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1.
Front Immunol ; 13: 842870, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35418979

RESUMO

Intestinal parasitic nematodes affect a quarter of the world's population, typically eliciting prominent effector Th2-driven host immune responses. As not all infected hosts develop protection against reinfection, our current understanding of nematode-induced memory Th2 responses remains limited. Here, we investigated the activation of memory Th2 cells and the mechanisms driving early recall responses to the enteric nematode Heligmosomoides polygyrus in mice. We show that nematode-cured mice harbor memory Th2 cells in lymphoid and non-lymphoid organs with distinct transcriptional profiles, expressing recirculation markers like CCR7 and CD62-L in the mesenteric lymph nodes (mLN), and costimulatory markers like Ox40, as well as tissue homing and activation markers like CCR2, CD69 and CD40L in the gut and peritoneal cavity (PEC). While memory Th2 cells persist systemically in both lymphoid and non-lymphoid tissues following cure of infection, peritoneal memory Th2 cells in particular displayed an initial prominent expansion and strong parasite-specific Th2 responses during early recall responses to a challenge nematode infection. This effect was paralleled by a significant influx of dendritic cells (DC) and eosinophils, both also appearing exclusively in the peritoneal cavity of reinfected mice. In addition, we show that within the peritoneal membrane lined by peritoneal mesothelial cells (PeM), the gene expression levels of cell adhesion markers VCAM-1 and ICAM-1 decrease significantly in response to a secondary infection. Overall, our findings indicate that the host peritoneal cavity in particular harbors prominent memory Th2 cells and appears to respond directly to H. polygyrus by an early recall response via differential regulation of cell adhesion markers, marking the peritoneal cavity an important site for host immune responses to an enteric pathogen.


Assuntos
Nematospiroides dubius , Infecções por Strongylida , Animais , Linfonodos , Camundongos , Cavidade Peritoneal , Células Th2
2.
Acta Parasitol ; 67(1): 94-101, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34143401

RESUMO

PURPOSE: Gastric infection with Strongyloides stercoralis (SS) usually occurs in immunocompromised patients. The unexpected observation of this parasite in an otherwise healthy young lady who had undergone upper endoscopy and biopsy sampling of the gastro-duodenal mucosa, prompted us to review the literature to ascertain the conditions favouring gastric colonization by SS. METHODS: Pathology files of gastroduodenal biopsies received at St. Mary's hospital, Northern Uganda, between 2007 and 2017 were reviewed. Pubmed search was performed under the headings "Strongyloides stercoralis", "Gastric parasitosis". RESULTS: Histology of the only gastroduodenal biopsy with SS infection showed parasite eggs, immature rhabditiform larvae, and numerous adult worms in gastric pits and rhabditiform larvae in interepithelial parasitic tunnels, causing reactive changes of the glandular epithelium. There was no significant acute inflammatory cell infiltrate surrounding the parasites. Literature review showed that gastric SS infection appears to be very uncommon and was, as expected, largely prevalent in immunodeficient individuals (84.2% of published cases). The rare gastric SS infection is a complication of systemic strongyloidiasis, either hyperinfective, or disseminated form. It is also commonly associated with duodenal infection at microscopical examination. CONCLUSION: Involvement of gastric mucosa in the absence of duodenal strongyloidiasis appears to be quite rare and false-negative histopathological exams are reported if only the stomach is biopsied.


Assuntos
Strongyloides stercoralis , Estrongiloidíase , Animais , Biópsia , Duodeno , Humanos , Estômago/parasitologia , Estrongiloidíase/diagnóstico
3.
Braz. J. Biol. ; 82: 1-6, 2022. tab
Artigo em Inglês | VETINDEX, VETINDEX | ID: vti-32490

RESUMO

Illnesses caused by human pinworm remains a pediatric health problem in developing nations including Pakistan. This study aimed to investigate the prevalence of Enterobius vermicularis in school children of four districts in Malakand region, Pakistan. Four hundred faecal specimens were screened from May 2014 to July 2017 using normal saline and Lugol Iodine solution. Twenty three (5.75%) individuals were found infected with E. vermicularis. Five children (1.25%) were infected with only E. vermicularis and eighteen (4.5%) were mixed with other helminths. E. vermicularis 23 (5.75%), hookworm 11 (2.75%), Ascaris lumbricoides 5 (1.25%), Taenia saginata 2 (0.5%) and Trichuris trichuira 4 (1%) were detected. Age wise 5-8 years were more parasitized followed by 13-15 and 9-12 years of age (0.0296, P<0.05). Male children were highly (0.06700, P<0.05) infected than female. Children in Malakand district were found more infected followed by Dir Upper, similar infection rate was noted in children of districts Lower Dir and Swat (0.0192, P<0.05). Children in primary level were highly (0.0013, P<0.05) infected than those of middle and high levels. Enterobiosis is still the most common parasitic diseases in children. Studies on enterobiosis should be conducted time by time to recognize the hazardous of such parasitic infection in remote areas of the country.(AU)


As doenças causadas pela traça humana continuam sendo um problema de saúde pediátrica nos países em desenvolvimento, incluindo o Paquistão. Este estudo teve como objetivo investigar a prevalência de Enterobius vermicularis em escolares de quatro distritos na região de Malakand, Paquistão. Quatrocentos espécimes fecais foram selecionados de maio de 2014 a julho de 2017, usando solução salina normal e solução de lugol iodo. Vinte e três (5,75%) indivíduos foram encontrados infectados por E. vermicularis. Cinco crianças (1,25%) foram infectadas apenas com E. vermicularis e dezoito (4,5%) foram misturadas com outros helmintos. Foram detectados E. vermicularis 23 (5,75%), ancilóstomo 11 (2,75%), Ascaris lumbricoides 5 (1,25%), Taenia saginata 2 (0,5%) e Trichuris trichuira 4 (1%). Com relação à idade, 5-8 anos foram mais parasitados, seguidos por 13-15 e 9-12 anos de idade (0,0296, P <0,05). Crianças do sexo masculino foram altamente (0,06700, P <0,05) infectadas do que as do sexo feminino. As crianças no distrito de Malakand foram encontradas mais infectadas, seguidas por Dir Upper, taxa de infecção semelhante foi observada em crianças dos distritos Lower Dir e Swat (0,0192, P <0,05). As crianças do nível primário foram altamente (0,0013, P <0,05) infectadas do que as dos níveis médio e alto. A enterobiose ainda é a doença parasitária mais comum em crianças. Os estudos sobre enterobiose devem ser conduzidos periodicamente para reconhecer a periculosidade dessa infecção parasitária em áreas remotas do país.(AU)


Assuntos
Humanos , Masculino , Feminino , Criança , Enterobius/parasitologia , Enterobíase/diagnóstico , Enterobíase/parasitologia , Helmintíase , Enteropatias Parasitárias/diagnóstico , Doenças Negligenciadas
4.
Braz. j. biol ; 82: e238769, 2022. tab
Artigo em Inglês | MEDLINE, LILACS, VETINDEX | ID: biblio-1285587

RESUMO

Abstract Illnesses caused by human pinworm remains a pediatric health problem in developing nations including Pakistan. This study aimed to investigate the prevalence of Enterobius vermicularis in school children of four districts in Malakand region, Pakistan. Four hundred faecal specimens were screened from May 2014 to July 2017 using normal saline and Lugol Iodine solution. Twenty three (5.75%) individuals were found infected with E. vermicularis. Five children (1.25%) were infected with only E. vermicularis and eighteen (4.5%) were mixed with other helminths. E. vermicularis 23 (5.75%), hookworm 11 (2.75%), Ascaris lumbricoides 5 (1.25%), Taenia saginata 2 (0.5%) and Trichuris trichuira 4 (1%) were detected. Age wise 5-8 years were more parasitized followed by 13-15 and 9-12 years of age (0.0296, P<0.05). Male children were highly (0.06700, P<0.05) infected than female. Children in Malakand district were found more infected followed by Dir Upper, similar infection rate was noted in children of districts Lower Dir and Swat (0.0192, P<0.05). Children in primary level were highly (0.0013, P<0.05) infected than those of middle and high levels. Enterobiosis is still the most common parasitic diseases in children. Studies on enterobiosis should be conducted time by time to recognize the hazardous of such parasitic infection in remote areas of the country.


Resumo As doenças causadas pela traça humana continuam sendo um problema de saúde pediátrica nos países em desenvolvimento, incluindo o Paquistão. Este estudo teve como objetivo investigar a prevalência de Enterobius vermicularis em escolares de quatro distritos na região de Malakand, Paquistão. Quatrocentos espécimes fecais foram selecionados de maio de 2014 a julho de 2017, usando solução salina normal e solução de lugol iodo. Vinte e três (5,75%) indivíduos foram encontrados infectados por E. vermicularis. Cinco crianças (1,25%) foram infectadas apenas com E. vermicularis e dezoito (4,5%) foram misturadas com outros helmintos. Foram detectados E. vermicularis 23 (5,75%), ancilóstomo 11 (2,75%), Ascaris lumbricoides 5 (1,25%), Taenia saginata 2 (0,5%) e Trichuris trichuira 4 (1%). Com relação à idade, 5-8 anos foram mais parasitados, seguidos por 13-15 e 9-12 anos de idade (0,0296, P <0,05). Crianças do sexo masculino foram altamente (0,06700, P <0,05) infectadas do que as do sexo feminino. As crianças no distrito de Malakand foram encontradas mais infectadas, seguidas por Dir Upper, taxa de infecção semelhante foi observada em crianças dos distritos Lower Dir e Swat (0,0192, P <0,05). As crianças do nível primário foram altamente (0,0013, P <0,05) infectadas do que as dos níveis médio e alto. A enterobiose ainda é a doença parasitária mais comum em crianças. Os estudos sobre enterobiose devem ser conduzidos periodicamente para reconhecer a periculosidade dessa infecção parasitária em áreas remotas do país.


Assuntos
Animais , Masculino , Feminino , Pré-Escolar , Criança , Enterobíase/epidemiologia , Helmintos , Paquistão/epidemiologia , Instituições Acadêmicas , Prevalência , Enterobius , Fezes
5.
Int J Mol Sci ; 22(16)2021 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-34445445

RESUMO

Ascariasis is a global health problem for humans and animals. Adult Ascaris nematodes are long-lived in the host intestine where they interact with host cells as well as members of the microbiota resulting in chronic infections. Nematode interactions with host cells and the microbial environment are prominently mediated by parasite-secreted proteins and peptides possessing immunomodulatory and antimicrobial activities. Previously, we discovered the C-type lectin protein AsCTL-42 in the secreted products of adult Ascaris worms. Here we tested recombinant AsCTL-42 for its ability to interact with bacterial and host cells. We found that AsCTL-42 lacks bactericidal activity but neutralized bacterial cells without killing them. Treatment of bacterial cells with AsCTL-42 reduced invasion of intestinal epithelial cells by Salmonella. Furthermore, AsCTL-42 interacted with host myeloid C-type lectin receptors. Thus, AsCTL-42 is a parasite protein involved in the triad relationship between Ascaris, host cells, and the microbiota.


Assuntos
Ascaris suum/metabolismo , Interações Hospedeiro-Parasita , Mucosa Intestinal/metabolismo , Lectinas Tipo C/metabolismo , Lectinas/metabolismo , Salmonella , Animais , Ascaríase/metabolismo , Ascaríase/microbiologia , Ascaris suum/microbiologia , Ascaris suum/fisiologia , Linhagem Celular , Lectinas/fisiologia , Proteínas Recombinantes , Sus scrofa/microbiologia , Sus scrofa/parasitologia
6.
Cureus ; 13(6): e15902, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34322346

RESUMO

Strongyloidiasis is a parasitic infestation caused by Strongyloides stercoralis (S. stercoralis). Most cases are asymptomatic or mildly symptomatic with respiratory, gastrointestinal, or non-specific cutaneous symptoms. However, in immunocompromised patients, such as patients on chronic corticosteroids, malignancy, or human immunodeficiency virus (HIV) infection, hyperinfection syndrome can occur. The following is a case of Strongyloides hyperinfection in an individual taking prednisone for uveitis who developed upper gastrointestinal (GI) bleed and gram-negative bacteremia.

7.
Biochem Biophys Res Commun ; 555: 168-174, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-33819747

RESUMO

When animals are infected with helminthic parasites, resistant hosts mount type II helper T (Th2) immune responses to expel worms. Recent studies have clearly shown that epithelial cell-derived cytokines contribute to the induction of Th2 immune responses. Here we demonstrate the role of endogenous thymic stromal lymphopoietin (TSLP) for protection against Strongyloides venezuelensis (S. venezuelensis) infection, utilizing TSLP receptor-deficient Crlf2-/- mice. The number of eggs per gram of feces (EPG) and worm burden were significantly higher in Crlf2-/- mice than in wild type (WT) mice. S. venezuelensis infection induced Tslp mRNA expression in the skin, lung, and intestine and also facilitated the accumulation of mast cells in the intestine in a TSLP-dependent manner. Furthermore, CD4+ T cells from S. venezuelensis-infected Crlf2-/- mice showed diminished capacity to produce Th2 cytokines in the early stage of infection. Finally, CD4+ cell-depleted Crlf2-/- mice still showed higher EPG counts and worm burden than CD4+ cell-depleted WT mice, indicating that TSLP contributes to protecting mice against S. venezuelensis infection in both CD4+ T cell-dependent and -independent manners.


Assuntos
Linfócitos T CD4-Positivos/parasitologia , Citocinas/fisiologia , Estrongiloidíase/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Resistência à Doença/fisiologia , Fezes/parasitologia , Interações Hospedeiro-Parasita , Imunoglobulina E/sangue , Imunoglobulinas/genética , Intestinos/parasitologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Receptores de Citocinas/genética , Estrongiloidíase/parasitologia
8.
Front Immunol ; 11: 1830, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33117327

RESUMO

Helminth parasites are effective in biasing Th2 immunity and inducing regulatory pathways that minimize excessive inflammation within their hosts, thus allowing chronic infection to occur whilst also suppressing bystander atopic or autoimmune diseases. Multiple sclerosis (MS) is a severe autoimmune disease characterized by inflammatory lesions within the central nervous system; there are very limited therapeutic options for the progressive forms of the disease and none are curative. Here, we used the experimental autoimmune encephalomyelitis (EAE) model to examine if the intestinal helminth Heligmosomoides polygyrus and its excretory/secretory products (HES) are able to suppress inflammatory disease. Mice infected with H. polygyrus at the time of immunization with the peptide used to induce EAE (myelin-oligodendrocyte glycoprotein, pMOG), showed a delay in the onset and peak severity of EAE disease, however, treatment with HES only showed a marginal delay in disease onset. Mice that received H. polygyrus 4 weeks prior to EAE induction were also not significantly protected. H. polygyrus secretes a known TGF-ß mimic (Hp-TGM) and simultaneous H. polygyrus infection with pMOG immunization led to a significant expansion of Tregs; however, administering the recombinant Hp-TGM to EAE mice failed to replicate the EAE protection seen during infection, indicating that this may not be central to the disease protecting mechanism. Mice infected with H. polygyrus also showed a systemic Th2 biasing, and restimulating splenocytes with pMOG showed release of pMOG-specific IL-4 as well as suppression of inflammatory IL-17A. Notably, a Th2-skewed response was found only in mice infected with H. polygyrus at the time of EAE induction and not those with a chronic infection. Furthermore, H. polygyrus failed to protect against disease in IL-4Rα-/- mice. Together these results indicate that the EAE disease protective mechanism of H. polygyrus is likely to be predominantly Th2 deviation, and further highlights Th2-biasing as a future therapeutic strategy for MS.


Assuntos
Antígenos de Helmintos/imunologia , Encefalomielite Autoimune Experimental/imunologia , Receptores de Superfície Celular/imunologia , Infecções por Strongylida/imunologia , Células Th2/imunologia , Animais , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nematospiroides dubius/imunologia
9.
Vet Parasitol ; 270: 49-55, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213241

RESUMO

Variation in the timing of development of immunity to gastro-intestinal nematode parasites was assessed in resistant and resilient Romney selection lines exposed to mixed natural infection. From weaning, at mean 92 days-of-age, animals (n = 53) were sampled for faecal egg count (FEC) expressed as eggs per gram of faeces (epg), saliva for immunoglobulin (IgG and IgA) determination and fasted live weight (LW) every 10 days until 351 days-of-age. Overall, mean back-transformed FEC were consistently low for resistant animals (<200 epg) whereas resilient counterparts' FEC increased with time to reach a peak of 1400 epg at day 230 for females and 1800 epg for males at day 280 before declining to less than 500 epg by day 300, respectively (P < 0.001). Resistant lambs reached a threshold for Trichostrongylus colubriformis L3-specific IgG which was indicative of the presence of immunity earlier at 220.6 ± 8.8 days-of-age compared with resilient-line animals which reach this threshold 40 days later at 263.4 ± 6.9 days-of-age (P < 0.001). In addition, resistant females reached sexual maturity earlier compared with their resilient counterparts viz. 263.5 ± 3.7 c.f. 274.4 ± 3.4 days-of-age, respectively, (P = 0.048). Mean fasted live weight (LW) showed a selection line by time interaction (P < 0.001) which reflected greater LW in the early phase of the study in resilient males but increasing for all groups until day 280 before declining and being similar for all groups from day 330. In summary, differences appear to exist in the timing of immune development between these Romney lines, with resistant animals developing immunity earlier and these resistant-line animals also appear to be more physiologically mature at the same chronological age than resilient animals. These observations have implications on the timing of identification and selection of resistant animals.


Assuntos
Cruzamento , Resistência à Doença/imunologia , Doenças dos Ovinos/imunologia , Tricostrongilose/veterinária , Animais , Feminino , Masculino , Seleção Genética , Maturidade Sexual , Ovinos , Tricostrongilose/imunologia
10.
Trop Med Infect Dis ; 4(1)2019 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-30832380

RESUMO

With the rise of global migration, international trade, and global environmental challenges such as climate change, it is not surprising that the interactions between humans and other animals are shifting. Salient infectious diseases, such as malaria and HIV (which have high burdens of disease), attract sophisticated public health frameworks and funding from global/regional organisations, such as the WHO. This unfortunately detracts attention from the many emerging zoonoses that fall under the radar as neglected tropical diseases (NTDs). This review considers the available literature and the attribution of burden of disease to the most insidious NTDs and recommends which five are deserving of policy prioritisation. In line with WHO analyses of NTDs, intestinal nematode infections, leishmaniasis, schistosomiasis, and lymphatic filariasis should be prioritised, as well as the burden of disease of cryptosporidiosis, which is largely underestimated. Both monitoring and treatment/prevention control methods for cryptosporidiosis are suggested and explored.

11.
Front Immunol ; 10: 445, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30915083

RESUMO

Currently, methods for monitoring changes of gut barrier integrity and the associated immune response via non-invasive means are limited. Therefore, we aimed to develop a novel non-invasive technique to investigate immunological host responses representing gut barrier changes in response to infection. We identified the mucous layer on feces from mice to be mainly composed of exfoliated intestinal epithelial cells. Expression of RELM-ß, a gene prominently expressed in intestinal nematode infections, was used as an indicator of intestinal cellular barrier changes to infection. RELM-ß was detected as early as 6 days post-infection (dpi) in exfoliated epithelial cells. Interestingly, RELM-ß expression also mirrored the quality of the immune response, with higher amounts being detectable in a secondary infection and in high dose nematode infection in laboratory mice. This technique was also applicable to captured worm-infected wild house mice. We have therefore developed a novel non-invasive method reflecting gut barrier changes associated with alterations in cellular responses to a gastrointestinal nematode infection.


Assuntos
Gastroenteropatias/patologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Mucosa Intestinal/patologia , Nematospiroides dubius/isolamento & purificação , Infecções por Strongylida/patologia , Animais , Biomarcadores/análise , Citocinas/análise , Células Epiteliais/fisiologia , Feminino , Gastroenteropatias/parasitologia , Mucosa Intestinal/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Nematospiroides dubius/imunologia , Infecções por Strongylida/imunologia , Infecções por Strongylida/parasitologia , Junções Íntimas/fisiologia
12.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 30(5): 567-570, 2018 May 16.
Artigo em Chinês | MEDLINE | ID: mdl-30567034

RESUMO

OBJECTIVE: To investigate the infection status of intestinal nematodes and their risk factors in rural residents of Jiangxia District, Wuhan City, so as to provide the reference for the establishment of targeted prevention and control measures. METHODS: According to the requirements of cross-sectional study of the national human key parasitic diseases, the residents in Shanpo Sub-district, Jiangxia District were randomly selected as the objects for the investigation of the infection status of Ascaris lumbricoides, hookworm and Trichuris trichiura. A questionnaire survey was performed simultaneously. RESULTS: Totally 236 residents received the stool tests, and only the hookworm eggs were found, with an infection rate of 7.63% (18 cases). The survey of intestinal parasitic infection status and their risk factors in 600 residents found 397 cases of suspected roundworm infection, 355 cases of suspected hookworm larvae dermatitis, 295 cases of suspected hookworm infection, and 145 cases of suspected whipworm infection, respectively. The Logistic regression analysis found that the risk factors of suspected roundworm infection included not always washing hands after toilet, using manure and fertilizer, and not often wearing shoes when doing farm work; the protective factors included knowing how roundworm infection was gained, and not using fresh dung for fertilization. The risk factors of suspected hookworm infection included using well water and pond water as the source of drinking water, eating food off the ground, using manure and fertilizers, and not washing when there was only one cutting board, and its protective factors included using tap water and well water as drinking water source, knowing how the roundworm infection was gained, and sometimes or not suing fresh feces for fertilization. The risk factors for suspected whipworm infection included eating food off the ground. CONCLUSIONS: The intestinal parasite prevalence in the residents of the Shanpo Sub-district, Jiangxia District in Wuhan City is relatively high, and some risk factors associated with their infection indeed exist. Therefore, the regional government and health department should strengthen the health education to improve the residents' knowledge about parasitic diseases and selfprotection awareness. At the same time, the residents should take physical examination regularly and take necessary deworming treatment to effectively control the prevalence and spread of intestinal parasitic diseases.


Assuntos
Enteropatias Parasitárias , Infecções por Nematoides , Animais , China/epidemiologia , Estudos Transversais , Fezes/parasitologia , Humanos , Enteropatias Parasitárias/epidemiologia , Infecções por Nematoides/epidemiologia , Prevalência , Fatores de Risco
13.
Front Immunol ; 9: 2132, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30283458

RESUMO

The immune responses against helminths have been investigated individually, and it is well-established that infected hosts develop an immunological memory to resist reinfection by the same pathogen. In contrast, it is poorly understood how the host immune system responds to subsequent infection by unrelated parasites after elimination of the first infection. We previously reported that infection of mice with Strongyloides venezuelensis induces the accumulation of group 2 innate lymphoid cells (ILC2s) in the lung. Here, we demonstrated that S. venezuelensis-experienced (Sv-exp) mice became significantly resistant against infection by Nippostrongylus brasiliensis. N. brasiliensis infection induced enhanced accumulation of ILC2s and eosinophils with increased expressions of mRNA for Th2 cytokines in the lungs of Sv-exp mice. The resistance was dependent on ILC2s, and eosinophils but not on CD4+ T cells. Furthermore, pulmonary ILC2s in Sv-exp mice acquired a highly responsive "trained" phenotype; in response to N. brasiliensis infection, they rapidly increased and produced IL-5 and IL-13, which in turn induced the early accumulation of eosinophils in the lungs. IL-33 was required for the accumulation of ILC2s and the resistance of mice against N. brasiliensis infection but insufficient for the induction of trained ILC2s. In conclusion, animals infected with one type of lung-migratory nematodes acquire a specific-antigen-independent resistance to another type of lung-migrating nematodes, providing animals with the capacity to protect against sequential infections with various lung-migratory nematodes.


Assuntos
Imunidade Inata/imunologia , Pulmão/imunologia , Linfócitos/imunologia , Infecções por Strongylida/imunologia , Animais , Eosinófilos/imunologia , Interleucina-13/imunologia , Interleucina-13/metabolismo , Interleucina-33/genética , Interleucina-33/imunologia , Interleucina-33/metabolismo , Interleucina-5/imunologia , Interleucina-5/metabolismo , Pulmão/parasitologia , Linfócitos/parasitologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nippostrongylus/imunologia , Nippostrongylus/fisiologia , Ratos Sprague-Dawley , Ratos Wistar , Infecções por Strongylida/parasitologia , Strongyloides/imunologia , Strongyloides/fisiologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-30131945

RESUMO

Ascariasis is a widespread soil-transmitted helminth infection caused by the intestinal roundworm Ascaris lumbricoides in humans, and the closely related Ascaris suum in pigs. Progress has been made in understanding interactions between helminths and host immune cells, but less is known concerning the interactions of parasitic nematodes and the host microbiota. As the host microbiota represents the direct environment for intestinal helminths and thus a considerable challenge, we studied nematode products, including excretory-secretory products (ESP) and body fluid (BF), of A. suum to determine their antimicrobial activities. Antimicrobial activities against gram-positive and gram-negative bacterial strains were assessed by the radial diffusion assay, while effects on biofilm formation were assessed using the crystal violet static biofilm and macrocolony assays. In addition, bacterial neutralizing activity was studied by an agglutination assay. ESP from different A. suum life stages (in vitro-hatched L3, lung-stage L3, L4, and adult) as well as BF from adult males were analyzed by mass spectrometry. Several proteins and peptides with known and predicted roles in nematode immune defense were detected in ESP and BF samples, including members of A. suum antibacterial factors (ASABF) and cecropin antimicrobial peptide families, glycosyl hydrolase enzymes such as lysozyme, as well as c-type lectin domain-containing proteins. Native, unconcentrated nematode products from intestine-dwelling L4-stage larvae and adults displayed broad-spectrum antibacterial activity. Additionally, adult A. suum ESP interfered with biofilm formation by Escherichia coli, and caused bacterial agglutination. These results indicate that A. suum uses a variety of factors with broad-spectrum antibacterial activity to affirm itself within its microbe-rich environment in the gut.


Assuntos
Antibacterianos/metabolismo , Antibiose , Ascaris suum/metabolismo , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Testes de Aglutinação , Animais , Antibacterianos/análise , Ascaris suum/química , Violeta Genciana/análise , Proteínas de Helminto/análise , Proteínas de Helminto/metabolismo , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Coloração e Rotulagem , Suínos
16.
Acta Parasitol ; 63(1): 167-174, 2018 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-29351071

RESUMO

The genus Baylisascaris (order Ascaridida) includes numerous relatively host-specific nematodes, which are common in intestines of wild mammals. Some of them may have impact on veterinary and public health, as their larvae have the potential to cause visceral, ocular, and/or neural larva migrans in a wide range of mammals, birds, and humans. Baylisascaris transfuga is a parasite occurring in a range of bear species throughout the world. We present the current data on B. transfuga occurrence in brown bears from a relatively restricted territory of the Polana Protected Landscape Area in Central Slovakia, obtained by traditional methods (faecal examination, morphology). Species affiliation was confirmed by employing molecular markers generating nuclear 28S and mitochondrial cox1 sequences in adult worms. Based on 17 examined samples (15 excrements and two intestines of young bear females), the occurrence of B. transfuga in the surveyed area was assessed as 52.9%. Both bear females were infected with adult and juvenile worms. Due to the high density of bears in the locality, the high infection rate with ascarids, and the huge number of eggs produced by the parasites, it is apparent that the respective environment, including the inhabited areas, might be markedly contaminated by Baylisascaris eggs. The ability of B. transfuga to serve as a zoonotic agent has not been unambiguously proved; however, this attribute should be considered and subjected to further research.


Assuntos
Infecções por Ascaridida/veterinária , Ascaridoidea/isolamento & purificação , Ursidae/parasitologia , Animais , Infecções por Ascaridida/epidemiologia , Infecções por Ascaridida/parasitologia , Ascaridoidea/anatomia & histologia , Ascaridoidea/classificação , Ascaridoidea/genética , Análise por Conglomerados , DNA de Helmintos/química , DNA de Helmintos/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Fezes/parasitologia , Microscopia , Filogenia , Prevalência , RNA Ribossômico 28S/genética , Análise de Sequência de DNA , Eslováquia/epidemiologia
17.
Parasit Vectors ; 10(1): 201, 2017 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-28438225

RESUMO

BACKGROUND: The parasitic nematode Haemonchus contortus shows highly variable life history traits. This highlights the need to have an average estimate and a quantification of the variation around it to calibrate epidemiological models. METHODS: This paper aimed to quantify the main life history traits of H. contortus and to identify explanatory factors affecting these traits using a powerful method based on a systematic review and meta-analysis of current literature. The life history traits considered are: (i) the establishment rate of ingested larvae; (ii) the adult mortality rate; (iii) the fertility (i.e. the number of eggs laid/female/day); and (iv) fecundity of female worms (i.e. the number of eggs per gram of faeces). RESULTS: A total of 37 papers that report single experimental infection with H. contortus in sheep and published from 1960 to 2015, were reviewed and collated in this meta-analysis. This encompassed 115 experiments on 982 animals. Each trait was analysed using a linear model weighted by its inverse variance. The average (± SE) larval establishment rate was 0.24 ± 0.02, which decreased as a function of the infection dose and host age. An average adult mortality rate of 0.021 ± 0.002) was estimated from the literature. This trait varied as a function of animal age, breed and protective response due to prior exposure to the parasite. Average female fertility was 1295.9 ± 280.4 eggs/female/day and decreased in resistant breeds and previously infected hosts. Average faecal egg count at necropsy was 908.5 ± 487.1 eggs per gram of faeces and varied as a function of infection duration and host resistance. The average sex ratio of H. contortus was 0.51 ± 0.006. CONCLUSION: This work is the first systematic review to summarise the available information on the parasitic phase of H. contortus in sheep. The results of the meta-analysis provide robust estimates of life history traits for parametrization of epidemiological models, their expected variation according to experimental factors, and provides correlations between these.


Assuntos
Hemoncose/veterinária , Haemonchus/fisiologia , Doenças dos Ovinos/parasitologia , Animais , Hemoncose/parasitologia , Reprodução , Ovinos
18.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 29(5): 637-639, 2017 Jul 28.
Artigo em Chinês | MEDLINE | ID: mdl-29469367

RESUMO

OBJECTIVE: To analyze the epidemiological situation of human intestinal nematode infections in Nanjing City from 2006 to 2015, so as to provide the reference for formulating prevention and control measures. METHODS: The surveillance data of human intestinal nematode infections in Nanjing City from 2006 to 2015 were collected and analyzed statistically. RESULTS: From 2006 to 2015, 98 804 person-times of residents were surveyed in Nanjing City, and 465 person-times of residents were detected with intestinal nematode infections. The highest infection rate was in 2006 (1.97%), and the lowest in 2013 and 2015 (both 0.05%). Moreover, the positive rate of human intestinal nematode infections showed a significantly declining trend in total ( χ2 = 552.19, P < 0.001). Meanwhile, the numbers of Ascaris lumbricoides, hookworm and Trichuris trichura cases were 329, 98 and 25 respectively, and the infection rates were 0.33%, 0.10% and 0.03% respectively. Among them, 443 cases had mild infection intensity (98.66%). There were 462 cases of single-infection (99.35%), and 3 of co-infection of two parasites (0.65%). From 2006 to 2015, 92 539 person-times of children under 12 years old were surveyed for Enterobius vermicularis infection and 352 cases were detected with E. vermicularis infection. Moreover, the positive rate showed a significantly decreasing trend in total (χ2 = 147.94, P <0.001). CONCLUSIONS: The control effect of human intestinal nematode infections in Nanjing City is remarkable. However, the surveillance and health education in key groups still should be strengthened, and the prevention and control programs should be adjusted promptly to further consolidating the effectiveness of intestinal nematode disease prevention and control.


Assuntos
Enteropatias Parasitárias/epidemiologia , Infecções por Nematoides/epidemiologia , Ancylostomatoidea , Animais , Ascaris lumbricoides , China/epidemiologia , Cidades , Coinfecção/epidemiologia , Enterobíase/epidemiologia , Educação em Saúde , Humanos , Trichuris
19.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 29(2): 206-208, 2016 Jul 18.
Artigo em Chinês | MEDLINE | ID: mdl-29469327

RESUMO

OBJECTIVE: To investigate the infection situation of intestinal nematodes and knowledge about the prevention and control of intestinal nematodiasis, so as to explore the effective control measures in Jingjiang City. METHODS: The towns where more floating people lived were randomly selected and the infection situation of intestinal nematodes was investigated with KatoKatz method, and the residents'awareness of the prevention and control of nematodiasis was surveyed with questionnaires. RESULTS: From 2013 to 2015, totally 4 555 local residents and 2 278 floating people were investigated in Jingjiang City. The infection rate of intestinal nematodes was 0.29% (13 cases) in the local people, while the rate was 0.75% (17 cases) in the floating people, and the difference was significant (χ2 = 7.380, P < 0.01). The differences of the intestinal nematode infection rates between sexes in both local residents and floating people were not significant (χ2 = 0.010, 0.048, both P > 0.05). The awareness rate of intestinal nematodiasis prevention and control of the local residents was significantly higher than that of the floating people (χ2 = 9.649-164.533, all P < 0.01). CONCLUSIONS: The floating people is the focus of intestinal nematodiasis control, and the health education of ancylostomiasis control should be strengthened in Jingjiang City.

20.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 28(3): 327-330, 2016 May 24.
Artigo em Chinês | MEDLINE | ID: mdl-29469433

RESUMO

OBJECTIVE: To evaluate the effect of the integrated strategy in prevention and control of intestinal nematodiasis in Hongze County, so as to provide the evidence for formulating the control strategies and measures in the future. METHODS: Since 1995, the integrated strategy has been carried out for intestinal nematodiasis, and the measures included deworming, health education, safe water, sanitation and environmental remediation. The effects of the integrated strategy were evaluated by the investigations of the prevalence of soil-transmitted nematodiasis, awareness of health knowledge and behaviors of residents. RESULTS: From 1995 to 2014, 601 900 person-times were administrated with deworming medication and the coverage rate of villages and towns was 100%. The benefit rate of safe water was 100%. The popularity rate of harmless toilets was 92.77%. The prevalence of intestinal nematodiasis decreased from 26.04% in 1995 to 0.56% in 2014, and the difference had statistical significance (χ2 = 693.54, P < 0.01). The awareness rate of health knowledge and correct rate of health behaviors increased from 43.13% and 40.94% in 1995 to 98.00% and 96.80% in 2012, respectively (χ2 = 181.97 and 182.14 respectively, P<0.01). CONCLUSIONS: The prevalence of intestinal nematodiasis has been controlled effectively through the integrated strategy in Hongze County, Jiangsu Province.


Assuntos
Enteropatias/prevenção & controle , Infecções por Nematoides/prevenção & controle , Antinematódeos/farmacologia , China/epidemiologia , Meio Ambiente , Comportamentos Relacionados com a Saúde , Humanos , Enteropatias/epidemiologia , Infecções por Nematoides/epidemiologia , Prevalência , Saneamento
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