• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.103-107
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• 2016

The objective of this study was to evaluate the effects of several different commercial disinfectants on the embryogenic development of Ascaris suum eggs. A 1-ml aliquot of each disinfectant was mixed with approximately 40,000 decorticated or intact A. suum eggs in sterile tubes. After each treatment time (at 0.5, 1, 5, 10, 30, and 60 min), disinfectants were washed away, and egg suspensions were incubated at $25^{\circ}C$ in distilled water for development of larvae inside. At 3 weeks of incubation after exposure, ethanol, methanol, and chlorohexidin treatments did not affect the larval development of A. suum eggs, regardless of their concentration and treatment time. Among disinfectants tested in this study, 3% cresol, 0.2% sodium hypochlorite and 0.02% sodium hypochlorite delayed but not inactivated the embryonation of decorticated eggs at 3 weeks of incubation, because at 6 weeks of incubation, undeveloped eggs completed embryonation regardless of exposure time, except for 10% povidone iodine. When the albumin layer of A. suum eggs remained intact, however, even the 10% povidone iodine solution took at least 5 min to reasonably inactivate most eggs, but never completely kill them with even 60 min of exposure. This study demonstrated that the treatment of A. suum eggs with many commercially available disinfectants does not affect the embryonation. Although some disinfectants may delay or stop the embryonation of A. suum eggs, they can hardly kill them completely.

• Parasites, Hosts and Diseases
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• v.56 no.2
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• pp.175-181
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• 2018

The giant roundworm Ascaris infects pigs and people worldwide and causes serious diseases. The taxonomic relationship between Ascaris suum and Ascaris lumbricoides is still unclear. The purpose of the present study was to investigate the genetic diversity and population genetic structure of 258 Ascaris specimens from humans and pigs from 6 sympatric regions in Ascaris-endemic regions of China using existing simple sequence repeat data. The microsatellite markers showed a high level of allelic richness and genetic diversity in the samples. Each of the populations demonstrated excess homozygosity (Ho0). According to a genetic differentiation index (Fst=0.0593), there was a high-level of gene flow in the Ascaris populations. A hierarchical analysis on molecular variance revealed remarkably high levels of variation within the populations. Moreover, a population structure analysis indicated that Ascaris populations fell into 3 main genetic clusters, interpreted as A. suum, A. lumbricoides, and a hybrid of the species. We speculated that humans can be infected with A. lumbricoides, A. suum, and the hybrid, but pigs were mainly infected with A. suum. This study provided new information on the genetic diversity and population structure of Ascaris from human and pigs in China, which can be used for designing Ascaris control strategies. It can also be beneficial to understand the introgression of host affiliation.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.466-471
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• 2011

Allergic asthma is complex inflammatory airway disorder caused by genetic and environmental factors. Sulfamethoxazole, a sulfonamide, is the cause of drug rash with eosinophilia and systemic symptoms syndrome. Parasites infection also related with eosinophilia and allergic diseases. In the present study, we investigated the modulating effects of parasitic derivative and sulfamethoxazole (SMX) on allergic airway inflammation in the ovalbumin (OVA)-induced murine asthma model. Histopathological changes, cytokine secretion, and total and allergen-specific IgE were investigated. BALB/c mice were treated with Ascaris suum extract or SMX for 4 weeks before sensitized and challenged to ovalbumin. Pre-treatment of Ascaris suum extract decreased allergic inflammation in lung tissue and IL-4, total IgE, and OVA-specific IgE levels in bronchoalveolar lavage fluid. However, pre-treatment of SMX did not show any effects on allergic airway inflammation. These results indicate that parasitic infection has protective effects on allergic asthma, but the sulfamamides may not relate with allergic asthma.

• Parasites, Hosts and Diseases
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• v.50 no.1
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• pp.83-87
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• 2012

To determine the effects of kimchi extracts at different temperatures on larval development, $Ascaris$ $suum$ eggs were mixed with soluble part of 7 different brands of commercially available kimchi and preserved at either $5^{\circ}C$ or $25^{\circ}C$ for up to 60 days. $A.$ $suum$ eggs incubated at $25^{\circ}C$ showed marked differences in larval development between kimchi extract and control group. While all eggs in the control group completed embryonation by day 21, only 30% of the eggs in the kimchi extract group became embryonated by day 36 and about 25% never became larvated even at day 60. At $5^{\circ}C$, however, none of the eggs showed larval development regardless of the incubation period or type of mixture group. To determine the survival rate of $A.$ $suum$ eggs that showed no embryonation after being preserved at $5^{\circ}C$, eggs preserved in kimchi extracts for 14, 28, and 60 at $5^{\circ}C$ were re-incubated at $25^{\circ}C$ for 3 weeks in distilled water. While all eggs in the control group became larvated, eggs in the kimchi extract group showed differences in their embryonation rates by the incubation period; 87.4 % and 41.7% of the eggs became embryonated after being refrigerated for 14 days and 28 days, respectively. When refrigerated for 60 days, however, no eggs mixed in kimchi extract showed larval development. Our results indicate that embryogenesis of $A.$ $suum$ eggs in kimchi extract was affected by duration of refrigeration, and that all eggs stopped larval development completely in kimchi kept at $5^{\circ}C$ for up to 60 days.

• Parasites, Hosts and Diseases
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• v.50 no.3
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• pp.243-247
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• 2012

Ascaris suum eggs are inactivated by composting conditions; however, it is difficult to find functional changes in heat-treated A. suum eggs. Here, unembryonated A. suum eggs were incubated at $20^{\circ}C$, $50^{\circ}C$, and $70^{\circ}C$ in vitro, and the gene expression levels related to viability, such as eukaryotic translation initiation factor 4E (IF4E), phosphofructokinase 1 (PFK1), and thioredoxin 1 (TRX1), and to apoptosis, such as apoptosis-inducing factor 1 (AIF1) and cell death protein 6 (CDP6), were evaluated by real-time quantitative RT-PCR. No prominent morphological alterations were noted in the eggs at $20^{\circ}C$ until day 10. In contrast, the eggs developed rapidly, and embryonated eggs and hatched larvae began to die, starting on day 2 at $50^{\circ}C$ and day 1 at $70^{\circ}C$. At $20^{\circ}C$, IF4E, PFK1, and TRX1 mRNA expression was significantly increased from days 2-4; however, AIF1 and CDP6 mRNA expression was not changed significantly. IF4E, PFK1, and TRX1 mRNA expression was markedly decreased from day 2 at $50^{\circ}C$ and $70^{\circ}C$, whereas AIF1 and CDP6 mRNA expression was significantly increased. The expressions of HSP70 and HSP90 were detected for 9-10 days at $20^{\circ}C$, for 3-5 days at $50^{\circ}C$, and for 2 days at $70^{\circ}C$. Taken together, incremental heat increases were associated with the rapid development of A. suum eggs, decreased expression of genes related to viability, and earlier expression of apoptosis-related genes, and finally these changes of viability- and apoptosis-related genes of A. suum eggs were associated with survival of the eggs under temperature stress.

• Parasites, Hosts and Diseases
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• v.50 no.3
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• pp.239-242
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• 2012

The influence of temperature on the development and embryonation of Ascaris suum eggs was studied using coarse sand medium in an environmental chamber with 50% humidity. The time required for development and embryonation of eggs was examined under 3 different temperature conditions, $5^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$. A. suum eggs did not develop over 1 month at the temperature of $5^{\circ}C$. However, other temperature conditions, $25^{\circ}C$ and $35^{\circ}C$, induced egg development to the 8-cell-stage at days 5-6 after incubation. All eggs examined developed to the 8-cell stage at day 6 after incubation in the sand medium at $25^{\circ}C$. The higher temperature, $35^{\circ}C$, slightly accelerated the A. suum egg development compared to $25^{\circ}C$, and the development to the 8-cell stage occurred within day 5 after incubation. The formation of larvae in A. suum eggs at temperatures of $35^{\circ}C$ and $25^{\circ}C$ appeared at days 17 and 19 after incubation, respectively. These findings show that $35^{\circ}C$ condition shortens the time for the development of A. suum eggs to the 8-cell-stage in comparison to $25^{\circ}C$, and suggest the possibility of accelerated transmission of this parasite, resulting from global warming and ecosystem changes.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.107-117
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• 1998

The cultivation for development of Ascaris suum from the second-stage larvae($L_2$) embryonated egg and the third-stage of rat-derived larvae($L_3$) recovered from lung of rats were performed to use the screening test of anthelmintics in vitro. The preparations of larvae for cultivation were that the artificially-hatched $L_2$ incubated the embryonated eggs of Ascaris suum in 0.1% formalin solution at $25^{\circ}C$ for 28 days and the rat-derived larvae($L_3$) recovered from the lung of rat infected with the embryonated eggs of Ascaris suum on 7 days after infection(DAI). The cultivation for development of Ascaris suum from the embryonated eggs($L_2$) and the rat-derived larvae($L_3$) for 14 days in RPMI medium 1640(with 5% bovine calf serum) were as follows : 1. The sizes of the liberated larvae($L_2$) which were artificially hatched from embryonated eggs with glass beads(diameter 5mm) were $190{\sim}250{\mu}m$ on 1 days in culture(DIC). The second-stage larvae were molted into third-stage larvae(early $L_3$; $250{\sim}300{\mu}m$) and the features of these larvae were first observed such as cephalic cuticle, esophageal lumen and anus etc. on 5 DIC and the sizes of late third-stage larvae were $250{\sim}450{\mu}m$ on 10 DIC. The sizes of early fourth-stage larvae($L_4$) were $500{\sim}700{\mu}m$ and the features of these larvae were more pronounced in internal organs on 15 DIC. 2. The sizes of third-stage larvae($L_3$) recovered from the lung of rats were $1,340{\sim}1,370{\mu}m$ and the feartures of cephalic cuticle, esophageal lumen, intestine, rectum, anus were visualized by inverted microscope on 1 DIC. The fourth-stage larva($L_4$) completed by third ecdysis were recognizable and sizes of early fourth-stage larvae were developed as $1,400{\sim}2,200{\mu}m$ on 5 DIC. The sizes of middle fourth-stage of larva were $1,900{\sim}2,300{\mu}m$ and the thickened epithelial rectum was observed on 10 DIC. The rectum and anus of late fourth-stage larva($L_4$ $2,500{\sim}3,200{\mu}m$) had developed completely in RPMI medium 1640 on 15 DIC.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.559-567
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• 1994

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, and a delicate relationship between host and parasite, in the present studies, SPF ICR mice were alloted to experiment 1(normal undefinitive host group) and experiment 2(immunosuppressive group treated with prednisolone acetate) and inoculated with a single dose of 1,100 embryonated A suum eggs. In normal group, the infection essentially terminates 4 days after inoculation(DAI) with the attainment of middle third-stage in the liver, although few larvae migrate to the lungs where a few advance to late third stage. In immunosuppressive group, significant numbers developed to late third-stage in liver 8 DAI. In general, increasing of the mast cells and the goblet cells in the jejunum mucosa, of T-cells in the spleen and of activity of peritoneal macrophages followed by expulsion of the worms in the both groups. Considering a series of the results, suitabilities for the host of the worm appeared the highest from rabbit, hamster and mouse in that order. In addition, patent infection of A suum in the mice was also not obviously observed in spite of immunosuppression by prednisolone acetate.

• Korean Journal of Veterinary Research
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• v.38 no.3
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• pp.589-594
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• 1998

The in vitro screening tests against the in vitro cultivated $L_3$ of Ascaris suum (in vitro $L_3$), which were cultivated from the embryonated egg to third-stage larva on 7 days in culture(DIC) and the in vivo rat's lung-derived $L_3$ of Ascaris suum (in vivo $L_3$), which were recovered from the lungs of rat on 7 days after infection, carried out in order to compare the anthelmintic efficacy of in vitro $L_3$ and that of in vivo $L_3$ in RPMI medium 1640 with 5% bovine calf serum. And also a screening test of efficacy against adult worms of Trichuris suis performed. The efficacies of screening tests were as follows : 1. The screening efficacies of abamectin and ivermectin against the in vitro $L_3$ were all 100% at the 10ppm concentration in RPMI medium 1640 on 5 DIC. 2. The screening efficacies of abamectin and ivermectin against the in vivo $L_3$ were all 100% at the 20ppm on 5 DIC or at 40ppm on 3 DIC. 3. The screening efficacies of abamectin and ivermectin against the adult worms of Trichuris suis were all 100% at 20ppm on 4 DIC. And therefore, the in vitro cultivated $L_3$ of Ascaris suum were used in the screening test as well as the in vivo rat's lung-derived $L_3$ of Ascaris suum. And also the adult worms such as Trichuris suis and filaroids which is small size and difficult to cultivate to vitro, were used in the screening test in vitro.

• Parasites, Hosts and Diseases
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• v.52 no.1
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• pp.111-115
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• 2014

To evaluate the effects of pesticides to parasite eggs, Ascaris suum eggs were incubated with 5 different pesticides (1:1,500-1:2,000 dilutions of 2% emamectin benzoate, 5% spinetoram, 5% indoxacarb, 1% deltamethrin, and 5% flufenoxuron; all v/v) at $20^{\circ}C$ for 6 weeks, and microscopically evaluated the egg survival and development on a weekly basis. The survival rate of A. suum eggs incubated in normal saline (control eggs) was $90{\pm}3%$ at 6 weeks. However, the survival rates of eggs treated with pesticides were 75-85% at this time, thus significantly lower than the control value. Larval development in control eggs commenced at 3 weeks, and $73{\pm}3%$ of eggs had internal larvae at 6 weeks. Larvae were evident in pesticide-treated eggs at 3-4 weeks, and the proportions of eggs carrying larvae at 6 weeks ($36{\pm}3%-54{\pm}3%$) were significantly lower than that of the control group. Thus, pesticides tested at levels similar to those used in agricultural practices exhibited low-level ovicidal activity and delayed embryogenesis of A. suum eggs, although some differences were evident among the tested pesticides.