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

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.

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

Current Pharmaceutical Design ◽

10.2174/1381612826666201210105638 ◽

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.

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Virulence Factors in Coagulase-Negative Staphylococci

Pathogens ◽

10.3390/pathogens10020170 ◽

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.

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Inhibition of biofilm formation, quorum sensing and other virulence factors in Pseudomonas aeruginosa by polyphenols of Gynura procumbens leaves

Journal of Biomolecular Structure and Dynamics ◽

10.1080/07391102.2020.1870563 ◽

2021 ◽

pp. 1-15

Author(s):

Zulkar Nain ◽

Fariha Jasin Mansur ◽

Shifath Bin Syed ◽

Md Ariful Islam ◽

Hiroyuki Azakami ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Virulence Factors ◽

Biofilm Formation

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Regulation of Enterococcus faecalis Biofilm Formation and Quorum Sensing Related Virulence Factors with Ultra-low Dose Reactive Species Produced by Plasma Activated Water

Plasma Chemistry and Plasma Processing ◽

10.1007/s11090-018-9930-2 ◽

2018 ◽

Vol 39 (1) ◽

pp. 35-49 ◽

Cited By ~ 7

Author(s):

Yinglong Li ◽

Jie Pan ◽

Dan Wu ◽

Ying Tian ◽

Jue Zhang ◽

...

Keyword(s):

Quorum Sensing ◽

Enterococcus Faecalis ◽

Virulence Factors ◽

Biofilm Formation ◽

Low Dose ◽

Reactive Species ◽

Plasma Activated Water

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

Antibiotics ◽

10.3390/antibiotics10060631 ◽

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.

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Virulence of Clinical Candida Isolates

Pathogens ◽

10.3390/pathogens10040466 ◽

2021 ◽

Vol 10 (4) ◽

pp. 466

Author(s):

Martyna Mroczyńska ◽

Anna Brillowska-Dąbrowska

Keyword(s):

Virulence Factors ◽

Biofilm Formation ◽

Galleria Mellonella ◽

Hydrolytic Enzymes ◽

Morphological Transition ◽

Candida Spp

The factors enabling Candida spp. infections are secretion of hydrolytic enzymes, adherence to surfaces, biofilm formation or morphological transition, and fitness attributes. The aim of this study was to investigate the correlation between known extracellular virulence factors and survival of Galleria mellonella larvae infected with clinical Candida. The 25 isolates were tested and the activity of proteinases among 24/24, phospholipases among 7/22, esterases among 14/23, hemolysins among 18/24, and biofilm formation ability among 18/25 isolates was confirmed. Pathogenicity investigation using G. mellonella larvae as host model demonstrated that C. albicans isolates and C. glabrata isolate were the most virulent and C. krusei isolates were avirulent. C. parapsilosis virulence was identified as varied, C. inconspicua were moderately virulent, and one C. palmioleophila isolate was of low virulence and the remaining isolates of this species were moderately virulent. According to our study, virulence of Candida isolates is related to the expression of proteases, hemolysins, and esterases.

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Correlation between virulence factors and in vitro biofilm formation by Escherichia coli strains

Microbial Pathogenesis ◽

10.1016/j.micpath.2008.03.003 ◽

2008 ◽

Vol 45 (2) ◽

pp. 86-91 ◽

Cited By ~ 82

Author(s):

Plínio Naves ◽

Gema del Prado ◽

Lorena Huelves ◽

Matilde Gracia ◽

Vicente Ruiz ◽

...

Keyword(s):

Escherichia Coli ◽

Virulence Factors ◽

Biofilm Formation

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Anti-quorum Sensing Potential of Ageratum Conyzoides L. (Asteraceae) Extracts

10.21203/rs.3.rs-492453/v1 ◽

2021 ◽

Author(s):

Eli COMPAORE ◽

Moussa COMPAORE ◽

Vincent OUEDRAOGO ◽

Ablassé ROUAMBA ◽

Martin KIENDREBEOGO

Keyword(s):

Quorum Sensing ◽

Virulence Factors ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Methanolic Extract ◽

Negative Impact ◽

Significant Inhibition ◽

High Morbidity ◽

Ageratum Conyzoides ◽

Phytochemical Content

Abstract Background: Pseudomonas aeruginosa causes infections in human particularly immunocompromised patients with cystic fibrosis, severe burns and HIV, resulting in high morbidity and mortality. The pathogenic bacteria P aeruginosa produces virulence factors regulated by the mechanism called quorum sensing system. Objective: The aim of this study was to assess the anti-quorum sensing activity of Ageratum conyzoides extracts Method: Chromobacterium violaceum reporter strain CV026 was used to highlight any interference with bacterium QS and strains derived from P. aeruginosa PAO1 were used to reveal any interference with the expression of quorum sensing genes, and to assess any impact of extract on the kinetics of the production of pyocyanin, elastases and biofilm formation. Results: Hydro-methanolic extract at the sub-inhibitory concentration of 100 μg/mL reduced quorum sensing virulence factors production such as, pyocyanin, elastases, rhamnolipids and biofilm formation in P. aeruginosa PAO1 after 18 hours monitoring. Extract showed significant inhibition in HSL-mediated violacein production on C. violaceum CV026 after 48 hours monitoring. Biofilm formation was inhibited up to 32%. It affected QS gene expression in PAO1. The regulatory genes lasR / rhlR and the lasI synthases were most affected. At 8hours, hydro-methanolic extract reduced both QS gene to more than 30% (lasI/lasR and rhlI/R respectively 33.8% /30.2% and 36% /33.2%). RhlA and lasB genes have been relatively affected (13.4% and 28.9%). After 18 h, this extract reduced significantly the expression of regulatory 30 genes lasR (31%) and rhlR (39.6%) although synthases genes seemed to be less affected (lasI/21.2% and rhlI/11.6%). A limited impact was observed on the downstream genes (lasB /20.0% and rhlA /15.3%). No negative impact was observed on CV026 and PAO1 growth and cell viability. Our study also showed that A. conyzoides having ample amount of phenolics, flavonoids and triterpenoids. This phytochemical content could be one of the factors for showing anti quorum potential. Conclusion: Results indicate that hydro methanol 80 % extract from A. conyzoides could be a source of potential QS inhibition compounds.

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