scholarly journals Enumeration, Resuscitation, and Infectivity of the Sublethally Injured Erwinia Cells Induced by Mild Acid Treatment

2004 ◽  
Vol 94 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Ching-Hsing Liao ◽  
Lisa M. Shollenberger
Keyword(s):  
Crystal Violet ◽  
Disease Ecology ◽  
Sublethal Effects ◽  
Current Knowledge ◽  
Sodium Dodecyl ◽  
Brain Heart Infusion ◽  
Soft Rot ◽  
Nutrient Broth ◽  
Selective Media ◽  
Cucumber Fruit

Current knowledge about microbial injury was derived mostly from studies with bacteria associated with processed foods. Demonstration of injury and repair in phytopathogenic bacteria and its implication on pathogen detection and disease ecology have not been reported. The objective of this study was to investigate the lethal and sublethal effects of acetic acid (AA) on soft-rot Erwinia spp. and the limitation of using selective media for isolation of injured cells. Following exposure to 0.3% AA for 6 min, 90 to 99% of E. carotovora subsp. carotovora, E. carotovora subsp. atroseptica, and E. chrysanthemi cells were killed. When AA-treated samples were plated on agar media, the number of bacteria recovered on nonselective media such as brain heart infusion agar was 3 log units higher than that recovered on selective media such as crystal violet pectate (CVP). Lethal and sublethal actions of AA on Erwinia spp. were affected greatly by acid concentration, exposure time, and bacterial strains tested. Injured Erwinia cells were able to repair and regain the ability to grow on CVP when placed in nutrient broth but not in selective broth containing crystal violet and sodium dodecyl sulfate. Injured cells also were able to resuscitate on cut surfaces of cucumber fruit and to induce soft rot on green bell pepper. Together, these results suggest that direct use of selective media for isolation of Erwinia spp. could limit the recovery of injured cells in samples that have been exposed to chemical or physical stresses. Enrichment of these samples in nutrient broth before plating on CVP is expected to improve the detection of injured Erwinia spp.

scholarly journals Pembentukan Biofilm Pseudomonas aeruginosa pada Beberapa Media Cair

2021 ◽  
Vol 10 (2) ◽  
pp. 35-40
Author(s):  
Didik Wahyudi ◽  
Endang Sutariningsih Soetarto
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Optical Density ◽  
Crystal Violet ◽  
Brain Heart Infusion ◽  
Microtiter Plate ◽  
Culture Technique ◽  
Luria Bertani ◽  
Nutrient Broth ◽  
Luria Bertani Broth ◽  
Plate Reader

Pseudomonas aeruginosa merupakan bakteri Gram negatif berbentuk batang bersifat patogen oportunistik yang menjadi penyebab utama infeksi nosokomial dan mampu membentuk biofilm pada media pertumbuhan, biofilm sering mengakibatkan pengobatan penyakit infeksi menjadi lebih sulit.  Media pertumbuhan bakteri ada beberapa jenis, komposisi dan merek. Tujuan penelitian ini adalah untuk mengetahui kemampuan P. aeruginosa dalam membentuk biofilm pada beberapa media biakan cair. P. aeruginosa diisolasi dari sampel klinis dari rumah sakit, media cair yang digunakan adalah nutrien broth, laktosa broth, brain-heart infusion (BHI), luria bertani broth, dan tripticase soy broth.  Uji pembentukan biofilm menggunakan metode microtiter plate culture technique, kemampuan pembetukan biofilm diukur berdasarakan optical density dengan menggunakan microtiter plate reader pada panjang gelombang 570nm, dengan pewarnaan crystal violet 0,1%, setelah inkubasi 24 jam pada suhu 37oC, dengan replikat 8 kali.  Hasil penelitian menunjukkan bahwa P. aeruginosa memiliki kemampuan membentuk biofilm pada nutrient broth 0,926±0,081, laktosa broth 0,521±0,041, BHI 1,283±0,031, luria bertani 1,301±0,043, dan media trypticase soy broth 1,563±0,032.  Pembentukan biofilm tertinggi pada trypticase soy broth, dan terendah pada laktosa broth, sedangkan pada media BHI dan luria bertani kemampuan pembentukan biofilm yang setara.  Kesimpulan penelitian ini adalah P. aeruginosa memiliki kemampuan yang berbeda dalam membentuk biofilm ketika ditumbuhkan pada media cair yang berbeda.Kata kunci : Biofilm, Pseudomonas aeruginosa, media cair

scholarly journals Conservation of biodiversity as a strategy for improving human health and well-being

2017 ◽  
Vol 372 (1722) ◽  
pp. 20160131 ◽  
Author(s):  
A. Marm Kilpatrick ◽  
Daniel J. Salkeld ◽  
Georgia Titcomb ◽  
Micah B. Hahn
Keyword(s):  
Public Health ◽  
Biodiversity Conservation ◽  
Disease Ecology ◽  
Current Knowledge ◽  
Public Health Intervention ◽  
Well Being ◽  
Pathogen Transmission ◽  
Policy Implications ◽  
Anthropogenic Processes ◽  
Conservation Interventions

The Earth's ecosystems have been altered by anthropogenic processes, including land use, harvesting populations, species introductions and climate change. These anthropogenic processes greatly alter plant and animal communities, thereby changing transmission of the zoonotic pathogens they carry. Biodiversity conservation may be a potential win–win strategy for maintaining ecosystem health and protecting public health, yet the causal evidence to support this strategy is limited. Evaluating conservation as a viable public health intervention requires answering four questions: (i) Is there a general and causal relationship between biodiversity and pathogen transmission, and if so, which direction is it in? (ii) Does increased pathogen diversity with increased host biodiversity result in an increase in total disease burden? (iii) Do the net benefits of biodiversity conservation to human well-being outweigh the benefits that biodiversity-degrading activities, such as agriculture and resource utilization, provide? (iv) Are biodiversity conservation interventions cost-effective when compared to other options employed in standard public health approaches? Here, we summarize current knowledge on biodiversity–zoonotic disease relationships and outline a research plan to address the gaps in our understanding for each of these four questions. Developing practical and self-sustaining biodiversity conservation interventions will require significant investment in disease ecology research to determine when and where they will be effective. This article is part of the themed issue ‘Conservation, biodiversity and infectious disease: scientific evidence and policy implications’.

scholarly journals Effect of Cationic/Anionic Mixed Micelles on Reaction Kinetics of Alkaline Hydrolysis of Crystal Violet

2019 ◽  
Vol 31 (3) ◽  
pp. 651-655
Author(s):  
Qidist Yilma ◽  
Dunkana Negussa ◽  
Y. Dominic Ravichandran
Keyword(s):  
Crystal Violet ◽  
Alkaline Hydrolysis ◽  
Mixed Micelles ◽  
Sodium Dodecyl ◽  
Binding Constants ◽  
Regression Parameters ◽  
Experimental Values ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Good Agreement

Kinetics of alkaline hydrolysis of crystal violet, a triphenylmethane dye in the micellar environment of cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfonate (SDS) and binary mixtures of these surfactants was studied. The regression parameters, together with rate constants and binding constants were obtained by analyzing the rate surfactant profiles using cooperativity model. It was observed that the reaction was catalyzed by both surfactants. The catalytic factor increased by 10 times in SDS and 38 times in CTAB indicating that binding of crystal violet to the micellar surface is stronger in pure CTAB than SDS but the strength drastically reduced in the mixtures of the surfactants. Reduction of binding constant became more important as the mole fraction of CTAB was improved in the mixture. The kinetic data were investigated using Piszkiewicz model and Raghavan-Srinivasan model. The data obtained from the models were in good agreement with the experimental values.

Investigating the Interaction of Crystal Violet Probe Molecules on Sodium Dodecyl Sulfate Micelles with Hyper-Rayleigh Scattering

2005 ◽  
Vol 109 (11) ◽  
pp. 5383-5387 ◽  
Author(s):  
Guillaume Revillod ◽  
Isabelle Russier-Antoine ◽  
Emmanuel Benichou ◽  
Christian Jonin ◽  
Pierre-François Brevet
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Crystal Violet ◽  
Rayleigh Scattering ◽  
Sodium Dodecyl ◽  
Probe Molecules ◽  
Dodecyl Sulfate

Detection and enumeration of Erwinia carotovora subsp. atroseptica using spiral plating and immunofluorescence colony staining

1997 ◽  
Vol 43 (9) ◽  
pp. 847-853 ◽  
Author(s):  
B. M. Schober ◽  
J. W. L. van Vuurde
Keyword(s):  
Crystal Violet ◽  
Pure Culture ◽  
Small Variation ◽  
Erwinia Carotovora ◽  
Soft Rot ◽  
New Technique ◽  
A New Technique ◽  
Positive Effect

Immunofluorescence colony staining (IFC) and a new technique using spiral plating combined with IFC were evaluated for the soft-rot pathogen Erwinia carotovora subsp. atroseptica in witloof chicory. Target bacteria could be detected in platings at various dilutions of plant washings. Brilliance of the stained colonies of E. carotovora subsp. atroseptica was high. Spiral plating, used for both the plating of the bacteria and for the delivery of the conjugated antiserum, had a positive effect on the reduction of the background compared with the staining of the bacteria. The combination of spiral plating and IFC proved to be a functional tool for the quantification of target and nontarget bacteria and the isolation of target bacteria as pure culture from IFC-positive colonies. The method uses less conjugated antiserum than traditional IFC and produces results with very small variation within replications. The recovery of the bacteria in both pure culture and plant washing is significantly higher than the recovery using crystal violet pectate medium.Key words: soft rot, witloof chicory, detection, Erwinia carotovora subsp. atroseptica.

scholarly journals Chemically defined inducers of alkylsulphatases present in Pseudomonas C12B

1974 ◽  
Vol 138 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Kenneth S. Dodgson ◽  
John W. Fitzgerald ◽  
William J. Payne
Keyword(s):  
Secondary Alcohol ◽  
Sodium Dodecyl ◽  
Nutrient Broth ◽  
Phase Cell ◽  
Alkyl Sulphate ◽  
Cell Extracts ◽  
Complex Process ◽  
Commercial Detergent ◽  
Process Studies ◽  
Long Chain

When Pseudomonas C12B is grown on nutrient broth to the stationary phase, cell extracts contain two secondary alkylsulphatases (S1 and S2) active towards potassium decan-5-yl sulphate but not towards potassium pentan-3-yl sulphate and one primary alkylsulphatase (P1) active towards sodium dodecan-1-yl sulphate (sodium dodecyl sulphate). When 10mm-sodium hexan-1-yl sulphate is included in the nutrient broth an additional primary alkylsulphatase (P2) is produced. The S1, S2, P1 and P2 enzymes are also present in extracts of cells grown on broth containing the commercial detergent Oronite, together with an additional secondary alkylsulphatase (S3) active towards pentan-3-yl sulphate as well as decan-5-yl sulphate. The P2 primary alkylsulphatase can be induced by a number of primary and secondary alkyl sulphate esters but the induction of the S3 enzyme appears to be a more specific and complex process. Studies on the ability of different fractions separated from Oronite to act as inducers suggest that the combination of a long-chain secondary alkyl sulphate(s) and a long-chain secondary alcohol(s) is responsible for the appearance of the S3 enzyme. Potassium hexadecan-2-yl sulphate or potassium tetradecan-2-yl sulphate, in combination with either hexadecan-2-ol or tetradecan-2-ol, can serve as inducers for the enzyme. Some characteristics of these specific inducer systems have been elucidated.

scholarly journals First Report of Leaf Spot Caused by Pseudomonas cichorii on Coreopsis lanceolata in Italy

Plant Disease ◽  
2009 ◽  
Vol 93 (9) ◽  
pp. 967-967 ◽  
Author(s):  
A. Garibaldi ◽  
G. Gilardi ◽  
C. Moretti ◽  
M. L. Gullino
Keyword(s):  
Leaf Spot ◽  
Casein Hydrolysate ◽  
Its Region ◽  
Soft Rot ◽  
Chrysanthemum Morifolium ◽  
Luria Bertani ◽  
Nutrient Broth ◽  
Bacterial Leaf Spot ◽  
Pseudomonas Cichorii ◽  
First Report

Coreopsis lanceolata L. (Compositae), an ornamental species grown in parks and gardens, is very much appreciated for its long-lasting flowering period. In August of 2008, pot-grown plants with necrotic leaf lesions were observed in a commercial nursery located near Biella (northern Italy). Lesions were present, especially along the margin of basal leaves, and sometimes had a chlorotic halo. On infected leaves, dark brown necrosis developed. Leaf stalks were sometimes affected. In many cases, the leaves, especially those at collar level, were withered. Of 1,500 plants, 15% were infected by the disease. Microscopic examination did not reveal any fungal structures within the lesions. Small fragments of tissue from 30 affected leaves were macerated for 15 min in casein hydrolysate and 0.1-ml aliquots of the resulting suspension were spread onto Luria Bertani agar (LB) and potato dextrose agar (PDA). Plates were maintained at 22 ± 1°C for 48 h. No fungi were isolated from the leaf spots on LB or PDA. Colonies similar to those of Pseudomonas spp. were consistently isolated on LB. Colonies were fluorescent on King's medium B, levan negative, oxidase positive, potato soft rot negative, arginine dihydrolase negative, and tobacco hypersensitivity positive (LOPAT test). The bacterial colonies were identified as Pseudomonas cichorii (2). The internal transcribed spacer (ITS) region of rDNA was amplified using primers 27F and 1492R and sequenced (GenBank Accession No. FJ534557). BLAST analysis (1) of the 998-bp segment showed a 98% homology with the sequence of P. cichorii. The pathogenicity of one isolate was tested twice by growing the bacterium in nutrient broth shake cultures for 48 h at 20 ± 1°C. The suspension was centrifuged, the cell pellet resuspended in sterile water to a concentration of 107 CFU/ml, and 30 4-month-old healthy coreopsis plants were sprayed with the inoculum. The same number of plants was sprayed with sterile nutrient broth as a control. After inoculation, plants were covered with plastic bags for 48 h and placed in a growth chamber at 20 ± 1°C. Five days after inoculation, lesions similar to those seen in the field were observed on all plants inoculated with the bacterium, but not on the controls. Ten days later, 40% of the leaves were withered. Isolations were made from the lesion margins on LB and the resulting bacterial colonies were again identified as P. cichorii. The pathogen caused the same symptoms also on plants of Dendranthema frutescens (cv. Camilla), Chrysanthemum morifolium (cvs. Eleonora and Captiva), and an Osteospermum sp. (cv. Wild side) when artificially inoculated with the pathogen with the same methodology. The same bacterial leaf spot caused by P. cichorii was observed in 2005 in other nurseries in the same area on Phlox paniculata (3). To our knowledge, this is the first report of bacterial leaf spot caused by P. cichorii on C. lanceolata in Italy. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) H. Bergey et al. Bergey's Manual on Determinative Bacteriology. Williams and Wilkins, Baltimore, MD, 1994. (3) A. Garibaldi et al. Plant Dis. 89:912, 2005.

scholarly journals Aggregates in aquatic ecosystems and implications for aquacultures

2020 ◽  
Vol 45 (2) ◽  
pp. 87-96
Author(s):  
Yustian Rovi Alfiansah
Keyword(s):  
Microbial Communities ◽  
Aquatic Ecosystems ◽  
Disease Ecology ◽  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Marine Aquaculture ◽  
Shrimp Pond ◽  
Aquaculture Management ◽  
Negative Side Effects

Agglomerations of suspended particulate matter serve various roles in aquatic ecosystems. They participate in nutrient and energy fluxes and are involved in important food web processes. While comprehensive studies on aggregates are available from natural freshwater and marine ecosystems, little is known about the roles of aggregates in aquacultures, particularly in shrimp pond farming. As particle-rich systems, shrimp ponds and marine aquaculture (mariculture) areas constitute interesting objects for aggregate studies, particularly as a source of natural feed, particle fluxes, microbial communities, including pathogenic bacteria, and possible vector of disease widespread. The aims of this review are i) to compile the current knowledge on the role of aggregates in aquatic ecosystems, particularly in aquaculture areas covering advantages and negative side effects of aggregates in aquacultures, ii) to explore the role of aggregates in disease ecology, and iii) perspective of aquaculture management in the context of aggregate utilization and management. Since Southeast Asia, especially Indonesia, is among the most important regions for aquaculture activities, this review focuses on Indonesian aquacultures. Although aquacultures produce important amounts of aggregates, including its associated microbial communities, they are rarely investigated in Indonesian aquacultures, particularly in shrimp pond farming. In contrast, most of the studies focused on bacterial cultivation and utilization of isolates for aquacultures. Thus, understanding the ecological roles of aggregates in aquacultures may support the improvement of aquaculture management and yields.

scholarly journals Effect of Chitosan on Tissue Maceration and Enzyme Production by Erwinia carotovora in Potato

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 512A-512 ◽  
Author(s):  
M.V. Bhaskara Reddy ◽  
Alain Asselin ◽  
Joseph Arul
Keyword(s):  
Wide Spectrum ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Erwinia Carotovora ◽  
Soft Rot ◽  
Reaction Products ◽  
Potato Tissue ◽  
Chitosan Concentration ◽  
Crude Extracts ◽  
Tissue Maceration

We have investigated the relationship between chitosan treatments and maceration of potato tissue by macerating enzymes secreted by Erwinia carotovora causal agent of soft rot of potato. Erwinia isolated from potato showing soft rot symptoms was used for inoculation. The bacteria secreted a wide spectrum of enzymes that degraded potato cell walls. Polygalacturonase (PG), pectate lyase (PL), pectinmethylesterase (PME), cellulase, xylanase, and protease showed the highest activity in potato tissue inoculated with the pathogen. Accordingly increased maceration and cell death were observed. On the other hand, in chitosan-treated tissue and challenged with the pathogen, significant decrease in enzymatic activity and tissue maceration were observed, more so with increasing chitosan concentration. This observation confirmed that chitosan interfered with multiplication and pathogenic powers of the bacteria, thereby improving cell texture and viability. Crude extracts obtained from treatments were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to assess pectinase activity. The electophoretic profiles showed significant lytic zone of pectin degradation in the control, which decreased with increase in chitosan concentrations. No lytic zone was observed at 8 mg·ml–1 chitosan concentration and was comparable to intact activity in untreated potato tissue. Pectic enzyme reaction products were analyzed to see the action pattern of pectinases in the crude extracts. Cellulose choromatographic profiles revealed monomers and dimers of polygalacturonic acid up to 6 mg·ml–1 chitosan concentrations. The results suggest that chitosan significantly inhibits bacterial growth and the production of macerating enzymes by the pathogen and thus chitosan can be a potential anti-bacterial agent.

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