2171. Antibacterial activity of seed extracts of Okra (Abelmoschus esculentus) against selected pathogenSandra Oloketuyi, 2017, original scientific article Abstract: The aim of the study was to determine the antibacterial potency of aqueous and ethanoic extracts of Abelmoschus esculentus seeds. Antibacterial activity of aqueous and ethanoic extracts of A. esculentus seeds were evaluated against selected foodborne pathogens; Listeria monocytogenes, Bacillus cereus, Salmonella enterica, Staphylococcus aureus and Escherichia coli) using agar well diffusion method by measuring the clear zone of inhibition diameter in (mm). It was observed that the aqueous and ethanoic extracts of the four samples of A. esculentus seeds showed broad range of inhibitory activity against the test bacteria especially L. monocytogenes. Thus, A. esculentus seed has a great potential as effective antilisterial and antibacterial activity. Practical Application: Consumption of okra seeds is highly recommended for its nutritive value and antibacterial activity against pathogens, which are most commonly attributed to foodborne diseases such as listeriosis, diarrhea, and salmonellosis. Also, further study could be conducted by isolating and identifying the active ingredient responsible for antibacterial potency for pharmaceutical purpose.
Keywords: Abelmoschus esculentus, antibacterial activity, foodborne pathogens, extracts, inhibition
Published in RUNG: 14.01.2021; Views: 2349; Downloads: 0
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2172. Strategies of biofilm inhibition and virulence attenuation of food borne pathogen-Escherichia coli O157:H7Sandra Oloketuyi, Fazlurrahman Khan, 2017, review article Abstract: Enterohemorrhagic Escherichia coli (E. coli) O157:H7, a gram-negative bacteria identified as a foodborne pathogen causing severe disease is of great concern worldwide. The pathogenicity of E. coli O157:H7 is due to the presence of some virulence factors and its ability to form biofilm which resist antimicrobial compounds, withstand harsh environmental condition and protects from the host immune responses. Formation of biofilm is a multistep process such as adhesion, cellular aggregation and productions of extracellular matrix in which colonies are embedded. There are high numbers of research in the discovery of natural and synthetic compounds which can attenuate the E. coli O157:H7 biofilm formation as well as suppress virulence-related genes. The present review article focuses on the steps involved in E. coli O157:H7 biofilm formation, factors associated with virulence and attenuation.
Keywords: Escherichia coli, pathogen, virulence
Published in RUNG: 14.01.2021; Views: 2315; Downloads: 0
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2173. Aircraft vertical profiles during summertime regional and Saharan dust scenarios over the north-western Mediterranean basin: aerosol optical and physical propertiesJesús Yus-Díez, Marina Ealo, Marco Pandolfi, Noemi Perez, Gloria Titos, Griša Močnik, Xavier Querol, A. Alastuey, 2021, original scientific article Abstract: Accurate measurements of the horizontal and vertical distribution of atmospheric aerosol particle optical properties are key for a better understanding of their impact on the climate. Here we present the results of a measurement campaign based on instrumented flights over north-eastern Spain. We measured vertical profiles of size-segregated atmospheric particulate matter (PM) mass concentrations and multi-wavelength scattering and absorption coefficients in the western Mediterranean basin (WMB). The campaign took place during typical summer conditions, characterized by the development of a vertical multi-layer structure, under both summer regional pollution episodes (REGs) and Saharan dust events (SDEs). REG patterns in the region form under high insolation and scarce precipitation in summer, favouring layering of highly aged fine-PM strata in the lower few kma.s.l.
The REG scenario prevailed during the entire measurement campaign. Additionally, African dust outbreaks and plumes from northern African wildfires influenced the study area. The vertical profiles of climate-relevant intensive optical parameters such as single-scattering albedo (SSA); the asymmetry parameter (g); scattering, absorption and SSA Ångström exponents (SAE, AAE and SSAAE); and PM mass scattering and absorption cross sections (MSC and MAC) were derived from the measurements. Moreover, we compared the aircraft measurements with those performed at two GAW–ACTRIS (Global Atmosphere Watch–Aerosol, Clouds and Trace Gases) surface measurement stations located in north-eastern Spain, namely Montseny (MSY; regional background) and Montsec d'Ares (MSA; remote site).
Airborne in situ measurements and ceilometer ground-based remote measurements identified aerosol air masses at altitudes up to more than 3.5 kma.s.l.
The vertical profiles of the optical properties markedly changed according to the prevailing atmospheric scenarios. During SDE the SAE was low along the profiles, reaching values < 1.0 in the dust layers. Correspondingly, SSAAE was negative, and AAE reached values up to 2.0–2.5, as a consequence of the UV absorption increased by the presence of the coarse dust particles. During REG, the SAE increased to > 2.0, and the asymmetry parameter g was rather low (0.5–0.6) due to the prevalence of fine PM, which was characterized by an AAE close to 1.0, suggesting a fossil fuel combustion origin. During REG, some of the layers featured larger AAE (> 1.5), relatively low SSA at 525 nm (< 0.85) and high MSC (> 9 m2 g−1) and were associated with the influence of PM from wildfires. Overall, the SSA and MSC near the ground ranged around 0.85 and 3 m2 g−1, respectively, and increased at higher altitudes, reaching values above 0.95 and up to 9 m2 g−1. The PM, MSC and MAC were on average larger during REG compared to SDE due to the larger scattering and absorption efficiency of fine PM compared with dust. The SSA and MSC had quite similar vertical profiles and often both increased with height indicating the progressive shift toward PM with a larger scattering efficiency with altitude.
This study contributes to our understanding of regional-aerosol vertical distribution and optical properties in the WMB, and the results will be useful for improving future climate projections and remote sensing or satellite retrieval algorithms.
Keywords: aerosol, climate change, Saharan dust, black carbon, aerosol absorption, aerosol scattering
Published in RUNG: 14.01.2021; Views: 2439; Downloads: 0
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2176. Regulation and controlling the motility properties of Pseudomonas aeruginosaFazlurrahman Khan, Dung Thuy Nguyen Pham, Sandra Oloketuyi, Young-Mog Kim, 2020, review article Abstract: Chronic infections caused by Pseudomonas aeruginosa have been a major concern as their spread and mortality continue to be on the rise. These infections are majorly attributed to biofilm formation via sequential steps where motility plays an essential role in initial attachment of bacterial cells onto biotic and abiotic surfaces, thereby contributing to multi-drug resistance among pathogens. Therefore, attenuating motility properties can be considered as highly potential for controlling P. aeruginosa biofilm formation. This strategy has employed the use of various natural and chemically synthesized compounds. The present review article explained the importance and regulation of different types of motilities properties. Furthermore, it also covered several important alternative approaches using anti-motility agents which could be helpful for controlling P. aeruginosa biofilm-associated infections. Further studies are required for in-depth understandings about the mechanisms of motilities controlling of these molecules at molecular levels.
Keywords: Biofilm, Motility, Attenuation, Antibiofilm drugs, Pseudomonas aeruginosa
Published in RUNG: 12.01.2021; Views: 2674; Downloads: 0
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