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Toxocariasis is caused by infection with the nematode species Toxocara canis and Toxocara cati. Serological methods using eggs, larvae and adult worms of Toxocara spp. as antigen have been used for the diagnosis of human toxocariasis. The current study aimed to evaluate indirect immunofluorescence assay (IFA) using embryonated eggs of Toxocara for diagnosis of human toxocariasis. A total of 58 sera including twenty sera from patients with toxocariasis, 20 from healthy persons and 18 from patients with other parasitic infections were collected and used for the study. The embryonated eggs of Toxocara were prepared as antigen. Indirect immunofluorescence assay was performed using the frozen section of uterus containing embryonated T. canis eggs and unembryonated T. cati eggs. All serum samples had a positive reaction using IFA. The eggs of Toxocara as antigen exposed to the serum samples of toxocariasis, other parasitic infections and healthy persons, followed by IFA gave a bright greenish-yellow fluorescence. A number of samples such as eggs of Toxocara, Toxascaris, Trichuris and strongyloides larvae, and adult worm of Ancylostoma exhibited the bright greenish-yellow autofluorescence under fluorescent microscope. IFA using cryocut of embryonated eggs of Toxocara cannot be used for the diagnosis of human toxocariasis due to the existence of autofluorescence of the unembryonated and embryonated eggs, the second stage larva and adult worms of Toxocara spp.
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Toxocara canis , Toxocaríase , Animais , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Larva , Toxocara , Toxocaríase/parasitologiaRESUMO
Regarding preparing and serving foods, food handlers have an influential role in the spreading of foodborne infections. Due to the great potential to cause foodborne infections, intestinal parasites (IPs) are considered a significant public health problem in today's societies. In Iran, despite several regional reports, national data on IPs prevalence in food handlers are lacking. The aim of the present study, therefore, is to estimate the pooled prevalence of IPs infections and associated pooled odds ratio of educational level among food handlers in Iran. PubMed, Web of Science, Scopus, Embase, and Google Scholar databases (international) and SID and Magiran databases (national) were systematically searched for studies that reporting the prevalence of IPs in food handlers in Iran, published between 2000 and 2020. Pooled prevalence was estimated using a random-effects model with a 95% confidence interval (CI) and depicted as a forest plot, while heterogeneity was evaluated using Cochran's Q-test. The overall pooled prevalence estimate for IPs was 19.3% (95% CI = 14.9-23.7%). Prevalence of the protozoan parasites (20%, 95% CI = 13.7-26.3%) was significantly higher than that of the helminthic parasites (1.6%, 95% CI = 1.1-2.0%). Giardia lamblia (5.2%), Entamoeba coli (5.0%), and Blastocystis spp. (4.4%), as protozoan parasites, and Ascaris lumbricoides (1.4%), Enterobius vermicularis (0.9%), and Hymenolepis nana (0.5%), as helminthic parasites, were the most commonly reported species. Food handlers with low educational levels were 20% more exposed to IPs infection, compared to those with high educational levels (OR = 1.21, 95% CI = 0.88 to 1.65). The prevalence of IPs infections among food handlers in Iran is significant. Besides taking into account this epidemiologic information, a holistic approach, including periodic stool screening, health education, and treatment of infected food handlers, will help in the control of these infections in Iran.
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Enteropatias Parasitárias/parasitologia , Parasitos/isolamento & purificação , Animais , Fezes/parasitologia , Manipulação de Alimentos , Inocuidade dos Alimentos , Serviços de Alimentação , Humanos , Enteropatias Parasitárias/epidemiologia , Irã (Geográfico)/epidemiologia , Parasitos/classificação , Parasitos/genética , PrevalênciaRESUMO
Background: Toxocara canis is one of the most important causes of animal toxocariasis with global distribution. We aimed to find out the seroprevalence of toxocariasis in dogs in a rural area in Fars Province, south of Iran. Methods: Dogs blood samples were collected from 60 dogs in three rural areas in the Sar Mashhad region, Fars Province. Dog sera were evaluated for anti-Toxocara antibodies by an indirect ELISA method. The association between the seropositivity and age, gender, and the sampling location were statistically evaluated. Results: Serological assay detected anti-Toxocara antibodies in sera of 32 out of 60 dogs, corresponding to a seroprevalence of 53.3%. The rate of seropositivity was higher in the male dogs. The rate of seropositivity was higher in old dogs. This rate increased with increasing age, however, the association between age and Toxocara seropositivity was not statistically significant. Conclusion: The high prevalence of Toxocara infection in dogs in the current study area confirms that infected dogs are an important source of Toxocara infection for their owners and people who are in close contact with these animals, especially children.
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BACKGROUND: This study aimed to determine the therapeutic efficacy of curcumin nanoemulsion (CUR-NE) in mice infected with Echinococcus granulosus sensu stricto protoscoleces. METHODS: Forty-two inbred BALB/c mice were divided into seven groups of six animals each. Six groups were inoculated intra-peritoneally with 1500 viable E. granulosus protoscoleces, followed for six months and used as infected groups. The infected groups were named as: CEI1 to CEI6 accordingly. The 7th group was not inoculated and was named cystic echinococcosis noninfected group (CENI7). CEI1 and CEI2 groups received 40 mg/kg/day and 20 mg/kg/day curcumin nanoemulsion (CUR-NE), respectively. CEI3 received nanoemulsion without curcumin (NE-no CUR), CEI4 received curcumin suspension (CUR-S) 40 mg/kg/day, CEI5 received albendazole 150 mg/kg/day and CEI6 received sterile phosphate-buffered saline (PBS). CENI7 group received CUR-NE 40 mg/kg/day. Drugs administration was started after six months post-inoculations of protoscoleces and continued for 60 days in all groups. The secondary CE cyst area was evaluated by computed tomography (CT) scan for each mouse before treatment and on the days 30 and 60 post-treatment. The CT scan measurement results were compared before and after treatment. After the euthanasia of the mice on the 60th day, the cyst area was also measured after autopsy and, the histopathological changes of the secondary cysts for each group were observed. The therapeutic efficacy of CUR-NE in infected groups was evaluated by two methods: CT scan and autopsied cyst measurements. RESULTS: Septal calcification in three groups of infected mice (CEI1, CEI2, and CEI4) was revealed by CT scan. The therapeutic efficacy of CUR-NE 40 mg/kg/day (CEI1 group) was 24.6 ± 26.89% by CT scan measurement and 55.16 ± 32.37% by autopsied cysts measurements. The extensive destructive effects of CUR-NE 40 mg/kg/day (CEI1 group) on the wall layers of secondary CE cysts were confirmed by histopathology. CONCLUSION: The current study demonstrated a significant therapeutic effect of CUR-NE (40 mg/kg/day) on secondary CE cysts in BALB/c mice. An apparent septal calcification of several cysts revealed by CT scan and the destructive effect on CE cysts observed in histopathology are two critical key factors that suggest curcumin nanoemulsion could be a potential treatment for cystic echinococcosis.
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Curcumina , Cistos , Equinococose , Animais , Camundongos , Curcumina/farmacologia , Curcumina/uso terapêutico , Camundongos Endogâmicos BALB C , Equinococose/diagnóstico por imagem , Equinococose/tratamento farmacológico , TomografiaRESUMO
Background: Toxocariasis is a zoonotic disease caused by the larvae of Toxocara canis or Toxocara cati. Patients with schizophrenia may be at higher risk of infection, possibly due to their cognitive and personal self-care impairments. We aimed to assess the association between Toxocara spp. exposure and schizophrenia. Methods: This case-control study was conducted on 109 patients with schizophrenia admitted to Ibn Sina Hospital, Shiraz, Iran, and 104 age- and gender-matched healthy controls from May to September 2021. A questionnaire was obtained and serum samples were tested for IgG antibodies to Toxocara excretory/secretory (TES) antigens using an enzyme-linked immunosorbent assay (ELISA). Results: Anti-Toxocara IgG was detected in 12 schizophrenic patients and 10 control subjects, giving respective seroprevalences of 11.0% (95% confidence interval [95% CI]=5.8-18.4%) and 9.6% (95% CI=4.7-17.0%). Univariate logistic analyses estimated an odds ratio (OR) of 1.16 (95% CI=0.44-3.16); however, it was not statistically significant (P=0.915). Individuals with a history of eating unwashed vegetables or fruits (23.1%, 95% CI=9.0-43.6, crude odds ratio [COR]=3.21, 95% CI=1.13-9.13) and rural residency (19.5%, 95% CI=8.8-34.9, COR=2.74, 95% CI=1.06-7.05) had significantly higher rates of seropositivity using the univariate logistic analyses. After multivariate logistic analyses, the differences were not statistically significant. Conclusion: The toxocariasis seroprevalence among schizophrenic and healthy participants was not significantly different (11% vs. 9.6%). Since the disease severity, onset, and cognitive sequelae are not the same among schizophrenic patients, clinically matched studies with larger samples are required to address the current inconsistency between the studies.
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Cystic echinococcosis (CE), is one of the common parasitic infections of domestic animals and humans caused by the larval stages of the tapeworm Echinococcus granulosus. This research aimed to identify of CE cysts in cattle isolates from Shiraz slaughterhouse using molecular technique. Thirty CE cysts isolates were collected and total DNA was extracted from protoscolices or the germinal layer of each cyst followed by polymerase chain reaction (PCR) using cytochrome c oxidase I (cox1) and NADH dehydrogenase subunit 1 (NADH-1) mitochondrial genes (~ 450 bp) and sequencing. The sequence results were compared with available reference sequences in GenBank by BLAST system. Phylogenetic analysis was performed using MEGA 5.0 software and the maximum likelihood method. The results showed that all 30 samples examined in this study were identified as E. granulosus sensu stricto (G1-G3 genotypes) with G1 dominant.
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BACKGROUND: The sensitivity of parasitological and molecular methods is unsatisfactory for the diagnosis of strongyloidiasis, and serological techniques are remaining as the most effective diagnostic approach. The present study aimed to design and produce a chimeric recombinant antigen from Strongyloides stercoralis immunoreactive antigen (SsIR) and Ss1a antigens, using immune-informatics approaches, and evaluated its diagnostic performance in an ELISA system for the diagnosis of human strongyloidiasis. METHODOLOGY/PRINCIPAL FINDINGS: The coding sequences for SsIR and Ss1a were selected from GenBank and were gene-optimized. Using bioinformatics analysis, the regions with the highest antigenicity that did not overlap with other parasite antigens were selected. The chimeric recombinant antigen SsIR- Ss1a, was constructed. The solubility and physicochemical properties of the designed construct were analyzed and its tertiary structures were built and evaluated. The construct was expressed into the pET-23a (+) expression vector and the optimized DNA sequences of SsIR-Ss1a (873 bp) were cloned into competent E. coli DH5α cells. Diagnostic performances of the produced recombinant antigen, along with a commercial kit were evaluated in an indirect ELISA system, using a panel of sera from strongyloidiasis patients and controls. The physicochemical and bioinformatics evaluations revealed that the designed chimeric construct is soluble, has a molecular with of 35 KDa, and is antigenic. Western blotting confirmed the immunoreactivity of the produced chimeric recombinant antigen with the sera of strongyloidiasis patients. The sensitivity and specificity of the indirect ELISA system, using the produced SsIR-Ss1a chimeric antigen, were found to be 93.94% (95% CI, 0.803 to 0.989) and 97.22% (95% CI, 0.921 to 0.992) respectively. CONCLUSIONS/SIGNIFICANCE: The preliminary findings of this study suggest that the produced SsIR-Ss1a chimeric antigen shows promise in the diagnosis of human strongyloidiasis. However, these results are based on a limited panel of samples, and further research with a larger sample size is necessary to confirm its accuracy. The construct has potential as an antigen in the ELISA system for the serological diagnosis of this neglected parasitic infection, but additional validation is required.
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Antígenos de Helmintos , Ensaio de Imunoadsorção Enzimática , Sensibilidade e Especificidade , Testes Sorológicos , Strongyloides stercoralis , Estrongiloidíase , Humanos , Estrongiloidíase/diagnóstico , Estrongiloidíase/imunologia , Animais , Testes Sorológicos/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Strongyloides stercoralis/imunologia , Strongyloides stercoralis/genética , Antígenos de Helmintos/genética , Antígenos de Helmintos/imunologia , Anticorpos Anti-Helmínticos/sangue , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Expressão GênicaRESUMO
Background: Toxocariasis is an important zoonotic infection, especially in tropical areas. One of the significant challenges in the serodiagnosis of human toxocariasis is the cross-reaction of Toxocara antigens with other parasites due to their relatively similar glycan structures. Removing the glycan structure from Toxocara excretory-secretory (TES) antigens may increase the efficacy of these antigens in the diagnosis of toxocariasis. The current study aimed to assess the efficacy of deglycosylated Toxocara cati excretory-secretory (dTES) antigens for the serodiagnosis of human toxocariasis. Methods: Toxocara ES antigens were prepared from T. cati second-stage larvae and deglycosylated using sodium hydroxide (NaOH). The TES antigens, along with the dTES antigens, were used in an ELISA as well as a western blotting system for the detection of anti-Toxocara antibodies. Sera samples collected from 30 confirmed cases of toxocariasis, 30 patients with other diseases, and 30 healthy subjects were evaluated by both systems. Results: The sensitivity of TES and dTES ELISA for the diagnosis of human toxocariasis was 96.67% (95% CI = 82.78-99.92) and 93.33% (95% CI = 77.93-99.18), respectively, while the specificity of dTES (88.33%; 95% CI = 77.43-95.18) increased significantly compared to the TES (80.00%; 95% CI = 67.67-89.22). The sensitivity of both antigens was 100% (95% CI = 88.43-100) by the western blotting system. Moreover, the specificity of TES and dTES antigens was 95% (95% CI = 86.08-98.96) and 98.33% (95% CI = 91.06-99.96), respectively, when using the western blotting system. Conclusion: Results of the current study indicate that the chemical removal of the glycan epitopes of T. cati ES antigens significantly reduces cross-reactivity rates with other parasitic infections. Considering the findings of the present study, the dTES antigens seem to be suitable antigens for the serodiagnosis of human toxocariasis.
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Toxocariasis as a common neglected disease is the culprit of infecting all age groups. The current cross-sectional study was designed to assess the seroprevalence of toxocariasis and risk factors associated with seropositivity of Toxocara infection among the general population of adults in the Kavar district, south of Iran. A total of 1060 participants with an age range of 35 to 70 years from the Kavar region entered the study. Manual ELISA was utilized to detect anti-Toxocara-specific antibodies in their serum samples. In addition, demographic information as well as risk factors related to toxocariasis was collected from individuals who participated in the survey. The mean age of the participants was 48.9 (±7.9) years old. Out of 1060 subjects, 532 (50.2%) were men, and 528 (49.8%) were women. The overall Toxocara seroprevalence was 5.8% (61/1060). The prevalence of Toxocara seropositive cases was significantly different between males and females (p = 0.023). The seropositive rate for Toxocara infection was also significantly higher in housewives (p = 0.003) and subjects with learning disabilities (p = 0.008). Multivariable logistic regression revealed that housewives (OR = 2.04, 95% CI: 1.18-3.51, p = 0.010) and subjects with learning disability (OR = 3.32, 95% CI: 1.29-8.52, p = 0.013) were at increased risk of Toxocara infection. The findings of the current study depicted a noticeable seroprevalence of Toxocara infection in the general population in the Kavar district, southern Iran. An increased risk of toxocariasis has been associated with learning disabilities and being a housewife. All of the toxocariasis-positive cases had contact with animals, at some point in their life. In perspective, it is necessary to raise awareness of this infection among the population while surveilling Toxocara infection in high-risk groups.
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Although the appendix is the most commonly resected and examined intra-abdominal organ, the pathogenesis and etiology of acute nonspecific appendicitis remain enigmatic. This retrospective study aimed to assess the prevalence of parasitic infection in surgically removed appendices and to evaluate the probable associations between the presence of parasites and the occurrence of appendicitis through parasitological and histopathological examinations of the appendectomy specimens. Materials and methods: This retrospective study was carried out from April 2016 to March 2021 among all patients referred to hospitals affiliated with Shiraz University of Medical Sciences, Fars Province, Iran, for appendectomy. Patient information, including age, sex, year of appendectomy, and type of appendicitis, was collected from the available data in the hospital information system database. In positive cases, all pathology reports were retrospectively evaluated for the presence of the parasite and its type, and analytical and descriptive statistics were carried out using SPSS software version 22. Results: A total of 7628 appendectomy materials were evaluated in the present study. Of the total participants, 4528 (59.4%, 95% CI: 58.2-60.5) were males, and 3100 (40.6%, 95% CI: 39.5-41.8) were females. The mean age of participants was 23.87±14.28 years. Overall, Enterobius vermicularis was observed in 20 appendectomy specimens. Fourteen of these patients (70%) were less than 20 years old. Conclusion: This study indicated that E. vermicularis is one of the common infectious agents that could be found in the appendix and may increase the risk of appendicitis. Therefore, in terms of appendicitis, clinicians, and pathologists must be aware of the possible presence of parasitic agents, especially E. vermicularis, to treat and manage the patients sufficiently.
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Intestinal parasitic infections (IPIs) are still a serious public health problem worldwide, particularly in developing countries. The COVID-19 pandemic has affected people's lifestyles and quality of life. Besides, the prevalence of IPIs is directly associated with environmental sanitation, overcrowding, and personal hygiene. Therefore, the current study aimed to determine the prevalence of IPIs among patients referred to hospitals affiliated to Shiraz University of Medical Sciences by reviewing the available data of hospital information system database in the pre- and post-COVID-19 pandemic. The total data of 13,686 patients referred to hospitals affiliated to Shiraz University of Medical Sciences, southern Iran were collected from March 2019 to March 2021. The overall prevalence of IPIs was found to be 4.4%, and Blastocystis spp. was the most common parasite. The prevalence of protozoan parasites (4.4%) was significantly higher than helminthic parasites (0.04%, P < 0.001). A significant association was observed between IPIs with age, gender, and year (P < 0.05). The prevalence of IPIs among those referred to hospitals before the COVID-19 pandemic was higher than those referred to hospitals during the COVID-19 pandemic (5.8% vs 2.8%), and the differences were statistically significant (P < 0.001). The odds of infection among people investigated during the COVID-19 pandemic was about 40% lower than those investigated before the COVID-19 pandemic (AOR: 0.60, 95% CI: 0.49-0.73, P < 0.001). Our results showed that the prevalence of IPIs has decreased during the COVID-19 pandemic. Improved sanitation, personal hygiene, and health education can be effective in reducing parasitic infections in the COVID-19 pandemic.
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Enteropatias Parasitárias , Animais , COVID-19/epidemiologia , Estudos Transversais , Fezes/parasitologia , Hospitais , Humanos , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Irã (Geográfico)/epidemiologia , Pandemias , Prevalência , Qualidade de Vida , Estudos Retrospectivos , Fatores de RiscoRESUMO
Cutaneous leishmaniasis (CL) is one of the most important parasitic diseases in the world. Despite the existence of many therapeutic strategies, the treatment of this infection still faces problems. Sodium chlorite as an antimicrobial agent has been shown to have acceptable tissue regenerative and wound healing properties. Therefore, the present study aimed to analyze the in vitro effects of different concentrations of sodium chlorite on Leishmania major promastigotes and macrophage cells. The inhibitory and toxicity effect of various concentrations (0.0035, - 1.8 mg/ml) of sodium chlorite on the standard Iranian strain of L. major promastigotes were evaluated via counting the cells and flow cytometry. Furthermore, cytotoxicity on promastigotes and J774 macrophage cell line were performed by MTT assay. The results of the inhibitory test demonstrated that sodium chlorite had dose-dependent, anti-leishmanial activities. The half-maximal inhibitory concentration (IC50) for promastigotes and J774 cells by cytotoxicity test was detected at 0.17 mg/ml and 0.08 mg/ml after 48 h respectively. Flow cytometry results showed that 27.34% death of promastigotes was observed in 0.0035 mg/ml of sodium chlorite and 78.12% in 1.8 mg/ml. The results of the present study showed that sodium chlorite could be used as an effective treatment for CL, especially in cases resistant to treatment with pentavalent compounds. However, the toxicity of this substance in high concentrations should be considered in clinical setting.
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Background: Parkinson's disease (PD) has been described in dopamine brain level reductions. Conversely, several studies have shown that Toxoplasma parasite can increase the level of dopamine in an infected host. This study was conducted to assess the serum, cerebral dopamine levels, and downregulation of Parkinson's disease manifestations in mice with chronic toxoplasmosis. Methods: PD induction was done by oral inoculation of rotenone into BALB/c mice. To induce the chronic infection, cysts of T. gondii Prugniaud strain (genotype II) were injected intraperitoneally into the mice. The rotarod test was used for the evaluation of functional motor disorders in experimental mice. The serum and cerebral dopamine levels of the mice were also measured by using high-performance liquid chromatography (HPLC) on consecutive periods (10 days). Results: Findings of the rotarod test showed the highest and lowest average of running duration belonged to the uninfected mice and PD mice, respectively. Remarkably, the running duration of infected mice with PD was higher than PD mice. As well, the level of serum and cerebral dopamine increased in mice with PD and toxoplasmosis in comparison with PD mice. Conclusion: Increasing the serum and cerebral dopamine levels in mice infected with toxoplasmosis is related to the presence of the parasite. Moreover, the dopamine upregulation due to the infection is effective in the reduction of PD complications.
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BACKGROUND: Baylisascaris devosi is an intestinal nematode found in several carnivores including fisher, wolverine, Beech marten, American marten and sable in different parts of the world, but this nematode has not been reported from Pine marten. Therefore, this study aimed to identify Baylisascaris isolated from a Pine marten in Iran using morphological and molecular approaches. METHODS: Specimens of B. devosi were collected from one road-killed Pine marten in northern Iran. Morphological features were evaluated using scanning electron microscopy, energy dispersive x-ray analysis and ion sectioning. The molecular characterization was carried out using partial Cox1, LSU rDNA and ITS-rDNA genes. RESULTS: The nematodes isolated from the Pine marten were confirmed to be B. devosi based on the morphological features and the sequence of ribosomal and mitochondrial loci. X-ray scans (EDAX) were completed on gallium cut structures (papillae, eggs, male spike and mouth denticles) of B. devosi using a dual-beam scanning electron microscope. The male spike and mouth denticles had a high level of hardening elements (Ca, P, S), helping to explain the chemical nature and morphology of the worm. Based on these genetic marker analyses, our sequence had the greatest similarity with Russian B. devosi isolated from sable. CONCLUSIONS: In this study, to our knowledge, the occurrence of B. devosi infection in Pine marten is reported for the first time. Molecular analysis showed that these three genes are suitable molecular markers for identification and inferring phylogenetic relationships of Baylisascaris species. Furthermore, the high divergence of Cox1 between Baylisascaris species indicates that Cox1 could be used for their phylogenetic and taxonomic studies.
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Ascaridoidea/anatomia & histologia , Ascaridoidea/classificação , Ascaridoidea/genética , Mustelidae/parasitologia , Filogenia , Animais , Ascaridoidea/isolamento & purificação , Sequência de Bases , DNA Ribossômico , Feminino , Irã (Geográfico) , Masculino , Federação Russa , Análise de Sequência de DNARESUMO
BACKGROUND: Human toxocariasis is caused by Toxocara canis and T. cati, the nematodes in the intestine of dogs and cats, respectively. Since the association between asthma and toxocariasis is controversial, the aim of the present study was to investigate the seroprevalence of Toxocara infection among asthmatic children in comparison with healthy children. METHODS: This case-control study was conducted on 92 asthmatic and 91 healthy children aged 1-16 years old in Shiraz City, Southern Iran in 2019-2020. The serum samples were tested for IgG anti-Toxocara antibodies by ELISA method using the T. canis larval excretory-secretory (E/S) antigens. The collected data were analyzed using SPSS software. RESULTS: The seroprevalence of toxocariasis in asthmatic patients was higher than the healthy children with no significant difference in Toxocara seropositivity between two groups (9.8% vs 8.8%, P = 0.817). The association between Toxocara infection and variables such as gender and age were not statistically significant. CONCLUSION: There was no significant association between toxocariasis and childhood asthma. Further study on different regions such as urban and rural areas with a large sample size and using questionnaire for considering risk factors of asthma and toxocariasis is recommended.
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BACKGROUND AND AIM: Parasitology course is one of the basic science courses in the educational curriculum for medical students. Since the integration of basic and clinical sciences has helped students better understand the basic science course content, the aim of the present study was to determine the effect of integration of basic and clinical aspects of a specific topic in a parasitology course on medical students learning. MATERIALS AND METHODS: A randomized controlled trial was conducted on 110 undergraduate fifth-semester medical students from April to July 2018. The students were randomly divided into two groups, based on student identification number: Intervention and control groups. The topic selected for this study from the parasitology course was "cutaneous leishmaniasis." At the beginning of the program, a dermatologist presented the clinical aspects of the topic to the intervention group. Then, a parasitologist delivered a traditional lecture about the basic aspects of the topic to both groups. The students' scores on questions related to cutaneous leishmaniasis in the final exam were used as a measure of learning and teaching outcomes. A questionnaire that consisted of seven items and three open-ended questions was used based on the objectives of the randomized controlled trial. Statistical analysis was performed by SPSS software. RESULTS: Based on the result of the final examination, there was no significant difference in the learning rate of students between the intervention and control groups (P ≥ 0.05). According to students' comments, the teaching of clinical science alongside basic science increased the importance of the topic and the students' interest in basic science. Most students agreed that this method prepares them for their clinical years. CONCLUSION: Many medical students believe that the content of many basic science courses are forgotten in the future. Therefore, basic science education alongside clinical science presentations are suggested.
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Mentally retarded individuals are more likely to become infected with soil-transmitted infections including toxocariasis. The current study aimed to determine the serostatus of toxocariasis among institutionalized mentally retarded individuals in Hormozgan Province, in the south of Iran. Subjects of the study were 117 mentally disabled individuals, including children and adults, maintained in a charity-based institution. Three millilitres of venous blood was taken from each subject. While sampling, demographic features of the subject were documented in a questionnaire. An ELISA system based on Toxocara larvae excretory-secretory antigens (TES) was utilized to detect anti-Toxocara IgG antibodies in the sera of the patients. The mean age of the subject was 27.6 (±12.31) years and consisted of 55 (47%) males and 62 (53%) females. Out of 117 cases, 33 (28.2%) were seropositive for toxocariasis. The seroprevalence was higher in females (37.1%) than males (18.2%), and the difference was statistically significant (p < 0.05). Out of 117 subjects, 76 (64.9%) had severe and 41 (35.1%) had profound mental retardation. Anti-Toxocara antibodies were detected in 18 (23.7%) patients with severe and 15 (35.6%) patients with profound mental retardation. The highest seroprevalence rate of toxocariasis (44.4%) was observed in the age group of ≤10 years followed by 21-30 years old (36.7%). No statistically significant association was seen between the age and also the duration of residency in the care center and seropositivity of toxocariasis (p > 0.05). The current study represents the high prevalence of toxocariasis in mentally retarded patients in Hormozgan Province, southern Iran. The elevated seroprevalence rate of toxocariasis in the current study indicates that these subjects constitute a high-risk group for Toxocara infection, which may be attributed to their behavioral patterns.
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BACKGROUND: Toxoplasma parasite alters the transduction of neurotransmitter signals and leads to changes in the level of brain neurotransmitters including tyrosine and dopamine, so behavior changes can occur in infected hosts. Based on this concept, this study was conducted for evaluation of the tyrosine and dopamine serum levels in infected mice with chronic toxoplasmosis. MATERIALS AND METHODS: Toxoplasma gondii (Prugniaud strain II) was injected intraperitoneally into BALB/c mice to induce chronic toxoplasmosis. Modified agglutination test (MAT), polymerase chain reaction (PCR), and microscopic methods were conducted to confirm the induction of chronic toxoplasmosis. The infected mouse sera were separated at days 40, 50, 60, 70, and 80 for evaluation of tyrosine and dopamine serum levels using high-performance liquid chromatography (HPLC). RESULTS: Microscopic methods confirmed the formation of the Toxoplasma cysts in mouse tissues. Inducing chronic toxoplasmosis is also confirmed by MAT, PCR, and histological methods. HPLC results indicated a decrease in serum tyrosine level at day 40 in infected mice in comparison to control, and the levels were too low to be measured at other times. However, a significantly high serum dopamine level was observed that gradually increased after parasite inoculation. CONCLUSIONS: No detection of tyrosine level in most of the sample groups is probably related to the very low concentration of tyrosine in sera. However, low concentration of tyrosine at day 40 and increase of dopamine in most of the sample groups suggest the production of dopamine from tyrosine due to the presence of Toxoplasma in infected mice.
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The most important pathogenesis factor in the Apicomplexa parasites is invasion to the host cell. Given the inhibitory role of Butanedione Monoxime (BDM) on myosin-actin interaction, this study aimed to investigate the effects of this molecule on the vitality and infectivity of Toxoplasma tachyzoites in order to provide a new option for vaccine development. The tachyzoites of the RH strain of Toxoplasma gondii were exposed to different concentrations (1, 2, 4, 8, 16, 32, 64, and 128 µg/mL) of BDM, and mortality effect was assessed by flow cytometry. Then, the penetration ability of the tachyzoites was investigated in HeLa and macrophage cell lines. The infectivity of exposed tachyzoites to BDM were also investigated in mice through following up and detecting the etiological factor. The highest percentage of mortality (72.69%) was seen in the tachyzoites exposed to 128 µg/mL of the compound. The tachyzoites exposed to 32, 64, and 128 µg/mL of BDM began the proliferation in HeLa cells after 48 h, while this proliferation was initiated within 24 h in macrophage cells. All the mice inoculated with the BDM-treated tachyzoites died after 13 days. The mean survival time of the mice receiving tachyzoites exposed to 128 µg/mL of BDM was 12.4 days, which was significantly different from the negative control group (p = 0.001). BDM, as the inhibitor of myosin-actin interaction, and other substances that block the entry of parasites into cells may be suitable candidates for vaccine production against Toxoplasma. Yet, future studies are required to be conducted on the issue.
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BACKGROUND: Human toxocariasis is caused by the larval stage of Toxocara canis and Toxocara cati. This cross-sectional study was conducted to evaluate the seroprevalence and the risk factors associated with Toxocara infection in nomads of Boyer-Ahmad County in the southwest of Iran. METHODS: A total of 968 blood samples were collected from nomads. A structured questionnaire, containing sociodemographic data, was completed for each participant. Sera were evaluated for anti-Toxocara antibodies, using the T. canis excretory-secretory antigens prepared from the second stage larvae, in an ELISA system. RESULTS: Among the 968 participants, 220 (22.7%) were males and 748 (77.3%) were females; the mean age was 40.71 y. Anti-Toxocara IgG antibodies were detected in 14 (1.4%) of the 968 nomads. The association between Toxocara infection and gender, age, contact with dogs, residential area and level of education were not statistically significant (p>0.05). CONCLUSIONS: The findings of the study revealed a low prevalence rate of toxocariasis in nomadic communities in southwest Iran. Geographic location and climatic conditions as well as the lifestyle and sociodemographic features of the participants may contribute to the low prevalence rate of Toxocara infection.