scholarly journals Evaluation of Antimicrobial Effect of Zinc Pyrithione against Airborne Fungi and Bacteria Growth Collected onto New and Loaded HVAC Fibrous Filters

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1528
Author(s):  
Safaa Abd Zaid Abd Ali ◽  
Aurélie Joubert ◽  
Yves Andrès
Keyword(s):  
Microbial Growth ◽  
Fungal Growth ◽  
Antimicrobial Effect ◽  
Airborne Fungi ◽  
Antimicrobial Treatment ◽  
Zinc Pyrithione ◽  
Bacteria Growth ◽  
Filtration Performance ◽  
Fibrous Filters ◽  
Hvac Filters

Microbial growth onto HVAC filters was observed in real conditions with possible degradation of the indoor air quality. The filtration performance of marketed antimicrobial filters containing zinc pyrithione was tested under laboratory conditions and compared to that of similar filters with the same classification, F7 (EN779:2002). The filtration performance of the two tested filters during loading with PM10 particles was quantified in an experimental setup with filter pressure drop measurement and particle counting upstream and downstream of the filters. The microbial growth on the new and loaded filters, both contaminated with a microbial airborne consortium composed of two bacteria (Gram-positive and -negative) and fungi, was quantified by colony-forming units after conditioning the filters for a few days under controlled temperature (25 °C) and humidity (50% or 90% relative humidity). The results reveal that there was no degradation of the filtration performance of the filters treated with the antimicrobial agent. The efficiency of the antimicrobial treatment, i.e., the ability to inhibit the growth of microorganisms during the incubation period, was significant with the new filters regarding the fungal growth, but the results demonstrate that the antimicrobial treatment became inefficient with the loaded filters.

scholarly journals Lime potentials as biopreservative as alternative to chemical preservatives in pineapple, orange and watermelon juice blend

Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 1878-1884
Author(s):  
A.F. Olaniran ◽  
R.O. Afolabi ◽  
H.E. Abu ◽  
A. Owolabi ◽  
Y.M. Iranloye ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Citric Acid ◽  
Economic Value ◽  
Fungal Growth ◽  
Antimicrobial Effect ◽  
Bacterial Count ◽  
Steady Increase ◽  
Lime Juice ◽  
Bacteria Growth ◽  
Chemical Preservatives

The major challenge influencing fruits economic value is the relatively short shelf-life. This study preserved fruit juice blend from pineapple, watermelon and orange using lime juice as biopreservative comparing its effectiveness with ascorbic acid and citric acid as chemical preservatives during storage at ambient temperature (27±2oC) for five weeks. The acceptability of the juice by consumer, biochemical changes and microbial load was also evaluated on a weekly basis. From the results, all the samples were acceptable on a 9-point hedonic scale (8.70-8.90) with 1% lime biopreserved juice blend was the most preferred. This shows that that lime effectively controlled the rate at which increase pH and decrease of TTA occurred during storage by double-fold when compared with ascorbic and citric acid used in the study. A minimal decrease in pH of 0.75% was documented during the five weeks of study. The specific gravity of the juice was relatively table during storage except for the unpreserved juice. Lime addition at 2 and 4% effectively suppressed fungal growth in the juice for five weeks of storage. Lime juice added as biopreservative at 4% showed the best bacteriostatic and fungistatic performance while the consistent increase in the bacteria growth from 60×102 - 11×1010 CFU/mL was recorded in unpreserved at ambient temperatures during storage. Ascorbic acid and citric acid as preservative effectively inhibited microbial growth of bacterial and fungal for 2 weeks, followed by a steady increase from 16×101 - 17×103 , 20×102 - 62×102 and 20×102 - 36×104 ; 21×102 - 48×102 CFU/mL respectively. Low Bacterial count was recorded in juice preserved with 1% lime (70×101 CFU/mL), 2% lime preserved (41×102 CFU/mL) and 4% lime (13×101 CFU/mL) at week 4 and week 5 respectively. The study established that lime is a good biopreservative with antimicrobial effect can serve as a replacement for chemical preservatives.

scholarly journals In VitroEvaluation of the Antimicrobial Efficacy of Four Endodontic Biomaterials againstEnterococcus faecalis,Candida albicans, andStaphylococcus aureus

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Duddi Narendra Nirupama ◽  
Mohan Thomas Nainan ◽  
Rajendran Ramaswamy ◽  
Sethumadhavan Muralidharan ◽  
Hulimangala Hosakote Lingareddy Usha ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Direct Contact ◽  
Microbial Growth ◽  
Antimicrobial Property ◽  
Recurrent Infection ◽  
Antimicrobial Effect ◽  
Ah Plus ◽  
Endodontic Sealers ◽  
Root Canal Sealers ◽  
Direct Contact Test

Root canal sealers that possess good antimicrobial property can prevent residual and recurrent infection and contribute to successful endodontic therapy. This study evaluated the antimicrobial activity of four endodontic sealers, AH Plus, Tubliseal EWT, EndoRez, and iRoot SP, against three different microorganisms,E. faecalis, C. albicans, andS. aureus, by direct contact test. 10 μL microbial suspensions were allowed to directly contact the four endodontic sealers for 1 hr at 37°C. Subsequently microbial growth was measured spectrophotometrically every 30 min for 18 hours. The microbial suspensions were simultaneously tested to determine the antimicrobial effect of components which are capable of diffusing into the medium. The results revealed that AH Plus and iRootSP had significantly higher antimicrobial activity againstE. faecalis. AH Plus and Tubliseal EWT showed significantly higher antimicrobial activity againstC. albicansandS. aureuscompared to iRoot SP and EndoRez. EndoRez showed the least antimicrobial activity against all the three microorganisms. Inhibition of microbial growth is related to the direct contact of microorganisms with the sealers. In conclusion AH Plus had significantly higher antimicrobial activity againstE. faecalis, C. albicans, andS. aureus.

scholarly journals Enhancing or Inhibitory Effect of Fruit or Vegetable Bioactive Compound on Aspergillus niger and A. oryzae

2021 ◽  
Vol 8 (1) ◽  
pp. 12
Author(s):  
Gülru Bulkan ◽  
Sitaresmi Sitaresmi ◽  
Gerarda Tania Yudhanti ◽  
Ria Millati ◽  
Rachma Wikandari ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Aspergillus Niger ◽  
Bioactive Compounds ◽  
Ellagic Acid ◽  
Microbial Growth ◽  
Biomass Yield ◽  
Antimicrobial Effect ◽  
Bioactive Compound ◽  
Inhibitory Effect ◽  
Processing Wastes

Fruit and vegetable processing wastes are global challenges but also suitable sources with a variety of nutrients for different fermentative products using bacteria, yeast or fungi. The interaction of microorganisms with bioactive compounds in fruit waste can have inhibitory or enhancing effect on microbial growth. In this study, the antimicrobial effect of 10 bioactive compounds, including octanol, ellagic acid, (−)-epicatechin, quercetin, betanin, ascorbic acid, limonene, hexanal, car-3-ene, and myrcene in the range of 0–240 mg/L on filamentous fungi Aspergillus oryzae and Aspergillus niger were investigated. These fungi were both found to be resistant to all compounds except octanol, which can be used as a natural antifungal agent, specifically against A. oryzae and A. niger contamination. On the contrary, polyphenols (quercetin and ellagic acid), ascorbic acid, and hexanal enhanced A. niger biomass yield 28%, 7.8%, 16%, and 6%, respectively. Furthermore, 240 mg/L car-3-ene was found to increase A. oryzae biomass yield 8%, while a 9% decrease was observed at lower concentration, 24 mg/L. Similarly, up to 17% decrease of biomass yield was observed from betanin and myrcene. The resistant nature of the fungi against FPW bioactive compounds shows the potential of these fungi for further application in waste valorization.

Examination of ultraviolet germicidal radiation for inactivating microorganisms in melted snow and ice samples

2021 ◽  
Author(s):  
Fumio Nakazawa ◽  
Kumiko Goto-Azuma
Keyword(s):  
Size Distribution ◽  
Water Samples ◽  
Microbial Growth ◽  
Particle Concentration ◽  
Ice Cores ◽  
Antimicrobial Effect ◽  
Uv Treatment ◽  
Melted Snow ◽  
Size Distribution Of Particles

<p>The storage of melted snow and/or ice samples from snow pits and ice cores in a refrigerator for long durations may be limited by an increase in particle concentration caused by microbial growth after approximately 1–2 weeks. In this study, we examined an ultraviolet (UV) disinfection method for the storage of melted snow and/or ice samples. Surface snow obtained from Glacier No. 31 in the Suntar-Khayata Range, eastern Siberia, Russia was divided into two portions for UV treatment and untreated controls. Particle concentrations in the samples were measured using a Coulter counter (Multisizer 4e; Beckman Coulter, USA). Whereas the particle concentration in untreated samples increased, no obvious increase was observed over 53 days in the samples subjected to UV treatment. In addition, the original particle concentrations were unaffected by UV treatment. These findings indicate that the antimicrobial effect of UV radiation is effective for long-term sample storage of melted water samples. A detailed analysis of the particle size distribution for untreated samples indicated that particles of 0.7–1.2 µm appeared within the first 7–14 days. Measurements using a viable particle counter (XL-10BT2 and XL-28A1; RION Co. Ltd., Japan) confirmed that these were biological particles, suggesting that microbial growth occurs during this period. Subsequently, the particles shifted to a smaller size and a higher concentration, suggesting that the decomposition of microorganisms occurred in the water samples. Therefore, the size distribution of particles in untreated samples reflected the growth and decomposition of microorganisms over time.</p>

Electrostatic Filtration Performance of Conductive Fibrous Filters

2019 ◽  
Vol 6 (3) ◽  
pp. 54-58
Author(s):  
Yao Qian ◽  
Baobao Zhao ◽  
He Bai ◽  
Hui Deng ◽  
Xiaoming Qian
Keyword(s):  
Filtration Performance ◽  
Fibrous Filters

scholarly journals Microbial Agents Causing Infective Corneal Ulcer and their Anti-microbial Susceptibility pattern

2019 ◽  
Vol 47 (2) ◽  
pp. 1-6
Author(s):  
Azima Aktar Jhuma ◽  
Md Moynul Haque ◽  
Jamil Ahmed ◽  
Shantanu Das ◽  
Tarun Kanti Paul ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Staphylococcus Epidermidis ◽  
Microbial Growth ◽  
Corneal Ulcer ◽  
Bacterial Pathogen ◽  
Fungal Growth ◽  
Penicillium Species ◽  
Corneal Ulcers ◽  
Microbial Agents ◽  
Susceptibility Patterns

This study was designed to identify the microbial agents causing infective corneal ulcer and to carry out the antimicrobial susceptibility patterns of isolated bacteria causing infective corneal ulcer. Out of 80 samples, 67 (83.75%) cases were positive by microscopy and culture. This study showed pure fungal growth in 39 (48.75%) cases, pure bacterial growth in 8 (10%) cases, mixed microbial growth (both fungi and bacteria) in 20 (25%) cases and no growth was observed in 13 (16.25%) cases. Among the fungal isolates, Aspergillus species was the leading agent detected in 37(46.3%) cases followed by Penicillium species in 7 (8.8%) instances. Pseudomonas aeruginosa was the most common bacterial pathogen found in 11 (13.8%) cases followed by Staphylococcus epidermidis present in 9 (11.3%) cases. Gentamicin, Ciprofloxacin and Levofloxacin were found to be better efficacious drugs against most of the bacterial pathogens noted in antimicrobial susceptibility test. This study showed that infective corneal ulcers are caused by both bacterial and fungal agents but fungal agents are more common. The findings of this study would help the ophthal- mologists in evidence based management of their patients of infective corneal ulcer. Bangladesh Med J. 2018 May; 47 (2): 1-6

Influence of Silver Loaded Antibacterial Agent on Knitted and Nonwoven Fabrics and Some Fabric Properties

2016 ◽  
Vol 11 (1) ◽  
pp. 155892501601100 ◽  
Author(s):  
Ramazan Erdem ◽  
Subbiyan Rajendran
Keyword(s):  
Silver Ions ◽  
Antimicrobial Effect ◽  
Nonwoven Fabric ◽  
Antimicrobial Treatment ◽  
Positive Bacterium ◽  
Knitted Fabrics ◽  
Nonwoven Fabrics ◽  
Spray Technique ◽  
Scouring Process ◽  
Antimicrobial Effectiveness

The antibacterial effect of silver on knitted and nonwoven structures has been investigated. Three types of interlocked knitted fabrics (100% polyester, 100% viscose and 50%/50% polyester/viscose) were scoured and treated with silver ions by pad-dry-cure method. A nonwoven fabric (100% bleached cotton) was also treated with silver ions by using a spray technique. Physical and tensile properties of the treated fabrics were analyzed and compared with those of corresponding untreated ones. Results indicate that scouring process and antimicrobial treatment influenced the physical properties and antimicrobial effectiveness of the fabrics. An increase in tensile strength of 100% polyester and 100% viscose is observed after the antimicrobial treatment. The absorbency of all the treated knitted fabrics is decreased but it is substantially increased in the case of nonwoven fabrics. Antimicrobial activity of the treated fabrics was tested against Gram-positive bacterium Staphylococcus aureus. The results show that the treated nonwoven and blended (50%/50% polyester/viscose) knitted fabrics registered highest antimicrobial effect.

scholarly journals Multicenter Clinical Evaluation of BacT/Alert Virtuo Blood Culture System

2017 ◽  
Vol 55 (8) ◽  
pp. 2413-2421 ◽  
Author(s):  
Michael R. Jacobs ◽  
Tony Mazzulli ◽  
Kevin C. Hazen ◽  
Caryn E. Good ◽  
Ayman M. Abdelhamed ◽  
...  
Keyword(s):  
Blood Culture ◽  
Culture System ◽  
Microbial Growth ◽  
Fungal Growth ◽  
Detection Algorithm ◽  
Blood Culture System ◽  
Gram Negative ◽  
Time To Detection ◽  
Clinically Significant ◽  
Organism Group

ABSTRACTBacT/Alert Virtuo is an advanced, automated blood culture system incorporating improved automation and an enhanced detection algorithm to shorten time to detection. A multicenter study of the investigational Virtuo system (bioMérieux, Inc., Durham, NC) compared to BacT/Alert 3D (BTA3D) for detection of bacteremia/fungemia in four bottle types, SA and FA Plus (aerobic) and SN and FN Plus (anaerobic), was performed in a clinical setting with patient samples in a matched system design clinical trial. Blood was added to paired aerobic or anaerobic bottles, with the volume in each bottle in each pair required to be ≤10 ml and with the volumes required to be within 30% of each other. Of 5,709 bottle sets (52.5% aerobic pairs and 47.5% anaerobic pairs), 430 (7.5%) were positive for bacterial or fungal growth, with 342 (6.0%) clinically significant and 83 (1.5%) contaminated. A total of 3,539 sets (62.0%) were volume compliant, with 203 sets (5.7%) clinically significant. The positivity rates for volume-compliant bottle pairs determined by the two systems were comparable, with 68.7% of clinically significant isolates detected by both instruments, 15.7% by Virtuo only, and 15.7% by BTA3D only. Virtuo detected microbial growth nearly 2 h sooner overall than BTA3D (mean, 15.9 h versus 17.7 h). Shorter time to detection by Virtuo was related to organism group, with the time to detection being significantly shorter for enteric Gram-negative bacilli and enterococci (means, 3.6 h and 2.3 h shorter, respectively). This large clinical study demonstrated that the Virtuo blood culture system produced results comparable to those seen with the long-established BTA3D system, with significantly shorter time to detection.

The ecology of fungi infecting untreated sapwood of Pinus radiata

1968 ◽  
Vol 46 (12) ◽  
pp. 1577-1589 ◽  
Author(s):  
John A. Butcher
Keyword(s):  
Moisture Content ◽  
Pinus Radiata ◽  
Fungal Growth ◽  
Soft Rot ◽  
Airborne Fungi ◽  
Effect Of Temperature ◽  
Decay Fungi ◽  
Source Of Infection ◽  
Blue Stain Fungi ◽  
Blue Stain

The succession of fungi colonizing untreated stakes of Pinus radiata sapwood was followed in aboveground, groundline, and belowground zones. The course and speed of the succession in these zones was influenced both by the source of infection and the moisture content of the wood. Aboveground moisture content of the stakes limited development, and colonization by airborne fungi (blue-stain fungi to molds) did not proceed to the stage where decay fungi became established. At groundline and below where the succession of organisms (primary molds to soft-rot fungi to secondary molds and basidiomycetes) was complete, moisture content was more favorable for fungal growth. The succession proceeded more slowly belowground than at groundline because of (1) higher moisture content of the wood and (2) colonization being restricted to soil-borne fungi. Relative frequencies of fungi in each zone are tabulated and discussed. Decay capability tests were made to aid in establishing the role of soft rot and basidiomycetous fungi. The basidiomycetes encountered were not those usually isolated from posts of P. radiata in an advanced state of decay. Comparative studies of the effect of temperature and pH on the growth rate of the various fungi isolated were of little value in explaining the broad bases for the successional trends. Some basic problems remaining in ecological studies of wood-inhabiting fungi are discussed.

scholarly journals Study on drainage layer strategy for improving performance of glass fibrous coalescing filter

2020 ◽  
Author(s):  
chengwei xu ◽  
chenglong xiao ◽  
Yan yu ◽  
xiaodong si
Keyword(s):  
Pressure Drop ◽  
Pore Size ◽  
High Efficiency ◽  
Size Difference ◽  
Drainage Layer ◽  
Filtration Performance ◽  
Fibrous Filters ◽  
Drainage Layers ◽  
Commercial Glass ◽  
Positive Effect

The drainage layer strategy is a common method for improving filtration performance of coalescing filter. In this study, using the commercial glass fibrous filters, the influence of sub-high efficiency drainage layers on high efficiency coalescing filters were investigated experimentally. The efficiency of coalescing filter slight increases, whereas the total wet pressure drop reduces 0.32 kPa after assembling drainage layer. In addition, the influence of pore size, thickness and wettability on performance were evaluated. While the pore size of drainage layer decrease, the wet pressure drop reduces and quality factor increase. Likewise, the thickness of drainage layer also has positive effect on filtration performance. By contrast, the wettability has a weak affect on the filtration performance. As different coalescing filter with the same drainage layer, the improvement in the filtration performance increase with the decrease of pore size difference between the coalescing and drainage layers.

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