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Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Most bacteria synthesize insoluble, extracellular polymers that accumulate outside the cell envelope. When these polymers accumulate around single cells or pairs of cells, the structures formed are usually referred to as capsules (Figure 15.6); whereas the term slime layer is used to describe similar material that is produced in rather copious amounts and surrounds clusters of cells. In some instances extracellular polymer diffuses away from the cells, resulting in increased viscosity of the surrounding liquid medium.
Basic Microbiology
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Capsules and slime layers—These are extracellular layers of carbohydrates that are well organized and firmly attached to the cell (capsule) or disorganized and loosely attached to the cell (slime layer) that are utilized for attachment to surfaces and sometimes to avoid host immune responses.
Management of endophthalmitis
Published in A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha, Vitreoretinal Surgical Techniques, 2019
Mandi D Conway, Gholam A Peyman
Bacterial endophthalmitis also occurs (rarely) after secondary IOL implantation. It is associated with diabetes, transscleral suture fixation of posterior chamber IOLs, polypropylene haptics, preoperative eyelid abnormalities, re-entry into the eye through a previous wound, and postoperative wound defects. When cultured, many of the eyes grow Staphylococcus epidermidis . This is easily treated, and subsequent visual outcomes are generally good.27 Some IOLs also may allow bacterial adhesion and subsequent endophthalmitis. The bacteria are embedded in a slime layer that allows replication and multiple microcolonies. In vitro studies have shown hydrophilic materials and hydrophilic acrylic to be less conducive to bacterial adhesion than silicone or polymethyl methacrylate (PMMA).28,29
Anti-biofouling properties of poly(dimethyl siloxane) with RAFT photopolymerized acrylate/methacrylate surface grafts against model marine organisms
Published in Biofouling, 2021
Cary A. Kuliasha, Rebecca L. Fedderwitz, Shane J. Stafslien, John A. Finlay, Anthony S. Clare, Anthony B. Brennan
Marine bacteria, including C. lytica, are some of the primary fouling species of surfaces that are responsible for the initial biofilm matrix or slime layer, which once established can enhance the settlement of some multicellular species such as certain invertebrates and macroalgae and can cue the settlement of some multicellular species such as certain invertebrate larvae (Huang and Hadfield 2003) and macroalgae (Joint et al. 2002). C. lytica is a motile, rod-shaped Gram-negative bacterium commonly found in coastal marine systems that forms a complex biofilm composed in part by extracellular proteins and polyanionic molecules (Johansen et al. 1999; Decho and Gutierrez 2017). C. lytica in vitro screening assays have been shown to effectively correlate with the ABF performance of coatings under oceanic ‘real-world’ testing (Stafslien et al. 2007). Several biofouling tests were performed using C. lytica to understand the ABF characteristics of the test surfaces including: (1) leachate testing to determine potential toxicity arising from the test surfaces, (2) biofilm growth of settled bacteria over 24h to determine AF performance, and (3) biofilm removal using a water jet to determine the FR performance. As with diatoms, the IS 1100SR industrial coating was also included in bacterial testing.
In situ characterisation of biofilms formed by psychrotrophic meat spoilage pseudomonads
Published in Biofouling, 2019
Nirmani N. Wickramasinghe, Joshua T. Ravensdale, Ranil Coorey, Gary A. Dykes, P. Scott Chandry
The meat industry uses chilled temperature conditions for storage and transportation of raw meat. Psychrotrophic microorganisms can survive and multiply under chilled- chain conditions which ultimately leads to spoilage. The key organoleptic degradation characteristics which render meat unacceptable for consumption are off odours, slime formation and discolorations. Even though considerable research has been undertaken characterising volatile organic compounds and microbial metabolic processes leading to meat spoilage, limited research has been done addressing slime formation (Ercolini et al. 2006; Casaburi et al. 2015; EFSA Panel on Biological Hazards (BIOHAZ) 2016). Slime formation in vacuum packed meat have been studied to some extent (Dykes et al. 1994; Duskova et al. 2013). However, surface slime formation on aerobically stored chilled meat has not been studied in detail. Slime is formed when bacteria grow on meat in as biofilms and excrete extracellular polymeric substances (Delaquis et al. 1992; Jay et al. 2003). The slime layer is composed of meat exudates, bacterial cells, extra cellular polymeric substances secreted by bacteria and hydrolysed muscle parts.
Effect of reserpine on Pseudomonas aeruginosa quorum sensing mediated virulence factors and biofilm formation
Published in Biofouling, 2018
Debaprasad Parai, Malabika Banerjee, Pia Dey, Arindam Chakraborty, Ekramul Islam, Samir Kumar Mukherjee
Congo red is a dye which binds to the biofilm EPS (Rollefson et al. 2011). Reserpine showed a notable reduction in EPS in the form of a slime layer observed around the colonies (Figure 4A). While the average diameters of the vehicle control colonies were measured to be 21 mm, they were reduced to 8 and 7 mm after the IC50 and IC80 treatments, respectively. However, the colony diameter did not vary notably at IC25 (20 mm). Pellicles were formed at the air–liquid interface of a standing liquid culture of P. aeruginosa PAO1 (Figure 4C). In this experiment, the untreated vehicle control and IC25 treated tubes showed the formation of robust pellicle with greenish pigments, but it visibly decreased after IC50 and IC80 treatments (Figure 4B and C).