Category Archives: Pseudomonas

Research – Dynamic Changes of Bacterial Communities and Microbial Association Networks in Ready-to-Eat Chicken Meat during Storage

MDPI

Ready-to-eat (RTE) chicken is a popular food in China, but its lack of food safety due to bacterial contamination remains a concern, and the dynamic changes of microbial association networks during storage are not fully understood. This study investigated the impact of storage time and temperature on bacterial compositions and microbial association networks in RTE chicken using 16S rDNA high-throughput sequencing. The results show that the predominant phyla present in all samples were Proteobacteria and Firmicutes, and the most abundant genera were WeissellaPseudomonas and Proteus. Increased storage time and temperature decreased the richness and diversity of the microorganisms of the bacterial communities. Higher storage temperatures impacted the bacterial community composition more significantly. Microbial interaction analyses showed 22 positive and 6 negative interactions at 4 °C, 30 positive and 12 negative interactions at 8 °C and 44 positive and 45 negative interactions at 22 °C, indicating an increase in the complexity of interaction networks with an increase in the storage temperature. Enterobacter dominated the interactions during storage at 4 and 22 °C, and Pseudomonas did so at 22 °C. Moreover, interactions between pathogenic and/or spoilage bacteria, such as those between Pseudomonas fragi and Weissella viridescensEnterobacter unclassified and Proteus unclassified, or those between Enterobacteriaceae unclassified and W.viridescens, were observed. This study provides insight into the process involved in RTE meat spoilage and can aid in improving the quality and safety of RTE meat products to reduce outbreaks of foodborne illness. View Full-Text

Research – Microbial Properties of Raw Milk throughout the Year and Their Relationships to Quality Parameters

MDPI

Raw milk microbiota is complex and influenced by many factors that facilitate the introduction of undesirable microorganisms. Milk microbiota is closely related to the safety and quality of dairy products, and it is therefore critical to characterize the variation in the microbial composition of raw milk. In this cross-sectional study, the variation in raw milk microbiota throughout the year (n = 142) from three farms in China was analyzed using 16S rRNA amplicon sequencing, including α and β diversity, microbial composition, and the relationship between microbiota and milk quality parameters. This aimed to characterize the contamination risk of raw milk throughout the year and the changes in quality parameters caused by contamination. Collection month had a significant effect on microbial composition; microbial diversity was higher in raw milk collected in May and June, while milk collected in October and December had the lowest microbial diversity. Microbiota composition differed significantly between milk collected in January–June, July–August, and September–December (p < 0.05). Bacterial communities represented in raw milk at the phylum level mainly included Proteobacteria, Firmicutes and Bacteroidota; PseudomonasAcinetobacterStreptococcus and Lactobacillus were the most common genera. Redundancy analysis (RDA) found strong correlations between microbial distribution and titratable acidity (TA), fat, and protein. Many genera were significantly correlated with TA, for example Acinetobacter (R = 0.426), Enhydrobacter (R = 0.309), Chryseobacterium (R = 0.352), Lactobacillus (R = −0.326), norank_o__DTU014 (R = −0.697), norank_f__SC-I-84 (R = −0.678), and Subgroup_10 (R = −0.721). Additionally, norank_f__ Muribaculaceae was moderately negatively correlated with fat (R = −0.476) and protein (R = −0.513). These findings provide new information on the ecology of raw milk microbiota at the farm level and contribute to the understanding of the variation in raw milk microbiota in China. View Full-Text

RASFF Alert – Mould – Pseudomonas – Mozzarella

RASFF

Deviating taste and high content of moulds and pseudomonads in buffalo mozzarella from Italy in Germany

Research – Biofilm Formation of Listeria monocytogenes and Pseudomonas aeruginosa in a Simulated Chicken Processing Environment

MDPI

This study aims to investigate the mono- and dual-species biofilm formation of Listeria monocytogenes and Pseudomonas aeruginosa incubated in different culture mediums, inoculum ratios, and incubation time. The planktonic cell population and motility were examined to understand the correlation with biofilm formation. The results showed that chicken juice significantly inhibited the biofilm formation of L. monocytogenes (p < 0.05). Pseudomonas aeruginosa was the dominant bacteria in the dual-species biofilm formation in the trypticase soy broth medium. The dynamic changes in biofilm formation were not consistent with the different culture conditions. The growth of planktonic L. monocytogenes and P. aeruginosa in the suspension was inconsistent with their growth in the biofilms. There was no significant correlation between motility and biofilm formation of L. monocytogenes and P. aeruginosa. Moreover, scanning electron microscopy (SEM) results revealed that the biofilm structure of L. monocytogenes was loose. At the same time, P. aeruginosa formed a relatively dense network in mono-species biofilms in an initial adhesion stage (24 h). SEM results also showed that P. aeruginosa was dominant in the dual-species biofilms. Overall, these results could provide a theoretical reference for preventing and controlling the biofilm formation of L. monocytogenes and P. aeruginosa in the food processing environment in the future. View Full-Text

Research – Spanish study finds organic produce contamination

Food Safety News

Early findings from researchers in Spain has found organic produce can be contaminated with a range of bacteria.

The study suggests that amoebas that live on organic leafy vegetables can shelter human pathogens like Pseudomonas, Salmonella, and Helicobacter.

Details are based on a poster presentation at the European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) in Lisbon, Portugal, from April 23 to 26. All abstracts were peer reviewed by a congress committee. There is no paper yet, but the research has been submitted to a medical journal for publication.

However, other scientists warned that while conclusions are interesting, the fact that data has not yet been peer reviewed means they cannot be put into context.

Research – Plant Extract and Essential Oil Application against Food-Borne Pathogens in Raw Pork Meat

MDPI

Herbal and plant extracts are being applied for a wide range of foods against different types of food-borne pathogens. In the present study, ethanolic and aqueous extracts (2% w/v) from cranberry (Vaccinium macrocarpon) and pomegranate (Punica granatum L.) plants were applied alone or in combination with two essential oils (thyme and oregano in a concentration of 0.150 μg/g) in pork meatballs and their antimicrobial activity was estimated. The extracts exhibited promising results (aqueous and ethanolic extracts of pomegranate and cranberry in a food-compatible concentration of 2% w/v) were applied to raw pork meatball production and their antimicrobial activity was recorded versus Enterobacteriaceae, total mesophilic bacteria, yeasts/molds, Staphylococcus spp., Pseudomonas spp. and lactic acid bacteria (LAB). The outcome demonstrated that meatballs containing aqueous extracts of pomegranate were more resistant to spoilage compared to all the other samples since they were preserved for more days. The chemical profiles of plant extracts were determined through LC-QTOF/MS and the chemical composition of the essential oils applied was determined with the use of GC/MS in order to identify the substances involved in the observed antimicrobial activity. Phenolic acids (quinic acid, chlorogenic acid), monoterpenes (p-cymene, carvacrol, thymol, limonene), organic acids (citric acid) and phenols were the main constituents found in the plant extracts and essential oils applied. These extracts of plant origin could be used as natural preservatives in meat products, even in low concentrations. View Full-Text

RASFF Alert – Pseudomonas fluorescens

RASFF

Burrata – Pseudomonas fluorescens – Italie in France

France – BURRATA ROUTE OF FLAVORS 200G – Pseudomonas fluorescens

Gov france

Identification information of the recalled product

  • Product category Food
  • Product subcategory Milk and dairy products
  • Product brand name ITINERARY OF FLAVORS
  • Model names or references BURRATA 200G
  • Identification of products
    GTIN Lot Dated
    3250392341695 L713 Use-by date 03/12/2022
    3250392341695 L423 Use-by date 05/03/2022
    3250392341695 L323 Use-by date 06/03/2022
    3250392341695 L903 Use-by date 20/03/2022
    3250392341695 L413 Use-by date 03/15/2022
    3250392341695 L613 Use-by date 03/13/2022
    3250392341695 L013 Use-by date 03/19/2022
    3250392341695 L123 Use-by date 08/03/2022
  • Packaging GREEN PRINTED PLASTIC POT
  • Marketing start/end date From 02/15/2022 to 03/03/2022
  • Storage temperature Product to be stored in the refrigerator
  • Health mark IT 16/153 CE
  • Geographic area of ​​sale Whole France
  • Distributors INTERMARCHE

Practical information regarding the recall

  • Reason for recall PRESENCE OF PSEUDOMONAS FLUORESCENS
  • Risks incurred by the consumer Pseudomonas
  • Additional description of the risk NO PATHOGENIC RISK – BUT PRODUCT DEGRADATION

France – BURRATA 100G – 120G – 200G – Pseudomonas fluorescens

Gov france

Identification information of the recalled product

  • Product category Food
  • Product subcategory Milk and dairy products
  • Product brand name TRADITIONI D’ITALIA
  • Model names or references BURRATA DI PUGLIA 200G – BURRATA DI ANDRIA IGP 120G and 200G – BURRATA CON TARTUFO ESTIVO 100G
  • Identification of products
    GTIN Lot Dated
    3760113766282 All lots Use-by date between 05/03/2022 and 19/03/2022
    3664335100322 All lots Use-by date between 05/03/2022 and 19/03/2022
    3760113768866 All lots Use-by date between 05/03/2022 and 19/03/2022
  • Packaging JARS OF 100G – 120G – 200G
  • Marketing start/end dateFrom 02/15/2022 to 03/03/2022
  • Storage temperature Product to be stored in the refrigerator
  • Health mark IT 16 153 EC
  • Geographic area of ​​sale Whole France
  • Distributors E.LECLERC

Practical information regarding the recall

  • Reason for recall Risk of presence of Pseudomonas fluorescens
  • Risks incurred by the consumer Pseudomonas
  • Additional description of the risk This bacterium is likely to degrade the product and give it a bad taste and a bluish color, making it inedible.

Research – Pathogenesis of the Pseudomonas aeruginosa Biofilm: A Review

MDPI

Pseudomonas aeruginosa is associated with several human infections, mainly related to healthcare services. In the hospital, it is associated with resistance to several antibiotics, which poses a great challenge to therapy. However, one of the biggest challenges in treating P. aeruginosa infections is that related to biofilms. The complex structure of the P. aeruginosa biofilm contributes an additional factor to the pathogenicity of this microorganism, leading to therapeutic failure, in addition to escape from the immune system, and generating chronic infections that are difficult to eradicate. In this review, we address several molecular aspects of the pathogenicity of P. aeruginosa biofilms. View Full-Text