The blue discoloration of fresh cheeses: A worldwide defect associated to specific contamination by Pseudomonas fluorescens

Food Control ◽  
2018 ◽  
Vol 86 ◽  
pp. 359-366 ◽  
Author(s):  
Ana del Olmo ◽  
Javier Calzada ◽  
Manuel Nuñez
Keyword(s):  
Pseudomonas Fluorescens ◽  
Blue Discoloration

Strain Diversity of Pseudomonas fluorescens Group with Potential Blue Pigment Phenotype Isolated from Dairy Products

2016 ◽  
Vol 79 (8) ◽  
pp. 1430-1435 ◽  
Author(s):  
MARGHERITA CHIERICI ◽  
CLAUDIA PICOZZI ◽  
MARISA GRAZIA LA SPINA ◽  
CARLA ORSI ◽  
ILEANA VIGENTINI ◽  
...  
Keyword(s):  
Pseudomonas Fluorescens ◽  
Sodium Succinate ◽  
16S Rrna Gene Sequencing ◽  
Pigment Production ◽  
Blue Pigment ◽  
Rrna Gene ◽  
Bacterial Populations ◽  
Strain Diversity ◽  
Blue Discoloration ◽  
Rrna Gene Sequencing

ABSTRACT The blue discoloration in Mozzarella cheese comes from bacterial spoilage due to contamination with Pseudomonas. Fourteen Pseudomonas fluorescens strains from international collections and 55 new isolates of dominant bacterial populations from spoiled fresh cheese samples were examined to assess genotypic and phenotypic strain diversity. Isolates were identified by 16S rRNA gene sequencing and tested for the production of the blue pigment at various temperatures on Mascarpone agar and in Mozzarella preserving fluid (the salty water in which the cheese is conserved, which becomes enriched by cheese minerals and peptides during storage). Pulsed-field gel electrophoresis analysis after treatment with the endonuclease SpeI separated the isolates into 42 genotypes at a similarity level of 80%. Based on the pulsotype clustering, 12 representative strains producing the blue discoloration were chosen for the multilocus sequence typing targeting the gyrB, glnS, ileS, nuoD, recA, rpoB, and rpoD genes. Four new sequence typing profiles were discovered, and the concatenated sequences of the investigated loci grouped the tested strains into the so-called “blue branch” of the P. fluorescens phylogenetic tree, confirming the linkage between pigment production and a specific genomic cluster. Growth temperature affected pigment production; the blue discoloration appeared at 4 and 14°C but not at 30°C. Similarly, the carbon source influenced the phenomenon; the blue phenotype was generated in the presence of glucose but not in the presence of galactose, sodium succinate, sodium citrate, or sodium lactate.

scholarly journals Antimicrobial activity of four essential oils against pigmenting Pseudomonas fluorescens and biofilmproducing Staphylococcus aureus of dairy origin

2017 ◽  
Vol 6 (4) ◽  
Author(s):  
Francesca Pedonese ◽  
Filippo Fratini ◽  
Luisa Pistelli ◽  
Federica Maria Porta ◽  
Pierluigi Di Ciccio ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Essential Oils ◽  
Pseudomonas Fluorescens ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Production Chain ◽  
Spectrometry Analysis ◽  
Blue Discoloration ◽  
Milk And Dairy Products

Essential oils (EOs) are mixtures of secondary metabolites of plant origin with many useful properties, among which the antimicrobial activity is also of interest for the food industry. EOs can exert their antimicrobial potential both directly, in food products and active packaging, and indirectly, as sanitizing and anti-biofilm agents of food facility surfaces. Aim of this research was to evaluate the antimicrobial activity of four EOs (bergamot, cinnamon, manuka and thyme) against Pseudomonas fluorescens and Staphylococcus aureus isolated from milk and dairy products. The chemical composition of EOs was evaluated by Gas Chromatography-Mass Spectrometry analysis. Minimum Inhibitory Concentration values were determined by a microplate method against 9 Ps. fluorescens from marketed mozzarella with blue discoloration defect, and 3 biofilm-producing S. aureus from milk. Reference ATCC strains were included. Pigment production activity by Ps. fluorescens was assessed both in culture and in cheese. EOs of manuka (leptospermone 23%) and thyme (carvacrol 30%, pcymene 20%, thymol 15%) showed the highest antimicrobial activity against S. aureus, MIC values were 0.012%-0.024% and 0.024% v/v, respectively; meanwhile EOs from thyme and cinnamon (cinnamaldehyde 55%) exhibited the best activity against Ps. fluorescens with MIC values of 0.098%-0.195% and 0.195%-0.391% v/v, respectively. The antimicrobial activity of these EOs is promising and they could be exploited in the dairy production chain.

Pepsin-digested bovine lactoferrin prevents Mozzarella cheese blue discoloration caused by Pseudomonas fluorescens

2015 ◽  
Vol 46 ◽  
pp. 15-24 ◽  
Author(s):  
Leonardo Caputo ◽  
Laura Quintieri ◽  
Daniela Manila Bianchi ◽  
Lucia Decastelli ◽  
Linda Monaci ◽  
...  
Keyword(s):  
Pseudomonas Fluorescens ◽  
Bovine Lactoferrin ◽  
Mozzarella Cheese ◽  
Blue Discoloration

Exemplar Abstract for Pseudomonas fluorescens Migula 1895 (Approved Lists 1980).

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Pseudomonas Fluorescens

Exemplar Abstract for Pseudomonas fluorescens Migula 1895 (Approved Lists 1980).

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Pseudomonas Fluorescens

Nomenclature Abstract for Pseudomonas fluorescens Migula 1895 (Approved Lists 1980).

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Pseudomonas Fluorescens

Sidrophore Production and Phosphate Solubilization by Bacillus cereus and Pseudomonas fluorescens Isolated from Iraqi Soils and Soil Characterization

2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Zaid Raad Abbas ◽  
Aqeel Mohammed Majeed Al-Ezee ◽  
Sawsan H
Keyword(s):  
Bacillus Cereus ◽  
Pseudomonas Fluorescens ◽  
Phosphate Solubilization ◽  
Bacterial Species ◽  
Nutrient Status ◽  
Bacterial Count ◽  
Soil Samples ◽  
Phosphate Solubilizing Bacteria ◽  
Clear Zone ◽  
Zone Formation

This study was conducted to explore the ability of Pseudomonas fluorescens and Bacillus cereus to solubilizing a phosphate in soil for enhancing the planting growth and, its relation with soill characterization. The isolates were identified as P.fluorescens and B. cereus using convential analysis and, its phosphate solubilization ability and sidrophore was shown by the clear zone formation on National Botanical Research Institute���s Phosphate medium. Moreover, Pseudomonas fluorescens isolates (n = 9) and three of B. cereus isolated from agricultural area in Baghdad university, Mustansiriyah university and Diyala bridge. Results displayed that bacterial count were varied in soil samples according to their region, and ranging from 30 to 60 *10 2 CFU/g in Baghdad university soil to 10���20 *10 2 CFU/g in Mustansiriyah university soil, the Baghdad soil macronutrient which included: NH4, NO3, P, and K were, 8.42, 20.53, 19.09, 218.73 respectively, While the physio analysis revealed that the mean of pH was 7.3 and EC was 8.63. on the other hand the micronutrient analysis indicated that the soil samples were included Ca, Fe, Mn, Zn and Cu which gave their mean 5025.9, 8.9, 4.9, 0.5 and 1.5 respectevily. Results revealed that all isolated bacteria (9 isolates of P.fluorescens and three isolates of B. cereus gave ahalo zone which mean their ability to be phosphate solubilizing bacteria at 100%. Results revealed that all isolated bacteria were detected a ability to produce high levels from chelating agents (siderophores)) by P.fluorescens and. B cereus at 100%, when appeared ahalo clear zone. Furthermore, the high levels of phosphate solubilization and siderophore production were grouped in bacterial species isolated from Iraqi soils. might be attributed to many soil factors such as soil nutrient status, soil acidity, water content, organic matter and soil enzyme activities.

ANTIBIOTIC PROFILE AND ANTIBACTERIAL ACTIVITY OF COPPER OXIDE NANOPARTICLES AGAINST Pseudomonas fluorescens ISOLATED FROM WOUND INFECTION

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Haider Qassim Raheem ◽  
Takwa S. Al-meamar ◽  
Anas M. Almamoori
Keyword(s):  
Antibacterial Activity ◽  
Copper Oxide ◽  
Pseudomonas Fluorescens ◽  
Wide Spectrum ◽  
Copper Oxide Nanoparticles ◽  
Morphological Properties ◽  
Clinical Samples ◽  
Oxide Nanoparticles ◽  
Cuo Nps ◽  
Disk Diffusion Assay

Fifty specimens were collected from wound patients who visited Al-Hilla Teaching Hospital. The samples were grown on Blood and MacConkey agar for 24-48 hr at 37oC. The bacterial isolates which achieved as a pure and predominant growth from clinical samples as Pseudomonas fluorescens, were identified using morphological properties and Vitek2 system. The anti-bacterial activity of copper oxide nanoparticles (CuO NPs) against was tested by (disk diffusion assay) using dilutions of (400, 200, 100, 50, 25, and 12.5‎µ‎g/ml). The (MIC and MBC) of each isolate was determined. CuO NPs shows wide spectrum antibacterial activity against tested bacteria with rise zone of inhibition diameter that is proportionate with the increase in nanoparticle concentration. The MIC of CuO NPs extended from 100-200‎µ‎g/ml and the MBC ranged from 200-400‎µ‎g/ml. The antibiotic profile was determined by Viteck 2 compact system (Biomérieux). CuO NPs‎ found highly effective and safe in P. fluorescens wounds infections comparing with used antibiotics.

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