• Parasites, Hosts and Diseases
• /
• v.54 no.1
• /
• pp.103-107
• /
• 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
• /
• v.56 no.2
• /
• pp.175-181
• /
• 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.

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

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

• Korean Journal of Veterinary Research
• /
• v.34 no.3
• /
• pp.559-567
• /
• 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
• /
• v.34 no.1
• /
• pp.127-134
• /
• 1994

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, a delicate relationship between host and parasite, in the present studies golden hamsters 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 1,500 embryonated Ascaris suum eggs. The recovery rates, sizes and features of the larvae and immunological responses in the hamsters were chronologically monitored according to somatic migration. In both experiments, the larvae failed to develop into the adults, but the more and larger larvae were observed for a longer period from experiment 2 in comparison with experiment 1. The numbers of the mast cells in the small intestinal mucosa and mesenteric lymph nodes, of the goblet cells in the small intestinal mucosa and of T-cells in the mesenteric lymph nodes, spleens and cardiac blood from experiment 2 were fewer than those from the experiment 1. In general, increasing of these cells followed by expulsion of the worms in the both groups. Profound leukopenia due to lymphopenia was found through trial period in experiment 2. Considering the experimental results, development or expulsion mechanism of somatic migrant larvae may be related to lymphopenia and temporary increasing tendency of the mast cells, the goblet cells and T-cells. In addition, patent infection of A suum in the hamsters was not obviously observed in spite of immunosuppression by prednisolone acetate.

• Korean Journal of Veterinary Research
• /
• v.33 no.4
• /
• pp.679-691
• /
• 1993

As a series of studies to investigate the effect of immunosuppression on Ascaris suum infection in undefinitive hosts, a delicate relationship between host and parasite, rabbits were divided into experiment 1(control group) and experiment 2(immnunosuppressive group treated with prednisolone acetate) and inoculated with a single dose of 5,000 embryonated A suum eggs. The recovery rates, sizes and morphology of the larvae and immunological responses in the rabbits were chronologically monitored according to somatic migration. In both experiments, the larvae failed to develop into the adults, but young adults in the experiment 2 grew somewhat faster and survied later than those in the experiment 1. The mast cells of small intestinal mucosa and mesenteric lymph nodes and the goblet cells of small intestinal mucosa in the worm detected cases of experiment 2 decreased remarkably in number comparing with those of experiment 1. Considering the experimental results. the expulsion mechanism of somatic migrant larvae may he related to the temporary increasing tendency of the mast cells, the goblet cells, T-cells of mesenteric lymph nodes and spleens, eosinophils in peripheral blood, degranulation rates of peritoneal mast cells and the migration inhibition rates of leucocytes. In addition, patent infection of A suum in the rabbits was not obviously observed despite of immunosuppression by prednisolone acetate.

• Parasites, Hosts and Diseases
• /
• v.50 no.3
• /
• pp.243-247
• /
• 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
• /
• v.50 no.3
• /
• pp.239-242
• /
• 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.

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