scholarly journals Optimization of some environmental and nutritional conditions using microtiter plate for Pseudomonas aeruginosa biofilm formation

2021 ◽  
Vol 9 (4) ◽  
pp. 1-4
Author(s):  
Shaymaa Fouad Rasheed Al-Khazraji ◽  
Mohammad Abdul Rahmman Al-Maeni
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Nutritional Conditions

scholarly journals Enhancement of pyocyanin production by subinhibitory concentration of royal jelly in Pseudomonas aeruginosa

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 14
Author(s):  
Dina Auliya Amly ◽  
Puspita Hajardhini ◽  
Alma Linggar Jonarta ◽  
Heribertus Dedy Kusuma Yulianto ◽  
Heni Susilowati
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
Royal Jelly ◽  
Microtiter Plate ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Antibiotic Tolerance ◽  
Subinhibitory Concentration ◽  
Pyocyanin Production

Background: Pseudomonas aeruginosa, a multidrug-resistant Gram-negative bacterium, produces pyocyanin, a virulence factor associated with antibiotic tolerance. High concentrations of royal jelly have an antibacterial effect, which may potentially overcome antibacterial resistance. However, in some cases, antibiotic tolerance can occur due to prolonged stress of low-dose antibacterial agents. This study aimed to investigate the effect of subinhibitory concentrations of royal jelly on bacterial growth, pyocyanin production, and biofilm formation of P. aeruginosa. Methods: Pseudomonas aeruginosa ATCC 10145 and clinical isolates were cultured in a royal jelly-containing medium to test the antibacterial activity. Pyocyanin production was observed by measuring the absorbance at 690 nm after 36 h culture and determined using extinction coefficient 4310 M-1 cm-1. Static microtiter plate biofilm assay performed to detect the biofilm formation, followed by scanning electron microscopy. Results: Royal jelly effectively inhibited the viability of both strains from a concentration of 25%. The highest production of pyocyanin was observed in the subinhibitory concentration group 6.25%, which gradually decreased along with the decrease of royal jelly concentration. Results of one-way ANOVA tests differed significantly in pyocyanin production of the two strains between the royal jelly groups. Tukey HSD test showed concentrations of 12.5%, 6.25%, and 3.125% significantly increased pyocyanin production of ATCC 10145, and the concentrations of 12.5% and 6.25% significantly increased production of the clinical isolates. Concentrations of 12.5% and 6.125% significantly induced biofilm formation of P. aeruginosa ATCC 10145, in line with the results of the SEM analysis. Conclusions: The royal jelly concentration of 25% or higher inhibits bacterial growth; however, the subinhibitory concentration increases pyocyanin production and biofilm formation in P. aeruginosa. It is advisable to determine the appropriate concentration of royal jelly to obtain beneficial virulence inhibiting activity.

scholarly journals Relationship between type III secretion toxins, biofilm formation, and antibiotic resistance in clinical Pseudomonas aeruginosa isolates

2021 ◽  
Vol 11 (6) ◽  
pp. 1075-1082
Author(s):  
S. Derakhshan ◽  
A. Rezaee ◽  
Sh. Mohammadi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Type Iii Secretion ◽  
Biofilm Formation ◽  
Virulence Gene ◽  
Microtiter Plate ◽  
P Value ◽  
Type Iii ◽  
Disk Diffusion Assay

Background and aim. Pseudomonas aeruginosa is considered as a notorious pathogen due to its multidrug resistance and life threatening infections. We investigated the relationship between type III secretion toxins, biofilm formation, and antibiotic resistance among clinical P. aeruginosa isolates. Methods. A total of 70 genetically distinct clinical P. aeruginosa isolates were characterized for antibiotic resistance by disk diffusion assay. Biofilm formation was evaluated by microtiter plate method and presence of four exo genes (exoS, exoU, exoT and exoY) was investigated by PCR. A p-value < 0.05 was regarded statistically significant. Results. The most effective antibiotics were Meropenem and Piperacillin. Multidrug resistance was more prevalent in the ciprofloxacin-resistant isolates than in the susceptible isolates. The most frequently identified exo was exoS (37.1%). Genotype exoS/exoT was found in 4 isolates, while genotype exoU/exoT was not found. Prevalence of exoS was generally higher in the susceptible isolates than in the resistant isolates. A significant association was found between the formation of strong biofilm and resistance to antibiotics (p < 0.05). Prevalence of exoY and exoU was higher in the non-strong biofilm producers compared to the strong biofilm producers. Conclusion. Our study revealed formation of strong biofilm along with antibiotic resistance and the presence of exo genes in P. aeruginosa isolates. Knowledge of virulence gene profiles and biofilm formation may be useful in deciding appropriate treatment.

scholarly journals Peptide Mix from Olivancillaria hiatula Interferes with Cell-to-Cell Communication in Pseudomonas aeruginosa

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Edward Ntim Gasu ◽  
Hubert Senanu Ahor ◽  
Lawrence Sheringham Borquaye
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Cell Communication ◽  
Microtiter Plate ◽  
Antibiofilm Activity ◽  
Dependent Manner ◽  
Biofilm Inhibition ◽  
Swarming Motility

Bacteria in biofilms are encased in an extracellular polymeric matrix that limits exposure of microbial cells to lethal doses of antimicrobial agents, leading to resistance. In Pseudomonas aeruginosa, biofilm formation is regulated by cell-to-cell communication, called quorum sensing. Quorum sensing facilitates a variety of bacterial physiological functions such as swarming motility and protease, pyoverdine, and pyocyanin productions. Peptide mix from the marine mollusc, Olivancillaria hiatula, has been studied for its antibiofilm activity against Pseudomonas aeruginosa. Microscopy and microtiter plate-based assays were used to evaluate biofilm inhibitory activities. Effect of the peptide mix on quorum sensing-mediated processes was also evaluated. Peptide mix proved to be a good antibiofilm agent, requiring less than 39 μg/mL to inhibit 50% biofilm formation. Micrographs obtained confirmed biofilm inhibition at 1/2 MIC whereas 2.5 mg/mL was required to degrade preformed biofilm. There was a marked attenuation in quorum sensing-mediated phenotypes as well. At 1/2 MIC of peptide, the expression of pyocyanin, pyoverdine, and protease was inhibited by 60%, 72%, and 54%, respectively. Additionally, swarming motility was repressed by peptide in a dose-dependent manner. These results suggest that the peptide mix from Olivancillaria hiatula probably inhibits biofilm formation by interfering with cell-to-cell communication in Pseudomonas aeruginosa.

scholarly journals Correlation of biofilm production with antibiotic susceptibility pattern of Pseudomonas aeruginosa from various clinical specimens

2022 ◽  
Vol 13 (1) ◽  
pp. 88-92
Author(s):  
M Swapna ◽  
G Sumathi ◽  
M Anitha
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Antibiotic Sensitivity ◽  
Microtiter Plate ◽  
Resistance Pattern ◽  
Sensitivity Testing ◽  
Clinical Specimens ◽  
Biofilm Production ◽  
Microbiological Methods

Background: Pseudomonas aeruginosa is one of the most prevalent nosocomial pathogens that cause a life-threatening infection. One of the important characteristics of P. aeruginosa is biofilm formation which leads to antibiotic resistance. Aims and Objectives: The aim of the study was to study the antibiotic resistance pattern of P. aeruginosa isolates and correlation with their biofilm-production. Materials and Methods: A total of 87 P. aeruginosa isolates from different clinical specimens were processed and confirmed by conventional microbiological methods as per standard methodology. Antibiotic sensitivity testing was done for all isolates. Biofilm producing isolates were identified by the microtiter plate method (MTPM). Results: Of 87 P. aeruginosa isolates, majority were from pus 33 (38%), followed by urine 26 (30%), sputum 19 (22%), body fluids 7 (8%), and blood 2 (2%). Biofilm producing isolates showed more resistance in comparison to non-biofilm producers. The observed difference between biofilm formation for multidrug resistant and susceptible isolates was found to be statistically significant. Conclusion: MTPM method was an effective test for detection of biofilm formation and was also able to verify biofilm production by P. aeruginosa. This indicated a higher propensity among the clinical isolates of P. aeruginosa to form biofilm and revealed a positive correlation between biofilm formation and antibiotic resistance. This indicates the need for testing of even susceptible isolates for virulence factors such as biofilm production.

scholarly journals Enhancement of pyocyanin production by subinhibitory concentration of royal jelly in Pseudomonas aeruginosa

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 14
Author(s):  
Dina Auliya Amly ◽  
Puspita Hajardhini ◽  
Alma Linggar Jonarta ◽  
Heribertus Dedy Kusuma Yulianto ◽  
Heni Susilowati
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
Royal Jelly ◽  
Microtiter Plate ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Antibiotic Tolerance ◽  
Subinhibitory Concentration ◽  
Pyocyanin Production

Background: Pseudomonas aeruginosa, a multidrug-resistant Gram-negative bacterium, produces pyocyanin, a virulence factor associated with antibiotic tolerance. High concentrations of royal jelly have an antibacterial effect, which may potentially overcome antibacterial resistance. However, in some cases, antibiotic tolerance can occur due to prolonged stress of low-dose antibacterial agents. This study aimed to investigate the effect of subinhibitory concentrations of royal jelly on bacterial growth, pyocyanin production, and biofilm formation of P. aeruginosa. Methods: Pseudomonas aeruginosa ATCC 10145 and clinical isolates were cultured in a royal jelly-containing medium to test the antibacterial activity. Pyocyanin production was observed by measuring the absorbance at 690 nm after 36 h culture and determined using extinction coefficient 4310 M-1 cm-1. Static microtiter plate biofilm assay performed to detect the biofilm formation, followed by scanning electron microscopy. Results: Royal jelly effectively inhibited the viability of both strains from a concentration of 25%. The highest production of pyocyanin was observed in the subinhibitory concentration group 6.25%, which gradually decreased along with the decrease of royal jelly concentration. Results of one-way ANOVA tests differed significantly in pyocyanin production of the two strains between the royal jelly groups. Tukey HSD test showed concentrations of 12.5%, 6.25%, and 3.125% significantly increased pyocyanin production of ATCC 10145, and the concentrations of 12.5% and 6.25% significantly increased production of the clinical isolates. Concentrations of 12.5% and 6.125% significantly induced biofilm formation of P. aeruginosa ATCC 10145, in line with the results of the SEM analysis. Conclusions: The royal jelly concentration of 25% or higher inhibits bacterial growth; however, the subinhibitory concentration increases pyocyanin production and biofilm formation in P. aeruginosa. It is advisable to determine the appropriate concentration of royal jelly to obtain beneficial virulence inhibiting activity.

scholarly journals Antibiofilm Activity of Methanol Extract of Rumex dentatus Against Pseudomonas aeruginosa

2020 ◽  
Vol 1 (1) ◽  
pp. 25-32
Author(s):  
Maryam Pezeshki Najafabadi ◽  
Maryam Mohammadi-Sichani ◽  
Mohammad Javad Kazemi ◽  
Mohammad Sadegh Shirsalimian ◽  
Majid Tavakoli
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Microtiter Plate ◽  
Extracellular Polysaccharides ◽  
Antibiofilm Activity ◽  
Plate Method ◽  
Hospital Acquired Infections ◽  
Hospital Acquired

Biofilm formation of Pseudomonas aeruginosa makes up a sizeable proportion of hospital-acquired infections, because bacteria in biofilms can resist antibiotic treatment. The extracellular polymeric substance of P. aeruginosa biofilm is an imprecise collection of extracellular polysaccharides, proteins and microbial cells. Rumex dentatus belongs to polygonaceae family. This family can be found in Middle East. The aim of this present study was to assess the effect of various concentrations of methanol extract of Rumex dentatus on biofilm formation of Pseudomonas aeruginosa after 48 h and 72 h. In this experimental study we collected Rumex dentatus from Khoramabad, Iran. The working extracts were 250, 125, 62.5, 31.25, 15.62, 7.81, 3.9, 1.95, 0.97 and 0.48 mg/ml. We used microtiter plate method to grow P. aeruginosa biofilm and assess the antibiofilm activity of plant extract. The composition of methanol extract obtained from Rumex dentatus was studied by gas chromatography. The minimum biofilm inhibitory concentration (MBIC) for P. aeruginosa found to be 250 mg/ml. GC-MS  analyses indicated that these fractions contained a variety of compounds including Bicyclo (3.1.1) heptan- 3 -one, 2, 6, 6- trimethyl,  Bicyclo (3.1.1) heptan, 6, 6- dimethyl and Eucalyptol. There were consequential correlations between antibiofilm activity and the concentration of extracts after 48 and 72 h.

scholarly journals Antibiofilm Activity of Methanol Extract of Rumex dentatus Against Pseudomonas aeruginosa

2020 ◽  
Vol 1 (1) ◽  
pp. 25-32
Author(s):  
Maryam Pezeshki Najafabadi ◽  
Maryam Mohammadi-Sichani ◽  
Mohammad Javad Kazemi ◽  
Mohammad Sadegh Shirsalimian ◽  
Majid Tavakoli
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Microtiter Plate ◽  
Extracellular Polysaccharides ◽  
Antibiofilm Activity ◽  
Plate Method ◽  
Hospital Acquired Infections ◽  
Hospital Acquired

Biofilm formation of Pseudomonas aeruginosa makes up a sizeable proportion of hospital-acquired infections, because bacteria in biofilms can resist antibiotic treatment. The extracellular polymeric substance of P. aeruginosa biofilm is an imprecise collection of extracellular polysaccharides, proteins and microbial cells. Rumex dentatus belongs to polygonaceae family. This family can be found in Middle East. The aim of this present study was to assess the effect of various concentrations of methanol extract of Rumex dentatus on biofilm formation of Pseudomonas aeruginosa after 48 h and 72 h. In this experimental study we collected Rumex dentatus from Khoramabad, Iran. The working extracts were 250, 125, 62.5, 31.25, 15.62, 7.81, 3.9, 1.95, 0.97 and 0.48 mg/ml. We used microtiter plate method to grow P. aeruginosa biofilm and assess the antibiofilm activity of plant extract. The composition of methanol extract obtained from Rumex dentatus was studied by gas chromatography. The minimum biofilm inhibitory concentration (MBIC) for P. aeruginosa found to be 250 mg/ml. GC-MS  analyses indicated that these fractions contained a variety of compounds including Bicyclo (3.1.1) heptan- 3 -one, 2, 6, 6- trimethyl,  Bicyclo (3.1.1) heptan, 6, 6- dimethyl and Eucalyptol. There were consequential correlations between antibiofilm activity and the concentration of extracts after 48 and 72 h.

scholarly journals Different effects of sub-minimum inhibitory concentrations of gentamicin on the expression of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Fateme Davarzani ◽  
Zahra Yousefpour ◽  
Navid Saidi ◽  
Parviz Owlia
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Microtiter Plate ◽  
Inhibitory Effect ◽  
Clinical Isolates ◽  
Minimum Inhibitory Concentrations ◽  
Alginate Production ◽  
Broth Microdilution Method ◽  
Encoding Genes

Background and Objectives: Antibiotics at sub-minimum inhibitory concentrations (sub-MIC) may alter bacterial viru- lence factors. The objective of this study was to investigate the effect of gentamicin at sub-MIC concentrations on the expres- sion of genes involved in alginate production and biofilm formation of Pseudomonas aeruginosa. Materials and Methods: The broth microdilution method was used to determine the MIC of gentamicin for three P. aeru- ginosa clinical isolates (P1-P3) and standard strains (PAO1 and 8821M). Alginate production and biofilm formation of the bacteria in the presence and absence of sub-MIC concentrations of gentamicin were measured using microtiter plate and carbazole assay, respectively. The real-time PCR method was used to determine the effect of gentamicin at sub-MIC con- centrations on the expression level of genes involved in biofilm formation (pelA and pslA) and alginate production (algD and algU). Results: Gentamicin at sub-MIC concentrations significantly reduced alginate production, biofilm formation, and the expres- sion of alginate and biofilm-encoding genes in clinical isolate P1. This inhibitory effect was also observed on the alginate production of 8821M strain and biofilm formation of PAO1strain. In clinical isolates, P2 and P3, alginate production, biofilm formation, and the expression of alginate and biofilm-encoding genes were significantly increased in exposure to sub-MIC concentrations of gentamicin. Conclusion: This study showed that different phenotypic changes in clinical isolates and standard strains of P. aeruginosa in exposure to sub-MIC concentrations of gentamicin are associated with changes in the expression of virulence genes. Further researches are required to understand the mechanisms involved in regulating the expression of virulence genes after exposure to sub-MIC concentrations of antibiotics.

scholarly journals An examination of potential differences in biofilm production among different genotypes of Pseudomonas aeruginosa

2014 ◽  
Vol 66 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Zorica Vasiljevic ◽  
B. Jovcic ◽  
Ivana Cirkovic ◽  
Slobodanka Djukic
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Band Pattern ◽  
Hospital Environment ◽  
Plate Test ◽  
Clinical Specimens ◽  
Biofilm Production

In the present study, we have examined if there is any difference in biofilm production among different genotypes of Pseudomonas aeruginosa. The study investigated 526 non-duplicate P. aeruginosa isolated from clinical specimens and from a hospital environment. Isolates were grouped into thirty-five genotypes based on an identical ERIC2-band pattern. Biofilm formation was quantified by the microtiter plate test and all strains were classified into the following categories: no biofilm producers (0), weak (+), moderate (+), or strong (+++) biofilm producers. Only 2.45% of examined strains were not biofilm producers. Among biofilm producers, 39.26% were strong biofilm producers, 34.36% were moderate biofilm producers, while 23.93% were weak biofilm producers. Although the majority of strong biofilm producers were in genotype groups 2 and 3, the degree of in vitro biofilm formation in our study was not significantly affected by the genotype of Pseudomonas aeruginosa. In this study, we demonstrated that the degree of in vitro biofilm formation is not significantly affected by the genotype of Pseudomonas aeruginosa.

scholarly journals Enhancement of pyocyanin production by subinhibitory concentration of royal jelly in Pseudomonas aeruginosa

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 14
Author(s):  
Dina Auliya Amly ◽  
Puspita Hajardhini ◽  
Alma Linggar Jonarta ◽  
Heribertus Dedy Kusuma Yulianto ◽  
Heni Susilowati
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Growth ◽  
Biofilm Formation ◽  
Royal Jelly ◽  
Microtiter Plate ◽  
Clinical Isolates ◽  
Antibiotic Tolerance ◽  
Subinhibitory Concentration ◽  
Subinhibitory Concentrations ◽  
Pyocyanin Production

Background: Pseudomonas aeruginosa, a multidrug-resistant Gram-negative bacterium, produces pyocyanin, a virulence factor associated with antibiotic tolerance. High concentrations of royal jelly have an antibacterial effect, which may potentially overcome antibacterial resistance. However, in some cases, antibiotic tolerance can occur due to prolonged stress of low-dose antibacterial agents. This study aimed to investigate the effect of subinhibitory concentrations of royal jelly on bacterial growth, pyocyanin production, and biofilm formation of P. aeruginosa. Methods: Pseudomonas aeruginosa ATCC 10145 and clinical isolates were cultured in a royal jelly-containing medium to test the antibacterial activity. Pyocyanin production was observed by measuring the absorbance at 690 nm after 36 h culture and determined using extinction coefficient 4310 M-1 cm-1. Static microtiter plate biofilm assay performed to detect the biofilm formation, followed by scanning electron microscopy. Results: Royal jelly effectively inhibited the viability of both strains from a concentration of 25%. The highest production of pyocyanin was observed in the subinhibitory concentration group 6.25%, which gradually decreased along with the decrease of royal jelly concentration. Results of one-way ANOVA tests differed significantly in pyocyanin production of the two strains between the royal jelly groups. Tukey HSD test showed concentrations of 12.5%, 6.25%, and 3.125% significantly increased pyocyanin production of ATCC 10145, and the concentrations of 12.5% and 6.25% significantly increased production of the clinical isolates. Concentrations of 12.5% and 6.125% significantly induced biofilm formation of P. aeruginosa ATCC 10145, in line with the results of the SEM analysis. Conclusions: Royal jelly concentrations of 25% or higher can inhibit bacterial growth; however, subinhibitory concentrations could increase pyocyanin production and biofilm formation in P. aeruginosa. It is advisable to determine the appropriate concentration of royal jelly to obtain beneficial virulence inhibiting activity.

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