scholarly journals Physical collection and viability of airborne bacteria collected under electrostatic field with different sampling media and protocols towards rapid detection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seongkyeol Hong ◽  
Myeong-Woo Kim ◽  
Jaesung Jang
Keyword(s):  
Electrostatic Field ◽  
Rapid Detection ◽  
Micrococcus Luteus ◽  
Sodium Dodecyl ◽  
Bottom Surface ◽  
Airborne Bacteria ◽  
Bacterial Cells ◽  
Biological Recovery ◽  
Sampling Protocols ◽  
Bacterial Aerosols

AbstractElectrostatic samplers have been increasingly studied for sampling of viral and bacterial aerosols, and bioaerosol samplers are required to provide concentrated liquid samples with high physical collection and biological recovery, which would be critical for rapid detection. Here, the effects of sampling media and protocols on the physical collection and biological recovery of two airborne bacteria (Pseudomonas fluorescens and Micrococcus luteus) under electrostatic field were investigated using a personal electrostatic particle concentrator (EPC). Deionized (DI) water with/without sodium dodecyl sulfate (SDS) and phosphate buffered saline were tested as sampling media. A polystyrene container was mounted onto the collection electrode of the EPC for stable storage and vortexing after capture. Many bacterial cells were found to be deposited on the bottom surface of the container submerged in the media via electrophoresis, and among the tested sampling protocols, wet sampling with a container and subsequent vortexing offered the most bacteria in the collection suspension. Experiments with several sampling media showed that 0.001–0.01% SDS-DI water demonstrated the highest recovery rate in the EPC. These findings would be valuable in the field of sampling and subsequent rapid detection of bioaerosols.

scholarly journals Physical Collection and Viability of Airborne Bacteria Collected under Electrostatic Field with Different Sampling Media and Protocols Towards Rapid Detection

2021 ◽  
Author(s):  
Seongkyeol Hong ◽  
Myeong-Woo Kim ◽  
Jaesung Jang
Keyword(s):  
Electrostatic Field ◽  
Rapid Detection ◽  
Micrococcus Luteus ◽  
Sodium Dodecyl ◽  
Bottom Surface ◽  
Airborne Bacteria ◽  
Bacterial Cells ◽  
Biological Recovery ◽  
Sampling Protocols ◽  
Bacterial Aerosols

Abstract Electrostatic samplers have been increasingly studied for sampling of viral and bacterial aerosols, and bioaerosol samplers are required to provide concentrated liquid samples with high physical collection and biological recovery, which would be critical for rapid detection. Here, the effects of sampling media and protocols on the physical collection and biological recovery of two airborne bacteria (Pseudomonas fluorescens and Micrococcus luteus) under electrostatic field were investigated using a personal electrostatic particle concentrator (EPC). Deionized (DI) water with/without sodium dodecyl sulfate (SDS) and phosphate buffered saline were tested as sampling media. A polystyrene container was mounted onto the collection electrode of the EPC for stable storage and vortexing after capture. Many bacterial cells were found to be deposited on the bottom surface of the container submerged in the media via electrophoresis, and among the tested sampling protocols, wet sampling with a container and subsequent vortexing offered the most bacteria in the collection suspension. Experiments with several sampling media showed that 0.01% SDS-DI water demonstrated a higher recovery rate and larger total bacterial concentrations in the EPC than in the BioSampler. These findings would be valuable in the field of sampling and subsequent rapid detection of bioaerosols.

scholarly journals Technical note: concentration and composition of airborne aerobic bacteria inside an enclosed rabbit shed

2016 ◽  
Vol 24 (1) ◽  
pp. 71 ◽  
Author(s):  
S. Li ◽  
M.Y. Li ◽  
T. Mu ◽  
Z.M. Miao
Keyword(s):  
Staphylococcus Epidermidis ◽  
Micrococcus Luteus ◽  
Technical Note ◽  
Aerobic Bacteria ◽  
Airborne Bacteria ◽  
Gram Negative Bacteria ◽  
Potential Threat ◽  
Gram Positive Bacteria ◽  
Colony Forming Unit ◽  
Bacterial Aerosols

<p>Numerous studies have been conducted to analyse bacterial aerosols in animal houses, which is beneficial for the control of animal diseases. However, little information on aerosols in enclosed rabbit sheds was available. An FA-1 sampler was employed to collect air samples in an enclosed rabbit house in the Qingdao region of China. Concentration, composition, and aerodynamics of bacterial aerosols inside the enclosed rabbit shed were systematically analysed. The concentration of airborne bacteria inside the rabbit shed was 2.11-6.36×104 colony forming unit/m3 (CFU/m3). Seventeen species of bacteria belonging to eight genera were identified. Among these, there were 11 species belonging to 4 genera of gram-positive bacteria, and 6 species belonging to 4 genera of gram-negative bacteria. The dominant species of bacteria were, in descending order, Micrococcus luteus (49.4%), Staphylococcus epidermidis (25.5%), and Alcaligenes odorans (10.2%). A total of about 76.3% of airborne bacteria was distributed in stages C-F of the FA-1 sampler (that ranges from A to F), with aerodynamic radii &lt;3.3 μm in diameter. These particulates could enter lower respiratory tracks and even alveoli, posing a potential threat to the health of both animals and breeders.</p>

scholarly journals Effect of the Structural and Morphological Properties of Surfactant-Assisted Hydroxyapatite on Dermal Irritation and Antibacterial Activity

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6522
Author(s):  
Giovanni García Domínguez ◽  
Sebastián Diaz De La Torre ◽  
Lorena Chávez Güitrón ◽  
Erasto Vergara Hernández ◽  
Joan Reyes Miranda ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Micrococcus Luteus ◽  
Hexagonal Phase ◽  
Sodium Dodecyl ◽  
Clinical Signs ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Streptococcus Anginosus ◽  
Dermal Irritation ◽  
Cationic And Anionic Surfactants

Hydroxyapatite (HAp) nanoparticles with a homogeneous rod morphology were successfully synthesized using the hydrothermal method. The powders were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The antibacterial and dermal irritation analyses of the samples were performed and discussed. The use of cationic and anionic surfactants, namely, cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS), respectively, at a low concentration (2.5 mol%) modified the length/diameter (L/D) ratio of the HAp rods. Structural characterizations of hydroxyapatite synthesized without surfactant (HA), with 2.5 and 5 mol% of SDS (SDS− and SDS+, respectively), and with 2.5 and 5 mol% of CTAB (CTAB− and CTAB+, respectively) revealed well-crystallized samples in the hexagonal phase. The CTAB− sample presented antibacterial activity against Pseudomonas aeruginosa, Escherichia coli, Streptococcus anginosus, Staphylococcus aureus, Micrococcus luteus, and Klebsiella pneumoniae, suggesting that antimicrobial susceptibility was promoted by the bacterial nature and the use of the surfactant. Dermal irritation showed no clinical signs of disease in rabbits during the study, where there was neither erythema nor necrosis at the inoculation sites.

scholarly journals Simultaneous Rapid Detection and Serotyping of Cronobacter sakazakii Serotypes O1, O2, and O3 by Using Specific Monoclonal Antibodies

2016 ◽  
Vol 82 (8) ◽  
pp. 2300-2311 ◽  
Author(s):  
Eva J. Scharinger ◽  
Richard Dietrich ◽  
Ina Kleinsteuber ◽  
Erwin Märtlbauer ◽  
Kristina Schauer
Keyword(s):  
Monoclonal Antibodies ◽  
Rapid Detection ◽  
Foodborne Pathogen ◽  
Cross Reactivity ◽  
Antigenic Determinants ◽  
Powdered Infant Formula ◽  
Bacterial Cells ◽  
Cronobacter Sakazakii ◽  
Content Type ◽  
Cell Counts

ABSTRACTCronobacter sakazakiiis a foodborne pathogen associated with rare but often lethal infections in neonates. Powdered infant formula (PIF) represents the most frequent source of infection. Out of the identified serotypes (O1 to O7), O1, O2, and O3 are often isolated from clinical and PIF samples. Serotype-specific monoclonal antibodies (MAbs) suitable for application in enzyme immunoassays (EIAs) for the rapid detection ofC. sakazakiihave not yet been developed. In this study, we created specific MAbs with the ability to bind toC. sakazakiiof serotypes O1, O2, and O3. Characterization by indirect EIAs, immunofluorescence, motility assays, and immunoblotting identified lipopolysaccharide (LPS) and exopolysaccharide (EPS) as the antigenic determinants of the MAbs. The established sandwich EIAs were highly sensitive and were able to detect between 2 × 103and 9 × 106CFU/ml. Inclusivity tests confirmed that 93% of serotype O1 strains, 100% of O2 strains, and 87% of O3 strains were detected at low cell counts. No cross-reactivity with >100 strains ofCronobacterspp. and otherEnterobacteriaceaewas observed, except for that withC. sakazakiiserotype O3 andCronobactermuytjensiiserotype O1. Moreover, the sandwich EIAs detectedC. sakazakiiin PIF samples artificially contaminated with 1 to 10 bacterial cells per 10 g of sample after 15 h of preenrichment. The use of these serotype-specific MAbs not only allows the reliable detection ofC. sakazakiistrains but also enables simultaneous serotyping in a simple sandwich EIA method.

Isolation and purification of a Campylobacter upsaliensis autolysin

1999 ◽  
Vol 45 (1) ◽  
pp. 23-30
Author(s):  
Somchai Santiwatanakul ◽  
Noel R Krieg
Keyword(s):  
Escherichia Coli ◽  
Molecular Mass ◽  
Micrococcus Luteus ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Isolation And Purification ◽  
Whole Cells ◽  
Sds Page ◽  
Autolytic Activity ◽  
Campylobacter Upsaliensis

Autolytic activity in the soluble and sediment fractions of sonicates of the spiral and the coccoid form of Campylobacter upsaliensis could not be demonstrated by native (nondenaturing) polyacrylamide gel electrophoresis (PAGE). Autolysins were detected, however, by using denaturing sodium dodecyl sulfate (SDS) - PAGE gels containing either purified Escherichia coli peptidoglycan or whole cells of Micrococcus luteus (Micrococcus lysodeikticus) as the turbid substrate, with subsequent renaturation by treatment with Triton X-100 buffer. In renaturing gels that contained Escherichia coli peptidoglycan, 14 putative autolytic bands ranging from 200 to 12 kDa were detected. In similar gels containing whole cells of M. luteus, only a single band appeared with a molecular mass of 34 kDa. This band corresponded to one of the bands present in the gels containing Escherichia coli peptidoglycan. This common autolysin was isolated by adsorbing it from Campylobacter upsaliensis soluble fractions onto M. luteus cells and then subjecting these cells to renaturing SDS-PAGE in gels containing Escherichia coli peptidoglycan. The 34-kDa autolysin differed from a single 51-kDa autolysin unique to the M. luteus cells, and when isolated from an SDS-PAGE gel, was pure when tested by isoelectric focusing. The N-terminal amino acid sequence analysis showed the first 15 amino acids of the 34-kDa autolysin to have 67% identity to a part of antigenic protein PEB4 of Campylobacter jejuni. The purified autolysin was used to immunize rabbits and the antibodies produced precipitated autolytic activity from cell lysates. The specificity of the antibodies was shown by Western blotting: only a single specific band occurred, with a molecular mass of 34 kDa, and thus it seems unlikely that the 34-kDa autolysin was derived from any of the other autolysins that were detected.Key words: autolysin, Campylobacter upsaliensis, zymogram, murein hydrolase.

scholarly journals Differential Damage in Bacterial Cells by Microwave Radiation on the Basis of Cell Wall Structure

2000 ◽  
Vol 66 (5) ◽  
pp. 2243-2247 ◽  
Author(s):  
Im-Sun Woo ◽  
In-Koo Rhee ◽  
Heui-Dong Park
Keyword(s):  
Microwave Radiation ◽  
Sodium Dodecyl ◽  
Cell Suspensions ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Dramatic Reduction ◽  
Severe Damage ◽  
Final Temperature ◽  
E Coli ◽  
Scanning Electron

ABSTRACT Microwave radiation in Escherichia coli andBacillus subtilis cell suspensions resulted in a dramatic reduction of the viable counts as well as increases in the amounts of DNA and protein released from the cells according to the increase of the final temperature of the cell suspensions. However, no significant reduction of cell density was observed in either cell suspension. It is believed that this is due to the fact that most of the bacterial cells inactivated by microwave radiation remained unlysed. Scanning electron microscopy of the microwave-heated cells revealed severe damage on the surface of most E. coli cells, yet there was no significant change observed in the B. subtilis cells. Microwave-injuredE. coli cells were easily lysed in the presence of sodium dodecyl sulfate (SDS), yet B. subtilis cells were resistant to SDS.

Microbial development in distillers wet grains produced during fuel ethanol production from corn (Zea mays)

2007 ◽  
Vol 53 (9) ◽  
pp. 1046-1052 ◽  
Author(s):  
R. Michael Lehman ◽  
Kurt A. Rosentrater
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Heterotrophic Bacteria ◽  
Micrococcus Luteus ◽  
Phospholipid Fatty Acid ◽  
Dry Mass ◽  
Fuel Ethanol ◽  
Fatty Acid Analysis ◽  
Yeast Cells ◽  
Bacterial Cells

Distillers grains are coproduced with ethanol and carbon dioxide during the production of fuel ethanol from the dry milling and fermentation of corn grain, yet there is little basic microbiological information on these materials. We undertook a replicated field study of the microbiology of distillers wet grains (DWG) over a 9 day period following their production at an industrial fuel ethanol plant. Freshly produced DWG had a pH of about 4.4, a moisture content of about 53.5% (wet mass basis), and 4 × 105 total yeast cells/g dry mass, of which about 0.1% were viable. Total bacterial cells were initially below detection limits (ca. 106 cells/g dry mass) and then were estimated to be ∼5 × 107 cells/g dry mass during the first 4 days following production. Culturable aerobic heterotrophic organisms (fungi plus bacteria) ranged between 104 and 105 CFU/g dry mass during the initial 4 day period, and lactic acid bacteria increased from 36 to 103 CFU/g dry mass over this same period. At 9 days, total viable bacteria and yeasts and (or) molds topped 108 CFU/g dry mass and lactic acid bacteria approached 106 CFU/g dry mass. Community phospholipid fatty acid analysis indicated a stable microbial community over the first 4 days of storage. Thirteen morphologically distinct isolates were recovered, of which 10 were yeasts and molds from 6 different genera, 2 were strains of the lactic-acid-producing Pediococcus pentosaceus and only one was an aerobic heterotrophic bacteria, Micrococcus luteus . The microbiology of DWG is fundamental to the assessment of spoilage, deleterious effects (e.g., toxins), or beneficial effects (e.g., probiotics) in its use as feed or in alternative applications.

scholarly journals Motility and the Polar Flagellum Are Required for Aeromonas caviae Adherence to HEp-2 Cells

2001 ◽  
Vol 69 (7) ◽  
pp. 4257-4267 ◽  
Author(s):  
Ali A. Rabaan ◽  
Ioannis Gryllos ◽  
Juan M. Tomás ◽  
Jonathan G. Shaw
Keyword(s):  
Epithelial Cells ◽  
Molecular Mass ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Kanamycin Resistance ◽  
Polar Flagellum ◽  
Bacterial Cells ◽  
Aeromonas Caviae ◽  
Human Epithelial Cells

ABSTRACT Aeromonas caviae is increasingly being recognized as a cause of gastroenteritis, especially among the young. The adherence of aeromonads to human epithelial cells in vitro has been correlated with enteropathogenicity, but the mechanism is far from well understood. Initial investigations demonstrated that adherence of A. caviae to HEp-2 cells was significantly reduced by either pretreating bacterial cells with an antipolar flagellin antibody or by pretreating HEp-2 cells with partially purified flagella. To precisely define the role of the polar flagellum in aeromonad adherence, we isolated the A. caviae polar flagellin locus and identified five polar flagellar genes, in the order flaA, flaB, flaG, flaH, and flaJ. Each gene was inactivated using a kanamycin resistance cartridge that ensures the transcription of downstream genes, and the resulting mutants were tested for motility, flagellin expression, and adherence to HEp-2 cells. N-terminal amino acid sequencing, mutant analysis, and Western blotting demonstrated that A. caviae has a complex flagellum filament composed of two flagellin subunits encoded by flaAand flaB. The predicted molecular mass of both flagellins was ∼31,700 Da; however, their molecular mass estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was ∼35,500 Da. This aberrant migration was thought to be due to their glycosylation, since the proteins were reactive in glycosyl group detection assays. Single mutations in either flaA orflaB did not result in loss of flagella but did result in decreased motility and adherence by approximately 50%. Mutation offlaH, flaJ, or both flagellin genes resulted in the complete loss of motility, flagellin expression, and adherence. However, mutation of flaG did not affect motility but did significantly reduce the level of adherence. Centrifugation of the flagellate mutants (flaA, flaB, and flaG) onto the cell monolayers did not increase adherence, whereas centrifugation of the aflagellate mutants (flaH, flaJ, and flaA flaB) increased adherence slightly. We conclude that maximum adherence of A. caviae to human epithelial cells in vitro requires motility and optimal flagellar function.

scholarly journals Investigation of Sources, Diversity, and Variability of Bacterial Aerosols in Athens, Greece: A Pilot Study

Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 45
Author(s):  
Angelina Metaxatos ◽  
Sydonia Manibusan ◽  
Gediminas Mainelis
Keyword(s):  
Field Application ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Airborne Bacteria ◽  
Urban Air ◽  
Operational Taxonomic Units ◽  
Bacterial Aerosol ◽  
Bacterial Aerosols ◽  
Taxonomic Categories

We characterized the composition, diversity, and potential bacterial aerosol sources in Athens’ urban air by DNA barcoding (analysis of 16S rRNA genes) during three seasons in 2019. Air samples were collected using the recently developed Rutgers Electrostatic Passive Sampler (REPS). It is the first field application of REPS to study bacterial aerosol diversity. REPS samplers captured a sufficient amount of biological material to demonstrate the diversity of airborne bacteria and their variability over time. Overall, in the air of Athens, we detected 793 operational taxonomic units (OTUs), which were fully classified into the six distinct taxonomic categories (Phylum, Class, Order, etc.). These OTUs belonged to Phyla Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes, Cyanobacteria, and Fusobacteria. We found a complex community of bacterial aerosols with several opportunistic or potential pathogens in Athens’ urban air. Referring to the available literature, we discuss the likely sources of observed airborne bacteria, including soil, plants, animals, and humans. Our results on bacterial diversity are comparable to earlier studies, even though the sampling sites are different or geographically distant. However, the exact functional and ecological role of bioaerosols and, even more importantly, their impact on public health and the ecosystem requires further air monitoring and analysis.

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