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Revue Neurologique Jun 2021
Topics: Animals; Encephalomyelitis; Encephalomyelitis, Acute Disseminated; Humans; Toxocara canis
PubMed: 33257028
DOI: 10.1016/j.neurol.2020.08.005 -
Journal of Helminthology Jul 2019We identified and characterized a new cosmocercid nematode species, Cosmocercoides wuyiensis n. sp., through microscopic examination and sequencing of the partial small...
We identified and characterized a new cosmocercid nematode species, Cosmocercoides wuyiensis n. sp., through microscopic examination and sequencing of the partial small ribosomal RNA gene (18S rDNA), internal transcribed spacer (ITS) and mitochondrial cytochrome c oxidase subunit 1 (COI) genes. The new species was isolated from the intestine of the Asiatic frog Amolops wuyiensis Liu and Hu, 1975 captured from four localities of the Anhui province in south-east China. Among the 25 recorded species of the Cosmocercoides genus, the morphology of C. wuyiensis n. sp. is closest to that of C. kiliwai and C. malayensis, which were isolated from various Mexican frog and Malaysian lizard species, respectively. However, C. wuyiensis n. sp. displayed several distinguishing features, such as small size of the male body, two spicules of unequal lengths in the male, small gubernaculum, pre-, ad- and post-cloacal caudal rosette papillae in the ratio of 18-24:2:6 and simple papillae in the ratio of 14:multiple:4, circle and number of punctation in each rosette at 1:11-16, sharply conical tail-end and the presence of lateral alae and somatic papillae in both sexes. BLAST and the phylogenetic analyses of the 18S rDNA and ITS sequences indicated that C. wuyiensis n. sp. belonged to the genus Cosmocercoides, while that of the COI gene sequence of C. wuyiensis n. sp. showed 16.36% nucleotide divergence with C. pulcher and 47.99% nucleotide divergence with C. qingtianensis. The morphological and molecular characterization of C. wuyiensis n. sp. provides new taxonomic data for this genus.
Topics: Animals; Anura; Ascaridida; China; DNA, Intergenic; DNA, Ribosomal; Electron Transport Complex IV; Female; Intestines; Male; Phylogeny
PubMed: 31296272
DOI: 10.1017/S0022149X19000518 -
Infection, Genetics and Evolution :... Dec 2021Cosmocercoid nematodes are common parasites in the digestive tract of amphibians. However, our knowledge of the species diversity, genetic data and molecular phylogeny...
Cosmocercoid nematodes are common parasites in the digestive tract of amphibians. However, our knowledge of the species diversity, genetic data and molecular phylogeny of the superfamily Cosmocercoidea are far from being well understood. In the present study, large numbers of cosmocercoid nematodes were collected from the fine-spined frog Sylvirana spinulosa (Smith) (Anura: Ranidae) and the white-spotted thigh tree-frog Polypedates megacephalus (Hallowell) (Anura: Rhacophoridae) in Guangxi Province, China. Integrated morphological and genetic evidence reveals these nematode specimens to be a new species of the genus Aplectana, A. dayaoshanensis n. sp. (Cosmocercoidea: Cosmocercidae). The molecular characterization of small ribosomal DNA (18S), internal transcribed spacer (ITS) and large ribosomal DNA (28S) of A. dayaoshanensis n. sp., together with the 28S of A. chamaeleonis (Baylis, 1929) (collected from Hyperolius kivuensis Ahl in Rwanda), were reported for the first time. Moreover, phylogenetic analyses using maximum likelihood (ML) inference based on 18S + 28S and ITS sequence data, respectively, both supported the family Cosmocercidae to be a monophyletic group and the family Kathlaniidae to be a paraphyletic group. Our phylogenetic results rejected the monophyly of the genus Aplectana. The present results contribute to the knowledge of the species diversity and genetic data of cosmocercoid nematodes, and preliminarily revealed the phylogenetic relationships of the major families and some genera in the Cosmocercoidea.
Topics: Animals; Anura; Ascaridida; Ascaridida Infections; China; Female; Male; Phylogeny; Ranidae
PubMed: 34688888
DOI: 10.1016/j.meegid.2021.105123 -
PLoS Neglected Tropical Diseases Apr 2022It remains largely unknown where and how infections with soil-transmitted helminths (STHs; Ascaris, Trichuris, Necator and Ancylostoma) occur. We therefore aimed to...
BACKGROUND
It remains largely unknown where and how infections with soil-transmitted helminths (STHs; Ascaris, Trichuris, Necator and Ancylostoma) occur. We therefore aimed to identify possible sources of infection by assessing the environmental contamination in an STH-endemic area.
METHODS
We first performed a series of laboratory experiments designed to optimize a soil straining-flotation method to detect and quantify Ascaris and Trichuris eggs in soil, and to validate the diagnostic performance of the optimized method when followed by microscopy and qPCR. In a second phase, we applied this method to assess the level of STH contamination in 399 environmental samples collected from 10 school compounds, 50 households and 9 open markets in Jimma Town (Ethiopia). Subsequently, we explored associations between the environmental contamination and both the corresponding STH epidemiology at the level of the schools and the household characteristics. Finally, we assessed the knowledge, attitude and practice (KAP) towards STHs in school children.
PRINCIPAL FINDINGS
Our soil straining-flotation method has an analytical sensitivity of 50 eggs per 100 grams of soil and egg recovery rate of 36.0% (Ascaris) and 8.0% (Trichuris). The analysis of field samples with both microscopy and qPCR revealed the presence of 8 different helminth species of medical importance, including but not limited to the human STHs. There was a significant association between the environmental contamination and prevalence of any STH infections at the school level only. The KAP indicated a lack of knowledge and awareness of STHs.
CONCLUSIONS/SIGNIFICANCE
Our optimized straining-flotation method has a moderate diagnostic performance and revealed that life stages of helminths are ubiquitous in the environment, which might be due to the poor sanitary facilities at both the schools and the households, and a poor level of KAP towards STHs. Further research is required to gain more insights into the contribution of these life stages to transmission.
Topics: Animals; Ascaris; Ascaris lumbricoides; Child; Ethiopia; Feces; Helminthiasis; Helminths; Humans; Prevalence; Soil; Trichuris
PubMed: 35377880
DOI: 10.1371/journal.pntd.0010307 -
Journal of Helminthology Oct 2022Amphibians are a widespread Chordata taxon and are important for maintaining the balance of both terrestrial and aquatic ecosystems. Brazil has a rich amphibian fauna;...
Amphibians are a widespread Chordata taxon and are important for maintaining the balance of both terrestrial and aquatic ecosystems. Brazil has a rich amphibian fauna; however, little is known about the role of their ecology and phylogenetic relationships during the assembly processes of associated endoparasite communities. Herein, we describe an endoparasite community in an anuran assemblage in the Caatinga, a unique biome of dry forests in north-eastern Brazil. We studied endoparasite diversity, as well as the effects of body length, body mass, body volume and sex on parasite abundance. We also investigated the influence of ecological and historical factors and anuran microhabitat use on endoparasite composition. We analysed individuals from 13 anuran species distributed across five families: Odontophrynidae (); Leptodactylidae (, , , and ); Hylidae (, , and ); Bufonidae ( and ); and Microhylidae (). We found nine species of endoparasites, including seven nematodes (, sp., , , , sp. and sp.), one species of Trematoda () and one non-identified cestode. There was no significant relationship between endoparasite abundance and host body length, body mass, body volume and sex. A phylogenetic principal component analysis showed that ecological factors had a greater influence on endoparasite assemblage than historical factors. Similarly, our results showed that ecological factors had a greater influence on anuran microhabitat use compared to historical factors, which contributed to the generalist characteristics presented by most of the sampled endoparasite species.
Topics: Humans; Animals; Ecosystem; Phylogeny; Nematoda; Forests; Trematoda; Ascaridida; Brazil; Anura
PubMed: 36305478
DOI: 10.1017/S0022149X22000682 -
Frontiers in Immunology 2023The COVID-19 pandemic has had devastating effects worldwide, but the trajectory of the pandemic has been milder in Low-and-Middle-Income Countries (LMICs), including...
INTRODUCTION
The COVID-19 pandemic has had devastating effects worldwide, but the trajectory of the pandemic has been milder in Low-and-Middle-Income Countries (LMICs), including those in Africa. Co-infection with helminths, such as Ascaris lumbricoides, has been suggested as a possible factor contributing to the reduced severity observed in these regions.
METHODS
The present study investigated the association between Ascaris-specific antibody levels and COVID-19 severity in 276 SARS-CoV-2-infected individuals in Benin. Participants were categorized into asymptomatic (n=100), mild (n=150), and severe (n=26) groups based on clinical disease severity. Sera were collected and analyzed using ELISA to measure Ascaris and SARS-CoV-2-specific antibodies, while Luminex was used to assess cytokines and SARS-CoV-2-specific neutralizing antibody expression.
RESULTS AND DISCUSSION
The results demonstrated that asymptomatic SARS-CoV-2 seropositive individuals expressed, on average, 1.7 and 2.2-times higher levels of Ascaris antibodies compared to individuals with mild and severe COVID-19, respectively. This finding suggests an inverse correlation between Ascaris antibody levels and COVID-19 severity. Notably, logistic regression analysis showed that Ascaris seropositivity was significantly associated with a reduced risk of severe COVID-19 (OR = 0.277, p = 0.021). Interestingly, COVID-19 patients with comorbidities such as type 2 diabetes and high blood pressure showed lower expression of Ascaris antibodies. Strikingly, no correlation was observed between Ascaris antibody levels and SARS-CoV-2-specific neutralizing antibodies. On the other hand, individuals seronegative for Ascaris displayed significantly higher levels of systemic pro-inflammatory markers compared to seropositive individuals. These findings suggest that higher expression of Ascaris antibodies is associated with asymptomatic SARS-CoV-2 infections and may contribute to the reduction of the risk to develop severe COVID-19. The beneficial effect of Ascaris seropositivity on COVID-19 outcomes in Benin may be attributed to a decrease in comorbidities and pro-inflammatory markers. These observations provide valuable insights into the milder COVID-19 trajectory observed in Africa and may have implications for future therapeutic strategies.
Topics: Humans; Animals; Ascaris lumbricoides; Benin; COVID-19; Diabetes Mellitus, Type 2; Pandemics; SARS-CoV-2; Ascaris; Antibodies, Neutralizing; Antibodies, Viral
PubMed: 37622109
DOI: 10.3389/fimmu.2023.1233082 -
Georgian Medical News Sep 2018Helminthiases caused by parasitic nematodes are widespread in different regions of the world. The main adaptation for overcoming adverse conditions is a barrier... (Review)
Review
Helminthiases caused by parasitic nematodes are widespread in different regions of the world. The main adaptation for overcoming adverse conditions is a barrier properties of the cuticle surface structure, which differs from the membrane teguments of trematodes and cestodes. Different types of nematodes have specific structural and biochemical adaptations at different stages of their life cycle. While creating specific areas of habitat and nutrition, some types of parasites change the morphology and functioning of the host tissues. Ascaris suum and Caenorabditis elegans were widely used as model organisms in the study of genetics, biochemistry of nematodes. Studying of biochemistry and molecular biology of structural components of nematode surfaces is important for development of effective and safe anthelmintic drugs. The differences in the structure and functioning of transport enzymes of parasites and humans will help to create effective specific inhibitors and anthelmintic remedies. An important point of application of anthelmintic drugs can serve as inorganic ions transport proteins in the membranes of the surfaces. Glycolipids of cuticle contribute to the evasion from the host immune system, protecting the surface proteins from degradation by proteases. Study of helminth surfaces makes an important contribution to the development of anthelmintic drugs and vaccines, for helminthiasis treat.
Topics: Animals; Anthelmintics; Ascaris; Caenorhabditis elegans; Helminth Proteins; Host-Parasite Interactions
PubMed: 30358556
DOI: No ID Found -
Journal of Wildlife Diseases Apr 2020The raccoon () roundworm, , is an emerging wildlife zoonosis of public health significance in North America. Although the adult stage typically causes no disease in...
The raccoon () roundworm, , is an emerging wildlife zoonosis of public health significance in North America. Although the adult stage typically causes no disease in raccoons, the larval stage can cause significant disease in a variety of species, including humans. Raccoons often use human environments, which may increase the risk of exposure in people, particularly in urban settings. Because of this, our objectives were to identify host and environmental risk factors associated with the prevalence and intensity of infection in raccoons in Ontario, Canada. Between 2013 and 2016, 1,539 raccoons were collected and examined for the presence of . Thereafter, we analyzed our data for the influence of age, sex, fat stores, human population size, land use classification, season, and year of collection on the prevalence and intensity of infection. With multilevel logistic regression models, we identified significant associations between prevalence and host age, prevalence and amount of fat stores, and prevalence and season of collection; a significant two-way interaction was also identified between host sex and land use classification. Additionally, by using multilevel negative binomial regression models, we identified significant associations between the intensity of parasite infection and season of collection, as well as three significant two-way interactions: host sex and land use classification, host age and land use classification, and host sex and amount of fat stores. These findings help provide a more complete understanding of ecology in raccoons, including identifying associations between different environments and , which may assist in the development of future risk management strategies.
Topics: Animals; Ascaridida Infections; Ascaridoidea; Female; Male; Ontario; Raccoons
PubMed: 31658429
DOI: No ID Found -
The American Journal of Tropical... Jul 2020
Topics: Adult; Animals; Ascaridida Infections; Ascaridoidea; Female; Fishes; Helminth Proteins; Humans; Japan; NADH Dehydrogenase; Palatine Tonsil; Phylogeny; Seafood; Tonsillectomy
PubMed: 32653049
DOI: 10.4269/ajtmh.20-0175 -
Poultry Science Aug 2022Free-range chickens are predisposed to diverse parasitic infections during scavenging. Accurate identification of these parasites using morphological characters has been...
Molecular identification of helminth parasites of the Heterakidae and Ascarididae families of free-ranging chickens from selected rural communities of KwaZulu-Natal province of South Africa.
Free-range chickens are predisposed to diverse parasitic infections during scavenging. Accurate identification of these parasites using morphological characters has been a challenge. Therefore, this study aimed to identify nematodes from the Heterakidae and Ascarididae family infecting free-ranging chickens from KwaZulu-Natal province of South Africa using a combination of morphological and molecular techniques. Forty-two free-ranging adult indigenous chickens were purchased from randomly selected households in Shongweni (n=12), Umzinto (n=10), Gingindlovu (n=10) and Ozwathini (n=10) rural villages and examined for nematodes of the Heterakidae and Ascarididae family. Collected specimen were identified morphologically and confirmed using mitochondrial and nuclear ribosomal markers. Results showed that Ascaridia galli was common, occurring at all sampling locations with an overall prevalence of 58.3%, while Heterakis gallinarum and H. beramporia occurred in three locations. Ascaridia galli had high prevalence in Shongweni (58.3%), followed by Gingindlovu (40%), Ozwathini (20%) and Umzinto (10%). Heterakis gallinarum infection was prevalent in three locations, with an overall prevalence of 90% in Gingindlovu, 80% in Ozwathini and 58.3 % in Shongweni. Heterakis gallinarum and H. beramporia were not recorded in Umzinto. Heterakis beramporia was recorded in low prevalence in Gingindlovu (20%), Ozwathini (10%) and Shongweni (8.3%) villages. Mixed infections of A. galli and H. gallinarum were recorded in Gingindlovu, Ozwathini and Shongweni, and H. gallinarum and H. beramporia in Gingindlovu. Molecular analysis confirmed identification of A. galli, and further showed close relationship with the GenBank-derived South African isolates. Haplotype network further confirmed their ancestral history, where all South African A. galli isolates formed five novel haplotypes corresponding with the structure of the phylogenetic tree. Similar structure was observed with Heterakis isolates, where analysis of the cox1 gene showed that H. gallinarum formed a well-supported monophyletic clade with other Heterakis species. The ITS marker identified three specimens from Gingindlovu, Ozwathini and Shongweni as H. beramporia, which formed strongly supported sister clade to H. indica and this is the first report confirming the occurrence of H. beramporia in South Africa.
Topics: Animals; Ascaridia; Chickens; Helminths; Parasites; Phylogeny; Poultry Diseases; Rural Population; South Africa
PubMed: 35797782
DOI: 10.1016/j.psj.2022.101979