scholarly journals RESISTANCE OF S. AUREUS ATCC 25923, E. COLI 055K59 No. 3912/41 AND P. AERUGINOSA 27/99 TO THE WASH-DISINFECTANT «MILKODEZ»

2020 ◽  
Vol 1 ◽  
pp. 55-60
Author(s):  
Mykola Verkholyuk ◽  
Ruslan Peleno ◽  
Iaromyr Turko

The aim of the work – the article presents the results of determining of the resistance of S. aureus ATCC 25923, E. coli 055K59 No. 3912/4 and P. aeruginosa 27/99 test cultures in planktonic form and in biofilm to our developed «Milkodez» acid detergent. Materials and methods. Microbial biofilms were grown on MPB in 5 cm disposable plastic Petri dishes. To determine the effect of disinfectants on microbial biofilms, 3 Petri dishes with biofilms of each of the test cultures were used. One of the Petri dishes served as control and she had for 15 minutes made 5 cm3 of saline NaCl solution, in the second – 5 cm3 of hot water (t=70±5 °C), and in the third – 5 cm3 of acidic detergent «Milkodez». Microbial biofilms were fixed for 10 min. 96º with ethyl alcohol for 10 min. were stained with a 0.1 % solution of crystalline violet, and the remnants of the unabsorbed paint were removed with phosphate buffer. The biofilm dye was extracted with 96º of ethyl alcohol, which was photocolometrically investigated at 570 nm to establish the density of the formed biofilms. The density of the formed microbial biofilms was considered low in optical density of the extract up to 0.5 units, average – from 0.5 to 1.0 units; and high – over 1.0 units The resistance of planktonic forms of test cultures of microorganisms to disinfectants was determined in sterile tubes, which made 10 cm3 (t=70±5 °C) of 0.5 % of their working solutions and 0.1 cm3 (1 billion microbial bodies) of the standard test – cultures. The culture was maintained for 15 min. and made ten – fold plantings on IPA in Petri dishes. Incubation of mesophilic microorganisms was carried out in a thermostat at a temperature of 30 °C, and psychrophilic – 20 °C. After 48 hours the calculation of the growing colonies were carried out. The results were expressed in colony forming units (CFU). Results. Due to the impact on microbial biofilms formed by the test cultures of S. aureus ATCC 25923, E. coli 055K59 No. 3912/41 and P. aeruginosa 27/99 for 15 min. 0.5 % solution of acid detergent «Milkodez» the optical density of the solutions was respectively 0.64, 0.72, 0.45 units. The results obtained indicate that the melkodez caused a decrease in the biofilm–forming ability of S. aureus ATCC 25923 3.2 times, in E. coli 055K59 No. 3912/41 – 1,7 times and in P. aeruginosa 27/99 – 2.8 times, compared to control. However, the density of one – day microbial biofilms formed by S. aureus ATCC 25923 and E. coli 055K59 No. 3912/41 was medium, and P. aeruginosa 27/99 was low. It has been proven that the «Milkodez» acid detergent developed is more effective than the prototype «Hypracid», since it caused the death of 100 % of planktonic test cultures and the number of S. aureus ATCC 25923, E. coli 055K59 No. 3912/41 and P. aeruginosa 27/99 formed in the biofilm that survived after its application was 2.7, 3.2 and 1.4 times lower, respectively. Conclusions. It was found that the test cultures were able to form high – density biofilms, since the optical density of the extract in the control was in the range from 1.28 to 2.05 units, which is greater than 1.0 units. Acid wash detergent «Milkodez» for 15 minutes of exposure causes the formation of S. aureus ATCC 25923, E. coli 055K59 No. 3912/41 and P. aeruginosa 27/99 biofilms of low and medium density and reduces their biofilm capacity by 3.2, 1.7 and 2.8 times, respectively. Its use provides the death of 100 % of the planktonic forms of the test cultures under study and reduces their number in the biofilm by 2.7, 3.2 and 1,4 times more, respectively, compared to «Hypracid» detergent.

2021 ◽  
Vol 23 (101) ◽  
pp. 67-74
Author(s):  
V. Kozhyn ◽  
M. Kukhtyn ◽  
V. Horiuk ◽  
O. Vichko ◽  
Y. Kryzhanivsky

Currently, the pharmaceutical industry is constantly working on the creation of ideal disinfectants that would have a wide spectrum of antimicrobial action in minimal concentrations, did not result in the formation of stability in bacteria, were not toxic, not corrosive, not allergenic, cheap. The purpose of the work was to investigate the activity of the “Enzidesis” disidissance to influence microbial biofilms in vitro conditions for various sampling parameters. The density of microbial biofilms and the effects of disinfectants were determined on sterile stainless steel plates, which were placed in a Petri dish. For this purpose, biofilms were grown on plates, washed out biofilms from planktonic cells, acted as a disguise for a certain concentration and for a period of 5–30 minutes, fixed and painted biofilms and determined the optical density of the flushing solution from biofilms spectrometrically. It has been established that the disinfectant “Enzidesis” destroys the biofilms taken in the experiment of museum test cultures S. aureus, E. coli and P. aeruginosa. In particular, for the influence of the lowest concentration in experiment, 0.075 % optical density of washing solutions from S. aureus biofilmes decreased by 2.6 times, E. coli and P. aeruginosa biofilm in 2.9 times, respectively, comparing with biofilms after treatment with water. Under the actions of such a concentration of the “Enzidesis” means, the biofilm though significantly degraded, but they were still a medium density, more than 0.5 units. Increasing the concentration of a means of 0.075 % to 0.5 % contributed to the intensity of degradation of test-cultures, an average of 3.0 times (P < 0.05) and they became a weak density (0.24–0.20 s). Increasing the concentration of the “Enzidesis” means up to 1.0 % or more, did not significantly destroy the matrix of the biofilm of microorganisms, since the optical density of the washing solutions was as in control. In determining the influence of the temperature of the working solutions of the “Enzidosis” means on its film-building activity, it has been found that with an increase in the disinfection agent “Enzidesis” with +20 to +60 °С there is an increase in the degradation of the biofilm formed S. aureus, E. coli and P. aeruginosa. Dezilities can be effectively used in 0.5 % concentration at room temperature of solutions. When substantiating the exposure time of the “Enzidesis” exhibition time, it has been found that to remove the S. aureus, E. coli and P. aeruginosa 0.5 % means at a solution temperature of +20 ± 1 °C, it is necessary that the action time is from 15 to 30 minutes.


2001 ◽  
Vol 64 (3) ◽  
pp. 310-314 ◽  
Author(s):  
STEVEN PAO ◽  
CRAIG L. DAVIS ◽  
MICKEY E. PARISH

Studies were conducted to evaluate the infiltration of dye and bacteria into the interior of orange fruit and the impact of possible infiltration on achieving a 5-log microbial reduction during fresh juice processing. Fresh orange fruit were treated at the stem end area with dye and either Salmonella Rubislaw or Escherichia coli strains expressing green fluorescent protein. Microscopic images showed that bacterial contaminants localized at the surface or near surface areas that may be sanitized by surface treatments. Dye infiltration was not a reliable indicator of bacterial penetration in citrus fruit. To quantify the reduction of bacterial contamination, orange fruit were inoculated with E. coli and processed with and without hot water treatments. Greater than 5-log reductions were achieved in juice extracted from fruit immersed in hot water for 1 or 2 min at 80°C, in comparison to the E. coli level detected in the control juice obtained by homogenization of inoculated fruit.


2021 ◽  
Vol 88 (3-4) ◽  
pp. 80-86
Author(s):  
O. I. Dronov ◽  
I. O. Kovalska ◽  
I. L. Nastashenko ◽  
T. O. Kondratiuk ◽  
L. V. Levchenko

Objective. Determination of impact of combination, consisted of 3% solution of silicon dioxide and antibacterial preparations, on bacterial cultures of S. aureus, P. aeruginosa, E. coli. Materials and methods. Clean cultures of bacteria, kept in Collection of Microorganisms in Department of Microbiology and Immunology of Training–Scientific Centre «Іnstitute of Biology and Medicine» of Taras Shevchenko National University: S. aureus (Rosenbach, 1884), P. aeruginosa (Schröter, 1872; Migula, 1900), E. coli (Migula, 1895; Castellani і Chalmers, 1919) were applied. Action of antibacterial preparations cefoperazon, cefoperazon–sulbactam, ampicillin–sulbactam, amicacin, as well as enterosorbent 3% solution of silicon dioxide, was investigated. In the investigation the impact of antibacterial preparations and silicon dioxide together with antibacterial preparations on test–cultures of bacteria was studied, using broth and agarised medium of Muller–Hinton. Results. The data, obtained in the investigation, trust efficacy of combined application of 3% solution of silicon dioxide, owing sorption capacity, with antibacterial preparations in reduction or elimination of subsequent growth of bacterial test–cultures of S. aureus, P. aeruginosa, E. coli. Combination of 3% solution of silicon dioxide with ampicillin–sulbactam in dilutions 64 and 32 mg/l promotes reduction of the E. coli growth on surface of agarised medium in comparison with the investigation variant without application of 3% solution of silicon dioxide. While polyresistence of P. aeruginosa revealed, 3%solution of silicon dioxide together with cefoperazon–sulbactam in concentrations 8 and 16 mg/l and ceftazidime in concentrations 8, 16, 32, 64 mg/l guarantees bactericidal effect for this microorganism. Growth of P. aeruginosa while application of 3% solution of silicon dioxide in combination with ampicillin–sulbactam in dilutions 8, 16, 32, 64 mg/l was arrested. Application of 3% solution of silicon dioxide in combination with amicacin–sulbactam 16 mg/l inhibits the S. aureus growth, what is observed, when combination of 3% solution of silicon dioxide with amicacin in dilutions 8, 16 mg/l and cefoperazon–sulbactam in dilutions 8, 16 mg/l are exploited. Growth of the microorganism do not evolve in variants of the investigation without 3% solution of silicon dioxide, as well as with him, if amikacin is applied in concentrations 64 and 32 mg/l. Conclusion. The biliary ducts drainage in obturative jaundice of tumoral genesis and subsequent presence of drainage (internal or external) constitute the main risk factors for their colonization by multiresistant microorganisms. At the same time, the biliary ducts drainage in combination with antibioticotherapy is estimated as an urgent method for control of the infection primary focus in an acute cholangitis. Establishing of procedure for application of 3% solution of silicon dioxide in combination with certain groups of antibacterial preparations for microorganisms revealed constitute important measure for bacteriobilia prophylaxis. The further investigations conduction with wider spectrum of antibacterial preparations and 3% solution of silicon dioxide for control of clinically significant species of microorganisms is necessary and perspective.


Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.


Author(s):  
Wayan Budiarsa Suyasa ◽  
Sri Kunti Pancadewi G. A ◽  
Iryanti E. Suprihatin ◽  
Dwi Adi Suastuti G. A.

In order to maintain the environmental carrying capacity of coastal tourism, this research was conducted to determine the condition of river water environmental pollution in the Petitenget beach area and pollutant source activities. Determination of water quality is carried out by analyzing the water quality taken at several sampling points in the four rivers that lead to the Petitenget beach. Determined the pollution index value (IP) of the physical chemical and biological pollution parameters. The results showed that the four rivers that flow into the Petitenget Beach area had been contaminated with indications of pH, BOD, COD, ammonia, Coliform and E. coli which exceeded water quality category III class quality (PerGub Bali No 16 Year 2016). The four rivers are included in the criteria of severe contamination. The four rivers have experienced physical damage or structural changes that have very high discharge fluctuations both in quantity and quality. Slimy basic structure, smelly and slum aesthetic waters. While the indication of the impact of pollution is waste water which is directly discharged into the river from hotels, restaurants, homestays, commercial centers and settlements.


2021 ◽  
Vol 11 (9) ◽  
pp. 3820
Author(s):  
Noelia Llantoy ◽  
Gabriel Zsembinszki ◽  
Valeria Palomba ◽  
Andrea Frazzica ◽  
Mattia Dallapiccola ◽  
...  

With the aim of contributing to achieving the decarbonization of the energy sector, the environmental impact of an innovative system to produce heating and domestic hot water for heating demand-dominated climates is assessed is evaluated. The evaluation is conducted using the life cycle assessment (LCA) methodology and the ReCiPe and IPCC GWP indicators for the manufacturing and operation stages, and comparing the system to a reference one. Results show that the innovative system has a lower overall impact than the reference one. Moreover, a parametric study to evaluate the impact of the refrigerant is carried out, showing that the impact of the overall systems is not affected if the amount of refrigerant or the impact of refrigerant is increased.


2021 ◽  
Vol 13 (9) ◽  
pp. 5322
Author(s):  
Gabriel Zsembinszki ◽  
Noelia Llantoy ◽  
Valeria Palomba ◽  
Andrea Frazzica ◽  
Mattia Dallapiccola ◽  
...  

The buildings sector is one of the least sustainable activities in the world, accounting for around 40% of the total global energy demand. With the aim to reduce the environmental impact of this sector, the use of renewable energy sources coupled with energy storage systems in buildings has been investigated in recent years. Innovative solutions for cooling, heating, and domestic hot water in buildings can contribute to the buildings’ decarbonization by achieving a reduction of building electrical consumption needed to keep comfortable conditions. However, the environmental impact of a new system is not only related to its electrical consumption from the grid, but also to the environmental load produced in the manufacturing and disposal stages of system components. This study investigates the environmental impact of an innovative system proposed for residential buildings in Mediterranean climate through a life cycle assessment. The results show that, due to the complexity of the system, the manufacturing and disposal stages have a high environmental impact, which is not compensated by the reduction of the impact during the operational stage. A parametric study was also performed to investigate the effect of the design of the storage system on the overall system impact.


Author(s):  
Daniella F Lato ◽  
G Brian Golding

Abstract Increasing evidence supports the notion that different regions of a genome have unique rates of molecular change. This variation is particularly evident in bacterial genomes where previous studies have reported gene expression and essentiality tend to decrease, while substitution rates usually increases with increasing distance from the origin of replication. Genomic reorganization such as rearrangements occur frequently in bacteria and allow for the introduction and restructuring of genetic content, creating gradients of molecular traits along genomes. Here, we explore the interplay of these phenomena by mapping substitutions to the genomes of Escherichia coli, Bacillus subtilis, Streptomyces, and Sinorhizobium meliloti, quantifying how many substitutions have occurred at each position in the genome. Preceding work indicates that substitution rate significantly increases with distance from the origin. Using a larger sample size and accounting for genome rearrangements through ancestral reconstruction, our analysis demonstrates that the correlation between the number of substitutions and distance from the origin of replication is often significant but small and inconsistent in direction. Some replicons had a significantly decreasing trend (E. coli and the chromosome of S. meliloti), while others showed the opposite significant trend (B. subtilis, Streptomyces, pSymA and pSymB in S. meliloti). dN, dS and ω were examined across all genes and there was no significant correlation between those values and distance from the origin. This study highlights the impact that genomic rearrangements and location have on molecular trends in some bacteria, illustrating the importance of considering spatial trends in molecular evolutionary analysis. Assuming that molecular trends are exclusively in one direction can be problematic.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Amandine Leroy ◽  
Xavier Falourd ◽  
Loïc Foucat ◽  
Valérie Méchin ◽  
Fabienne Guillon ◽  
...  

Abstract Background Biomass recalcitrance is governed by various molecular and structural factors but the interplay between these multiscale factors remains unclear. In this study, hot water pretreatment (HWP) was applied to maize stem internodes to highlight the impact of the ultrastructure of the polymers and their interactions on the accessibility and recalcitrance of the lignocellulosic biomass. The impact of HWP was analysed at different scales, from the polymer ultrastructure or water mobility to the cell wall organisation by combining complementary compositional, spectral and NMR analyses. Results HWP increased the kinetics and yield of saccharification. Chemical characterisation showed that HWP altered cell wall composition with a loss of hemicelluloses (up to 45% in the 40-min HWP) and of ferulic acid cross-linking associated with lignin enrichment. The lignin structure was also altered (up to 35% reduction in β–O–4 bonds), associated with slight depolymerisation/repolymerisation depending on the length of treatment. The increase in $${T}_{1\rho }^{H}$$ T 1 ρ H , $${T}_{HH}$$ T HH and specific surface area (SSA) showed that the cellulose environment was looser after pretreatment. These changes were linked to the increased accessibility of more constrained water to the cellulose in the 5–15 nm pore size range. Conclusion The loss of hemicelluloses and changes in polymer structural features caused by HWP led to reorganisation of the lignocellulose matrix. These modifications increased the SSA and redistributed the water thereby increasing the accessibility of cellulases and enhancing hydrolysis. Interestingly, lignin content did not have a negative impact on enzymatic hydrolysis but a higher lignin condensed state appeared to promote saccharification. The environment and organisation of lignin is thus more important than its concentration in explaining cellulose accessibility. Elucidating the interactions between polymers is the key to understanding LB recalcitrance and to identifying the best severity conditions to optimise HWP in sustainable biorefineries.


Proteomes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 16
Author(s):  
Shomeek Chowdhury ◽  
Stephen Hepper ◽  
Mudassir K. Lodi ◽  
Milton H. Saier ◽  
Peter Uetz

Glycolysis is regulated by numerous mechanisms including allosteric regulation, post-translational modification or protein-protein interactions (PPI). While glycolytic enzymes have been found to interact with hundreds of proteins, the impact of only some of these PPIs on glycolysis is well understood. Here we investigate which of these interactions may affect glycolysis in E. coli and possibly across numerous other bacteria, based on the stoichiometry of interacting protein pairs (from proteomic studies) and their conservation across bacteria. We present a list of 339 protein-protein interactions involving glycolytic enzymes but predict that ~70% of glycolytic interactors are not present in adequate amounts to have a significant impact on glycolysis. Finally, we identify a conserved but uncharacterized subset of interactions that are likely to affect glycolysis and deserve further study.


Sign in / Sign up

Export Citation Format

Share Document