Molecular Biology Can Change the Classic Laboratory Approach for Intestinal Protozoan Infections.
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ABSTRACT:
SUBMITTER: Formenti F
PROVIDER: S-EPMC5681914 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The small intestinal epithelium is the primary route of infection for many protozoan parasites. Understanding the mechanisms of infection, however, has been hindered due to the lack of appropriate models that recapitulate the complexity of the intestinal epithelium. Here, we describe an in vitro platform using stem cell-derived intestinal organoids established for four species that are important hosts of Apicomplexa and other protozoa in a zoonotic context: human, mouse, pig and chicken. The focus was set to create organoid-derived monolayers (ODMs) using the transwell system amenable for infection studies, and we provide straightforward guidelines for their generation and differentiation from organ-derived intestinal crypts. To this end, we reduced medium variations to an absolute minimum, allowing generation and differentiation of three-dimensional organoids for all four species and the subsequent generation of ODMs. Quantitative RT-PCR, immunolabeling with antibodies against marker proteins as well as transepithelial-electrical resistance (TEER) measurements were used to characterize ODM's integrity and functional state. These experiments show an overall uniform generation of monolayers suitable for Toxoplasma gondii infection, although robustness in terms of generation of stable TEER levels and cell differentiation status varies from species to species. Murine duodenal ODMs were then infected with T. gondii and/or Giardia duodenalis, two parasites that temporarily co-inhabit the intestinal niche but have not been studied previously in cellular co-infection models. T. gondii alone did not alter TEER values, integrity and transcriptional abundance of tight junction components. In contrast, in G. duodenalis-infected ODMs all these parameters were altered and T. gondii had no apparent influence on the G. duodenalis-triggered phenotype. In conclusion, we provide robust protocols for the generation, differentiation and characterization of intestinal organoids and ODMs from four species. We show their applications for comparative studies on parasite-host interactions during the early phase of a T. gondii infection but also its use for co-infections with other relevant intestinal protozoans.
| S-EPMC7937733 | biostudies-literature
Project description:BACKGROUND:Intestinal parasitic infections are common in rural areas with poor infrastructure and low socioeconomic status. The aim of this study was to estimate the prevalence of selected parasitic infections in marginalized rural areas in the northern part of the Palestinian West Bank Region, using conventional and PCR-based methods, and also to assess risk predictors of infection. METHODS:A cross-sectional study was conducted on 104 individuals from three rural villages in the Jordan Valley. Stool samples were collected and examined by a battery of tests that included microscopy of wet fecal samples in normal saline with iodine, concentration by ethyl acetate sedimentation and also by zinc sulfate floatation, a conventional PCR and a real-time PCR (qPCR). Risk factors were assessed that included demographic, socioeconomic, and behavioral characteristics. Data on method performance was analyzed by kappa-statistic, Cochrane's Q, and McNemar post hoc test. Mid-P exact test and odds ratio were used to discern association between outcome and risk predictors. RESULTS:The overall prevalence of intestinal parasitic infections was 48% (49/102). The predominant parasites were Giardia lamblia at 37% (37/102) and Hymenolepis nana at 9% (9/102). To concentrate cysts and eggs, sedimentation can be used as an alternative to floatation with a loss of 1% of positive cases. The methods employing PCRs proved crucial as it increased the detected infection rate of G. lamblia approximately three-fold from 13% by the conventional methods to 37% by the qPCR. Multiple infections were present in 13% (13/102) of the study group, which included double (10%) and triple (3%) infections. Regarding the genus Entamoeba, E. dispar and E. coli were detected at rates of 2 and 8%, respectively. While none of the individuals were infected with the pathogenic E. histolytica, E. nana (4%) was detected for the first time in the area. Age was a risk predictor for infection (OR?=?2.61, CI 95% 1.05-6.45, P =?0.038). CONCLUSIONS:The increased prevalence of intestinal parasitic infections in children in marginalized rural areas in Palestine is worrying. The addition of PCR-based methods is important for the diagnosis of such infections as, with cautious interpretation, it increases proficiency and overcomes underestimation and misdiagnosis of cases. Control measures including education on personal hygiene and environmental sanitation, should be introduced to reduce the prevalence of the intestinal parasites and, thus, the infections they cause in this and other areas.
| S-EPMC6907214 | biostudies-literature
Project description:Intestinal parasitic infections, caused by helminths and protozoa, are globally distributed and major causes of worldwide morbidity. The gut microbiota may modulate parasite virulence and host response upon infection. The complex interplay between parasites and the gut microbiota is poorly understood, partly due to sampling difficulties in remote areas with high parasite burden. In a large study of children in Guinea-Bissau, we found high prevalence of intestinal parasites. By sequencing of the 16S rRNA genes of fecal samples stored on filter paper from a total of 1,204 children, we demonstrate that the bacterial microbiota is not significantly altered by helminth infections, whereas it is shaped by the presence of both pathogenic and nonpathogenic protozoa, including Entamoeba (E.) spp. and Giardia (G.) lamblia. Within-sample diversity remains largely unaffected, whereas overall community composition is significantly affected by infection with both nonpathogenic E. coli (R2 = 0.0131, P = 0.0001) and Endolimax nana (R2 = 0.00902, P = 0.0001), and by pathogenic E. histolytica (R2 = 0.0164, P = 0.0001) and G. lamblia (R2 = 0.00676, P = 0.0001). Infections with multiple parasite species induces more pronounced shifts in microbiota community than mild ones. A total of 31 bacterial genera across all four major bacterial phyla were differentially abundant in protozoan infection as compared to noninfected individuals, including increased abundance of Prevotella, Campylobacter and two Clostridium clades, and decreased abundance of Collinsella, Lactobacillus, Ruminococcus, Veillonella and one Clostridium clade. In the present study, we demonstrate that the fecal bacterial microbiota is shaped by intestinal parasitic infection, with most pronounced associations for protozoan species. Our results provide insights into the interplay between the microbiota and intestinal parasites, which are valuable to understand infection biology and design further studies aimed at optimizing treatment strategies.
| S-EPMC7959362 | biostudies-literature
Project description:Widely used in research laboratories, immunohistochemistry (IHC) is a transferable skill that prepares undergraduate students for a variety of careers in the biomedical field. We have developed an inquiry-based learning IHC laboratory exercise, which introduces students to the theory, procedure, and data interpretation of antibody staining. Students are tasked with performing IHC using an "unknown" antibody and then asked to identify the cells or molecular structures within the nervous systems specific for that unknown antibody. In two lab sessions, students are exposed to handling of delicate brain slices, fluorescent microscopy, and data analysis using the Allen Brain Atlas (ABA), an online freely accessible database of mRNA transcript expression patterns in the brain. Here, we present guidelines for easy implementation in the classroom and assess learning gains achieved by the students upon completion of the IHC laboratory module. Students clearly displayed an increase in knowledge in data interpretation, procedural knowledge, and theory surrounding IHC. Thus, this module works as an inquiry-based learning based method to introduce IHC principles to undergraduate students.
| S-EPMC9304200 | biostudies-literature
Project description:Organisation EGAO00000001143
| EGAO00000001143 | EGA
Project description:In introductory laboratory courses, many universities are turning from traditional laboratories with predictable outcomes to inquiry-inspired, project-based laboratory curricula. In these labs, students are allowed to design at least some portion of their own experiment and interpret new, undiscovered data. We have redesigned the introductory biology laboratory course at Brandeis University into a semester-long project-based laboratory that emphasizes concepts and contains an element of scientific inquiry. In this laboratory, students perform a site-directed mutagenesis experiment on the gene encoding human γD crystallin, a human eye lens protein implicated in cataracts, and assess the stability of their newly created protein with respect to wild-type crystallin. This laboratory utilizes basic techniques in molecular biology to emphasize the importance of connections between DNA and protein. This project lab has helped engage students in their own learning, has improved students' skills in critical thinking and analysis, and has promoted interest in basic research in biology.
| S-EPMC3046884 | biostudies-literature
Project description:BACKGROUND:Intestinal parasites such as Cryptosporidium spp., Giardia lamblia and Entamoeba histolytica can cause severe diarrhea, especially among children in developing countries. This study aims to determine the frequency of Cryptosporidium spp., Giardia lamblia and Entamoeba histolytica in children with diarrhea and identify risk factors for infection. METHODOLOGY:We conducted a cross-sectional study in children aged 0-168 months hospitalized with diarrhea in three regions of Mozambique, from June 2014 to January 2018. Following consent, caretakers were interviewed and a single stool specimen was collected from each child to diagnose Cryptosporidium spp., G. lamblia and E. histolytica using commercial immune-enzymatic assay (TechLab, Inc, Blacksburg, VA, USA). Anthropometric data were collected from the clinical reports. Multivariable logistic regression models were built to identify risk factors for Cryptosporidium spp. and G. lamblia infection. RESULTS:Twenty-one percent of all specimens (212/1008) presented at least one parasitic infection. Cryptosporidium spp. infection was the most common 12.0% (118/985), followed by G. lamblia 9.7% (95/983) and E. histolytica 2.0% (20/1004). Risk factors for infection by Cryptosporidium spp. were: provenience (children from Nampula province showed the highest risk, OR: 8.176; CI: 1.916-34.894; p-value < 0.01); animal contact (children with animal contact had a protective effect OR: 0.627; CI: 0.398-0.986; p-value < 0.05); underweight (children severely underweight showed a risk of 2.309; CI: 1.310-4.069; p-value < 0.05). Risk factors for infection by G. lamblia were: age (group with highest risk, 60-168 months (OR: 2.322; CI: 1.000-5.393, p-value > 0.05)); and living in a household with five or more members (OR: 2.141; CI: 1.286-3.565, p-value < 0.01). CONCLUSIONS:Parasitic infection is common among children with diarrhea. Routine testing, standard treatment, and assessment for risk exposure of children with diarrhea should be implemented at health facilities in Mozambique.
| S-EPMC7176080 | biostudies-literature
Project description:In order to solve increasingly challenging protein structures with crystallography, crystallization reagents and screen formulations are regularly investigated. Here, we briefly describe 96-condition screens developed at the MRC Laboratory of Molecular Biology: the LMB sparse matrix screen, Pi incomplete factorial screens, the MORPHEUS grid screens and the ANGSTROM optimization screen. In this short review, we also discuss the difficulties and advantages associated with the development of protein crystallization screens.
| S-EPMC4911435 | biostudies-literature
Project description:The accelerating expansion of online bioinformatics tools has profoundly impacted molecular biology, with such tools becoming integral to the modern life sciences. As a result, molecular biology laboratory education must train students to leverage bioinformatics in meaningful ways to be prepared for a spectrum of careers. Institutions of higher learning can benefit from a flexible and dynamic instructional paradigm that blends up-to-date bioinformatics training with best practices in molecular biology laboratory pedagogy. At North Carolina State University, the campus-wide interdisciplinary Biotechnology (BIT) Program has developed cutting-edge, flexible, inquiry-based Molecular Biology Laboratory Education Modules (MBLEMs). MBLEMs incorporate relevant online bioinformatics tools using evidenced-based pedagogical practices and in alignment with national learning frameworks. Students in MBLEMs engage in the most recent experimental developments in modern biology (e.g., CRISPR, metagenomics) through the strategic use of bioinformatics, in combination with wet-lab experiments, to address research questions. MBLEMs are flexible educational units that provide a menu of inquiry-based laboratory exercises that can be used as complete courses or as parts of existing courses. As such, MBLEMs are designed to serve as resources for institutions ranging from community colleges to research-intensive universities, involving a diverse range of learners. Herein, we describe this new paradigm for biology laboratory education that embraces bioinformatics as a critical component of inquiry-based learning for undergraduate and graduate students representing the life sciences, the physical sciences, and engineering.
| S-EPMC8758113 | biostudies-literature
Project description:BackgroundHelminthiases are very prevalent worldwide, yet their treatment and control rely on a handful of drugs. Emodepside, a marketed broad-spectrum veterinary anthelminthic with a unique mechanism of action, undergoing development for onchocerciasis is an interesting anthelmintic drug candidate. We tested the in vitro and in vivo activity of emodepside on nematode species that serve as models for human soil-transmitted helminth infection as well as on schistosomes.MethodsIn vitro viability assays were performed over a time course of 72 hours for Trichuris muris, Necator americanus, Ancylostoma ceylanicum, Heligmosomoides polygyrus, Strongyloides ratti, Schistosoma mansoni and Schistosoma haematobium. The drug effect was determined by the survival rate for the larvae and by phenotypical scores for the adult worms. Additionally, mice infected with T. muris and hamsters harboring hookworm infection (N. americanus or A. ceylanicum) were administered orally with emodepside at doses ranging from 1.25 to 75 mg/kg. Expelled worms in the feces were counted until 3 days post-drug intake and worms residing in the intestines were collected and counted after dissection.ResultsAfter 24 hours, emodepside was very active in vitro against both larval and adult stages of the nematodes T. muris, A. ceylanicum, N. americanus, H. polygyrus and S. ratti (IC50 < 4 µM). The good in vitro activity was confirmed in vivo. Hamsters infected with the hookworms were cured when administered orally with 2.5 mg/kg of the drug. Emodepside was also highly active in vivo against T. muris (ED50 = 1.2 mg/kg). Emodepside was moderately active on schistosomula in vitro (IC50 < 8 µM) 24 h post-drug incubation and its activity on adult S. mansoni and S. haematobium was low (IC50: 30-50 µM).ConclusionsEmodepside is highly active against a broad range of nematode species both in vitro and in vivo. The development of emodepside for treating soil-transmitted helminth infections should be pursued.
| S-EPMC6515646 | biostudies-literature