STUDIES ON STRONGYLOIDES OF PRIMATES: IV. EFFECT OF TEMPERATURE ON THE MORPHOLOGY OF THE FREE-LIVING STAGES OF STRONGYLOIDES FULLEBORNI

1958 ◽  
Vol 36 (4) ◽  
pp. 623-628 ◽  
Author(s):  
Premvati
Keyword(s):  
Morphological Changes ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Free Living ◽  
Infective Larvae ◽  
Complete Development

The optimum temperature for the complete development of the free-living and the infective larvae of Strongyloides fülleborni is 25 °C. Morphological changes are seen at higher or lower temperatures.

The effect of temperature on the development and survival of the infective larvae of Strongyloides ratti Sandground, 1925

Parasitology ◽  
1968 ◽  
Vol 58 (3) ◽  
pp. 641-651 ◽  
Author(s):  
J. Barrett
Keyword(s):  
Culture Media ◽  
Maximum Activity ◽  
Temperature Adaptation ◽  
Effect Of Temperature ◽  
Free Living ◽  
Larval Stages ◽  
Infective Larvae ◽  
Significant Difference ◽  
Show Maximum Activity ◽  
Different Temperatures

The development of the free-living infective larvae of a homogonic strain Strongyloides ratti is described.The larvae develop only between 15 and 34 °C. Transfer experiments show the temperature block to be in the preparation for the second moult.Within the temperature range 15–34 °C, increasing the temperature speeds up the rate of development of all the larval stages equally, the Q10 for development being 2·5.The maximum percentage development occurs at 20 °C. The percentage development is highest in faeces–peat culture (95% development at 20 °C), whilst the percentage development in charcoal and vermiculite cultures is about the same (75% development at 20 °C.).Larvae grown on charcoal cultures are larger than those grown on vermiculite, which are larger than those grown on peat. No significant difference was found in the length:oesophagus and length:width ratios or in the variability of larvae grown at different temperatures or on different culture media.Different worm densities in the cultures of from 2000 to 10000 larvae per g of culture did not affect either the size of the infective larve or the percentage development.The optimum temperature for survival is 15 °C. Worms grown at 20 °C lived longer than worms grown at any other temperature. There was no evidence of temperature adaptation by the larvae.The infective larvae are positively thermotactic, and show maximum activity at 37 °C.I should like to thank my supervisor, Dr Tate, for his advice and encouragement. The work was carried out during the tenure of a Medical Research Council Scholarship.

Effect of temperature on the development of free-living adults of Strongyloides papillosus (Wedl, 1856)

Parasitology ◽  
1963 ◽  
Vol 53 (3-4) ◽  
pp. 483-489 ◽  
Author(s):  
Premvati
Keyword(s):  
Life Cycle ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Free Living ◽  
Laboratory Conditions ◽  
Humidity Chamber

Strongyloides papillosus is found to be very common in the Lucknow area where 90% of the sheep are infected. The life-cycle is predominantly indirect, or heterogonic. The development of mature free-living adults takes place between 20° and 37° C., and 34° C. is the optimum temperature. At a temperature of 25° C., the percentage of free-living adults is 60–65 in summer (March to November) and practically 100 in winter (December to February). Immature females can develop at 40° C. in summer, but not in winter, under laboratory conditions.Inhibition experiments in a hot oven incubator with varying percentages of humidity, and in a humidity chamber incubator with constant 100% humidity, maintained at temperatures varying from 40° to 50° C., show that in the humidity chamber incubator mature free-living adults develop at 34° C. after incubation for 12 hr. at 40° C., after 4 hr. at 42° C., after 2 hr. at 45° C. and after 15 min. at 50° C. The hot oven incubator allows mature free-living adults to develop at 34° C. after 8 hr. at 40° C., after 2 hr. at 42° C., after 1 hr. at 45° C. and after 15 min. at 50° C.

THE EFFECTS OF TEMPERATURE AND HUMIDITY ON THE FREE-LIVING STAGES OF TRICHOSTRONGYLUS RETORTAEFORMIS

1959 ◽  
Vol 37 (3) ◽  
pp. 305-316 ◽  
Author(s):  
Devandra Prasad
Keyword(s):  
Infective Stage ◽  
Optimum Temperature ◽  
Free Living ◽  
Infective Larvae ◽  
Faecal Culture ◽  
Temperature And Humidity ◽  
Effects Of Temperature ◽  
Eggs And Larvae

The optimum temperature for development of Trichostrongylus retortaeformis is about 25 °C in a wet faecal culture, when the infective stage is reached in from 3 to 5 days, but at 3 to 5 °C a few larvae can develop in 8 to 10 weeks, and infective larvae can survive for 13 weeks. Both eggs and larvae can survive desiccation for considerable periods.

Some observations on the free-living stages of Ostertagia ostertagi, a stomach worm of cattle

Parasitology ◽  
1961 ◽  
Vol 51 (3-4) ◽  
pp. 295-307 ◽  
Author(s):  
J. H. Rose
Keyword(s):  
Technical Assistance ◽  
Effect Of Temperature ◽  
Free Living ◽  
Ostertagia Ostertagi ◽  
Rate Of Development ◽  
Infective Larvae ◽  
Grazing Animal ◽  
Temperature And Humidity ◽  
Eggs And Larvae

Outdoor observations were made on the rate of development of the free-living stages of O. ostertagi at different times of the year, and on the migratory activities and longevity of the larvae in faeces, on herbage and in soil.The effect of temperature on the rate of development of eggs and larvae in faeces, and the effect of temperature and humidity on the longevity of eggs and larvae when separated from faeces, were studied in the laboratory.The results of these observations are discussed in relation to translation (that is, the process whereby eggs in faeces become infective larvae on herbage available to the grazing animal) and to the transmission of infection in the field.I wish to thank Mr J. F. Michel for providing the infected faeces, and Mr D. A. Griffiths for technical assistance.

Effect of Temperature, Velocity Gradient and I.V. Heparin on in Vitro Blood Coagulation and Platelet Aggregation

1967 ◽  
Vol 17 (01/02) ◽  
pp. 112-119 ◽  
Author(s):  
L Dintenfass ◽  
M. C Rozenberg
Keyword(s):  
Blood Coagulation ◽  
Velocity Gradient ◽  
Elevated Temperatures ◽  
Morphological Changes ◽  
Effect Of Temperature ◽  
Clotting Time ◽  
Progressive Change ◽  
Aggregation Of Platelets ◽  
Microscopic Techniques

SummaryA study of blood coagulation was carried out by observing changes in the blood viscosity of blood coagulating in the cone-in-cone viscometer. The clots were investigated by microscopic techniques.Immediately after blood is obtained by venepuncture, viscosity of blood remains constant for a certain “latent” period. The duration of this period depends not only on the intrinsic properties of the blood sample, but also on temperature and rate of shear used during blood storage. An increase of temperature decreases the clotting time ; also, an increase in the rate of shear decreases the clotting time.It is confirmed that morphological changes take place in blood coagula as a function of the velocity gradient at which such coagulation takes place. There is a progressive change from the red clot to white thrombus as the rates of shear increase. Aggregation of platelets increases as the rate of shear increases.This pattern is maintained with changes of temperature, although aggregation of platelets appears to be increased at elevated temperatures.Intravenously added heparin affects the clotting time and the aggregation of platelets in in vitro coagulation.

Effect of Temperature on Development Rate, Survival and Fecundity of Cotton Tipworm, Crocidosema-Plebejana Zeller (Lepidoptera, Tortricidae)

1991 ◽  
Vol 39 (2) ◽  
pp. 191 ◽  
Author(s):  
JG Hamilton ◽  
MP Zalucki
Keyword(s):  
Linear Model ◽  
Development Rate ◽  
Population Increase ◽  
Effect Of Temperature ◽  
Direct Result ◽  
Immature Stages ◽  
Optimum Temperature ◽  
Development Rates ◽  
Non Linear ◽  
Female Weight

C. plebejana were reared from egg to adult at a range of constant temperatures. At 10-degrees-C no immature stages survived. Development rates increased over the temperature range 14-34-degrees-C; these were simulated with a non-linear model. Females emerged before males. Fecundity decreased with increased rearing temperature as a direct result of reduced adult female weight. At 34-degrees-C development rate and survival were reduced and all eggs laid were infertile. Optimum temperature for population increase was 28-degrees-C. Validation of a non-linear model for development rate shows that the species of host-plant affects mean development rates of tipworm. Although 5.3 tipworm generations are possible on cotton annually, only one occurs; reasons for this are suggested.

scholarly journals Predatory activity of Arthrobotrys oligospora and Duddingtonia flagrans on pre-parasitic larval stages of cyathostominae under different constant temperatures

2001 ◽  
Vol 31 (5) ◽  
pp. 839-842 ◽  
Author(s):  
Clóvis de Paula Santos ◽  
Terezinha Padilha ◽  
Maria de Lurdes de Azevedo Rodrigues
Keyword(s):  
Optimum Temperature ◽  
Duddingtonia Flagrans ◽  
Arthrobotrys Oligospora ◽  
Egg Development ◽  
Free Living ◽  
Predatory Activity ◽  
Larval Stages ◽  
Different Temperatures ◽  
Reduction Percentage

The effect of different temperatures on the predatory activity of Arthrobotrys oligospora and Duddingtonia flagrans on the free-living larval stages of cyathostomes were evaluated in an experiment where feces of horses containing the parasites’ eggs were treated with these fungi and incubated under different constant temperatures (10°C, 15°C, 20°C, 25°C and 30°C ). The results indicated that the optimum temperature for egg development was 25°C. At 10°C the number of L3 recovered was practically zero, and at 15°C and 20°C, the percentage of larvae recovered was less than 3% of the total number of eggs per gram of feces. When these cultures subsequently were incubated for an additional period of 14 days at 27°C, they allowed the development of L3. In all the cultures inoculated with fungi a significant reduction in the number of larvae was observed. When incubated at 25°C or 30°C, the fungi caused reductions above 90%, in the number of L3. The samples cultivated at 10°C, 15°C, 20°C, 25°C and 30°C, when incubated for an additional period of 14 days at 27°C the reduction percentage of larvae was above 90% for A. oligospora. However, the same did not occur for D. flagrans. Here a reduction percentage between 47.5% and 41.8% was recorded when the cultures were incubated at 10°C and 20°C, respectively. The two species of fungi tested showed to be efficient in reducing the number of L3 when mixed with equine feces and maintained at the same temperature for the development of larval pre-parasitic stages of cyathostomes.

scholarly journals Recovery of Trichostrongylus colubriformis infective larvae from three grass species contaminated in the autumn

2012 ◽  
Vol 21 (4) ◽  
pp. 372-378 ◽  
Author(s):  
Raquel Abdallah da Rocha ◽  
Patrizia Ana Bricarello ◽  
Gilberto Pedroso da Rocha ◽  
Alessandro Francisco Talamini do Amarante
Keyword(s):  
Dry Matter ◽  
Cynodon Dactylon ◽  
Larval Survival ◽  
Grass Species ◽  
Panicum Maximum ◽  
Free Living ◽  
Trichostrongylus Colubriformis ◽  
Brachiaria Decumbens ◽  
Infective Larvae ◽  
Experimental Plots

This experiment aimed to assess the recovery of infective larvae (L3) of Trichostrongylus colubriformis from Brachiaria decumbens cv. Australiana, Cynodon dactylon cv. Coast-cross and Panicum maximum cv. Aruana. The experimental module comprised six plots, with two plots per herbage species. Larval survival was assessed from autumn to winter, under the effect of two herbage-paring heights (5 and 30 cm). TThe paring was carried out immediately before contamination with faces containing T. colubriformis eggs. The feces and herbage were collected at one, two, four, eight, 12 and 16 weeks after feces had been deposited in the experimental plots. In general, larvae were recovered from both herbage and feces until the 16th week. The longer persistence of these larvae in the environment was probably due to warmer temperatures. The number of L3 recovered from the pasture was not influenced by the height of plants, except for Brachiaria and Aruana herbage in the fourth week. Regarding the concentrations of larvae per kg of dry matter (L3/kg DM), recovery was higher from low pasture in all three herbage species. During the autumn, the development and survival of the T. colubriformis free-living stages were not affected by the different herbage species.

scholarly journals Spatial epidemiological modelling of infection by Vibrio aestuarianus shows that connectivity and temperature control oyster mortality

2020 ◽  
Vol 12 ◽  
pp. 511-527
Author(s):  
C Lupo ◽  
BL Dutta ◽  
S Petton ◽  
P Ezanno ◽  
D Tourbiez ◽  
...  
Keyword(s):  
Reproduction Number ◽  
Effect Of Temperature ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Free Living ◽  
Oyster Population ◽  
Marine Connectivity ◽  
Oyster Mortality ◽  
Adult Oyster ◽  
Oyster Farms

Vibrio aestuarianus infection in oyster populations causes massive mortality, resulting in losses for oyster farmers. Such dynamics result from host-pathogen interactions and contagion through water-borne transmission. To assess the spatiotemporal spread of V. aestuarianus infection and associated oyster mortality at a bay scale, we built a mathematical model informed by experimental infection data at 2 temperatures and spatially dependent marine connectivity of oyster farms. We applied the model to a real system and tested the importance of each factor using a number of modelling scenarios. Results suggest that introducing V. aestuarianus in a fully susceptible adult oyster population in the bay would lead to the mortality of all farmed oysters over 6 to 12 mo, depending on the location in which infection was initiated. The effect of temperature was captured by the basic reproduction number (R0), which was >1 at high seawater temperatures, as opposed to values <1 at low temperatures. At the ecosystem scale, simulations showed the existence of long-distance dispersal of free-living bacteria. The western part of the bay could be reached by bacteria originating from the eastern side, though the spread time was greatly increased. Further developments of the model, including the consideration of the anthropogenic movements of oysters and oyster-specific sensitivity factors, would allow the development of accurate maps of epidemiological risks and help define aquaculture zoning.

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