scholarly journals Quorum sensing systems and related virulence factors in Pseudomonas aeruginosa isolated from chicken meat and ground beef

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gökhan İnat ◽  
Belgin Sırıken ◽  
Ceren Başkan ◽  
İrfan Erol ◽  
Tuba Yıldırım ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Protease Activity ◽  
Ground Beef ◽  
Homoserine Lactone ◽  
Chicken Meat ◽  
Molecular Techniques ◽  
Isolation And Identification ◽  
Conventional Culture

AbstractThe objective of this study was to evaluate 50 [chicken meat (n = 45) and ground beef (n = 5)] Pseudomonas aeruginosa isolates to determine the expression of the lasI and rhl QS systems, related virulence factors, and the presence of N-3-oxo-dodecanoyl homoserine lactone (AHL: 3-O-C12-HSL). For the isolation and identification of P. aeruginosa, conventional culture and oprL gene-based molecular techniques were used. In relation to QS systems, eight genes consisting of four intact and four internal (lasI/R, rhlI/R) genes were analyzed with PCR assay. The two QS systems genes in P. aeruginosa isolates from ground beef (80.00%) and chicken meat (76.00%) were present at quite high levels. The 3-O-C12-HSL was detected in 14.00% of the isolates. Both biofilm formation and motility were detected in 98.00% of the isolates. Protease activity was determined in 54.00% of the isolates. Pyocyanin production was detected in 48.00% of the isolates. The las system scores strongly and positively correlated with the rhl system (p ˂ .01). PYA moderately and positively correlated with protease (p ˂ .05). In addition, there was statistically significance between lasI and protease activity (p < .10), and rhlI and twitching motility (p < .10). In conclusion, the high number of isolates having QS systems and related virulence factors are critical for public health. Pyocyanin, protease, and biofilm formation can cause spoilage and play essential role in food spoilage and food safety.

scholarly journals Inhibition of Quorum Sensing in Pseudomonas aeruginosa by N-Acyl Cyclopentylamides

2007 ◽  
Vol 73 (10) ◽  
pp. 3183-3188 ◽  
Author(s):  
Takenori Ishida ◽  
Tsukasa Ikeda ◽  
Noboru Takiguchi ◽  
Akio Kuroda ◽  
Hisao Ohtake ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Homoserine Lactone ◽  
Ring Structure ◽  
Response Regulators ◽  
Maximal Inhibition ◽  
Sensing Systems ◽  
Reporter Assays

ABSTRACT N-Octanoyl cyclopentylamide (C8-CPA) was found to moderately inhibit quorum sensing in Pseudomonas aeruginosa PAO1. To obtain more powerful inhibitors, a series of structural analogs of C8-CPA were synthesized and examined for their ability to inhibit quorum sensing in P. aeruginosa PAO1. The lasB-lacZ and rhlA-lacZ reporter assays revealed that the chain length and the ring structure were critical for C8-CPA analogs to inhibit quorum sensing. N-Decanoyl cyclopentylamide (C10-CPA) was found to be the strongest inhibitor, and its concentrations required for half-maximal inhibition for lasB-lacZ and rhlA-lacZ expression were 80 and 90 μM, respectively. C10-CPA also inhibited production of virulence factors, including elastase, pyocyanin, and rhamnolipid, and biofilm formation without affecting growth of P. aeruginosa PAO1. C10-CPA inhibited induction of both lasI-lacZ by N-(3-oxododecanoyl)-l-homoserine lactone (PAI1) and rhlA-lacZ by N-butanoyl-l-homoserine lactone (PAI2) in the lasI rhlI mutant of P. aeruginosa PAO1, indicating that C10-CPA interferes with the las and rhl quorum-sensing systems via inhibiting interaction between their response regulators (LasR and RhlR) and autoinducers.

scholarly journals Revisiting the quorum-sensing hierarchy in Pseudomonas aeruginosa: the transcriptional regulator RhlR regulates LasR-specific factors

Microbiology ◽  
2009 ◽  
Vol 155 (3) ◽  
pp. 712-723 ◽  
Author(s):  
Valérie Dekimpe ◽  
Eric Déziel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Transcriptional Regulator ◽  
Homoserine Lactone ◽  
The Other ◽  
Virulence Determinants ◽  
Late Stationary Phase ◽  
Regulatory Systems ◽  
Specific Factors

Pseudomonas aeruginosa uses the two major quorum-sensing (QS) regulatory systems las and rhl to modulate the expression of many of its virulence factors. The las system is considered to stand at the top of the QS hierarchy. However, some virulence factors such as pyocyanin have been reported to still be produced in lasR mutants under certain conditions. Interestingly, such mutants arise spontaneously under various conditions, including in the airways of cystic fibrosis patients. Using transcriptional lacZ reporters, LC/MS quantification and phenotypic assays, we have investigated the regulation of QS-controlled factors by the las system. Our results show that activity of the rhl system is only delayed in a lasR mutant, thus allowing the expression of multiple virulence determinants such as pyocyanin, rhamnolipids and C4-homoserine lactone (HSL) during the late stationary phase. Moreover, at this stage, RhlR is able to overcome the absence of the las system by activating specific LasR-controlled functions, including production of 3-oxo-C12-HSL and Pseudomonas quinolone signal (PQS). P. aeruginosa is thus able to circumvent the deficiency of one of its QS systems by allowing the other to take over. This work demonstrates that the QS hierarchy is more complex than the model simply presenting the las system above the rhl system.

scholarly journals Targeting Acyl Homoserine Lactone (AHL) of Pseudomonas aeruginosa Responsible for Biofilm Formation using Plant Metabolites

2019 ◽  
Vol 13 (3) ◽  
pp. 1841-1846
Author(s):  
Sree Samanvitha K ◽  
Sanjay Kumar S ◽  
Antony V. Samrot ◽  
Raji P ◽  
Ponnaiah Paulraj ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Homoserine Lactone ◽  
Acyl Homoserine Lactone ◽  
Plant Metabolites

scholarly journals Biofilm Formation and Virulence Factors Among Pseudomonas aeruginosa Isolated From Burn Patients

2015 ◽  
Vol 8 (10) ◽  
Author(s):  
Zahra Ghanbarzadeh Corehtash ◽  
Ahmad Khorshidi ◽  
Farzaneh Firoozeh ◽  
Hosein Akbari ◽  
Azam Mahmoudi Aznaveh
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Burn Patients

scholarly journals Yersinia enterocolitica: Prevalence, virulence, and antimicrobial resistance from retail and processed meat in Egypt

2019 ◽  
Vol 12 (7) ◽  
pp. 1078-1084 ◽  
Author(s):  
Gamal Younis ◽  
Mona Mady ◽  
Amal Awad
Keyword(s):  
Yersinia Enterocolitica ◽  
Biofilm Formation ◽  
Ground Beef ◽  
Chicken Meat ◽  
Diffusion Method ◽  
Processed Meat ◽  
Beef Meat ◽  
Beef Burger ◽  
Retail Chicken Meat

Aim: The objectives of this study were to investigate the prevalence of Yersinia enterocolitica in retail chicken meat, ground and processed beef meat, determine their virulence-associated genes, antimicrobial susceptibility pattern, molecular detection of extended-spectrum β-lactamases, and their capability of biofilm formation in vitro. Materials and Methods: A total of 210 samples (120 retail chicken meat, 30 ground beef, 30 beef burger, and 30 sausage samples) were collected from different retail chicken outlets and markets located at Mansoura city between December 2016 and April 2017. Meat samples were examined bacteriologically for the existence of Y. enterocolitica; bacterial colonies that displayed positive biochemical properties were subjected to polymerase chain reaction targeting 16 rRNA gene. Y. enterocolitica isolates were tested for their susceptibility to six antimicrobial agents using disk diffusion method. Uniplex PCR was used for screening Y. enterocolitica isolates for the presence of two virulence chromosome-associated genes (ail and yst), and β-lactamases (blaTEM and blaSHV). The capability of Y. enterocolitica to form biofilms was detected by tube method. Results: Thirty Y. enterocolitica isolates (14.29%) were recovered including 19 (15.83%) isolates from chicken meat, 3 (10%) from ground beef, 5 (16.67%) from beef burger, and 3 (10%) from sausage samples. Regarding ail gene, it was detected in 6.67% (2/30), while yst gene detected in 20% (6/30) Y. enterocolitica isolates. About 80%, 70%, 63.33%, and 50% of Y. enterocolitica isolates were sensitive to ciprofloxacin, gentamicin, cefotaxime, and streptomycin, respectively, while 83.33% of Y. enterocolitica isolates were resistant to both ampicillin and cephalothin. Interestingly, 21 (70%) isolates had the capability of biofilms formation in vitro. Among the multidrug-resistant (MDR) strains, a significant difference (p<0.05) was found between MDR and biofilm formation. However, biofilm formation was correlated with the resistance of the isolates to β-lactam antimicrobials and the presence of β-lactam-resistant genes. Conclusion: The presence of Y. enterocolitica in chicken meat, ground and processed beef meat represents a significant health risk for meat consumers, which reflects the contamination of slaughterhouses and processing operations, therefore, strict hygienic measures should be applied to minimize carcasses contamination.

Isolation and Identification of Fungal Isolates caused Otomycosis from some Hospitals and Clinics in Mosul with Determination of Their Virulence Factors

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Nabeel Al-Sharrad ◽  
Muhammad A. Al-Kataan ◽  
Maha A. Al-Rejaboo
Keyword(s):  
Fungal Infection ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Fungal Pathogens ◽  
Candida Parapsilosis ◽  
Isolation And Identification ◽  
Fungal Isolates ◽  
Biofilm Production ◽  
Etiological Agents

Otomycosis is a fungal infection that frequently involves the external auditory canal. In this study, we aimed to isolation and identification the fungal isolates as etiological agents of otomycosis from some hospitals and clinics in Mosul with determination of their virulence factors of fungal etiological agents. Positive fungal infection was found in (43) samples (71.6%). The most common fungal pathogens were Candida and Aspergillus species, with Candida parapsilosis being the predominant isolates in (11) samples (16.6%). Otomycosis was more common in Female in (26) samples (43.3%).Otomycosis was the highest prevalence aged group 15-40 years (19) samples (31.3%). The present study of virulence factors revealed that the highest biofilm formation isolates were C. parapsilosis is (10) isolates which were distributed between (2) strong and (8) weak biofilm formation.Where C.trpicales, was recorded as least isolates for biofilm production.

scholarly journals Recombinant N-acyl homoserine lactone-Lactonase AiiAQSI-1 Attenuates Aeromonas hydrophila Virulence Factors, Biofilm Formation and Reduces Mortality in Crucian Carp

Marine Drugs ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. 499 ◽  
Author(s):  
Bao Zhang ◽  
Xiyi Zhuang ◽  
Liyun Guo ◽  
Robert J. C. McLean ◽  
Weihua Chu
Keyword(s):  
Virulence Factors ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Crucian Carp ◽  
Homoserine Lactone ◽  
In Vivo Studies ◽  
Acyl Homoserine Lactone ◽  
Signal Molecule ◽  
Promising Alternative ◽  
Feed Supplementation

Quorum quenching (QQ) is a promising alternative infection-control strategy to antibiotics that controls quorum-regulated virulence without killing the pathogens. Aeromonas hydrophila is an opportunistic gram-negative pathogen living in freshwater and marine environments. A. hydrophila possesses an N-acyl homoserine lactone (AHL)-based quorum-sensing (QS) system that regulates virulence, so quorum signal-inactivation (i.e., QQ) may represent a new way to combat A. hydrophila infection. In this study, an AHL lactonase gene, aiiA was cloned from Bacillus sp. strain QSI-1 and expressed in Escherichia coli strain BL21(DE3). The A. hydrophila hexanoyl homoserine lactone (C6-HSL) QS signal molecule was degraded by AiiAQSI-1, which resulted in a decrease of bacterial swimming motility, reduction of extracellular protease and hemolysin virulence factors, and inhibited the biofilm formation of A. hydrophila YJ-1 in a microtiter assay. In cell culture studies, AiiAQSI-1 decreased the ability of A. hydrophila adherence to and internalization by Epithelioma papulosum cyprini (EPC) cells. During in vivo studies, oral administration of AiiAQSI-1 via feed supplementation attenuated A. hydrophila infection in Crucian Carp. Results from this work indicate that feed supplementation with AiiAQSI-1 protein has potential to control A. hydrophila aquaculture disease via QQ.

scholarly journals Quorum-Sensing Genes in Pseudomonas aeruginosa Biofilms: Their Role and Expression Patterns

2001 ◽  
Vol 67 (4) ◽  
pp. 1865-1873 ◽  
Author(s):  
Teresa R. De Kievit ◽  
Richard Gillis ◽  
Steve Marx ◽  
Chris Brown ◽  
Barbara H. Iglewski
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Fluorescent Protein ◽  
Expression Patterns ◽  
Homoserine Lactone ◽  
Lower Percentage ◽  
Spatial Studies ◽  
Green Fluorescent ◽  
Biofilm Development

ABSTRACT Acylated homoserine lactone molecules are used by a number of gram-negative bacteria to regulate cell density-dependent gene expression by a mechanism known as quorum sensing (QS). InPseudomonas aeruginosa, QS or cell-to-cell signaling controls expression of a number of virulence factors, as well as biofilm differentiation. In this study, we investigated the role played by the las and rhl QS systems during the early stages of static biofilm formation when cells are adhering to a surface and forming microcolonies. These studies revealed a marked difference in biofilm formation between the PAO1 parent and the QS mutants when glucose, but not citrate, was used as the sole carbon source. To further elucidate the contribution of lasI andrhlI to biofilm maturation, we utilized fusions to unstable green fluorescent protein in concert with confocal microscopy to perform real-time temporal and spatial studies of these genes in a flowing environment. During the course of 8-day biofilm development,lasI expression was found to progressively decrease over time. Conversely, rhlI expression remained steady throughout biofilm development but occurred in a lower percentage of cells. Spatial analysis revealed that lasI andrhlI were maximally expressed in cells located at the substratum and that expression decreased with increasing biofilm height. Because QS was shown previously to be involved in biofilm differentiation, these findings have important implications for the design of biofilm prevention and eradication strategies.

scholarly journals Plantain Herb Extracts significantly attenuate the quorum sensing-controlled virulence factors and inhibit biofilm formation in Pseudomonas aeruginosa PAO1

2019 ◽  
Vol 78 ◽  
pp. 01004
Author(s):  
Shan Li ◽  
Jiangning Yao ◽  
Haoming Li
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Significant Inhibition ◽  
Control Group ◽  
Produce Cell ◽  
Group B ◽  
Herb Extracts

Pseudomonas aeruginosa is a Gram-negative organism that can survive under harsh conditions, and it is also an opportunistic pathogen that can produce cell-associated extracellular virulence factors. Several of these virulence factors have been demonstrated to be regulated by quorum sensing (QS). Plantain Herb has been used as antibacterial agents for many centuries in China. In this study, we analyzed Plantain Herb Extracts (PHE) at the concentration of 16 μg/mL (Group A, MIC), 8 μg/mL (Group B, 1/2 MIC) and 4 μg/mL (Group C, 1/4 MIC) for inhibition of the virulence factors production and biofilm formation in P. aeruginosa PAO1. The virulence factors included pyocyanin, rhamnolipids, protease and alginate. PHE showed significant inhibition of virulence factors as compared to the control group without interfering its growth. Thus, PHE might be a potent QS inhibitor and anti-biofilm agent in the treatment of Pseudomonas aeruginosa infections.

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