scholarly journals Random Mutagenesis Applied to Reveal Factors Involved in Oxidative Tolerance and Biofilm Formation in Foodborne Cronobacter malonaticus

2019 ◽  
Vol 10 ◽  
Author(s):  
Maofeng Zhang ◽  
Xiyan Zhang ◽  
Liaowang Tong ◽  
Dexin Ou ◽  
Yaping Wang ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Random Mutagenesis ◽  
Oxidative Tolerance

scholarly journals Biofilm Formation in a Hydrodynamic Environment by Novel FimH Variants and Ramifications for Virulence

2001 ◽  
Vol 69 (3) ◽  
pp. 1322-1328 ◽  
Author(s):  
Mark A. Schembri ◽  
Per Klemm
Keyword(s):  
Urinary Tract ◽  
Biofilm Formation ◽  
Random Mutagenesis ◽  
Cumulative Effect ◽  
Growth Conditions ◽  
E Coli ◽  
Enrichment Technique ◽  
Naturally Occurring ◽  
Abiotic Surfaces ◽  
Hydrodynamic Environment

ABSTRACT Type 1 fimbriae are surface-located adhesion organelles ofEscherichia coli that are directly associated with virulence of the urinary tract. They mediated-mannose-sensitive binding to different host surfaces by way of the minor fimbrial component FimH. Naturally occurring variants of FimH that bind strongly to terminally exposed monomannose residues have been associated with a pathogenicity-adaptive phenotype that enhances E. coli colonization of extraintestinal locations such as the urinary tract. The FimH adhesin also promotes biofilm formation in a mannose-inhibitable manner on abiotic surfaces under static growth conditions. In this study, we used random mutagenesis combined with a novel selection-enrichment technique to specifically identify mutations in the FimH adhesin that confer onE. coli the ability to form biofilms under hydrodynamic flow (HDF) conditions. We identified three FimH variants from our mutant library that could mediate an HDF biofilm formation phenotype to various degrees. This phenotype was induced by the cumulative effect of multiple changes throughout the receptor-binding region of the protein. Two of the HDF biofilm-forming FimH variants were insensitive to mannose inhibition and represent novel phenotypes not previously identified in naturally occurring isolates. Characterization of our enriched clones revealed some similarities to amino acid alterations that occur in urinary tract infection (UTI) strains. Subsequent screening of a selection of UTI FimH variants demonstrated that they too could promote biofilm formation on abiotic surfaces under HDF conditions. Interestingly, the same correlation was not observed for commensal FimH variants. FimH is a multifaceted protein prone to rapid microevolution. In addition to its previously documented roles in adherence and invasion, we have now demonstrated its function in biofilm formation on abiotic surfaces subjected to HDF conditions. The study indicates that UTI FimH variants possess adaptations that enhance biofilm formation and suggests a novel role for FimH in UTIs associated with medical implants such as catheters.

Bacterial biofilm behavior in water-supply lines of dental units

1992 ◽  
Vol 50 (1) ◽  
pp. 882-883
Author(s):  
B.D. Tall ◽  
K.S. George ◽  
R. T. Gray ◽  
H.N. Williams
Keyword(s):  
Water Supply ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Bacterial Biofilm

Studies of bacterial behavior in many environments have shown that most organisms attach to surfaces, forming communities of microcolonies called biofilms. In contaminated medical devices, biofilms may serve both as reservoirs and as inocula for the initiation of infections. Recently, there has been much concern about the potential of dental units to transmit infections. Because the mechanisms of biofilm formation are ill-defined, we investigated the behavior and formation of a biofilm associated with tubing leading to the water syringe of a dental unit over a period of 1 month.

Biofilm-formation ability of S. aureus on collagen matrices

2020 ◽  
Vol 26 (5) ◽  
pp. 26-31
Author(s):  
O. Iungin ◽  
L. Maistrenko ◽  
P. Rebrykova ◽  
I. Duka
Keyword(s):  
Biofilm Formation ◽  
Collagen Matrices

Bioactivity of Phenolic Compounds Extracted from Strawberry against Formation of Pseudomonas aeruginosa Biofilm

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Baydaa Hussein ◽  
Zainab A. Aldhaher ◽  
Shahrazad Najem Abdu-Allah ◽  
Adel Hamdan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Phenolic Compounds ◽  
Biofilm Formation ◽  
Opportunistic Infections ◽  
Formation Rate ◽  
Hydrocarbon Chain ◽  
Health Concern ◽  
Gas Chromatography Mass Spectrometry ◽  
Phenolic Contents

Background: Biofilm is a bacterial way of life prevalent in the world of microbes; in addition to that it is a source of alarm in the field of health concern. Pseudomonas aeruginosa is a pathogenic bacterium responsible for all opportunistic infections such as chronic and severe. Aim of this study: This paper aims to provide an overview of the promotion of isolates to produce a biofilm in vitro under special circumstances, to expose certain antibiotics to produce phenotypic evaluation of biofilm bacteria. Methods and Materials: Three diverse ways were used to inhibited biofilm formation of P.aeruginosa by effect of phenolic compounds extracts from strawberries. Isolates produced biofilm on agar MacConkey under certain circumstances. Results: The results showed that all isolates were resistant to antibiotics except sensitive to azithromycin (AZM, 15μg), and in this study was conducted on three ways to detect the biofilm produced, has been detected by the biofilm like Tissue culture plate (TCP), Tube method (TM), Congo Red Agar (CRA). These methods gave a clear result of these isolates under study. Active compounds were analyzed in both extracts by Gas Chromatography-mass Spectrometry which indicate High molecular weight compound with a long hydrocarbon chain. Conclusion: Phenolic compounds could behave as bioactive material and can be useful to be used in pharmaceutical synthesis. Phenolic contents which found in leaves and fruits extracts of strawberries shows antibacterial activity against all strains tested by the ability to reduce the production of biofilm formation rate.

The comparative study among the MRSAcin, Nisin A and vancomycin, on biofilm formation by Methicillin resistance Staphylococcus aureus isolated from food sources.

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
¹Hind H. Muunim ◽  
Muna T Al-Mossawei ◽  
Mais Emad Ahmed
Keyword(s):  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Microbial Control ◽  
Antibiotic Sensitivity ◽  
Raw Milk ◽  
Sensitivity Test ◽  
Food Sources ◽  
Resistant Bacteria ◽  
Biochemical Tests ◽  
Food Preservatives

Biofilms formation by pathogens microbial Control considered important in medical research because it is the hazarded virulence factor leading to becoming difficult to treat because of its high resistance to antimicrobials. Glycopeptide antibiotic a (Vancomycin) and the commercial bacteriocin (Nisin A) were used to comparative with purification bacteriocin (MRSAcin) against MRSA biofilm. One hundred food samples were collected from Baghdad markets from July 2016 to September 2016, including (cheese, yogurt, raw milk, fried meat, grilled meat, and beef burger). All samples were cultures; S. aureus was confirmation by macroscopic culture and microscopic examination, in addition to biochemical tests. Methicillin resistance S. asureus (MRSA) were identification by antibiotic sensitivity test (AST), Vitek 2 system. The result shown the 60(60%) isolate were identified as S. aureus and 45(75%) gave positive result as MRSA isolate, M13 isolate was chosen as MRSA isolates highest biofilm formation for treatment with MRSAcin, Nisin A(bacteriocin) and Vancomycin (antibiotic) to compared the more antimicrobial have bacteriocidal effect. The sensitivity test uses to determine the effect of MRSAcin, Nisin A, and Vancomycin MIC on MRSA planktonic cell by (WDA). The new study shows the impacts of new kind Pure Bacteriocins (MRSAcin) from methicillin-resistant S. aureus (MRSA) highly effects then (Vancomycin and Nisin A) at different concentration. In a current study aimed to suggest new Bacteriocin is potent highly for the treatment of resistant bacteria biofilm infections in food preservatives

Sign in / Sign up

Export Citation Format

Share Document