Bacteriophage-Mediated Modulation of Bacterial Competition during Selective Enrichment of Campylobacter

Abstract Seafood, including fish, shrimp, clam, crab, mussel, oyster, lobster, squid, octopus, and cuttlefish samples, was used to compare the recovery of Salmonella serovars by different selective enrichment and isolation media. The samples were selectively enriched in Rappaport-Vassiliadis (RV) broth and tetrathionate broth (TT), followed by selective isolation on Hektoen enteric (HE) agar, xylose lysine desoxycholate (XLD) agar, bismuth sulfite (BS) agar, and Brilliant Green (BG) agar media. Of 443 seafood samples analyzed, 108 were found to be contaminated with Salmonella. The role of selective enrichment in Salmonella spp. recovery with RV medium was distinctly high (70%) compared to TT broth (30%). The selective enrichment in RV broth followed by selective isolation on XLD, HE, BS, and BG agar recovered Salmonella at levels of 56, 41, 28, and 16%, respectively. Similarly, after enrichment in TT broth, XLD and HE agars recovered 27 and 23 respectively. The recovery of Salmonella with enrichment in TT followed by isolation on BS and BG was abysmally low at 4.6 and 5, respectively. There was no significant difference (P > 0.05) in the recovery of Salmonella using the combinations of XLD and HE media with selective enrichment in RV broth. However, performance difference (P <0.05) was observed in the recovery when BS and BG with RV, and XLD, HE, BS, and BG agars with TT broth were used. The present study showed that the combination of RV with XLD was the most efficient media for isolation of Salmonella from seafood when compared to other isolation media combinations.

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ABC Medium, a New Chromogenic Agar for Selective Isolation of Salmonella spp.

Journal of Clinical Microbiology ◽

10.1128/jcm.37.3.766-768.1999 ◽

1999 ◽

Vol 37 (3) ◽

pp. 766-768 ◽

Cited By ~ 30

Author(s):

John D. Perry ◽

Michael Ford ◽

Jeffrey Taylor ◽

Amanda L. Jones ◽

Roger Freeman ◽

...

Keyword(s):

Galactosidase Activity ◽

Selective Isolation ◽

Salmonella Spp ◽

Chromogenic Medium ◽

Selective Enrichment ◽

The Family ◽

Direct Inoculation ◽

Chromogenic Agar ◽

Stool Samples ◽

High Degree

We describe a new chromogenic agar medium, ABC medium (αβ-chromogenic medium), which includes two substrates, 3,4-cyclohexenoesculetin-β-d-galactoside and 5-bromo-4-chloro-3-indolyl-α-d-galactopyranoside, to facilitate the selective isolation of Salmonella spp. This medium exploits the fact that Salmonella spp. may be distinguished from other members of the familyEnterobacteriaceae by the presence of α-galactosidase activity in the absence of β-galactosidase activity. A total of 1,022 strains of Salmonella spp. and 300 other gram-negative strains were inoculated onto this medium. Of these, 1,019 (99.7%) strains of Salmonella spp. produced a characteristic green colony, whereas only 1 strain (0.33%) of non-Salmonellaproduced a green colony. A total of 283 stool samples were cultured onto desoxycholate citrate (DC) agar and ABC medium by direct inoculation and after selective enrichment in selenite broth. Overall, the sensitivity and specificity were superior for ABC medium (100 and 90.5%, respectively) than for DC agar (88 and 26.9%, respectively). We conclude that ABC medium offers a high degree of specificity for the detection of Salmonella spp. in stool samples.

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Unravelling a microbial synergy to boost caproate production via carboxylates chain elongation with ethanol

HKIE Transactions ◽

10.33430/v26n2thie-2018-0041 ◽

2019 ◽

Vol 26 (2) ◽

pp. 63-71

Author(s):

Ling Leng ◽

Ying Wang ◽

Peixian Yang ◽

Takashi Narihiro ◽

Masaru Konishi Nobu ◽

...

Keyword(s):

Fatty Acids ◽

Volatile Fatty Acids ◽

Microbial Consortia ◽

Chain Elongation ◽

Desulfovibrio Vulgaris ◽

Rrna Gene ◽

Selective Enrichment ◽

Microbial Network ◽

Cost Efficient ◽

Rrna Gene Sequencing

Chain elongation of volatile fatty acids for medium chain fatty acids production (e.g. caproate) is an attractive approach to treat wastewater anaerobically and recover resource simultaneously. Undefined microbial consortia can be tailored to achieve chain elongation process with selective enrichment from anaerobic digestion sludge, which has advantages over pure culture approach for cost-efficient application. Whilst the metabolic pathway of the dominant caproate producer, Clostridium kluyveri, has been annotated, the role of other coexisting abundant microbiomes remained unclear. To this end, an ethanol-acetate fermentation inoculated with fresh digestion sludge at optimal conditions was conducted. Also, physiological study, thermodynamics and 16 S rRNA gene sequencing to elucidate the biological process by linking the system performance and dominant microbiomes were integrated. Results revealed a possible synergistic network in which C. kluyveri and three co-dominant species, Desulfovibrio vulgaris, Fusobacterium varium and Acetoanaerobium sticklandii coexisted. D. vulgaris and A. sticklandii (F. varium) were likely to boost the carboxylates chain elongation by stimulating ethanol oxidation and butyrate production through a syntrophic partnership with hydrogen (H2) serving as an electron messenger. This study unveils a synergistic microbial network to boost caproate production in mixed culture carboxylates chain elongation.

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Bone marrow cell morphology in congenital diserythropoietic anemia: selective enrichment of the studied cell population for light and electron microscopy using a microarray and centrifugation in a density gradient

Pediatric Hematology/Oncology and Immunopathology ◽

10.24287/1726-1708-2018-17-1-104-107 ◽

2018 ◽

Vol 17 (1) ◽

pp. 104-107

Author(s):

S.I. Obydennyi ◽

◽

O.S. Fedyanina ◽

A.N. Khvastunova ◽

A.O. Zakirova ◽

...

Keyword(s):

Electron Microscopy ◽

Bone Marrow ◽

Density Gradient ◽

Cell Population ◽

Bone Marrow Cell ◽

Cell Morphology ◽

Marrow Cell ◽

Light And Electron Microscopy ◽

Selective Enrichment

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A method for selective separation of scandium (III) from yttrium and a number of rare-earth elements for its subsequent determination

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2018-84-11-23-27 ◽

2018 ◽

Vol 84 (11) ◽

pp. 23-27

Author(s):

M. I. Degtev ◽

A. A. Yuminova ◽

A. S. Maksimov ◽

A. P. Medvedev

Keyword(s):

Rare Earth ◽

Aqueous Phase ◽

Selective Isolation ◽

Optimum Ratio ◽

Extraction Condition ◽

Sulfosalicylic Acid ◽

Salting Out ◽

Subsequent Determination ◽

Toxic Organic Solvents ◽

Metal Ions Extraction

The possibility of using an aqueous stratified system of antipyrine — sulfosalicylic acid — water for the selective isolation of scandium macro- and microquantities for subsequent determination is studied. The proposed extraction system eliminates the usage of toxic organic solvents. The organic phase with a volume of 1.2 to 2.0 ml, resulting from delamination of the aqueous phase containing antipyrine and sulfosalicylic acid is analysed to assess the possibility of using such systems for metal ions extraction. Condition necessary for the formation of such a phase were specified: the ratio of the initial components, their concentration, presence of inorganic salting out agents. The optimum ratio of antipyrine to sulfosalicylic acid is 2:1 at concentrations of 0.6 and 0.3 mol/liter in a volume of the aqueous phase of 10 ml. The obtained phase which consists of antipyrinium sulfosalicylate, free antipyrine and water, quantitatively extracts macro- and microquantities of scandium at pH = 1.54. Macro- and microquantities of yttrium, terbium, lanthanum, ytterbium and gadolinium are not extracted under the aforementioned conditions thus providing selective isolation of scandium from the bases containing yttrium, ytterbium, terbium, lanthanum, and gadolinium.

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Faculty Opinions recommendation of Kinase-selective enrichment enables quantitative phosphoproteomics of the kinome across the cell cycle.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1123808.580893 ◽

2008 ◽

Author(s):

Jonathan Chernoff

Keyword(s):

Cell Cycle ◽

Selective Enrichment ◽

Quantitative Phosphoproteomics

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Fabrication of acylsemicarbazide-based porous organic polymer for selective enrichment of glycopeptides

Chinese Journal of Chromatography ◽

10.3724/sp.j.1123.2017.05014 ◽

2017 ◽

Vol 35 (7) ◽

pp. 688

Author(s):

Hongwei WANG ◽

Zhongshan LIU ◽

Xiaojun PENG ◽

Junjie OU ◽

Mingliang YE

Keyword(s):

Organic Polymer ◽

Selective Enrichment ◽

Porous Organic Polymer

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Modelling of the micromorphology of the activated sludge floc: low do, low F/M bulking

Water Science & Technology ◽

10.2166/wst.1995.0110 ◽

1995 ◽

Vol 31 (2) ◽

pp. 235-243 ◽

Cited By ~ 7

Author(s):

Imre Takács ◽

Ernö Fleit

Keyword(s):

Activated Sludge ◽

Bulk Concentration ◽

Diffusion Limitation ◽

Selective Enrichment ◽

System A ◽

Common Causes ◽

Do Concentration ◽

Soluble Substrate ◽

Positive Feedback Effect ◽

Do So

Two common causes of filamentous bulking of activated sludge are low dissolved oxygen (DO) concentration and low food to microorganism (F/M) ratio in the activated sludge system. A dynamic mathematical model was developed to simulate the population dynamics of two groups of bacteria, floc-formers and filaments within the microenvironment of the activated sludge floc. An arbitrary grid of 50 by 50 elements was applied to a hypothetical floc of maximum 100 μm in diameter. The concentration of DO and soluble substrate was calculated inside the floc core under different bulk concentration conditions in order to simulate the effect of heterogeneous, gradient-governed microenvironments on dual species composition. Dynamic simulation runs were performed to calculate the growth of the two morphological types of microorganisms inside the floc under diffusion governed conditions. The results indicate that the method accurately predicts the onset of excessive filamentous growth (directly linked to bulking) even when traditional models neglecting diffusion limitation fail to do so. The positive feedback effect of the non-random (unidirectional) growth on the selective enrichment of filamentous organisms under electron acceptor (DO) or soluble substrate (F/M) limited conditions is demonstrated.

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Use of gene probes for the detection of quiescent enteric bacteria in marine and fresh waters

Water Science & Technology ◽

10.2166/wst.1995.0628 ◽

1995 ◽

Vol 31 (5-6) ◽

pp. 291-298

Author(s):

Sally A. Anderson ◽

Gillian D. Lewis ◽

Michael N. Pearson

Keyword(s):

Membrane Filtration ◽

Enteric Bacteria ◽

Probe Method ◽

Detection Methods ◽

23S Rrna ◽

Specific Gene ◽

Gene Probe ◽

Selective Media ◽

Selective Enrichment ◽

E Coli

Specific gene probe detection methods that utilise a non-selective culturing step were tested for the ability to recognise the presence of quiescent enteric bacteria (Escherichia coli and Enterococcus faecalis ) within illuminated freshwater and seawater microcosms. An E. coli specific uidA gene probe and a 23S rRNA oligonucleotide probe for Enterococci were compared with recoveries using membrane filtration and incubation on selective media (mTEC and mE respectively). From these microcosm experiments a greater initial detection (from 4 hours to 1 day) of E. coli and Ent. faecalis using gene probe methods was observed. Additionally, a comparison of E. coli direct viable counts (DVC) in sunlight exposed microcosms with recoveries by selective media and gene probe methods revealed a large number of viable non-culturable cells. This suggests that enumeration of E. coli by a gene probe method is limited by the replication of the bacteria during the initial non-selective enrichment step. The detection of stressed Ent. faecalis by the oligonucleotide gene probe method was significantly greater than recovery on selective mE agar, indicating an Enterococci non-growth phase.

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