Food-borne Parasitic Zoonosis Research Articles

In vivo Study of Nano Chitosan Beads-Based ELISA versus Traditional Sandwich ELISA for the Early Diagnosis of Trichinosis

Human trichinosis is a serious foodborne parasitic zoonosis. Diagnosing human trichinosis is usually difficult due to the nonspecific clinical picture and the limited effectiveness of serological tests in acute infections. While ELISA can detect circulating Trichinella antigens, aiding in early diagnosis, its sensitivity may be low. The application of nanoparticles can improve the sensitivity of ELISA and allow a specific early diagnosis of the disease. This work compares the nano chitosan beads-based ELISA (NCSB-ELISA) and traditional sandwich ELISA for the detection of circulating Trichinella spiralis (T. spiralis) crude extract-antigen (CEA) in serum samples of experimentally infected mice.Fifty-seven mice included in this study were classified into 3 groups: T. spiralis infected group (Group I) (36 mice), which was equally subdivided into six subgroups according to the time of sacrifice (6, 8, 10, 12, 14 and 16) day post-infection (dpi), cross-reactivity group (Group II) (9 mice) and negative control group (Group III) (12 mice). T. spiralis AW-CEA prepared from the adult worms were used to produce anti- T. spiralis IgG-polyclonal antibodies in rabbits; these antibodies were utilized to detect AW-CEA in serum samples by traditional sandwich ELISA and NCSB-ELISA. Using NCSB-ELISA, T. spiralis AW-CEA was detected in sera collected at 8 dpi, with a sensitivity of 50% and a specificity of 100%. Meanwhile, traditional sandwich ELISA could not detect the antigen at the same time interval. Both ELISA techniques were able to detect the antigen in samples collected at 10, 12, 14 and 16 dpi with a sensitivity of 16.67%, 50%, 67.67% and 83.67%, respectively, for traditional sandwich-ELISA and a specificity of 100% at 10, 12 and 14 dpi while at 16 dpi specificity was decreased to 90.91%. In contrast, the sensitivity of NCSB-sandwich ELISA on the same days was 66.67%, 83.34%, 100% and 100%, respectively, with a specificity of 100% at all days. False positive detection of T. spiralis AW-CEA in the serum of mice in GII was recorded on day 16 pi by only traditional sandwich ELISA.This study concluded that NCSB-ELISA is a promising and sensitive technique for the early and specific diagnosis of acute trichinosis in an animal model.

Infection and biogeographical characteristics of Paragonimus westermani and P. skrjabini in humans and animal hosts in China: A systematic review and meta-analysis.

Paragonimiasis, primarily caused by Paragonimus westermani and P. skrjabini in China, is a common food-borne parasitic zoonosis. However, the national distribution of Paragonimus spp. infection and its associated environmental determinants remain poorly understood. In this paper, we summarize the infection of P. westermani and P. skrjabini and describe key biogeographical characteristics of the endemic areas in China. Data on Paragonimus infection in humans and animal hosts were extracted from eight electronic databases, including CNKI, CWFD, Chongqing VIP, SinoMed, Medline, Embase, PubMed, and Web of Science. A random-effects meta-analysis model was used to estimate the pooled prevalence. All survey locations were georeferenced and plotted on China map, and scatter plots were used to illustrate the biogeographical characteristics of regions reporting Paragonimus infection. A total of 28,948 cases of human paragonimiasis have been documented, with 2,401 cases reported after 2010. Among the 11,443 cases with reported ages, 88.05% were children or adolescents. The pooled prevalence of P. skrjabini is 0.45% (95% CI: 0.27-0.66%) in snails, 31.10% (95% CI: 24.77-37.80%) in the second intermediate host, and 20.31% (95% CI: 9.69-33.38%) in animal reservoirs. For P. westermani, the pooled prevalence is 0.06% (95% CI: 0.01-0.13%) in snails, 52.07% (95% CI: 43.56-60.52%) in the second intermediate host, and 21.40% (95% CI: 7.82-38.99%) in animal reservoirs. Paragonimus are primarily distributed in regions with low altitude, high temperature, and high precipitation. In northeastern China, only P. westermani infections have been documented, while in more southern areas, infections of both P. westermani and P. skrjabini have been reported. Paragonimiasis remains prevalent in China, particularly among children and adolescents. Variations exist in the intermediate hosts and geographical distribution of P. westermani and P. skrjabini. Additionally, altitude, temperature, and precipitation may influence the distribution of Paragonimus.

Diagnosis of Experimental Trichinosis by Nano-Based ELISA and Nano-Based Latex Agglutination Test Compared with Traditional Sandwich ELISA

Abstract Human trichinellosis is a serious foodborne parasitic zoonosis. The main route for contracting the infection is eating raw or undercooked meat, especially pork containing a sufficient load of infective viable larvae. Early diagnosis is crucial before the larval encystation in skeletal muscles, so detection of circulating antigens can be helpful. The objective of the present study was to evaluate the novel Nanomagnetic beads based-ELISA (NMB-ELISA), and Nanomagnetic beads based latex agglutination test (NMB-LAT) for the diagnosis of experimental trichinellosis compared to sandwich ELISA through the detection of Trichinella spiralis adult worm crude extract antigen AW-CEA in serum. The study included thirty-eight (38) mice classified into 3 groups; T. spiralis infection group (GI) which was equally subdivided into 5 subgroups according to the time of sacrifice (6, 8, 10, 12, and 14 dpi), other parasitic infections group (GII) and healthy control group (GIII). T. spiralis AW-CEA was prepared from the adult worms through homogenization and ultra-sonication and then used to produce anti- T. spiralis IgG-pAbs in rabbits which were subsequently utilized to detect AW-CEA in serum samples by sandwich ELISA, NMB-ELISA, and NMB-LAT. Using NMB-ELISA, T. spiralis AW-CEA was detected in sera collected at 6 and 8 dpi, with a sensitivity of 50%, and 75%, respectively, and a specificity of 100%. Meanwhile, sandwich ELISA and NMB-LAT couldn’t detect the antigen at the same time intervals. Both ELISA formats were able to detect the antigen in samples collected at 10, 12, and 14 dpi with a sensitivity of 100% for NMB-ELISA, and 25%, 75%, and 100% respectively, for sandwich-ELISA. On the other hand, NMB-LAT couldn't detect T. spiralis AW-CEA until 12 dpi with a sensitivity of 50% and specificity of 75%. In conclusion, the NMB-ELISA is a promising sensitive technique for early and specific diagnosis of acute trichinellosis in an animal model. Thus, it can be used as a potential alternative to the standard ELISA to obtain confident results. In addition, the use of NMB-LAT for AW-CEA detection could be a valuable screening diagnostic technique in field surveys.

Seroprevalence and Risk Factors of Toxoplasma gondii Infection of Cattle and Goats in Farms of Hunan Province, China.

Background: Toxoplasmosis is one of the most widespread foodborne parasitic zoonoses caused by the obligate intracellular protozoan Toxoplasma gondii. Although a number of studies have reported on the seroprevalence and risk factors of T. gondii infection in ruminants in China, information about T. gondii infection in cattle in Hunan province of China is not available. Material and Methods: Sera of 985 cattle and 1147 goats were examined for the presence of specific antibodies against T. gondii using the indirect hemagglutination test. Some risk factors related to the presence of cats, herd size, gender, age, and geographical origin were determined using a binary logistic regression. Results: Specific IgG against T. gondii were detected in 8.3% (82/985) and 13.3% (153/1147) of the cattle and goats, respectively. Based on statistical analysis, the presence of cats and gender were considered important risk factors for T. gondii infection in cattle and goats in the farms in this study (P < 0.05). Conclusion: Our results provide a baseline for future prevention and control of T. gondii infection in cattle and goats in Hunan province, subtropical China. This is the first report of T. gondii seroprevalence in cattle in Hunan province, China.

The impact of MIF deficiency on alterations of fecal microbiota in C57BL/6 mice induced by Trichinella spiralis infection.

Trichinellosis caused by Trichinella spiralis (T. spiralis) is a major food-borne parasitic zoonosis worldwide. Prevention of trichinellosis is an effective strategy to improve patient quality of life. Macrophage migration inhibitory factor (MIF) is closely related to the occurrence and development of several parasitic diseases. Studying the impact of MIF deficiency (Mif-/- ) on the alterations in host fecal microbiota due to T. spiralis infection may contribute to proposing a novel dual therapeutic approach for trichinellosis. To reveal the diversity and differences in fecal microbial composition, feces were collected from T. spiralis-uninfected and T. spiralis-infected wild-type (WT) and MIF knockout (KO) C57BL/6 mice at 0, 7, 14, and 35 days post-infection (dpi), and the samples were sent for 16S rRNA amplicon sequencing on the Illumina NovaSeq platform. Flow cytometry was used to determine the expression levels of IFN-γ and IL-4 in the CD4+ /CD8+ T-cell sets of mouse spleens. The results showed that operational taxonomic unit (OTU) clustering, relative abundance of microbial composition, alpha diversity, and beta diversity exhibited significant changes among the eight groups. The LEfSe analysis selected several potential biomarkers at the genus or species level, including Akkermansia muciniphila, Lactobacillus murinus, Coprococcus catus, Firmicutes bacterium M10_2, Parabacteroides sp. CT06, and Bacteroides between the KTs and WTs groups. The predicted bacterial functions of the fecal microbiota were mainly involved in metabolism, such as the metabolism of carbohydrates, amino acids, energy, cofactors, vitamins, nucleotides, glycans, and lipids. Flow cytometry revealed an increased CD3+ CD8- /CD3+ CD8+ T-cell ratio and increased IFN-γ and IL-4 levels in CD3+ CD8- T-cell sets from WT and MIF KO mice at 7 dpi. The results indicated that both MIF KO and infection time have a significant influence on the CD3+ CD8- IFN-γ+ and CD3+ CD8- IL-4+ response in mice after T. spiralis. In conclusion, this research showed alterations of the fecal microbiota and immune response in both WT and MIF KO mice before and after T. spiralis infection. These results revealed a potential role of MIF in regulating the pathogenesis of trichinellosis related to the intestinal microbiota. Importantly, the selected potential biomarkers combined with MIF will also offer a novel therapeutic approach to treat trichinellosis in the future.

Spread of Toxoplasma gondii among animals and humans in Northern Italy: A retrospective analysis in a One-Health framework

Toxoplasmosis occurs worldwide and is considered one of the most important food-borne parasitic zoonoses. The consumption of undercooked meat containing viable tissue cysts and ingestion of environmental oocyst are the most important sources of infection. The aim of this retrospective study was to evaluate the spread of Toxoplasma gondii in the province of Bologna (Emilia-Romagna region) in northern Italy, with a One Health approach, comparing seropositivity rates in different animal species and in humans over the last 19 and 4 years respectively. Analyses were performed on serological data collected over different periods at three separate locations: Istituto Zooprofilattico Sperimentale della Lombardia e della Emilia-Romagna (IZSLER); Veterinary University Hospital Clinical Pathology Service, Department of Veterinary Medical Sciences, University of Bologna; and Unit of Microbiology, St. Orsola Hospital, Bologna. Most relevant seropositivity rates observed in animals were 15.5% (wild boar), 25% (roe deer), 18.7% (goat), 29.9% (sheep), 9.7% (pigs), 42.9% and 21.8% in cat and dog, respectively. A comprehensive screening was conducted on a population of 36,814 individuals, revealing a prevalence of 20.4%. Among pregnant women, a frequence of 0.39% for active toxoplasmosis was observed. Despite certain limitations, this study provided valuable insights into the extensive distribution of this parasitic infection among diverse animal species and human populations in the province of Bologna. These findings underscore the importance of implementing consistent and proactive toxoplasmosis screening protocols during pregnancy, while emphasizing the critical need for adopting a One Health approach for effective control of this parasitic disease.

Raw fish consumption in Portugal: Commonly consumed fish species and associated risk factors for anisakiosis

Foodborne parasitic zoonoses from fish and shellfish products are of significant health concern. Anisakiosis is an important fish-borne zoonosis caused by nematodes of the genus Anisakis. Humans are infected through consumption of raw or undercooked fish or cephalopods containing Anisakis spp. Third stage larvae. Infection can result in both gastrointestinal and allergic symptoms. Globalization has resulted in a growth in demand for raw or undercooked food, and this may increase the population at risk of anisakiosis. Our study's main aim was to investigate the risk of anisakiosis from the five fish species most frequently consumed raw or undercooked in Portugal, as identified by a previous study. In addition, a study was carried out to identify the fish species most commonly used in raw fish dishes in Asian restaurants serving Japanese food in the Porto district. The results of this study were incorporated into the risk investigation. The 5 fish species most commonly eaten raw were salmon, tuna, cod, hake and sardines. This was similar to our findings in the restaurant survey, which identified salmon and tuna as the most popular fish served in raw dishes. It also identified nigiri, sashimi and temaki as the most popular raw fish dishes. After examination of the production practices and parasite prevalence for each of the five fish species, we concluded that the main risk groups for anisakiosis were consumers who prepare raw or lightly processed fish dishes at home, if they are unaware of methods to prevent anisakiosis. Some cooked fish dishes may also present a risk, lightly grilled wild salmon or sardines have the potential to contain viable Anisakis larvae. We identified a need for further studies, to establish the level of consumption of wild salmon and wild tuna, and a large-scale study to examine the level of sensitization to Anisakis within the Portuguese population. Our findings highlight the need for more consumer education campaigns regarding the risks associated with raw fish consumption, and prevention methods for anisakiosis. In addition, our study emphasises the need for a more standardized approach to inspection measures within the fish supply chain, to prevent products contaminated with parasites reaching the market.

Global Prevalence of Echinococcosis in Goats: A Systematic Review and Meta-Analysis.

Echinococcosis is a foodborne parasitic zoonosis caused by the larvae of Echinococcus. This disease can affect goats and other mammals. In this study, a systematic review and meta-analysis for echinococcosis in global goats were performed based on the following five databases (China National Knowledge Infrastructure [CNKI], VIP Chinese Journal Database, Wanfang Data, PubMed, and ScienceDirect). In total, 108,197 samples were collected. The global prevalence of echinococcosis in goats was identified to be 10.85% (3217/108,197). The prevalence of echinococcosis in goats was 6.16% (1369/22,208) and 13.27% (874/5932) in South America and Africa, respectively. The prevalence of echinococcosis in goats before 2010 (9.76%; 112/713) was significantly higher than that from 2010 to 2014 (1.44%; 45/32,145) or after 2014 (2.95%; 154/3889). The prevalence of echinococcosis in goats aged <12 months (4.48%; 70/2911) was higher than that in goats aged ≥12 months (2.88%; 36/819). We also investigated the effects of geographical factors and climates on the prevalence of echinococcosis in goats. The results showed that the prevalence of echinococcosis was higher in the areas with high altitude and cold climate. This meta-analysis indicated that echinococcosis was ubiquitous in goats. Thus, we should improve the feeding conditions for goats, and strengthen the control measures of echinococcosis epidemic in goats, with the aims of reducing the economic losses of animal husbandry and providing protection for humans in the aspects of food security and health.

Lentinula edodes extract increases goblet cell number and Muc2 expression in an intestinal inflammatory model of Trichinella spiralis infection.

AHCC® is a standardized extract of cultured mushroom (Lentinula edodes) mycelia with a wide variety of therapeutic effects including anti-inflammatory, antitumor and antiviral effects. Trichinellosis, a food-borne parasitic zoonosis is caused by the nematode Trichinella spp. Infection with Trichinella is characterized by the induction of a Th1-type response at the beginning of the intestinal phase, followed by a dominant Th2-type response which is essential for parasite expulsion. The aim of this study was to evaluate the immunomodulatory effect of AHCC® in a murine model of Trichinella spiralis infection. Swiss CD1 mice were infected with T. spiralis larvae and treated with AHCC®. Standard treatment with albendazole (ABZ) was used as control in the assessment of parasite burden. The small intestine was taken out and the proximal segment was evaluated for several parameters: gene expression of immune and stress-reticulum mediators, histological damage score, goblet cell count and Mucin 2 (Muc2) gene expression. AHCC® modulated expression levels of both Th1 and Th2 cytokines and reduced histological damage score. In addition, AHCC® diminished the number of adults of T. spiralis in treated animals. AHCC® treatment anticipates T. spiralis expulsion and increases goblet cell number and Muc2 gene expression.

Dynamic changes of macrophage activation in mice infected with Trichinella spiralis

Trichinellosis is a serious food-borne parasitic zoonosis worldwide. Different host macrophage subsets play various roles during helminth infection; however, the dynamic changes in macrophage subsets following Trichinella spiralis infection have not been reported. Here, flow cytometry and immunofluorescence were used to assess macrophage activation in mesenteric lymph nodes (MLN), spleen, intestine, and muscle from T. spiralis-infected mice at 1, 5, 15, and 30 days post infection (dpi). Macrophages in the intestine, MLN, and spleen tended to be activated M1-type at 1 and 5 dpi, while at 15 dpi, M2-type macrophages started to become a major constituent of the spleen macrophage population, and in the intestine and MLN, macrophages were primarily mixed M1 and M2 type. At 30 dpi, macrophages in the intestine, muscle, MLN, and spleen were all mainly activated M2 cells. Additionally, mouse macrophages were cleared and the adult T. spiralis load were determined to evaluate the impact of macrophages on adult parasite expulsion. The results suggested that predominantly M1 macrophages contribute to adult T. spiralis expulsion in the enteral stage of infection. At the newborn larvae migration stage, M2 macrophage-mediated immunity had a weak scavenging effect on adults, but primarily promoted tissue repair and assisted muscle larva immune escape. Our study reveals further details of the interaction between T. spiralis and the host immune system.

Vaccines as a Strategy to Control Trichinellosis.

Trichinellosis caused by Trichinella spiralis is a worldwide food-borne parasitic zoonosis. Several approaches have been performed to control T. spiralis infection, including veterinary vaccines, which contribute to improving animal health and increasing public health by preventing the transmission of trichinellosis from animals to humans. In the past several decades, many vaccine studies have been performed in effort to control T. spiralis infection by reducing the muscle larvae and adult worms burden. Various candidate antigens, selected from excretory-secretory (ES) products and different functional proteins involved in the process of establishing infection have been investigated in rodent or swine models to explore their protective effect against T. spiralis infection. Moreover, different types of vaccines have been developed to improve the protective effect against T. spiralis infection in rodent or swine models, such as live attenuated vaccines, natural antigen vaccines, recombinant protein vaccines, DNA vaccines, and synthesized epitope vaccines. However, few studies of T. spiralis vaccines have been performed in pigs, and future research should focus on exploring the protective effect of different types of vaccines in swine models. Here, we present an overview of the strategies for the development of effective T. spiralis vaccines and summarize the factors of influencing the effectiveness of vaccines. We also discuss several propositions in improving the effectiveness of vaccines and may provide a route map for future T. spiralis vaccines development.

Co-occurrence of Angiostrongylus malaysiensis and Angiostrongylus cantonensis DNA in cerebrospinal fluid: Evidence from human eosinophilic meningitis after ingestion of raw snail dish in Thailand

Angiostrongylus cantonensis, the main causative agent of human neuroangiostrongyliasis, is a food-borne parasitic zoonosis, particularly in Southeast Asia and Mainland China. Angiostrongylus malaysiensis, a cryptic species, has not been unequivocally identified as a causative agent for human angiostrongyliasis. Here, we investigated a local incidence of human angiostrongyliasis in Kalasin Province, northeastern part of Thailand. Field and laboratory investigations, clinical symptoms, and treatment of the disease are also discussed. Five sera and three cerebrospinal fluid samples were taken from each patient who displayed clinical symptoms of mild or severe headache without neck stiffness after ingesting a local dish containing Pila virescens. With molecular evidence using PCR and DNA sequencing approaches, we confirmed the presence of A. malaysiensis and A. cantonensis DNA in the patient samples. In addition, P. virescens and Pomacea canaliculata collected in the vicinity were also examined for the existence of angistrongylid larvae. The rate of infection in the snail population was 33.3% (18 infection out of 54 examined), with A. cantonensis as the predominant species. Notably, two snails were found to be co-infected with both A. malaysiensis and A. cantonensis. This discovery comes after several years of suspicion that it could be a zoonotic pathogen. Therefore, our findings are important for public health and clinical diagnosis since clinicians are not aware of the zoonotic potential of A. malaysiensis in humans.

Towards an Integrated Approach for Monitoring Toxoplasmosis in Southern Italy.

Simple SummaryToxoplasmosis is a significant public health issue worldwide, caused by the intracellular protozoan Toxoplasma gondii. It has a heteroxenous life cycle in which felines act as definitive reservoirs and a wide range of warm-blooded animals, including humans, act as intermediate hosts. Due to the complex life cycle, monitoring, prevention and control of this parasite are very difficult. A thorough analysis of the epidemiology of T. gondii in humans, animals and food as well as the risk factors associated with the infection are needed to plan adequate control strategies in a given geographical area. Based on this, an integrated approach for monitoring toxoplasmosis was developed and conducted in an endemic area of southern Italy. The main tasks of this approach were based on the following strategies: parasitological and risk factor analysis for T. gondii in livestock farms, serological and molecular monitoring in meat-producing livestock at slaughterhouses, hospital discharge records (HDRs) analysis and outreach activities. The findings of this study confirmed the spread of T. gondii infection in southern Italy with high prevalence values in ruminants and the need of valid control strategies based on comprehensive and transdisciplinary actions according to the One Health approach.Toxoplasmosis is a widespread worldwide zoonotic infection caused by the intracellular protozoan Toxoplasma gondii. This protozoan infection is considered one of the most important food-borne parasitic zoonoses globally. Beyond its impact on public health, toxoplasmosis has also important veterinary implications, because it causes miscarriage or congenital malformations in livestock with negative economic impacts. An integrated monitoring programme aimed to deepen the epidemiological data on toxoplasmosis and to identify the risk factors that may favour T. gondii infections in animals and humans was conducted in an endemic area of southern Italy. The monitoring activities were based on the following tasks: (i) parasitological analysis and risk factors for T. gondii in livestock (sheep, goat, cattle and water buffalo) farms; (ii) serological and molecular monitoring at slaughterhouse in meat-producing livestock; (iii) analysis of hospital discharge records (HDRs); (iv) outreach activities (information, dissemination and health education) to farmers, vet practitioners and school-age children. The present study confirmed a very high seroprevalence of T. gondii infection in livestock farms (e.g., up to 93.1% in sheep farms) in southern Italy and highlighted the potentially significant public health risk in this area.

Galectin-Receptor Interactions Regulates Cardiac Pathology Caused by Trichinella spiralis Infection.

The parasitic nematode Trichinella spiralis causes trichinellosis, a serious food-borne parasitic zoonosis worldwide. Infection with T. spiralis may also cause myocarditis. In the present study, we used mouse models to assess the impact of blockage of galectin-receptor interactions by α-lactose on cardiac immunopathology during acute T. spiralis experimental infection. Our data demonstrated that, after T. spiralis infection, blockage of galectin-receptor interactions resulted in cardiac dysfunction detected by transthoracic conventional echocardiography, and increased serum Gal-3 level, a biomarker of myocardial damage. In addition, there were increased eosinophil number in peripheral blood, and increased eosinophil infiltration in the heart and spleen tissues accompanied with increased mRNA levels of eosinophil granule proteins (including eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO)) and IL-5 in these organs; increased cardiac fibrosis accompanied with increased Gal-3 and collagen 1 expressions in the hearts of mice with blockage of galectin-receptor interactions after T. spiralis infection. Correlation analysis showed that significant positive correlations existed between the mRNA levels of Gal-3 and ECP/EPO/eosinophil major basic protein/IL-5/CCL11/CCR3/α-SMA/collagen 1 in the hearts of both T. spiralis-infected mice and T. spiralis-infected mice with blockage of galectin-receptor interactions. Our data suggest that galectin-receptor interactions play a pivotal role during acute T. spiralis infection, and lack of galectin-receptor interactions upregulates Gal-3 which, in turn, leads to elevated heart eosinophil recruitment, exacerbated heart pathology and fibrosis, and heart functional damage.

Gnathostomiasis in a traveller returning from Madagascar.

Gnathostomiasis is a foodborne parasitic zoonosis known to be endemic in Southeast Asia, India, Central and South America, with recent cases reported in Zambia, Botswana and South Africa. We report a case of gnathostomiasis acquired in Madagascar and alert clinicians of the emerging risk in southern Africa.

Primary characterization of the immune responses in Tibetan pigs infected with Chinese Tibet isolate of Trichinella spiralis

BackgroundTrichinellosis, caused by Trichinella spiralis, is a serious foodborne parasitic zoonosis. Tibetan pig is an infrequent, endemic plateau pig species, mainly distributed in Tibet Plateau, China. Because of the free-range system, Tibetan pigs are at risk of infection with Trichinella. The present study aimed to primarily profile the characteristics of T. spiralis infection in Tibetan pigs, including IgG levels, larvae burdens, and cytokines.ResultsThe immune responses to Chinese Tibet T. spiralis isolate infection in Tibetan pigs with different doses were investigated in a tracking duration of 49 days. The muscle larvae per gram (lpg) were evaluated at 105 days post-infection (dpi). The results showed that the mean larval number of T. spiralis in Tibetan pigs increased with infective dose, with average lpg values of 3.5, 50.4 and 115.6 for Tibetan pigs infected with 200, 2,000, and 20,000 muscle larvae (ML) of T. spiralis. The anti-Trichinella IgG increased with inoculum dose and dpi, and peaked at 49 dpi. The kinetics of cytokines in the sera was detected by microarray, including interferon-γ (IFN-γ), interleukin (IL)-1β, IL-8, IL-12, IL-4, IL-6, IL-10, Granulocyte-macrophage Colony Stimulating Factor (GM-CSF), tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β1. The Th1/Th2 mixed cytokines were detectable in all samples. Interleukin-12 demonstrated the highest concentration compared to other cytokines and peaked at 42 dpi. Almost all cytokines were maintained at a high level at 42 dpi. Additionally, we also report a Trichinella seropositive rate of 43.9 % (18 out of 41) from field samples of Tibetan pigs.ConclusionsThe present study showed an increased Th1/Th2 mixed cytokines in Tibetan pigs elicited by T. spiralis. The high seroprevalence of Trichinella infection in field samples of Tibetan pigs further raises serious concern for the prevention and control of trichinellosis in this host for public health safety.

Sparganosis in wild-caught Javanese keelback water snakes (Fowlea melanzostus) from Indonesia

Sparganosis is a globally important water and food-borne parasitic zoonosis, caused by the plerocercoid (spargana) stage of Spirometra spp. However, in Indonesia sparganosis is still categorized as neglected zoonotic disease due to paucity of reports on the prevalence of spargana in naturally infected hosts. Therefore, this study aimed to investigate the prevalence of spargana infection in wild-caught Javanese keelback water snakes (Fowlea melanzostus) from Banyuwangi District, East Java Province, Indonesia. Microscopic examination using semichen-acetic carmine staining method was used to confirm plerocercoid stage of Spirometra spp., in which the anterior end had specific structure (bothria) and was broader compared to the posterior end. The study revealed a very high prevalence rate of 92.72% (51/55) of spargana in these snakes. Spargana were mostly distributed in muscle tissues (57.97%), followed by subcutaneous tissues (25.08%) and visceral organs (13.62%). To our knowledge, this study not only records the first report but also reveals the role of aquatic snakes as transmitters of sparganosis in Asia. Regarding the high prevalence, further studies are recommended to explain the role of various species of snakes which can serve as intermediate hosts in the spread of sparganosis in the natural environment.

Bioinformatic Prediction and Production of Four Recombinant Proteins from Different Developmental Stages of Trichinella spiralis and Testing of Their Diagnostic Sensitivity in Mice

Background:Trichinellosis is a serious food-borne parasitic zoonosis, thus finding high quality antigens is the key to serodiagnosis of trichinosis. This article reports the characterization and sensitivity of four recombinant proteins expressed by four genes (Wn10, Zh68, T668, and Wm5) from different developmental stages of Trichinella spiralis for the diagnosis of trichinellosis in mice.Methods:This study was conducted in Jilin University and National Institute of Parasitic Diseases of Chinese Center for Disease Control and Prevention in 2017–2018. The structures and functions of the proteins encoded by four genes were predicted by bioinformatics analysis. The four genes were cloned and expressed, and the recombinant proteins were purified. Anti-Trichinella IgM and IgG antibodies in the sera of mice infected with T. spiralis from 1-45 d post-infection (dpi) were evaluated by ELISA.Results:The optimal antigen epitopes of four proteins (P1, P2, P3, and P4) encoded by the four genes from T- and B-cells were predicted, and four purified recombinant proteins (r-P1, r-P2, r-P3, and r-P4) were successfully produced. For IgM, the antibody levels detected by the four recombinant antigens were approximately equal to the cut-off value. Anti-Trichinella IgG antibodies were first detected by r-P1 at 8 dpi, followed by r-P2, r-P3, and r-P4 at 10 dpi, 14 dpi, and 16 dpi, respectively, and the antibody levels remained high until 45 dpi.Conclusion:The recombinant antigens r-P1, r-P2, r-P3, and r-P4 could be antigens that react with antibodies, they showed high sensitivity in the detection of anti-Trichinella IgG antibodies in mice. Among these proteins, r-P1 may be a candidate antigen for the detection of anti-Trichinella IgG antibodies in the early infection phase and exhibited the best sensitivity among the antigens.

A Rare Case of Fasciola Hepatica and its Treatment

Fascioliasis is a re-emerging food-borne parasitic zoonosis which presents with nonspecific clinical symptoms. Definitive diagnosis requires demonstration of parasitic ova in stool which may often be elusive. Imaging plays a crucial role in raising the possibility of this diagnosis early in the disease course. Contrast-Enhanced Computed Tomography (CECT) of the abdomen was performed in a 44-year-old male with fever, right upper quadrant pain and dyspepsia. The patient later underwent an ultrasound-guided biopsy of liver lesions. The stool examination for ova was negative. Biopsy of the liver lesions showed ill-defined granulomas. Imaging plays a crucial role in establishing the early diagnosis of hepatic fascioliasis especially in nonendemic regions where the clinical suspicion for this diagnosis is low. This article places emphasis on the description of typical imaging features of this condition and the usage of additional investigative/testing techniques recommended by the Center for Disease Control and Prevention (CDC).

The Impact of Stem Cells on Parenteral Phase of Experimental Trichinosis during Vaccination Trial

Background and study aim: Trichinellosis is a severe food-borne parasitic zoonosis. The protective immunity against infection from crude larval antigens (CLA) was performed effectively which suggests that the whole larvae would be possible vaccine candidates. Bone marrow mesenchymal stem cells (BM MSCs) induce immunomodulatory impacts through affection of T-cell proliferation and cytokine production. Methods: Ninety healthy mice were divided into five main groups, 10 mice each, 30 mice were for attaining BM MSCs and 10 mice for CLA preparation. Group 1 & 2 as control, Group 3: immunized with CLA then infected, Group 4: immunized with MSCs then infected. Group 5 immunized with CLA and MSCs then infected. Mice were challenged by orally infective dose with 500 Trichinella spiralis (T. spiralis) larvae. Results: Showed that significant reduction in the number of T. spiralis larvae was in group 5 (received CLA + MSCs) followed by group 3 (received CLA only) then group 4 (received MSCs only) with percentage reductions of 85.4 %, 82 % and 68.9 %, respectively. G2 (infected only) showed absence of CD8+ infiltration. G3 showed moderate density of CD8+ infiltration, G4 and G5 showed high density CD8+ infiltration. However, muscle sections from G2 showed high density of tumor necrosis factor α (TNFα) infiltration; G3 showed moderate density of TNFα infiltration; G4 showed very low density of TNFα infiltration and G5 showed complete absence of TNFα infiltration. Conclusion: We concluded that immunization by CLA combined with BM MSCs as adjuvant generated T-helper type 2 (Th2)-mediated responses with increased CD8+ cell infiltration and decreased TNF-α required for immunity against trichinellosis with a 85.4% reduction in muscle larvae compared with the control group.