scholarly journals Strongyloses ratti and S. stercoralis: effects of cambendazole, thiabendazole and mebendazole in vitro

1986 ◽  
Vol 28 (2) ◽  
pp. 97-103 ◽  
Author(s):  
David I. Grove ◽  
Carolyn Northern
Keyword(s):  
The Other ◽  
Free Living ◽  
Second Stage ◽  
Infective Larvae ◽  
In Vitro Incubation ◽  
Living Adult

The effects of in vitro incubation of three henzimidazole anthelmintics, thiabendazole, mebendazole and cambendazole on Strongyloides were compared. No drug affected hatching of S. ratti eggs or the viability of infective larvae or parasitic adult worms, but all three inhibited moulting of S. ratti larvae. In addition, cambendazole, but not thiabendazole or mebendazole, impaired the viability of S. ratti first- and second-stage larvae. The three drugs had no effect on isolated S. stercorais free-living adult worms, but they all prevented development of S. stercoralis rhabditiform larvae. Thiabendazole and mebendazole had no effect on the infectivity of either S. ratti or S. stercoralis infective larvae, but infection with these worms was abrogated by prior incubation with cambendazole. These results indicate that cambendazole acts in a different manner to the other two drugs. Since it is active against larvae migrating through the tissues, it is potentially of much greater value than thiabendazole or mebendazole in the therapy of strongyloidiasis.

Development in vitro of free-living infective larvae to the parasitic stage of Strongyloides venezuelensis by temperature shift

Parasitology ◽  
1994 ◽  
Vol 109 (5) ◽  
pp. 643-648 ◽  
Author(s):  
N. Tsuji ◽  
K. Fujisaki
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Temperature Shift ◽  
Parasitic Stage ◽  
Free Living ◽  
2D Page ◽  
Infective Larvae ◽  
Immunodominant Antigen ◽  
Strongyloides Venezuelensis ◽  
Development In Vitro

Free-living infective larvae Strongyloides venezuelensis were cultured in Dulbecco's modified Eagle's medium at 25 and 37 °C, and development to the parasitic stage was evaluated using morphological, protein and antigenicity criteria. Few larvae cultured at 25 °C showed development whereas, in most of the larvae cultured at 37 °C, there appeared characteristic changes such as a bulb-like head and droplets under the cuticle with an increase of body width of the larvae. The results obtained from two-dimensional polyacrylamide gel electrophoresis(2D–PAGE) revealed that the protein spot patterns of the larvae cultured at 25 and 37 °C were differentiated by 17 specific spots. In addition, Western blot analysis combined with 2D–PAGE for reaction with serum obtained from an infected rat revealed that protein spots showing immunodominant antigen at 37 °C were almost the same as those of the larvae recovered from the rats rather than those of the larvae at 25 °C. These results strongly suggested that a temperature shift from 25 to 37 °C has an important role in the development of free-living infective larvae to the parasitic stage of S. venezuelensis. The culture system established in the present study was useful for biological and biochemical studies in the development from/of the free-living to the parasitic stage of Strongyloides species.

In vitro trapping capability of Arthrobotrys spp. on infective larvae of Haemonchus contortus and Nacobbus aberrans

1994 ◽  
Vol 68 (3) ◽  
pp. 223-229 ◽  
Author(s):  
P. Mendoza-de Gives ◽  
E. Zavaleta-Mejia ◽  
D. Herrera-Rodriguez ◽  
H. Quiróz-Romero
Keyword(s):  
Microscopic Examination ◽  
Haemonchus Contortus ◽  
Three Dimensional ◽  
Arthrobotrys Oligospora ◽  
Second Stage ◽  
Infective Larvae ◽  
Third Stage ◽  
Nacobbus Aberrans

AbstractThe trapping capability of Arthrobotrys oligospora and A. conoides (Hyphomycetales) against third stage larvae (L3) of Haemonchus contortus (Trichostrongylidae) was evaluated in an in vitro trial. Arthrobotrys oligospora showed a 35.87% and 25.71% trapping effectiveness against H. contortus infective larvae at 18 and 25°C, respectively; whereas the trapping capability of A. conoides was 92.17% and 90.40% at the same temperatures, respectively. Microscopic examination demonstrated that A. conoides spontaneously developed a large quantity of three-dimensional loops before the nematodes were added. Neither of the two species studied developed three-dimensional adhesive loops at 30°C, consequently no trapped nematode was observed. In a second trial, the trapping capability of A. conoides against H. contortus (L3) and second stage larvae (J2) of Nacobbus aberrans (Pratylenchidae), was evaluated at 25°C. The trapping capability shown by A. conoides was higher than 90% for both kinds of nematode. The possible use of A. conoides to control ovine haemonchosis is discussed.

scholarly journals The influence of desiccation and UV radiation on the development and survival of free-living stages of cyathostomins under field and laboratory conditions

2008 ◽  
Vol 45 (1) ◽  
pp. 32-40 ◽  
Author(s):  
I. Langrová ◽  
I. Jankovská ◽  
J. Vadlejch ◽  
M. Libra ◽  
A. Lytvynets ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Field Experiments ◽  
The Other ◽  
Infective Stage ◽  
Free Living ◽  
Infective Larvae ◽  
Laboratory Conditions ◽  
Other Hand ◽  
Field And Laboratory Conditions

AbstractThe present work describing both laboratory and field experiments was performed to assess the effects of desiccation and UV radiation on the development and survival of free-living stages of equine cyathostomins.Cyathostomin larvae in horse faeces did not develop to the infective stage when faecal humidity levels dropped below 23 %, nonetheless solitary preinfective larvae were still recovered after 151 days (humidity 19.5 %). The development to infective stage after remoistening occurred for the last time after 54 days following desiccation.Preinfective stages are susceptible to the effects of the direct desiccation stage. The preinfective larvae were rapidly killed within one minute, the cyathostomin eggs within 5 hours. The numerous normal mobile infective larvae were encountered after 35 days of the desiccated period. The preinfective stage of cyathostomins also showed very little tolerance to direct sun radiation: most eggs were killed by the exposure within 3 hours and the preinfective larvae within 1 hour. The survival of infective larvae was, on the other hand, unaffected by sun radiation after 7 days (P < 0.05). However, desiccated infective larvae were then found to be susceptible to UV radiation, resulting in total mortalities after 5 days.

THE MORPHOLOGY AND DEVELOPMENT OF THE SHEEP NEMATODE, STRONGYLOIDES PAPILLOSUS (WEDL, 1856)

1950 ◽  
Vol 28d (3) ◽  
pp. 173-196 ◽  
Author(s):  
M. A. Basir
Keyword(s):  
The Body ◽  
The Other ◽  
Free Living ◽  
Experimental Animals ◽  
Infective Larvae ◽  
Time Required ◽  
Parasitic Generation

In studying the morphology and development of Strongyloides papillosus it has been shown that four molts occur during the development of the free-living sexual adults, two molts in the formation of the infective larvae, and two molts in the development of the parasitic adults from the infective larvae. The last two occur in the body of the host, one in the lungs and the other in the intestine. The time required by the eggs to hatch and the larvae to develop to either the infective larvae or the free-living adults varies with temperature; at 27 °C. it is 6 hr. and 28 hr., respectively. The so-called "spears" in the oesophagus of the free-living adults were found to be the cuticularized tubular endings of the rays of the oesophageal lumen. The head in the free-living adults bears two well developed lips and four papillae, while in parasitic adults it has four lips and four papillae. The tail of the free-living male bears two pairs of preanal and two pairs of postanal papillae. No males were found in the parasitic generation, while parasitic females were found only in the intestine of experimental animals.

scholarly journals Effects of Melia azedarach L. leaf and fruit on mineralization of carbon in soil

2014 ◽  
Vol 43 (1) ◽  
pp. 119-122
Author(s):  
Nacide Kizildag ◽  
Sahen Cenkseven ◽  
Husniye Aka Sagliker ◽  
Cengiz Darici
Keyword(s):  
Incubation Time ◽  
Carbon Mineralization ◽  
The Other ◽  
Melia Azedarach ◽  
In Vitro Incubation

Carbon mineralization in soil increased significantly due to additions of pure azadirachtin and powdered leaves and fruits of Melia azedarach L. under in vitro incubation for 30 days at 28°C. Cumulative respired C(CO2) clearly increased with incubation time in all treatments except in soil mixed with pure azadirachtin (p < 0.001). Carbon mineralization ratio in soils mixed with single doses of powdered leaf and fruit were significantly higher than the other doses tested.  

The survival of desiccation by the free-living stages of Trichostrongylus colubriformis (Nematoda: Trichostrongylidae)

Parasitology ◽  
1982 ◽  
Vol 84 (3) ◽  
pp. 455-462 ◽  
Author(s):  
D. A. Wharton
Keyword(s):  
Relative Humidity ◽  
Prolonged Exposure ◽  
Infective Larva ◽  
Survival Times ◽  
Free Living ◽  
Trichostrongylus Colubriformis ◽  
Second Stage ◽  
Infective Larvae

SummaryThe survival of the free-living stages of Trichostrongylus colubriformis under defined conditions of temperature and relative humidity was investigated. The survival of embryonated eggs was poor at 0, 33 and 54·5 % relative humidity (rel. hum.) at 20 °C but hatching occurred from a proportion of eggs even after exposure for 104 days to 76 and 98% rel. hum. at 20 °C. Second-stage larvae were desiccation-susceptible and were killed within 6 h even at 98% rel. hum. and 20 °C. Infective larvae, dried separately or in clumps, survived prolonged exposure to desiccation at 33–98% rel. hum. and 20 °C with 50% survival times of 58–164 days. Clump formation did not enhance survival in this range. Infective larvae also survived exposure to vacuum desiccation with 50% survival times of 8·8 h in clumps and 4·5 h when dried separately. The infective larva thus readily survives desiccation and may prove a useful model for the study of anhydrobiosis.

Degradation of mimosine by rumen contents: effects of feed composition and Leucaena substrates

1983 ◽  
Vol 34 (3) ◽  
pp. 289 ◽  
Author(s):  
B Tangendjaja ◽  
JP Hogan ◽  
RBH Wills
Keyword(s):  
Rumen Fluid ◽  
The Other ◽  
Buffer Solution ◽  
Feed Composition ◽  
Rapid Degradation ◽  
Enzyme Systems ◽  
In Vitro Incubation

Samples of rumen fluid obtained from sheep that had been fed on different diets were fractionated into microorganism and supernatant fractions, and the former divided into bacteria-rich and protozoa-rich fractions. The fractions were evaluated for their ability to degrade purified mimosine during in vitro incubation. The rumen contents of sheep fed on a lucerne-oats mixture produced a more rapid degradation of mimosine than did that from sheep fed on lucerne hay, which was greater than that from a Digitaria pentrii diet. Most activity was in the bacteria-rich fraction for the lucerne-oats diet and in the protozoa-rich fraction for the other diets. The rate of degradation of endogenous mimosine in Leucaena leaf during incubation in ruinen fluid was much greater than for the purified mimosine. The substantial degradation observed when a buffer solution was substituted for rumen fluid was attributed to endogenous leaf enzymes. These enzyme systems were more efficient at degrading mimosine than were the microorganisms in the rumen liquor.

In vitro nematicidal effects of medicinal plants from the Sierra de Huautla, Biosphere Reserve, Morelos, Mexico against Haemonchus contortus infective larvae

2008 ◽  
Vol 82 (1) ◽  
pp. 25-31 ◽  
Author(s):  
U. López-Aroche ◽  
D.O. Salinas-Sánchez ◽  
P. Mendoza de Gives ◽  
M.E. López-Arellano ◽  
E. Liébano-Hernández ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Larval Mortality ◽  
Evaluation Criteria ◽  
Anthelmintic Activity ◽  
Biosphere Reserve ◽  
The Other ◽  
Post Exposure ◽  
Infective Larvae ◽  
Third Stage

AbstractTwenty extracts from plants from Sierra de Huautla Biosphere Reserve, Morelos, Mexico were evaluated against Haemonchus contortus infective larvae in an in vitro assay. The plant species evaluated were Bursera copallifera, B. grandifolia, Lippia graveolens, Passiflora mexicana, Prosopis laevigata, Randia echinocarpa and Urtica dioica. The plants were separated into their parts and macerated with different solvents (n-hexane, acetone, ethanol and methanol). An in vitro assay was used to evaluate the anthelmintic activity against unsheathed third stage H. contortus infective larvae. The experiment was carried out in 24-well cell culture plates at room temperature with three replicates per treatment and using a concentration of 20 mg ml− 1. Ten 5 μl aliquots were taken from the corresponding wells and deposited on a slide for microscopical observation at 24, 48, 72 and 96 h post-exposure. The evaluation criteria were based on the average numbers of live and/or dead larvae in the different treatments. Alive and dead larval numbers were statistically analysed through the ANOVA test (P>0.01). The Tukey test was used as a complementary tool to determine which treatment was different from the other treatments (P>0.05). The highest mortality was observed with P. laevigata hexanic extract from stem and leaves combined, which produced 51%, 81% and 86% larval mortality at 24, 48 and 72 h post-exposure, respectively. On the other hand, B. copallifera stem acetonic extract exhibited 18%, 59% and 66% nematicidal activity after 24, 48 and 72 h of exposure, respectively.

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