  
Probiotic Effect

scholarly journals Attenuation of Aeromonas hydrophila Infection in Carassius auratus by YtnP, a N-acyl Homoserine Lactonase from Bacillus licheniformis T-1

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 631
Author(s):  
Mengfan Peng ◽  
Wentao Tong ◽  
Zhen Zhao ◽  
Ling Xiao ◽  
Zhaoyue Wang ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Bacillus Licheniformis ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Carassius Auratus ◽  
Quorum Quenching ◽  
Inhibition Rate ◽  
Sequence Identity

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.

The effect of some chemical materials against virulence factors of Candida ssp isolated from UTI patients

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Fatima Abdul Hussein Mejbel
Keyword(s):  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Germ Tube ◽  
Laboratory Culture ◽  
Candida Spp ◽  
Other Substances ◽  
Chemical Materials

 During the period from September 2016 to December 2017,135 urine samples were collected from urinary tract infection patients attending to AL-Zahraa Hospital in AL-Najaf Governorate. The present study was conducted to isolate and identify Candida spp. isolated from urinary tract infection patients by different methods including direct examination, laboratory culture, biochemical test and by modern techniques (Api Candida kit) and determine the virulence factors phenotypic to Candida spp which involved (biofilm formation,phospholipase and germ tube). The percentage of females to males was as following, female (84) 62.2 % (21) infected and male (51) 37.8% (1) infected with all age categories. The results in this study are explain that is some Candida spp. such as C. albicans, have high susceptible to eugenole follow by phenol and umbellulone. The efficiency of some chemical substances such as (eugenole,umbellulone, and phenol) was evaluated to inhibit the growth of Candida ssp as well as some virulence factors such as biofilm formation,germ tube and phospholipase,which were studied in this research. Statistically analysis results have been significance difference between the results of the substance concentrations and the concentrations of the different other substances.

Quorum Sensing – A Stratagem for Conquering Multi-Drug Resistant Pathogens

2020 ◽  
Vol 26 ◽  
Author(s):  
Madison Tonkin ◽  
Shama Khan ◽  
Mohmmad Younus Wani ◽  
Aijaz Ahmad
Keyword(s):  
Drug Resistance ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Cell Communication ◽  
Natural Compounds ◽  
Quorum Sensing Inhibitors ◽  
Communication Technique ◽  
Multicellular Organisms ◽  
Chemical Strategies

: Quorum sensing is defined as cell to cell communication between microorganisms, which enables microorganisms to behave as multicellular organisms. Quorum sensing enables many collaborative benefits such as synchronisation of virulence factors and biofilm formation. Both quorum sensing as well as biofilm formation encourage the development of drug resistance in microorganisms. Biofilm formation and quorum sensing are causally linked to each other and play role in the pathogenesis of microorganisms. With the increasing drug resistance against the available antibiotics and antifungal medications, scientists are combining different options to develop new strategies. Such strategies rely on the inhibition of the communication and virulence factors rather than on killing or inhibiting the growth of the microorganisms. This review encompasses the communication technique used by microorganisms, how microorganism resistance is linked to quorum sensing and various chemical strategies to combat quorum sensing and thereby drug resistance. Several compounds have been identified as quorum sensing inhibitors and are known to be effective in reducing resistance as they do not kill the pathogens but rather disrupt their communication. Natural compounds have been identified as anti-quorum sensing agents. However, natural compounds present several related disadvantages. Therefore, the need for the development of synthetic or semi-synthetic compounds has arisen. This review argues that anti-quorum sensing compounds are effective in disrupting quorum sensing and could therefore be effective in reducing microorganism drug resistance.

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

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.

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
Keyword(s):  
Streptococcus Agalactiae ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Vibrio Harveyi ◽  
Quorum Quenching ◽  
Indicator Bacteria ◽  
Antibiofilm Activity ◽  
Fish Pathogen ◽  
Phyllosphere Bacteria

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.

scholarly journals Virulence Factors in Coagulase-Negative Staphylococci

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 170
Author(s):  
Angela França ◽  
Vânia Gaio ◽  
Nathalie Lopes ◽  
Luís D. R. Melo
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Biofilm Formation ◽  
Antibiotic Resistance Genes ◽  
Coagulase Negative Staphylococci ◽  
Healthcare Associated ◽  
Major Pathogens

Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.

Differences in biofilm formation and virulence factors between clinical and fecal enterococcal isolates of human and animal origin

2012 ◽  
Vol 52 (6) ◽  
pp. 336-343 ◽  
Author(s):  
Giorgos Tsikrikonis ◽  
Antonios N. Maniatis ◽  
Maria Labrou ◽  
Eleni Ntokou ◽  
Giorgos Michail ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Biofilm Formation ◽  
Animal Origin
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