Category Archives: Pseudomonas aeruginosa

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


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 – Decontamination of Pathogenic and Spoilage Bacteria on Pork and Chicken Meat by Liquid Plasma Immersion


In this research, we aimed to reduce the bacterial loads of Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coliCampylobacter jejuniStaphylococcus aureus, and Pseudomonas aeruginosa in pork and chicken meat with skin by applying cold plasma in a liquid state or liquid plasma. The results showed reductions in S. Enteritidis, S. Typhimurium, E. coli, and C. jejuni on the surface of pork and chicken meat after 15 min of liquid plasma treatment on days 0, 3, 7, and 10. However, the efficacy of the reduction in S. aureus was lower after day 3 of the experiment. Moreover, P. aeruginosa could not be inactivated under the same experimental conditions. The microbial decontamination with liquid plasma did not significantly reduce the microbial load, except for C. jejuni, compared with water immersion. When compared with a control group, the pH value and water activity of pork and chicken samples treated with liquid plasma were significantly different (p ≤ 0.05), with a downward trend that was similar to those of the control and water groups. Moreover, the redness (a*) and yellowness (b*) values (CIELAB) of the meat decreased. Although the liquid plasma group resulted in an increase in the lightness (L*) values of the pork samples, these values did not significantly change in the chicken samples. This study demonstrated the efficacy of liquid plasma at reducing S. Enteritidis, S. Typhimurium, E. coliC. jejuni, and S. aureus on the surface of pork and chicken meat during three days of storage at 4–6 °C with minimal undesirable meat characteristics. View Full-Text

Research – PDIA, an Iminosugar Compound with a Wide Biofilm Inhibitory Spectrum Covering Both Gram-Positive and Gram-Negative Human Bacterial Pathogens


Many difficult-to-treat human infections related to catheters and other indwelling devices are caused by bacteria residing in biofilms. One of the key properties of microorganisms residing in a biofilm is decreased susceptibility towards antimicrobial agents. Therefore, many different approaches have been researched to destroy or inhibit biofilm production by bacteria. Different iminosugars (IS) were reported to inhibit biofilm formation in S. mutansS. aureus, and P. aeruginosa. The aim of this study was to look for a spectrum of the activity in one of these IS. The iminosugar PDIA beta-1-C-propyl-1,4-dideoxy-1,4-imino-L-arabinitol was tested in vitro at the same concentration against 30 different strains of the most important Gram-negative and Gram-positive human pathogens looking for their biofilm production and viability at different time intervals. It appeared that PDIA inhibited biofilm production of Enterobacter spp., P. aeruginosaEnterococcus spp. and S. aureus in 8 h, and Klebsiella spp., Acinetobacter spp. and S.epidermidis in 24 h. PDIA caused no growth inhibition of the tested bacteria at a concentration of 0.9 mM. Our results indicate a broad-spectrum biofilm inhibitory activity of PDIA. which may be the basis for future application studies that will help in control of the associated device and biofilm-related infections caused by a wide spectrum of the causative agents. 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 – Pathogenesis of the Pseudomonas aeruginosa Biofilm: A Review


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

USA – FDA Enforcement Report – MaryRuth’s Organic Infants Liquid Probiotic; Unflavored, a Dietary Supplement – Pseudomonas aeruginosa.


Product Description:  Updated

MaryRuth’s Organic Infants Liquid Probiotic; Unflavored, a Dietary Supplement.1 fl. oz. (30 mL)UPC: 8 56645 00858 7Serving size (five drops – start with one and work up to 5)Organic Proprietary Probiotic Blend 250 mg. Bifidobacterium lactis Bifidobacterium infantis Bifidobacterium bifidum Lactobacillus reuteri Other ingredients: A blend of probiotics in an enzyme enriched substrate, extracted with water from a proprietary blend of three organic grasses.

Reason for Recall: Internal testing found the presence of Pseudomonas aeruginosa in the product.

Product Quantity: Lot# 100420218 = 23,223 Lot# 100520218 = 2,450

Recall Number: F-0214-2022

Code Information: lots: 100420218, expiry 4/2023 and 100520218, expiry 5/2023

Classification: Class I

Event ID: 88956

Voluntary / Mandated:

Voluntary: Firm initiated

Product Type: Food

Recalling Firm:

1171 S Robertson Blvd #
Los Angeles, CA 90035-1403
United States

Recall Initiation Date: 10/28/2021

Center Classification Date: 11/19/2021

Date Terminated:2/18/2022

UK – Water quality – Risk assessments for Pseudomonas aeruginosa and other waterborne pathogens. Code of practice


CDC Pseudomonas


What is BS 8580-2 – Risk assessments for Pseudomonas aeruginosa about?

Our experts identified a lack of guidance on how to conduct risk assessments for Pseudomonas aeruginosa (PA) and other opportunistic waterborne pathogens other than Legionella. To fill that gap, BS 8580-2 is a new British Standard recommending a PA risk assessment process and supplying information and support on how to understand microbial hazards, prioritize actions and minimize risks.

Who is BS 8580-2 – Risk assessments for Pseudomonas aeruginosa for?

BS 8580-2 on risk assessments for pseudomonas aeruginosa applies in all types of healthcare provision, including hospitals, and care, nursing and residential homes, together with other settings where water systems and associated equipment can pose a risk. This can include in the educational, travel, industrial, leisure and beauty sectors, including health spas, nail bars and tattoo parlours.

Users of BS 8580-2 will be building and design engineers and architects; providers of fittings, outlets and components for water systems; installers and commissioners; risk assessors; regulatory bodies; building services engineers; water treatment consultants; travel, leisure and other relevant buildings owners and operators; and those responsible for the safe management of water systems, especially within leisure centres, schools, swimming pools, passenger vessels, spa pools, hot tubs etc.

BS 8580-2 will also interest clinicians, microbiologists, augmented care specialists and infection controllers in healthcare.

What does BS 8580-2 – Risk assessments for Pseudomonas aeruginosa cover?

BS 8580-2 gives recommendations and guidance on how to carry out risk assessments for pseudomonas aeruginosa (PA) and other waterborne pathogens whose natural habitat is within constructed water systems and the aqueous environment (autochthonous), rather than those present as a result of a contamination event. It includes those pathogens that can colonize and grow within water systems and the associated environment.

BS 8580-2 also covers risk assessments of distributed water systems and associated equipment, system components and fittings as well as above ground drainage systems. It covers PA risk assessment reviews and reassessments where a previous assessment has been undertaken and risk factors identified. It takes account of all relevant environmental and clinical factors and aspects of human behaviour leading to contamination events. It considers risk factors within the associated environment leading to conditions which can encourage the colonization and growth of waterborne pathogens and transfer of antibiotic resistance.

NOTE: BS 8580-2 does not cover risk assessments for Legionella spp.; these are covered in BS 8580-1, or risk assessments for enteric microorganisms derived from human or animal faecal contamination or sewage ingress.

Why should you use BS 8580-2 – Risk assessments for Pseudomonas aeruginosa?

You should use BS 8580-2 on risk assessments for pseudomonas aeruginosa because:

  • It plugs an information gap in relation to pseudomonas aeruginosa (PA) risk assessments, taking its unique additional considerations into account
  • It codifies the latest and most efficient approach to multidisciplinary PA risk assessments
  • Its recommended processes can be applied to other opportunistic waterborne pathogens
  • It can help healthcare providers demonstrate compliant risk management in respect of Dept of Health Guidance
  • It can help leisure sector organizations maintain compliance with their legal health and safety obligations
  • It can help users develop their expertise in risk assessment and strengthen organizational risk management

BS 8580-2 contributes to UN Sustainable Development Goal 3 on good health and well-being and Goal 6 on clean water and sanitation.

Research – Detrimental Effect of Ozone on Pathogenic Bacteria


Background: Disinfection of medical devices designed for clinical use associated or not with the growing area of tissue engineering is an urgent need. However, traditional disinfection methods are not always suitable for some biomaterials, especially those sensitive to chemical, thermal, or radiation. Therefore, the objective of this study was to evaluate the minimal concentration of ozone gas (O3) necessary to control and kill a set of sensitive or multi-resistant Gram-positive and Gram-negative bacteria. The cell viability, membrane permeability, and the levels of reactive intracellular oxygen (ROS) species were also investigated;

Material and Methods: Four standard strains and a clinical MDR strain were exposed to low doses of ozone at different concentrations and times. Bacterial inactivation (cultivability, membrane damage) was investigated using colony counts, resazurin as a metabolic indicator, and propidium iodide (PI). A fluorescent probe (H2DCFDA) was used for the ROS analyses;

Results: No reduction in the count colony was detected after O3 exposure compared to the control group. However, the cell viability of E. coli (30%), P. aeruginosa (25%), and A. baumannii (15%) was reduced considerably. The bacterial membrane of all strains was not affected by O3 but presented a significant increase of ROS in E. coli (90 ± 14%), P. aeruginosa (62.5 ± 19%), and A. baumanni (52.6 ± 5%);

Conclusion: Low doses of ozone were able to interfere in the cell viability of most strains studied, and although it does not cause damage to the bacterial membrane, increased levels of reactive ROS are responsible for causing a detrimental effect in the lipids, proteins, and DNA metabolism. View Full-Text

RASFF Alert- Pseudomonas aeruginosa – Natural Mineral Water


Presence of Pseudomonas aeruginosa in Alcalia Natural Mineral Water from Bulgaria in Ireland and Poland

Research – The Application of Bacillus subtilis for Adhesion Inhibition of Pseudomonas and Preservation of Fresh Fish


Inhibiting the growth of spoilage bacteria, such as Pseudomonas spp., is key to reducing spoilage in fish. The mucus adhesion test in vitro showed that the adhesion ability of Bacillus subtilis was positively correlated with its inhibition ability to Pseudomonas spp. In vivo experiments of tilapia showed that dietary supplementation with B. subtilis could reduce the adhesion and colonization of Pseudomonas spp. in fish intestines and flesh, as well as reduce total volatile basic nitrogen (TVB-N) production. High throughput and metabolomic analysis showed treatment with B. subtilis, especially C6, reduced the growth of Pseudomonas spp., Aeromonas spp., Fusobacterium spp., and Enterobacterium spp., as well as aromatic spoilage compounds associated with these bacteria, such as indole, 2,4-bis(1,1-dimethylethyl)-phenol, 3-methyl-1-butanol, phenol, and 1-octen-3-ol. Our work showed that B. subtilis could improve the flavor of fish by changing the intestinal flora of fish, and it shows great promise as a microecological preservative. View Full-Text