THE LIFE CYCLE OF TRICHINELLA SPIRALIS: I. THE INTESTINAL PHASE OF DEVELOPMENT

1967 ◽  
Vol 45 (6) ◽  
pp. 1255-1260 ◽  
Author(s):  
C. S. Shanta ◽  
E. Meerovitch
Keyword(s):  
Life Cycle ◽  
Post Infection ◽  
Sexual Maturity ◽  
Trichinella Spiralis ◽  
Seminal Vesicles ◽  
Intestinal Phase ◽  
Experimental Infections

In experimental infections in mice, Trichinella spiralis larvae in the intestines molted twice before reaching sexual maturity. In both sexes, the first molt occurred between 12 and 16 hours post infection; in males, the second molt occurred between 24 and 32 hours, and in females, between 22 and 30 hours. The females were inseminated after the 36th hour post infection, but some males had spermatozoa in the seminal vesicles before the completion of the second molt. Structures, believed to be amphids, were observed after 2 hours post infection; they increased in size up to the 6th hour, after which they regressed and finally disappeared. The function of these amphids is believed to be related to osmoregulation.

scholarly journals Characterization of a Novel Glutamine Synthetase From Trichinella spiralis and Its Participation in Larval Acid Resistance, Molting, and Development

2021 ◽  
Vol 9 ◽  
Author(s):  
Tong Xu Zhuo ◽  
Zhen Wang ◽  
Yan Yan Song ◽  
Shu Wei Yan ◽  
Ruo Dan Liu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Life Cycle ◽  
Glutamine Synthetase ◽  
Enzymatic Activity ◽  
Post Infection ◽  
Catalytic Domain ◽  
Trichinella Spiralis ◽  
Acid Resistance ◽  
Muscle Larvae

Trichinella spiralis is a major foodborne parasite worldwide. After the encapsulated muscle larvae (ML) in meat are ingested, the ML are liberated in the stomach of the host and activated into intestinal infectious larvae (IIL), which develop into adult worm after molting four times. A novel glutamine synthetase (TsGS) was identified from T. spiralis IIL at 10 h post-infection, but its biological role in T. spiralis life cycle is not clear. The aim of this study was to investigate the biological characteristics of TsGS and its functions in larval acid resistance, molting, and development. TsGS has a glutamine synthetase (GS) catalytic domain. Complete TsGS sequence was cloned and expressed in Escherichia coli BL21. rTsGS has good immunogenicity. qPCR and Western blotting showed that TsGS was highly expressed at IIL stage, and immunofluorescence revealed that TsGS was principally localized at the cuticle and intrauterine embryos of this nematode. rTsGS has enzymatic activity of natural GS to hydrolyze the substrate (Glu, ATP, and NH4+). Silencing of TsGS gene significantly reduced the IIL survival at pH 2.5, decreased the IIL burden, and impeded larval molting and development. The results demonstrated that TsGS participates in T. spiralis larval acid resistance, molting and development, and it might be a candidate vaccine target against Trichinella molting and development.

scholarly journals Changes in the expression of TLR2 during the intestinal phase of trichinellosis

2020 ◽  
Vol 64 (2) ◽  
pp. 269-274
Author(s):  
Agnieszka Wojtkowiak-Giera ◽  
Monika Derda ◽  
Elżbieta Wandurska-Nowak ◽  
Paweł P. Jagodziński ◽  
Agnieszka Kolasa-Wołosiuk ◽  
...  
Keyword(s):  
Immune Response ◽  
Small Intestine ◽  
Real Time Pcr ◽  
Post Infection ◽  
Trichinella Spiralis ◽  
Mrna Level ◽  
Quantitative Real Time Pcr ◽  
Defence Mechanisms ◽  
Intestinal Phase ◽  
Fast Activation

AbstractIntroductionToll-like receptors (TLRs) play an important role in fast activation of the immune response to a variety of pathogens, including parasites. In this study, we focused on TLR2, because this receptor is one of the best known and most frequently analysed members of the TLR family. The aim of this study was to assess the effect of Trichinella spiralis on expression of TLR2 during the intestinal stage of infection.Material and MethodsThe experimental material consisted of isolates prepared from the intestines (jejunum and colon) of BALB/c mice infected with T. spiralis taken at 4, 8, and 16 days post infection.ResultsOur results based on quantitative real-time PCR showed that the mRNA level for TLR2 was statistically significantly higher in the jejuna of mice infected with T. spiralis than in this tissue of uninfected mice. In addition, the presence of TLR2 protein in the intestinal phase of trichinellosis was confirmed by a strong positive immunohistochemical reaction.ConclusionOur results indicate that infection with T. spiralis changes the expression of TLR2 in the small intestine of the mouse host and suggest a contribution of these receptors to the host defence mechanisms during experimental trichinellosis.

Modulation of the anti-phosphorylcholine immune response duringTrichinella spiralisinfections in mice

Parasitology ◽  
1987 ◽  
Vol 95 (3) ◽  
pp. 583-592 ◽  
Author(s):  
F. M. Ubeira ◽  
J. Leiro ◽  
M. T. Santamarina ◽  
M. L. Sanmartin-Duran
Keyword(s):  
Immune Response ◽  
Life Cycle ◽  
Antibody Response ◽  
Red Blood Cells ◽  
Post Infection ◽  
Blood Cells ◽  
Trichinella Spiralis ◽  
Heterologous Antigen ◽  
Specific Suppression ◽  
Antigenic Fraction

SUMMARYThe nematodeTrichinella spiralisis able to modulate the antibody response, as measured by the plaque-forming cell (PFC) technique, to three thymus-dependent (TD) antigens: (1) a heterologous antigen unrelated to the parasite (sheep red blood cells (SRBC)); (2) an antigenic fraction, rich in phosphorylcholine (PC), obtained fromT. spiralis(FCpl) and (3) a heterologous antigen unrelated to the parasite, but sharing the PC epitope with the FCpl fraction (PC-KLH). During the life-cycle of the parasite in BCF1 mice, two opposing immunomodulating activities occur: (1) an immuno-potentiating activity in mice infected during the intestinal and larval migratory stages, for all three antigens, and (2) a carrier-specific immunosuppressive response in mice infected and immunized with the FCpl fraction during the muscle phase of the life-cycle. The anti-PC PFC response of these mice is dependent on the infection dose and decreases from day 35 post-infection (p.i.) until at least day 85 p.i.. The factor responsible for the stimulating effect observed during this stage is the presence of migratory larvae in the host. All the foregoing seems to indicate thatT. spiraliscan use specific suppression mechanisms to aid in its own survival.

Rites of Passage

2018 ◽  
Author(s):  
Axel Michaels
Keyword(s):  
Life Cycle ◽  
Old Age ◽  
Sexual Maturity ◽  
Rites Of Passage ◽  
Life And Death ◽  
Transformational Process ◽  
Local Contexts ◽  
Vulnerable Community ◽  
History Of ◽  
The Individual

This chapter examines the classical Hindu life-cycle rites, the term saṃskāra and its history, and the main sources (Gṛhyasūtras and Dharma texts). It presents a history of the traditional saṃskāras and variants in local contexts, especially in Nepal. It describes prenatal, birth and childhood, initiation, marriage, old-age, death, and ancestor rituals. Finally, it analyzes the transformational process of these life-cycle rituals in the light of general theories on rites of passage. It proposes, in saṃskāras, man equates himself with the unchangeable and thus seems to counteract the uncertainty of the future, of life and death, since persons are confronted with their finite existence. For evidently every change, whether social or biological, represents a danger for the cohesion of the vulnerable community of the individual and society. These rituals then become an attempt of relegating the effects of nature or of mortality: birth, teething, sexual maturity, reproduction, and dying.

THE DESCRIPTION AND LIFE CYCLE OF MARITREMA LARICOLA SP. N. (TREMATODA: MICROPHALLIDAE)

1963 ◽  
Vol 41 (5) ◽  
pp. 881-888 ◽  
Author(s):  
Hilda Lei Ching
Keyword(s):  
Life Cycle ◽  
Experimental Infections ◽  
Size And Morphology ◽  
Hemigrapsus Oregonensis ◽  
Larus Glaucescens

Maritrema laricola sp. n. from the intestine of the glaucous-winged gull, Larus glaucescens, differs from other species in the genus in having an elongate body, small cirrus sac, and short, curved cirrus. The life cycle of the species was followed from sporocyst stage in Littorina scutulata and Littorina sitchana, to the metacercarial stage in Hemigrapsus oregonensis and H. nudus, and to the adult in natural and experimental hosts. In experimental infections of H. oregonensis, the cercariae penetrate and develop in the gills after which they migrate to the haemocoel of the crab and encyst. The metacercariae are fully developed in from 6 to 9 weeks, and similar in size and morphology to natural infections in crabs. Excystment of the metacercariae occurs in the following cultures at 40 °C: 3% pepsin plus 1% HCl, 0.85% saline, and seawater diluted 1:4. Metacercariae live for about 3 days in diluted seawater but do not produce eggs in any of the cultures. Only immature worms were recovered from mice and newly hatched chicks when they were fed the metacercariae, but mature worms were found in natural and experimental infections of the glaucous-winged gull. In a review of the genus Maritrema, the following transfers are made: Maritrema uca Sarkisian, 1957 to the genus Mecynophallus Cable, Connor, and Balling, 1960, and Maritreminoides raminellae Dery, 1958 to Pseudospelotrema Yamaguti, 1939.

Life cycle of the western school prawn, Metapenaeus dalli Racek, in a Western Australian estuary

1986 ◽  
Vol 37 (1) ◽  
pp. 95 ◽  
Author(s):  
IC Potter ◽  
JW Penn ◽  
KS Brooker
Keyword(s):  
Life Cycle ◽  
Western Australia ◽  
Sexual Maturity ◽  
Second Year Of Life ◽  
Second Year ◽  
Australian Estuary ◽  
Western Australian

The absence of marine records for M. dalli below latitude 31�S., together with data on gonadal stages and spermatophore deposition on females of this species in the Swan estuary, provide very strong indications that the western school prawn typically breeds in estuarine environments in south-western Australia. The 0 + recruits, which first appeared in samples in February, remained in the estuary during the following months and by November had reached a size suitable for exploitation. At this time they were approaching sexual maturity and were starting to move from the shallows to the deeper waters of the estuary where they remained for their second year of life. In contrast to Australian Penaeus species, M. dalli mates during the intermoult period when the shell is hard rather than immediately after moulting.

Efficacy of ivermectin against Parastrongylus malaysiensis infection in rats

1992 ◽  
Vol 66 (4) ◽  
pp. 293-296
Author(s):  
S. Ambu ◽  
J. W. Mak ◽  
C. S. Ng
Keyword(s):  
Post Infection ◽  
Larval Stages ◽  
Experimental Infections ◽  
Significant Pathology

ABSTRACTThe efficacy of ivermectin on experimental infections of P. malaysiensis in rats was determined. Ivermectin was 99·4% and 97·9% effective at a dosage of 400 mcg and 800 mcg respectively at seven days post-infection. The same two dosages of ivermectin when given at 14 days post infection had an efficacy of 100%. However, as an adulticide it had only 40·7% efficacy. Ivermectin may therefore be useful for the treatment of parastrongyliasis due to the larval stages of the worm which can cause significant pathology in man and animals.

scholarly journals Detection of circulating antigens in serum samples of mice experimentally infected with Trichinella spiralis by a sandwich ELISA based on IgY

2014 ◽  
Vol 51 (3) ◽  
pp. 181-189 ◽  
Author(s):  
F. Jing ◽  
J. Cui ◽  
R. Liu ◽  
L. Liu ◽  
P. Jiang ◽  
...  
Keyword(s):  
Post Infection ◽  
Trichinella Spiralis ◽  
Sandwich Elisa ◽  
Egg Yolk ◽  
Mouse Serum ◽  
Serum Samples ◽  
Egg Yolk Immunoglobulin ◽  
Muscle Larvae ◽  
Sandwich Elisa Assay ◽  
Circulating Antigens

AbstractIn the present study, a sandwich ELISA based on IgY (egg yolk immunoglobulin) was developed for detection of circulating antigens (CAg) in sere of mice experimentally infected with Trichinella spiralis. The IgY-sandwich ELISA assay involved the use of chicken antibody IgY against excretory-secretory (ES) antigens of Trichinella spiralis muscle larvae as a capture antibody and mouse polyclonal antibody IgG to ES antigens as a detecting antibody. This method was able to detect as little as 3 ng/ml of ES antigens added to normal mouse serum. A group of sixteen mice was orally inoculated with 500 T. spiralis muscle larvae per animal. The serum samples from the infected mice were taken during 1–35 days post-infection (dpi). The CAg was detectable as early as 8 dpi in the sera of infected mice. The level of CAg increased dramatically during 13–15 dpi and reached a peak at 22 dpi and remained a plateau for 3 days, then declined gradually. Another peak of CAg occurred at 31 dpi. The anti-Trichinella antibodies was first detected in 14.3 % of the infected mice at 2 weeks post-infection (wpi), and reached a peak positive rate of 100 % at 5 wpi. Moreover, the infected mice were treated with abendazole at 5 wpi and the serum CAg levels increased significantly during 2–6 days posttreatment (dpt) and then declined rapidly during 8–14 dpt. By 42 dpt, the CAg levels decreased to the undetected level, but the detection rate of antibodies was still 100 %. The IgY-sandwich ELISA appears to be a sensitive for detection of antigenemia of T. spiralis and valuable to judge the efficacy of chemotherapy in trichinellosis.

scholarly journals Parvatrema duboisi (Digenea: Gymnophallidae) Life Cycle Stages in Manila Clams, Ruditapes philippinarum, from Aphae-do (Island), Shinan-gun, Korea

2021 ◽  
Vol 59 (1) ◽  
pp. 83-88
Author(s):  
Bong-Kwang Jung ◽  
Taehee Chang ◽  
Hyejoo Shin ◽  
Seungwan Ryoo ◽  
Sooji Hong ◽  
...  
Keyword(s):  
Life Cycle ◽  
Post Infection ◽  
Ruditapes Philippinarum ◽  
Manila Clam ◽  
Long Tail ◽  
5.8S Rdna ◽  
Rdna Its2 ◽  
Life Cycle Stages ◽  
Second Intermediate Host

Life cycle stages, including daughter sporocysts, cercariae, and metacercariae, of Parvatrema duboisi (Dollfus, 1923) Bartoli, 1974 (Digenea: Gymnophallidae) have been found in the Manila clam Ruditapes philippinarum from Aphaedo (Island), Shinan-gun, Jeollanam-do, Korea. The daughter sporocysts were elongated sac-like and 307-570 (av. 395) μm long and 101-213 (av. 157) μm wide. Most of the daughter sporocysts contained 15-20 furcocercous cercariae each. The cercariae measured 112-146 (av. 134) μm in total length and 35-46 (av. 40) μm in width, with 69-92 (av. 85) μm long body and 39-54 (av. 49) μm long tail. The metacercariae were 210-250 (av. 231) μm in length and 170-195 (av. 185) μm in width, and characterized by having a large oral sucker, genital pore some distance anterior to the ventral sucker, no ventral pit, and 1 compact or slightly lobed vitellarium, strongly suggesting P. duboisi. The metacercariae were experimentally infected to ICR mice, and adults were recovered at day 7 post-infection. The adult flukes were morphologically similar to the metacercariae except in the presence of up to 20 eggs in the uterus. The daughter sporocysts and metacercariae were molecularly (ITS1-5.8S rDNA-ITS2) analyzed to confirm the species, and the results showed 99.8-99.9% identity with P. duboisi reported from Kyushu, Japan and Gochang, Korea. These results confirmed the presence of various life cycle stages of P. duboisi in the Manila clam, R. philippinarum, playing the role of the first as well as the second intermediate host, on Aphae-do (Island), Shinan-gun, Korea.

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