New methodology for microbiological quality assurance
R. M. Baird, S. F. Bloomfield in Microbial quality assurance in cosmetics, toiletries and non-sterile Pharmaceuticals, 2017
Table 14.3 lists organisms which typically cause contamination problems in pharmaceuticals, toiletries and cosmetics. The list is divided into two groups: those that are mainly isolated and those that occur less frequency. Other organisms have also occasionally caused contamination problems in the past (see chapter 2). Pseudomonas is probably the most commonly isolated group of organisms (McCarthy 1980), particularly Pseudomonas fluorescens and P. cepacia, although in some instances difficulty in identification can make accurate categorization a problem. Many of these micro-organisms have very simple growth requirements and are adaptable to a wide range of environments (Stanier et al. 1966). As a result their detection by new methodologies must take into account the conditions in which they are found.
Physiology of Moss-Bacterial Associations
R. N. Chopra, Satish C. Bhatla in Bryophyte Development: Physiology and Biochemistry, 2019
The possibility that the growth-promoting effects of some bacteria depend on production of iron-chelating siderophores has been investigated. The Pseudomonas fluorescens-putida group is often used as an inoculant on crop plants because it increases yields by antagonizing deleterious fungi and bacteria. The production of siderophores which reduce the available iron for growth of the harmful organisms appears necessary for this response.28,29 The increase in plant growth by root-colonizing fluorescent pseudomonads in the rhizosphere is also thought to be due to siderophore production under iron-limiting conditions.30 Evidence that supports this hypothesis includes the observation that addition of iron abolishes the effect, siderophore-negative mutants do not promote growth, and addition of siderophores promotes growth. The promotion of growth and suppression of inhibition also may be due to competition for carbon compounds or the production of hormones, antibiotics, or bacteriocins.29
Potential of Piper Germplasm Against Pathogenic Bacteria: Tropical Bay Islands in India
Megh R. Goyal, Durgesh Nandini Chauhan in Assessment of Medicinal Plants for Human Health, 2020
In case of Pseudomonas fluorescens, results revealed that extracts of all the genotypes were effective as their zone of inhibition was statistically on par with the control chloramphenicol. Low antibacterial activity was recorded in extracts of P. chaba and P. betle. However, zone of inhibition of all the extracts remained much lower than the streptomycin control (Table 5.5). Low inhibitory activities of P. betle against P. fluorescence have already been recorded.27
Biofilm formation under high shear stress increases resilience to chemical and mechanical challenges
Published in Biofouling, 2022
L. C. Simões, I. B. Gomes, H. Sousa, A. Borges, M. Simões
Pseudomonas fluorescens ATCC 13525T was used throughout this study. This strain has already been used as model for biofilm control testing (Simões et al. 2005, 2009; Fernandes et al. 2020). Bacterial cells were grown overnight using a synthetic nutrient medium, with glucose as the main carbon source (glucose 5g l−1, peptone 2.5g l−1, yeast extract 1.25g l−1 and 0.2M phosphate buffer at pH 7) (Simões et al. 2009) at 25±3 °C and under agitation (120rpm) in an orbital incubator (New Brunswick Scientific, I26, USA). All growth medium compounds were purchased from Merck (VWR, Portugal). Cells were harvested by centrifugation (Eppendorf centrifuge 5810R) at 3,777 ×g, 5min, washed twice with 0.2M phosphate saline buffer (PBS; 8g l−1 of NaCl – Labkem, Spain, 0.2g l−1 of KCl – VWR, Belgium, 1.44g l−1 of Na2HPO4 and 0.24g l−1 of KH2PO – Chem-Lab NV, Belgium; pH 7) and resuspended in the same buffer (for antimicrobial activity assessment against planktonic cells) or the appropriate medium (for biofilm formation) to achieve the bacterial concentration required for further experiments.
Evaluation of the antimicrobial mechanism of biogenic selenium nanoparticles against Pseudomonas fluorescens
Published in Biofouling, 2023
Ying Xu, Ting Zhang, Jiarui Che, Jiajia Yi, Lina Wei, Hongliang Li
Refrigerated food is now playing an important role in people’s life. Pseudomonas fluorescens are dominant psychrophilic bacteria causing spoilage of refrigerated food (Remenant et al. 2015), which are gram-negative, straight rod-shaped (0.7–0.8 μm wide and 2.3–2.8 μm long), asporogenic, and bipolar flagellation. Under cold chain conditions (≤4 °C) the hydrolysis of some endogenous proteases can facilitate the growth and reproduction of bacteria, thus reducing the quality of perishable foods such as dairy products, fish, or shrimp (Jaspe et al. 2000; Wang et al. 2018; Carminati et al. 2019), and ultimately leading to the decline of food safety and economic value. In clinical research, when endotoxin produced and released by P. fluorescens enters the human blood, it will cause a series of symptoms such as intravascular coagulation and infectious shock (Gao et al. 2015). Therefore, it is necessary to inhibit the growth of P. fluorescens in foods.
Serological markers facilitate the diagnosis of Crohn’s disease
Published in Postgraduate Medicine, 2021
Xin Gao, Yan Zhang
Dysbacteriosis and an aberrant recognition of luminal microbial antigens have been emphasized in the pathogenesis of CD [1,2]. To date, a number of standardized commercial assay products for serological markers against intestinal microorganisms have emerged, with varying degrees of sensitivity and specificity. Similar to ASCA, both anti-glycosylmannose antibody (AYMA) and anti-glycosylchitosan antibody (AYCA) are polysaccharide antibodies, deriving from polysaccharides in cytoderms of bacteria, saccharomyces, or other microorganisms. FI2Y is a recombinant protein directed against Pseudomonas fluorescens. In the present study, we evaluated the value of several serological markers including ASCA, AYMA, AYCA, FI2Y, and pANCA in a Chinese cohort of suspected CD patients and tried to elucidate the associations between disease phenotype and the expression of serological markers.
Related Knowledge Centers
- Bacteria
- Cellular Respiration
- Flagellum
- Nitrate
- Obligate Aerobe
- Oxygen
- Pseudomonas
- Metabolism
- Gram-Negative Bacteria
- 16S Ribosomal Rna