Rapid Methods in Cosmetic Microbiology
Philip A. Geis in Cosmetic Microbiology, 2020
Impedance microbiology is based on the premise that microbial growth results in the breakdown of larger, relatively uncharged molecules into smaller, highly charged molecules (e.g., proteins into amino acids, fats into fatty acids and polysaccharides/sugars into lactic acid). Growth may be detected by monitoring the movement of ions between electrodes (conductance) or the storage of charge at an electrode surface (capacitance). Impedance systems can detect changes in measurable electrical threshold in liquid media (during microbial growth) when microorganisms proliferate in containers that include electrodes. Growth may, therefore, be detected prior to the liquid media showing any signs of turbidity. Impedance systems were utilized as one of the original rapid methods for screening antimicrobials and preservatives in the early 1990s. The Sy-Lab BacTrac system is an example of this technology that is available currently.
Synovial Fluid
Verna Wright, Eric L. Radin in Mechanics of Human Joints, 2020
The turbidity usually parallels the leukocyte concentration. However, in some chronic arthritis fluids, mostly from RA patients, large amounts of so-called rice bodies gives a totally opaque fluid, although leukocyte counts are only moderately elevated. Rice bodies consist of collagen fibers, cellular debris, and fibrin. The collagen in the rice bodies originates from the synovium , not from the cartilage (45,46). Rice bodies commonly obstruct the needle, and it is often difficult to obtain complete SF withdrawal when they are present. Purulent synovial fluids are creamy white and relatively easy to aspirate, since the viscosity is much reduced (3), but they may coagulate rapidly. However, the viscosity may be high because of the presence of coagulase-positive staphylococci (3). In septic arthritis SF may also be bloody.
Ecology
Paul Pumpens in Single-Stranded RNA Phages, 2020
Meanwhile, the putative protectors against the phage MS2 inactivation by the UV irradiation were identified. Thus, coagulation of the phage MS2 with kaolin clay particles or aggregation by alum into viral clumps prior to the UV exposure reduced the inactivation efficiency (Templeton et al. 2003, 2005). The humic acid−coated MS2 particles were, however, more resistant to the UV inactivation (Templeton et al. 2006b). The phage MS2 particles that were associated with iron oxide particles in groundwater were shielded from UV light (Templeton et al. 2006a). The water turbidity had a negative impact on UV disinfection due to particle association with the seeded phage MS2 (Hu et al. 2007). The phage MS2 was involved as an indicator in the large study on a potential of naturally occurring particles to protect indigenous coliform by the UV irradiation of the unfiltered surface water (Cantwell and Hofmann 2008).
Inhibitory effect of proteinase K against dermatophyte biofilms: an alternative for increasing the antifungal effects of terbinafine and griseofulvin
Published in Biofouling, 2022
Raimunda Sâmia Nogueira Brilhante, Raissa Geovanna Pereira Lopes, Lara de Aguiar, Jonathas Sales de Oliveira, Géssica dos Santos Araújo, Germana Costa Paixão, Waldemiro de Aquino Pereira-Neto, Rosemayre Souza Freire, João Victor Serra Nunes, Renan Pereira de Lima, Flávia Almeida Santos, José Júlio Costa Sidrim, Marcos Fábio Gadelha Rocha
Inocula were prepared as described in a previous study (Costa-Orlandi et al. 2014) from colonies grown for seven days on potato dextrose agar (Difco-Dickinson), at 28 °C, or oatmeal agar for T. rubrum, as recommended by CLSI (2017). Cultures were covered with 5 ml of sterile 0.9% saline solution and the surface of the colonies was scraped with sterile swabs. Each resulting mixture was transferred to a sterile tube and allowed to decant for 5–10 min for sedimentation of the hyphae. Then, the supernatant containing micro and macroconidia was transferred to a new sterile tube. Turbidity was then adjusted to 0.5 on the McFarland scale, containing 2–6 × 106 CFU ml−1. Subsequently, the inoculum was diluted with sterile 0.9% saline to final concentrations of 1 × 103 CFU ml−1 for planktonic testing and 1 × 106 CFU ml−1 for the formation of biofilm in vitro, using a haemocytometer.
In Vitro and In Silico Evaluation of Betulin on Calcium Oxalate Crystal Formation
Published in Journal of the American College of Nutrition, 2019
Ranjeet Kumar Nirala, Pratuyasha Dutta, Md Zubbair Malik, Lalita Dwivedi, Tulsidas G. Shrivastav, Sonu Chand Thakur
Nucleation is a consecutive step for renal stone formation. Figure 3a shows the effect of the different concentrations of the betulin and cystone on the nucleation of CaOx crystals. Urine without phytochemical was considered as a control. With respect to control, the absorbance in betulin-containing tubes increased with increasing concentrations of betulin in a dose-dependent manner. Cystone was used as a positive control, which showed the higher antiurolithiatic activity at all concentrations as compared to betulin. The values are depicted as mean ± SD. In nucleation assay, the turbidity was found to be 0.16 ± 0.02 on addition of 5 µg betulin in comparison to cystone, which gave 0.17 ± 0.047. At 160 µg concentration of betulin the turbidity (OD) increases to 0.528 ± 0.017 in comparison to cystone, which gave 0.681 ± 0.021. This indicates that betulin helps in preventing crystal formation in nucleation assay. Turbidity was directly proportional to the concentration phytochemical used.
Using ultraviolet light for improved antifouling performance on ship hull coatings
Published in Biofouling, 2019
Kelli Z. Hunsucker, Cierra Braga, Harrison Gardner, Michel Jongerius, Roelant Hietbrink, Bart Salters, Geoffrey Swain
The impact of turbidity is important to consider when implementing UV systems in the marine environment. Increased turbidity can decrease the UV transmittance and affect the delivery to the surface. It can also shield microorganisms from the UV light, altering the dose–response curve (Wen-jun and Yong-ji 2006). As seen with the current results, the lower transmission through seawater (60%) resulted in the lower threshold intensity for preventing biofouling settlement. Turbidity can vary based on environmental conditions as well as geographical location. A greater distance of travel for the UVC through the seawater will also impact the overall AF area on the surface. In this study, there was no significant difference with the presence fouling organisms between the two tested distances (25 and 50 mm). However, should this distance have been greater, noticeable differences in the overall fouling accumulation would have been seen (Braga 2018).
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