Modelling Bacterial Growth Patterns in the presence of Antibiotic

2006 ◽  
Author(s):  
R. Walshe
Keyword(s):  
Bacterial Growth ◽  
Growth Patterns

scholarly journals Modeling of Scale-Dependent Bacterial Growth by Chemical Kinetics Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Haydee Martínez ◽  
Joaquín Sánchez ◽  
José-Manuel Cruz ◽  
Guadalupe Ayala ◽  
Marco Rivera ◽  
...  
Keyword(s):  
Chemical Kinetics ◽  
Bacterial Growth ◽  
Liquid Surface ◽  
Growth Dynamics ◽  
Volume Ratio ◽  
Growth Patterns ◽  
Open Flow ◽  
E Coli ◽  
Bacterial Cultures ◽  
Fitting Procedures

We applied the so-called chemical kinetics approach to complex bacterial growth patterns that were dependent on the liquid-surface-area-to-volume ratio (SA/V) of the bacterial cultures. The kinetic modeling was based on current experimental knowledge in terms of autocatalytic bacterial growth, its inhibition by the metabolite CO2, and the relief of inhibition through the physical escape of the inhibitor. The model quantitatively reproduces kinetic data of SA/V-dependent bacterial growth and can discriminate between differences in the growth dynamics of enteropathogenicE. coli,E. coli  JM83, andSalmonella typhimuriumon one hand andVibrio choleraeon the other hand. Furthermore, the data fitting procedures allowed predictions about the velocities of the involved key processes and the potential behavior in an open-flow bacterial chemostat, revealing an oscillatory approach to the stationary states.

Effectiveness of Cold-serving Units Using Two Cold-holding Methods in Foodservice Operations1

1990 ◽  
Vol 53 (4) ◽  
pp. 336-340 ◽  
Author(s):  
ANGELA M. FRASER ◽  
CAROL A. SAWYER
Keyword(s):  
Bacterial Growth ◽  
Statistical Significance ◽  
Growth Patterns ◽  
Operating Conditions ◽  
Cottage Cheese ◽  
Load Factor ◽  
Laboratory Setting ◽  
Length Of Service ◽  
Actual Operating ◽  
Higher Temperature

Effectiveness of two cold-holding methods commonly used to maintain temperatures of products held on cold-serving units (CSU) was determined by time-temperature and bacterial growth patterns of three products. Products used were bulk (2.27 kg) and portioned (100 g) cottage cheese, portioned (100 g) tuna salad, and deviled eggs halves (100 ± 10 g). All products were held on a cold-serving unit using the mechanical/ice cold-holding method (mechanical cooling used in combination with 3 to 10 cm ice) for 24 h (control; laboratory setting), as well as on three separate cold-serving units using the mechanical cold-holding method (at three university residence hall field sites under actual operating conditions) for 4 h (maximum length of service). Temperatures of all bulk and portioned products held on CSUs using the mechanical/ice cold-holding method (initial temperatures of food were 4 to 8.2°C) were >7.2°C after 2 h with a 50% load factor. When the mechanical cold-holding method was used, all portioned products (initial temperatures were 8.2 to 11°C) were <7.2°C after 2 h with a 75% load factor. Temperature differences between the mechanical and mechanical/ice cold-holding methods were attributed to ice on the cold-serving unit. The ice insulated the products from the mechanically cooled basin and allowed internal temperatures of the products to increase. Statistical significance for bacterial growth patterns was reported only for products held on cold-serving units using the mechanical/ice cold-holding method: mesophilic growth in deviled eggs (p<0.05) and psychrotrophic growth in tuna salad (p<0.001). As expected, bulk cottage cheese had a significantly higher temperature over time (p<0.05) than did portioned cottage cheese for both methods of cold-holding. Based on results of this study, portioned foods on cold-serving units should be held less than 2 h when the mechanical/ice cold-holding method is used, or up to 4 h when the mechanical cold-holding method is available.

scholarly journals Classification of In Vitro Phage–Host Population Growth Dynamics

2021 ◽  
Vol 9 (12) ◽  
pp. 2470
Author(s):  
Patricia E. Sørensen ◽  
Duncan Y. K. Ng ◽  
Luc Duchateau ◽  
Hanne Ingmer ◽  
An Garmyn ◽  
...  
Keyword(s):  
Bacterial Growth ◽  
Phage Therapy ◽  
Growth Dynamics ◽  
Host Population ◽  
Growth Patterns ◽  
Bacterial Cells ◽  
Bacterial Killing ◽  
Promising Alternative ◽  
Group 2

The therapeutic use of bacteriophages (phage therapy) represents a promising alternative to antibiotics to control bacterial pathogens. However, the understanding of the phage–bacterium interactions and population dynamics seems essential for successful phage therapy implementation. Here, we investigated the effect of three factors: phage species (18 lytic E. coli-infecting phages); bacterial strain (10 APEC strains); and multiplicity of infection (MOI) (MOI 10, 1, and 0.1) on the bacterial growth dynamics. All factors had a significant effect, but the phage appeared to be the most important. The results showed seven distinct growth patterns. The first pattern corresponded to the normal bacterial growth pattern in the absence of a phage. The second pattern was complete bacterial killing. The remaining patterns were in-between, characterised by delayed growth and/or variable killing of the bacterial cells. In conclusion, this study demonstrates that the phage–host dynamics is an important factor in the capacity of a phage to eliminate bacteria. The classified patterns show that this is an essential factor to consider when developing a phage therapy. This methodology can be used to rapidly screen for novel phage candidates for phage therapy. Accordingly, the most promising candidates were phages found in Group 2, characterised by growth dynamics with high bacterial killing.

scholarly journals CarboLogR: a Shiny/R application for statistical analysis of bacterial utilisation of carbon sources

2019 ◽  
Author(s):  
Kevin Vervier ◽  
Hilary P. Browne ◽  
Trevor D. Lawley
Keyword(s):  
Statistical Analysis ◽  
Bacterial Growth ◽  
Statistical Power ◽  
Carbon Sources ◽  
Growth Curves ◽  
Growth Patterns ◽  
Supplementary Information ◽  
Phenotype Microarray ◽  
Link Type ◽  
High Level

AbstractSummaryThe Biolog Phenotype Microarray (PM) and Anaerobic MicroPlates (AN) 96-well plates utilise colorimetric redox reactions to rapidly screen bacteria for the ability to utilise different carbon sources and other metabolites. Measurement of substrate utilisation as bacterial growth curves typically involves extended data normalization, outlier detection, and statistical analysis. The CarboLogR package streamlines this process with a Shiny application, guiding users from raw data generated from Biolog assays to growth profile comparison. We applied chemoinformatics approaches to define clusters of carbon sources, based on molecular similarities, increasing statistical power. Altogether, CarboLogR is a novel integrated tool providing automatic and high-level resolution for bacterial growth patterns and carbon source usage.Availability and ImplementationCarboLogR application can be downloaded and installed from Github repository https://github.com/kevinVervier/CarboLogR. Tutorial, data, and examples can be downloaded at https://github.com/kevinVervier/CarboLogR/[email protected] InformationSupplementary data are available at Bioinformatics online.

scholarly journals Differential Induction of Gamma Interferon in Legionella pneumophila- Infected Macrophages from BALB/c and A/J Mice

2001 ◽  
Vol 69 (6) ◽  
pp. 3605-3610 ◽  
Author(s):  
Sheldon Salins ◽  
Catherine Newton ◽  
Ray Widen ◽  
Thomas W. Klein ◽  
Herman Friedman
Keyword(s):  
Antibacterial Activity ◽  
Mhc Class Ii ◽  
Bacterial Growth ◽  
Legionella Pneumophila ◽  
Initial Period ◽  
Gamma Interferon ◽  
Growth Patterns ◽  
Interleukin 12 ◽  
Antibody Treatment ◽  
Ifn Γ

ABSTRACT Gamma interferon (IFN-γ), a pleiotropic cytokine, is now known to be produced by macrophages as well as by NK cells, γδ cells, and activated T cells. The autocrine biological functions of IFN-γ on the macrophage include the upregulation of major histocompatibility complex MHC class II and the activation to an antiviral state. In this study, the production of IFN-γ by macrophages was demonstrated to correspond to antibacterial activity. Legionella pneumophilareplicates intracellularly in thioglycolate (TG)-elicited macrophages (TG-macrophages) from A/J mice, while TG-macrophages from BALB/c mice restrict bacterial growth after an initial period of growth. BALB/c TG-macrophages were shown to express IFN-γ mRNA at 24 and 28 h, which corresponded to the initiation of anti-L. pneumophilaactivity. Moreover, IFN-γneutralization by antibody treatment of the cultures resulted in increased L. pneumophila growth in the macrophages. In contrast, no IFN-γ mRNA was expressed in TG-macrophages from A/J mice, where L. pneumophila grew unrestricted. As would be expected, IFN-γ treatment decreased bacterial growth. An IFN-γ-mediated antibacterial activity was, however, inducible in A/J macrophages by the addition of interleukin-12 following L. pneumophila infection. Thus, autocrine IFN-γ is involved in anti-L. pneumophila activity associated with different growth patterns and appears to be important during intracellular infection.

Diagnostic Value of Electron Microscopy in Soft Tissue Tumors

1970 ◽  
Vol 28 ◽  
pp. 220-221
Author(s):  
Gerald Fine ◽  
Azorides R. Morales
Keyword(s):  
Cardiac Myxoma ◽  
Osteogenic Sarcoma ◽  
Diagnostic Value ◽  
Soft Tissue Tumors ◽  
Amelanotic Melanoma ◽  
Growth Patterns ◽  
Light Microscopic Level ◽  
Mesenchymal Tumors ◽  
Good Agreement

For years the separation of carcinoma and sarcoma and the subclassification of sarcomas has been based on the appearance of the tumor cells and their microscopic growth pattern and information derived from certain histochemical and special stains. Although this method of study has produced good agreement among pathologists in the separation of carcinoma from sarcoma, it has given less uniform results in the subclassification of sarcomas. There remain examples of neoplasms of different histogenesis, the classification of which is questionable because of similar cytologic and growth patterns at the light microscopic level; i.e. amelanotic melanoma versus carcinoma and occasionally sarcoma, sarcomas with an epithelial pattern of growth simulating carcinoma, histologically similar mesenchymal tumors of different histogenesis (histiocytoma versus rhabdomyosarcoma, lytic osteogenic sarcoma versus rhabdomyosarcoma), and myxomatous mesenchymal tumors of diverse histogenesis (myxoid rhabdo and liposarcomas, cardiac myxoma, myxoid neurofibroma, etc.)

Episodic whole plant growth patterns in Ligustrum

1993 ◽  
Vol 89 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Jeff S. Kuehny ◽  
Mary C. Halbrooks
Keyword(s):  
Plant Growth ◽  
Growth Patterns ◽  
Whole Plant

Larval Behavior and Protective Implications for Sea Scallops and Surf Clams within the Middle Atlantic Bight: Part Two, Variability of Physical Environment and Larval Behaviors

2019 ◽  
Vol 2 (2) ◽  
Keyword(s):  
Physical Environment ◽  
Climate Changes ◽  
Larval Growth ◽  
Growth Patterns ◽  
Larval Behavior ◽  
Larval Release ◽  
Physical Conditions ◽  
Climatic Variations ◽  
Middle Atlantic ◽  
Sea Scallops

Larval growth and settlement rates are important larval behaviors for larval protections. The variability of larval growthsettlement rates and physical conditions for 2006-2012 and in the future with potential climate changes was studied using the coupling ROMS-IMBs, and new temperature and current indexes. Forty-four experimental cases were conducted for larval growth patterns and release mechanisms, showing the spatial, seasonal, annual, and climatic variations of larval growthsettlement rates and physical conditions, demonstrating that the slight different larval temperature-adaption and larval release strategies made difference in larval growth-settlement rates, and displaying that larval growth and settlement rates highly depended upon physical conditions and were vulnerable to climate changes.

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