Day 2 :
- Tropical Diseases | Vector-borne diseases | Wildlife and Fisheries Parasitology | Parasitic Zoonoses
Location: Chicago, Illinois, USA
University of Illinois, USA
Sun Yat-sen University, China
Title: Clonochis sinensis lysophospholipase A upregulates IL-25 expression in macrophages as a potential pathway to liver fibrosis
Time : 10:00-10:30
Yan Huang is currently working in the Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China. She has her expertise in genome, functional genomics of Clonorchis sinensis (Chinese liver fluke) and pathogenesis of food-borne parasitic diseases.
Statement of the Problem: Liver fibrosis is an excessive wound-healing reaction requiring the participation of inflammatory cells and hepatic stellate cells (HSCs). The pathogenesis of liver fibrosis caused by viruses and alcohol has well been elaborated, but the molecular mechanisms of Clonorchis sinensis-induced liver fibrosis are poorly understood. Lysophospholipase A (LysoPLA) which is characterized as deacylating lysophospholipids plays a critical role in virulence and pathogenesis of parasites and fungi; however, the roles of C. sinensis lysophospholipase A (CsLysoPLA) in C. sinensis induced liver fibrosis remain unknown.
Methodology & Theoretical Orientation: Mouse macrophage cell line (RAW264.7) was cultured and treated with CsLysoPLA. IL-25 and signaling pathway were detected by quantitative real-time PCR, Western blotting or immunofluorescent staining. Human hepatic stellate cell line (LX-2) was cultured and exposed to IL-25. The activation markers of LX-2 cells were examined with quantitative real-time PCR, Western blotting and immunofluorescent staining. The migration was analyzed by Transwell plate.
Findings: We show that treatment of RAW264.7 cells with CsLysoPLA significantly induced IL-25 expression. The elevation of PKA, B-Raf, and ERK1/2 mRNA levels and phosphorylations of B-Raf and ERK1/2 were detected in CsLysoPLA-stimulated RAW264.7 cells. Whereas, PKA inhibitor H-89 weakened the phosphorylations of B-Raf and ERK1/2 and AKT activator SC79 attenuated the phosphorylation of ERK1/2 in RAW264.7 cells. Both H-89 and SC79 could inhibit IL-25 up-regulation induced by CsLysoPLA. In addition, stimulation of LX-2 cells with IL-25 up-regulated the expression of mesenchymal cell markers including α-smooth muscle actin (α-SMA) and collagen type I (Collagen-I) and promoted migration of the cells.
Conclusion & Significance: Our results propose that CsLysoPLA activates HSC by up-regulation of IL-25 in macrophage through PKA-dependent B-Raf/ERK1/2 pathway and plays a potential promotion role in hepatic fibrosis during the C. sinensis infection.
Universidad de las Fuerzas Armadas-ESPE, Ecuador
Title: Lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in North of Ecuador
Time : 10:30-11:00
Angel Fabian Villavicencio Abril has completed his PhD at the Peoples Friendship University of Russia. He teaches Parasitology, Tropical Animal Medicine, Zoonosis at Universidad de las Fuerzas Armadas-ESPE, Ecuador. He has published 7 papers and is a Member of the Editorial Board of several scientific journals in Ecuador. His research is focused on liver fluke parasitic Fasciola hepatica, snails and epidemiology in Ecuador highlands.
Fascioliasis, one of the main diseases of ruminants, is caused by the liver fluke Fasciola hepatica. This worldwide distributed disease occasionally affects humans and produces an important economic impact on livestock due to reduced weight gain, lowered fertility and abortion, progressive decrease in milk production, as well as liver condemnation. The annual losses are estimated to be US$ 2.2 million, with over 600 million animals infected worldwide. In Ecuador prevalence of F. hepatica in livestock remains uncertain because most of the data is collected by sanitary inspectors from slaughter houses. The Andean region is the endemic area of fascioliasis, where prevalence of infection in livestock ranges from 20 to 60% and in humans from 24 to 53%. This region is habited by 23.6 and 52.9% of the total and rural population, respectively; almost 200,000 people are infected and 1% is at risk of infection. Despite fascioliasis being a serious health problem in the country, very little is known about snails of the genus Lymnaea, the intermediate hosts responsible for F. hepatica transmission. Fasciola hepatica needs a lymnaeid snail as intermediate host to complete its life cycle. Some of the lymnaeid species occurring in Andean countries are as follows: L. truncatula Müller, 1774 from Bolivian highlands and Venezuela; L. columella Say, 1817 from Venezuela and north of Ecuador; L. cubensis Peiffer, 1839 from Venezuela and L. cousini Jousseaume, 1887. L. cousini has been found in Ecuador, Colombia and Venezuela.
Sun Yat-sen University, China
Title: Advanced enzymology, expression profile and immune response of Clonorchis sinensis hexokinase show its application potential for prevention and control of clonorchiasis
Time : 11:20-11:50
Tingjin Chen has obtained his PhD degree from Department of Parasitology at Sun Yat-sen University in 2015. He has developed a research program that provides new ideas for vaccine development against C. sinensis infection.
Clonorchiasis, caused by Clonorchis sinensis infection, is a kind of neglected tropical disease. Approximately 35 million people are infected with C. sinensis globally, of whom 15 million are in China. Glycolytic enzymes are recognized as crucial molecules for trematode survival and have been targeted for vaccine and drug development. Hexokinase of C. sinensis (CsHK), as the first key regulatory enzyme of the glycolytic pathway, was investigated in the current study. CsHK possesses typical characteristics of non-mammalian HKs regarding the amino acid sequence and spatial structure. rCsHK is a homotrimer and a distinct 50 kDa G6P-sensitive allosteric HK. There were differences in spatial structure and affinities for hexoses and phosphate donors between CsHK and HKs from humans or rats, the definitive hosts of C. sinensis. Effectors (AMP, PEP and citrate) and a small molecular inhibitor (2-phenyl-1, 2-benzisoselenazol-3(2H)-one, EbSe) regulated the enzymatic activity of rCsHK and various allosteric systems were detected. CsHK was distributed in the worm extensively as well as in liver tissue and serum from C. sinensis infected rats. Furthermore, high-level specific IgG1 and IgG2a were induced in rats by immunization with rCsHK. The enzymatic activity of CsHK was suppressed by the antibody in vitro. Additionally, the survival of C. sinensis was inhibited by the antibody in vivo and in vitro. Due to differences in putative spatial structure and enzymology between CsHK and HK from the host, its extensive distribution in adult worms and its expression profile as a component of excretory/secretory products, together with its good immunogenicity and immunoreactivity, as a key glycolytic enzyme, shows potential as a vaccine and as a promising drug target for clonorchiasis.
Sun Yat-sen University, China
Title: A field survey for Wolbachia and phage WO infections of Aedes albopictus in Guangzhou City, China
Time : 11:50-12:20
Xiaoying Zheng is a associate Professor at Department of Parasitology, Zhongshan School of Medicine, Sun Yat-sen University has her expertise in mosquitos and Wolbachia bacteria. She is the In-charge of Community Engagement and Coordinating for the laboratory research and field test.
Wolbachia are maternal endosymbiotic bacterium, which infect a diverse range of arthropods, ranging from 20 to 76% in nature. They are capable of inducing a wide range of reproductive abnormalities to their hosts, such as cytoplasmic incompatibility (CI), which has been proposed to be used as a tool to modify mosquitoes that are resistant to the development of pathogen as an alternative vector control strategy. Here, we evaluated the prevalence of Wolbachia and phage WO infections in the field population of Aedes albopictus in Guangzhou City via polymerase chain reaction (PCR) assay using the Wolbachia specific Wolbachia surface protein (wsp) and phage WO orf7 gene primers. Based on the results of PCR and phylogeny analysis, we found that A. albopictus in Guangzhou City were infected with two Wolbachia strains, wAlbA and wAlbB. Phage WO, the virus-infected Wolbachia, was also detected in A. albopictus. One hundred and ten (110) female individuals were screened via PCR, with 109 super-infected with Wolbachia and one sample single infected with wAlbB strain. And 104 of 113 male individuals were both infected with wAlbA and wAlbB, and nine male samples were found to be infected with wAlbA strain only. The infection rates of phage WO in female and male individuals were 82.73 and 46.02%, respectively. These results showed that the natural Wolbachia and phage WO infections in A. albopictus population in Guangzhou were at a higher frequency at present, indicating that Wolbachia appear to be a better candidate nature resource for biological control insect vectors to reduce vector-borne diseases.
Kuwait University, Kuwait
Title: Toxoplasma chorioretinitis: Role of host genetics and cytokines in determining tissue damage and disease severity
Time : 12:20-12:50
Jamshaid Iqbal is an Associate Professor and Director, Faculty of Medicine, Kuwait University, Consultant, Mubarak Al-Kabir Teaching Hospital, Kuwait. His main research work is to Study of Tropical & Parasitic infections in Kuwait with specific focus on immuno- and molecular diagnosis.
Objective: To study the role of host genetics and cytokine responses to ocular tissue damage post-virulent T. gondii (RH) infection.
Background: Toxoplasmosis is generally self-limiting in healthy adults but it may cause toxoplasmic retinochoroiditis in cases of congenital infection leading to blindness. The importance of host genetics in determining disease severity in ocular toxoplasmosis has been shown in different inbred mouse strains using low-virulence Toxoplasma strain.
Material & Methods: In this study, we studied intraocular immune response and tissue alterations in the genetically resistant BALB/c and susceptible MF1 mice infected with a virulent type-I RH T. gondii strain by intravitreal route.
Results: We observed a significant up-regulation of IFN-γ and TNF-α to >2200 pg/ml and >300 pg/ml respectively in the blood of both BALB/c and MF1mice during the early stages of post intraocular infection (p<0.01) but the levels dropped sharply to normal during the late stages of the infection on day 26. The cytokine levels detected were higher in the MF1 mice compared with the BALB/c mice and relatively higher levels were observed in the aqueous humor (AqH) than in the blood of both groups of mice. The TGF-β1 level in the blood and AqH of BALB/c mice remained low throughout the infection period compared with MF1 mice which showed gradual increase to 50 pg/ml in the blood and AqH during the early stages of infection which then further increased 2-fold to 132 pg/ml on day 11 (p<0.01) and remained high till the last day of observation on day 26 except that the TGF-β1 level in AqH dropped sharply to normal level.
Conclusions: Our results support that TGF-β1 down-regulates the effector functions of anti-Toxoplasma cellular immunity during acute infection. We document that a mild Th1 pro-inflammatory response in BALB/c mice with high IFN-γ and TNF-α and, low TGF-β1 levels during the early stages of infection may have contributed to an effective cellular immune response leading to lower morbidity, mortality and less ocular tissue damage. However in the MF1 mice, a significantly high TGF-β1 level in the blood and in the AqH during the acute infection may have adversely interfered with an effective cellular immune response leading to an increased mortality and extensive ocular tissue damage with parasite tachyzoites observed in the pigment epithelium layers.
Daniel Asfaw Erku has completed his BPharm from University of Gondar, Ethiopia. Currently, he is working as an Assistant Lecturer and a Director of Drug Information Center at Gondar University Referral Hospital. He has published more than 15 original research articles in peer-reviewed journals. He was also awarded by Ethiopian Pharmaceutical Association in 2014/15 for his outstanding academic achievements in pharmacy.
Statement of the Problem: Although Ivermectin is distributed free of charge through the African Program for Onchocerciasis Control (APOC), not all eligible individuals within communities receives the annual treatment. There are individuals who do not comply with the annual mass treatment, which contributes to the continuity for disease transmission. The purpose of this study is to determine factors associated with compliance to Community Directed Treatment with Ivermectin (CDTI) and provides a basis for trying to understand how best to sustain long-term compliance.
Methodology & Theoretical Orientation: Community-based cross-sectional study was conducted in Kaffa zone, Ethiopia September 1 to 30, 2016. Systematic random sampling was used to select head of households and structured, pre-tested questionnaire was used to interview the study participants. Descriptive statistics, univariate and multivariate logistic regression tools were performed to assess the effects of independent variables on the outcome variable.
Findings: Majority of respondents in this study (79.8%) reported that they completed Ivermectin. Significantly higher rate of treatment compliance was reported by participants’ age ≥35 years, participants who stayed in the area for more than 10 years, participants who perceive that they are at risk of contracting the disease, participants who perceive community drug distributors (CDDs) are doing their work well and participants who know at least one CDD in their village.
Conclusion & Significance: The majority of the study participants in the present study complied with Ivermectin treatment. Yet, intervention packages should consider factors such as age, residence duration and community’s perception of the disease to improve adherence.
Alexandria University, Egypt
Rasha Fadly Mady has her expertise in Medical Parasitology. She is an Assistant Professor at Alexandria Faculty of Medicine. She also had good experience in propagation of toxoplasma and leishmanial in laboratory. She had Post-Doctoral Research in Welcome Trust Laboratory, Natural History Museum, London.
Leishmaniasis is one of the most neglected tropical diseases. The available drugs have many side effects and drug resistance. In the current work the leishmanicidal effect of three approved drugs acting on three different enzymes namely Auranofin, Aluvia and Sorafenib had been analyzed. Their synergistic, additive or antagonistic effects against L. infantum promastigotes were investigated. The ultrastructural changes of the parasite treated by the aforementioned drugs were studied. This study demonstrated evidences that Auranofin, Aluvia and Sorafenib had significant antileishmanial effect against the promastigotes of L. infantum and Auranofin showed the highest effect. The combined administration of the drugs in two way combinations led to additive interactions. Furthermore, the combination of the three drugs had shown synergistic action. The electron microscopic study revealed that the three drugs exerted their leishmanicidal action by inducing apoptosis while Alluvia lead also to autophagy.