scholarly journals Replication Kinetics of Rickettsia raoultii in Tick Cell Lines

2021 ◽  
Vol 9 (7) ◽  
pp. 1370
Author(s):  
Nurul Aini Husin ◽  
Jing Jing Khoo ◽  
Mulya Mustika Sari Zulkifli ◽  
Lesley Bell-Sakyi ◽  
Sazaly AbuBakar
Keyword(s):  
Cell Lines ◽  
Cell Cultures ◽  
Growth Kinetics ◽  
Growth Curves ◽  
Growth Characteristics ◽  
Tick Cell ◽  
Rickettsia Raoultii ◽  
Generation Times ◽  
Causative Agents ◽  
Kinetics Of

Rickettsia raoultii is one of the causative agents of tick-borne lymphadenopathy in humans. This bacterium was previously isolated and propagated in tick cell lines; however, the growth characteristics have not been investigated. Here, we present the replication kinetics of R. raoultii in cell lines derived from different tick genera (BME/CTVM23, RSE/PILS35, and IDE8). Tick cell cultures were infected in duplicate with cryopreserved R. raoultii prepared from homologous cell lines. By 12–14 days post infection, 100% of the cells were infected, as visualized in Giemsa-stained cytocentrifuge smears. R. raoultii growth curves, determined by rickettsiae-specific gltA qPCR, exhibited lag, exponential, stationary and death phases. Exponential phases of 4–12 days and generation times of 0.9–2.6 days were observed. R. raoultii in BME/CTVM23 and RSE/PILS35 cultures showed, respectively, 39.5- and 37.1-fold increases compared to the inoculum. In contrast, multiplication of R. raoultii in the IDE8 cultures was 110.1-fold greater than the inoculum with a 7-day stationary phase. These findings suggest variation in the growth kinetics of R. raoultii in the different tick cell lines tested, amongst which IDE8 cells could tolerate the highest levels of R. raoultii replication. Further studies of R. raoultii are needed for a better understanding of its persistence within tick populations.

Growth Kinetics of Cell Cultures

2011 ◽  
pp. 271-357 ◽  
Author(s):  
John Villadsen ◽  
Jens Nielsen ◽  
Gunnar Lidén
Keyword(s):  
Cell Cultures ◽  
Growth Kinetics ◽  
Kinetics Of

scholarly journals Initiation of primary cell cultures from embryonic Haemaphysalis bispinosa ticks 

2017 ◽  
Vol 22 (3) ◽  
pp. 323 ◽  
Author(s):  
Fang-shiang Lim ◽  
Jing-jing Khoo ◽  
Fezshin Chen ◽  
Lesley Bell-sakyi ◽  
Chee-sieng Khor ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cell Cultures ◽  
Embryonic Cell ◽  
Rrna Gene ◽  
Hard Tick ◽  
Tick Cell ◽  
Haemaphysalis Bispinosa ◽  
Ornithodoros Moubata ◽  
Floating Cell ◽  
Axenic Conditions

Tick cell cultures have been widely used as an important tool for the study of tick-associated microorganisms, specifically for medically important bacteria or viruses that may be difficult to isolate or culture in axenic conditions. In this study, primary embryonic tick cell cultures were initiated separately from each of the egg batches laid by 10 female ticks belonging to the hard tick genus Haemaphysalis. All cultures were maintained at 28°C. After 10 months, 4 healthy cultures were identified with the potential for developing into continuous tick cell lines. These cultures comprise large cells predominantly forming floating cell clumps with multicellular vesicles, which are morphologically similar to cell lines derived from the soft tick Ornithodoros moubata. Subculture has not yet been performed due to the low cell density at the time of writing. Amplification and sequencing of a fragment of the 16S rRNA gene from DNA extracted from the parent ticks showed 99%-100% similarity to published sequences of Haemaphysalis bispinosa. This is the first report of the initiation of embryonic cell cultures from Haemaphysalis ticks found in Malaysia. Such tick cell cultures will be useful for studies of tick-borne pathogens in this region, where recent studies have shown that Haemaphysalis ticks are highly represented and harbor medically important bacteria. 

Model for Aerobic Growth of Shigella flexneri Under Various Conditions of Temperature, pH, Sodium Chloride and Sodium Nitrite Concentrations

1992 ◽  
Vol 55 (7) ◽  
pp. 509-513 ◽  
Author(s):  
LAURA L. ZAIKA ◽  
JOHN G. PHILLIPS ◽  
ROBERT L. BUCHANAN
Keyword(s):  
Sodium Chloride ◽  
Growth Kinetics ◽  
Sodium Nitrite ◽  
Shigella Flexneri ◽  
Brain Heart Infusion ◽  
Growth Curves ◽  
Quadratic Model ◽  
Aerobic Growth ◽  
Gompertz Equation ◽  
Kinetics Of

A modified factorial design was used to measure the effects and interactions of temperature (10 to 37°C), pH (5.5 to 7.5), sodium chloride (0.5 to 5.0%), and sodium nitrite (0 to 1000 ppm) on the aerobic growth kinetics of Shigella flexneri in brain heart infusion broth. A total of 592 cultures were analyzed, with growth curves being generated using the Gompertz equation. A quadratic model for growth of S. flexneri in terms of temperature, pH, sodium chloride, and sodium nitrite concentrations was obtained by response surface analysis. This model provides an estimate of bacterial growth in response to any combination of the variables studied within the specified ranges. Estimates obtained with the model compared favorably with growth of S. flexneri in milk.

scholarly journals Kinetics of Single Cells: Observation and Modeling of a Stochastic Process

2006 ◽  
Vol 72 (3) ◽  
pp. 2163-2169 ◽  
Author(s):  
Carmen Pin ◽  
József Baranyi
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Growth Curves ◽  
Lag Time ◽  
Inoculum Size ◽  
Detectable Level ◽  
Empirical Distributions ◽  
Generation Times ◽  
K 12 ◽  
Kinetics Of

ABSTRACT The successive generation times for single cells of Escherichia coli K-12 were measured as described by A. Elfwing, Y. LeMarc, J. Baranyi, and A. Ballagi (Appl. Environ. Microbiol. 70:675-678, 2004), and the histograms they generated were used as empirical distributions to simulate growth of the population as the result of the multiplication of its single cells. This way, a stochastic birth model in which the underlying distributions were measured experimentally was simulated. To validate the model, analogous bacterial growth curves were generated by the use of different inoculum levels. The agreement with the simulation was very good, proving that the growth of the population can be predicted accurately if the distribution of the first few division times for the single cells within that population is known. Two questions were investigated by the simulation. (i) To what extent can we say that the distribution of the detection time, i.e., the time by which a single-cell-generated subpopulation reaches a detectable level, can be identified with that of the lag time of the original single cell? (ii) For low inocula, how does the inoculum size affect the lag time of the population?

Adaptation and Growth Kinetics of the Universal Host CHO Cell Lines in Serum-Free Medium

2001 ◽  
pp. 438-440
Author(s):  
F. Verhoeye ◽  
Caroline Burteau ◽  
S. Chenu ◽  
Jean Louis Goergen ◽  
Annie Marc ◽  
...  
Keyword(s):  
Cell Lines ◽  
Growth Kinetics ◽  
Serum Free Medium ◽  
Free Medium ◽  
Cho Cell ◽  
Serum Free ◽  
Kinetics Of

The Effect of Nisin on Growth Kinetics from Activated Bacillus cereus Spores in Cooked Rice and in Milk

2002 ◽  
Vol 65 (2) ◽  
pp. 419-422 ◽  
Author(s):  
THEREZA CHRISTINA VESSONI PENNA ◽  
DANTE AUGUSTO MORAES ◽  
DALETE NOGUEIRA FAJARDO
Keyword(s):  
Bacillus Cereus ◽  
Growth Kinetics ◽  
Lag Phase ◽  
White Rice ◽  
Decimal Reduction Time ◽  
Cooked Rice ◽  
Generation Times ◽  
Different Temperatures ◽  
D Values ◽  
Kinetics Of

The growth kinetics of germinated cells from activated spores of Bacillus cereus in cooked white rice and in milk were evaluated at different temperatures for control samples and for samples with 25 μg of nisin per ml added. Nisin was applied in the form of Nisaplin (106 IU/g), which contained 25,000 μg of nisin per g. The length of the lag phase for cooked white rice controls was 120 h at 10°C, 8 h at 25°C, and 2.5 h at 33°C. The generation times for cooked rice were 327.7 min at 10°C, 59.0 min at 25°C, and 42.3 min at 33°C; those for milk without nisin were 297.0 min at 20°C, 31.2 min at 30°C, 28.6 min at 35°C, and 33.7 min at 40°C; and those for milk with nisin added were 277.2 min at 20°C, 66.9 min at 30°C, and 66.4 min at 35°C. No development of B. cereus was observed for milk with nisin added at 40°C for 12 h, in which germinated cells decreased by a decimal reduction time (D) of 4.7 h. A temperature of 45°C was shown to be harmful to B. cereus, decreasing the germinated cells in both formulations with D-values of 4.3 to 4.6 h. Similar inhibition of cell growth at 40°C was not observed with lower nisin concentrations.

The growth kinetics of ledges during phase transformations: multistep interactions

1982 ◽  
Vol 384 (1786) ◽  
pp. 107-133 ◽  
Keyword(s):  
Steady State ◽  
Phase Transformations ◽  
Growth Kinetics ◽  
Volume Diffusion ◽  
Asymptotic Methods ◽  
Parent Phase ◽  
Growth Characteristics ◽  
Controlling Factor ◽  
Kinetics Of ◽  
Equal Height

An analysis of the growth characteristics of a train of ledges is presented, where volume diffusion in the parent phase is assumed to be the rate­- controlling factor. First a train of steps of unequal height is considered where the step heights are assumed to be consistent with a steady-state motion so that each step moves with the same speed. It is possible to analyse this situation by asymptotic methods when the steps are either far apart or close together. Explicit results are given for both two- and three-step trains and it is shown how the step heights must vary if a given train is to move steadily at a specified speed. Trains of steps of equal height are also considered and an analysis is made of the relative velocities of such steps due to their interaction.

Growth Characteristics of Virulent Bacillus anthracis and Potential Surrogate Strains

2006 ◽  
Vol 69 (7) ◽  
pp. 1720-1723 ◽  
Author(s):  
TARA DE SIANO ◽  
SALLY PADHI ◽  
DONALD W. SCHAFFNER ◽  
THOMAS J. MONTVILLE
Keyword(s):  
Confidence Interval ◽  
Bacillus Anthracis ◽  
Brain Heart Infusion ◽  
Growth Curves ◽  
Growth Characteristics ◽  
Department Of Agriculture ◽  
Generation Times ◽  
Lag Times ◽  
The U.S ◽  
Bacillus Strains

The objectives of this study were to compare generation and lag times of virulent Bacillus anthracis strains with those of other Bacillus strains, to identify possible surrogates for growth studies, and to determine if the B. cereus module of the U.S. Department of Agriculture Pathogen Modeling Program (PMP) had predictive value for B. anthracis. Growth characteristics of B. anthracis, B. cereus, B. mycoides, and B. subtilis strains in brain heart infusion broth at pH 6.5, 6.0, and 5.5 were determined by absorbance measurements. Growth curves of B. anthracis Sterne and B. cereus strains appeared similar, and the generation times for strain Sterne fell within the PMP's 95% confidence interval for B. cereus. However, the virulent B. anthracis strains Vollum and Pasteur had shorter generation times than the avirulent Sterne strain and most other surrogates and were lower than the PMP's 95% confidence interval for B. cereus. Growth curves of B. cereus ATCC 9818 and B. subtilis ATCC 6633 were more similar to those of virulent B. anthracis strains, but all potential surrogates had significantly different generation times and lag times under some conditions.

Ultrastructural analysis of the invasion of tick cells by Lyme disease spirochetes (Borrelia burgdorferi) in vitro

1994 ◽  
Vol 72 (6) ◽  
pp. 977-994 ◽  
Author(s):  
T. J. Kurtti ◽  
U. G. Munderloh ◽  
S. F. Hayes ◽  
D. E. Krueger ◽  
G. G. Ahlstrand
Keyword(s):  
Electron Microscopy ◽  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Cell Lines ◽  
Cell Cultures ◽  
Dense Body ◽  
Tick Cell ◽  
Coated Pits ◽  
Intracellular Digestion

The association of Lyme disease spirochetes, Borrelia burgdorferi, with tick cell cultures was characterized by electron microscopy. These cells were active in endocytosis and intracellular digestion, containing coated vesicles, pits, and phagosomes. Borrelia burgdorferi in tick cell cultures resembled those described in tick tissues. In RAE25 cultures, isolated from Rhipicephalus appendiculatus embryos, invasion of cells was mediated by coated pits, indicating active host cell participation. The invading, tapered end of B. burgdorferi contained an electron-dense body that persisted throughout invasion. A host-derived membrane surrounded invading and intracellular borreliae as observed by transmission electron microscopy of cross and longitudinal sections, whereas degenerating ones lay inside secondary lysosomes. Borrelia burgdorferi cocultivated with cell lines from Ixodes scapularis were mainly found at the cell surface or within lysosomes. The differences seen in invasion of these cell lines are interpreted to reflect differences in cell types rather than species. Gemmae, indicative of degenerative changes in the spirochetes, were observed extra- and intra-cellularly. Membrane blebs were liberated by the spirochetes into the medium and onto the cells, and were avidly endocytosed. Tick cell cultures are a useful tool to elucidate spirochete – vector cell interactions that may be obscured in vivo.

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