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Frontiers in Cellular and Infection... 2017Rodents, in particular , have a long and invaluable history as models for human diseases in biomedical research, although their translational value has been challenged... (Review)
Review
Rodents, in particular , have a long and invaluable history as models for human diseases in biomedical research, although their translational value has been challenged in a number of cases. We provide some examples in which rodents have been suboptimal as models for human biology and discuss confounders which influence experiments and may explain some of the misleading results. Infections of rodents with protozoan parasites are no exception in requiring close consideration upon model choice. We focus on the significant differences between inbred, outbred and wild animals, and the importance of factors such as microbiota, which are gaining attention as crucial variables in infection experiments. Frequently, mouse or rat models are chosen for convenience, e.g., availability in the institution rather than on an unbiased evaluation of whether they provide the answer to a given question. Apart from a general discussion on translational success or failure, we provide examples where infections with single-celled parasites in a chosen lab rodent gave contradictory or misleading results, and when possible discuss the reason for this. We present emerging alternatives to traditional rodent models, such as humanized mice and organoid primary cell cultures. So-called recombinant inbred strains such as the Collaborative Cross collection are also a potential solution for certain challenges. In addition, we emphasize the advantages of using wild rodents for certain immunological, ecological, and/or behavioral questions. The experimental challenges (e.g., availability of species-specific reagents) that come with the use of such non-model systems are also discussed. Our intention is to foster critical judgment of both traditional and newly available translational rodent models for research on parasitic protozoa that can complement the existing mouse and rat models.
Topics: Age Factors; Animals; Cytokines; Disease Models, Animal; Humans; Immune System; Mice; Mice, Inbred Strains; Microbiota; Proteins; Protozoan Infections; Rats; Research; Rodent Diseases; Rodentia; Sex Factors; Species Specificity
PubMed: 28638807
DOI: 10.3389/fcimb.2017.00238 -
FEMS Immunology and Medical Microbiology Feb 2010Parasitic protozoa of the genus Leishmania are the causative agents of leishmaniasis. Survival and transmission of these parasites in their different hosts require... (Review)
Review
Parasitic protozoa of the genus Leishmania are the causative agents of leishmaniasis. Survival and transmission of these parasites in their different hosts require membrane-bound or extracellular factors to interact with and modify their host environments. Over the last decade, several approaches have been applied to study all the extracellular proteins exported by an organism at a particular time or stage in its life cycle and under defined conditions, collectively termed the secretome or the exoproteome. In this review, we focus on emerging data shedding light on the secretion mechanisms involved in the production of the Leishmania exoproteome. We also describe other methodologies currently available that could be used to analyse the Leishmania exoproteome. Understanding the complexity of the Leishmania exoproteome is a key component to elucidating the mechanisms used by these parasites for exporting proteins to the extracellular space during its life cycle. Given the importance of extracellular factors, a detailed knowledge of the Leishmania exoproteome may provide novel targets for rational drug design and/or a source of antigens for vaccine development.
Topics: Animals; Host-Parasite Interactions; Humans; Leishmania; Leishmaniasis; Life Cycle Stages; Macrophages; Proteome; Protozoan Proteins; Psychodidae; Virulence Factors
PubMed: 19807787
DOI: 10.1111/j.1574-695X.2009.00608.x -
Journal of Dairy Science May 1984Nitrogen metabolism is reviewed with emphasis on methods for quantitating various nitrogen-transactions in the rumen of animals on a variety of diets. Ammonia kinetics,... (Review)
Review
Nitrogen metabolism is reviewed with emphasis on methods for quantitating various nitrogen-transactions in the rumen of animals on a variety of diets. Ammonia kinetics, microbial cell synthesis, the inputs of endogenous nitrogen, degradation of dietary protein, and availability to the animal of dietary bypass protein are discussed. The efficiency of microbial protein from the rumen is discussed in relation to the ratio of protein to energy in the nutrients available to meet the requirements of the animal. The ratio is determined largely by the maintenance requirements of microbes and the breakdown of microbial materials, which result in the recycling of microbial nitrogen in the rumen. Emphasis is placed on the role of rumen protozoa in decreasing the ratio of protein to energy in absorbed nutrients in ruminants on diets that are marginally deficient in protein. Recent studies of the dynamics of protozoa in the rumen and their contribution to microbial protein outflow are summarized.
Topics: Amino Acids; Ammonia; Animals; Animals, Domestic; Artiodactyla; Bacteria; Cattle; Dietary Proteins; Eukaryota; Fatty Acids, Volatile; Female; Male; Models, Biological; Nitrogen; Rumen; Urea
PubMed: 6376562
DOI: 10.3168/jds.S0022-0302(84)81409-5 -
Parasitology Aug 2019Microbial parasites adapted to thrive at mammalian mucosal surfaces have evolved multiple times from phylogenetically distant lineages into various extracellular and...
Microbial parasites adapted to thrive at mammalian mucosal surfaces have evolved multiple times from phylogenetically distant lineages into various extracellular and intracellular life styles. Their symbiotic relationships can range from commensalism to parasitism and more recently some host-parasites interactions are thought to have evolved into mutualistic associations too. It is increasingly appreciated that this diversity of symbiotic outcomes is the product of a complex network of parasites-microbiota-host interactions. Refinement and broader use of DNA based detection techniques are providing increasing evidence of how common some mucosal microbial parasites are and their host range, with some species being able to swap hosts, including from farm and pet animals to humans. A selection of examples will illustrate the zoonotic potential for a number of microbial parasites and how some species can be either disruptive or beneficial nodes in the complex networks of host-microbe interactions disrupting or maintaining mucosal homoeostasis. It will be argued that mucosal microbial parasitic diversity will represent an important resource to help us dissect through comparative studies the role of host-microbe interactions in both human health and disease.
Topics: Adaptive Immunity; Animals; Host Microbial Interactions; Host-Parasite Interactions; Humans; Immunity, Innate; Mucous Membrane; Parasitic Diseases; Phylogeny; Symbiosis; Zoonoses
PubMed: 31378213
DOI: 10.1017/S0031182019000647 -
Frontiers in Cellular and Infection... 2023, , and are gastrointestinal protozoa parasites that cause diarrhea in various animals. However, information regarding the detection and phylogenetic characterization...
INTRODUCTION
, , and are gastrointestinal protozoa parasites that cause diarrhea in various animals. However, information regarding the detection and phylogenetic characterization of gastrointestinal protozoa parasites in cats is limited throughout South Korea. Therefore, this study aimed to determine the detection and identify subspecies of gastrointestinal protozoa parasites in cats from South Korea.
METHODS
A total of 290 fecal samples were collected from stray, companion, and shelter cats in six provinces. , , and were identified by PCR. All positive samples were subtyped by PCR and sequencing of , , , , and .
RESULTS
The overall detection of gastrointestinal protozoan parasitic infection was 17.93%. was the most prevalent, with 7.93%, followed by spp. (7.24%) and spp. (4.48%). In addition, (n=10), (n=2), (n=1), (n=14), (n=5), (n=1), spp. were identified in subspecies analysis of positive samples. showed a significant association with diarrhea (7.81%) and living condition (6.04%), and Cystoisospora felis in diarreha (9.38%) according to detection. Through phylogenetic analysis of the tpi, bg, and gdh genes from 23 G. duodenalispositive samples, it was confirmed that the samples of present study belonged to assemblage A, B, C, and D.
DISCUSSION
South Korean cats have a high rate of gastrointestinal protozoan parasites infection with cat-specific Cryptosporidium and Cystoisospora, which are associated with living conditions and diarrhea symptoms. Moreover, zoonotic and other animal-specific subtype of protozoan parasites have been detected in cat feces.
Topics: Cats; Animals; Giardia lamblia; Cryptosporidium; Cryptosporidiosis; Giardiasis; Phylogeny; Intestinal Diseases, Parasitic; Parasites; Diarrhea; Feces; Republic of Korea; Felis; Prevalence; Genotype
PubMed: 38029266
DOI: 10.3389/fcimb.2023.1296118 -
Animal : An International Journal of... Jun 2013A wide range of plant bioactive components (phytochemicals) have been identified as having potential to modulate the processes of fermentation in the rumen. The use of... (Review)
Review
A wide range of plant bioactive components (phytochemicals) have been identified as having potential to modulate the processes of fermentation in the rumen. The use of plants or plant extracts as natural feed additives has become a subject of interest not only among nutritionists but also other scientists. Although a large number of phytochemicals (e.g. saponins, tannins and essential oils) have recently been investigated for their methane reduction potential, there have not yet been major breakthroughs that could be applied in practice. A key tenet of this paper is the need for studies on the influence of plant components on methane production to be performed with standardized samples. Where there are consistent effects, the literature suggests that saponins mitigate methanogenesis mainly by reducing the number of protozoa, condensed tannins both by reducing the number of protozoa and by a direct toxic effect on methanogens, whereas essential oils act mostly by a direct toxic effect on methanogens. However, because the rumen is a complex ecosystem, analysis of the influence of plant components on the populations of methanogens should take into account not only the total population of methanogens but also individual orders or species. Although a number of plants and plant extracts have shown potential in studies in vitro, these effects must be confirmed in vivo.
Topics: Animal Feed; Animals; Bacteria; Eukaryota; Euryarchaeota; Fermentation; Livestock; Methane; Plant Extracts; Plants; Rumen
PubMed: 23739468
DOI: 10.1017/S1751731113000852 -
Journal of Microbiological Methods Mar 2017In this study, the use of skimmed milk flocculation (SMF) to simultaneously concentrate viruses, bacteria and protozoa was evaluated. We selected strains of faecal...
Characterization of the efficiency and uncertainty of skimmed milk flocculation for the simultaneous concentration and quantification of water-borne viruses, bacteria and protozoa.
In this study, the use of skimmed milk flocculation (SMF) to simultaneously concentrate viruses, bacteria and protozoa was evaluated. We selected strains of faecal indicator bacteria and pathogens, such as Escherichia coli and Helicobacter pylori. The viruses selected were adenovirus (HAdV 35), rotavirus (RoV SA-11), the bacteriophage MS2 and bovine viral diarrhoea virus (BVDV). The protozoa tested were Acanthamoeba, Giardia and Cryptosporidium. The mean recoveries with q(RT)PCR were 66% (HAdV 35), 24% (MS2), 28% (RoV SA-11), 15% (BVDV), 60% (E. coli), 30% (H. pylori) and 21% (Acanthamoeba castellanii). When testing the infectivity, the mean recoveries were 59% (HAdV 35), 12% (MS2), 26% (RoV SA-11) and 0.7% (BVDV). The protozoa Giardia lamblia and Cryptosporidium parvum were studied by immunofluorescence with recoveries of 18% and 13%, respectively. Although q(RT)PCR consistently showed higher quantification values (as expected), q(RT)PCR and the infectivity assays showed similar recoveries for HAdV 35 and RoV SA-11. Additionally, we investigated modelling the variability and uncertainty of the recovery with this method to extrapolate the quantification obtained by q(RT)PCR and estimate the real concentration. The 95% prediction intervals of the real concentration of the microorganisms inoculated were calculated using a general non-parametric bootstrap procedure adapted in our context to estimate the technical error of the measurements. SMF shows recoveries with a low variability that permits the use of a mathematical approximation to predict the concentration of the pathogen and indicator with acceptable low intervals. The values of uncertainty may be used for a quantitative microbial risk analysis or diagnostic purposes.
Topics: Animals; Bacteria; Cattle; Cryptosporidium; Cryptosporidium parvum; Escherichia coli; Flocculation; Giardia; Microbiological Techniques; Milk; Real-Time Polymerase Chain Reaction; Uncertainty; Viruses; Water; Water Microbiology
PubMed: 28093213
DOI: 10.1016/j.mimet.2017.01.006 -
Trends in Immunology Apr 2023Malaria is caused by Plasmodium protozoa that are transmitted by anopheline mosquitoes. Plasmodium sporozoites are released with saliva when an infected female mosquito... (Review)
Review
Malaria is caused by Plasmodium protozoa that are transmitted by anopheline mosquitoes. Plasmodium sporozoites are released with saliva when an infected female mosquito takes a blood meal on a vertebrate host. Sporozoites deposited into the skin must enter a blood vessel to start their journey towards the liver. After migration out of the mosquito, sporozoites are associated with, or in proximity to, many components of vector saliva in the skin. Recent work has elucidated how Anopheles saliva, and components of saliva, can influence host-pathogen interactions during the early stage of Plasmodium infection in the skin. Here, we discuss how components of Anopheles saliva can modulate local host responses and affect Plasmodium infectivity. We hypothesize that therapeutic strategies targeting mosquito salivary proteins can play a role in controlling malaria and other vector-borne diseases.
Topics: Humans; Animals; Female; Anopheles; Saliva; Mosquito Vectors; Malaria; Sporozoites
PubMed: 36964020
DOI: 10.1016/j.it.2023.02.005 -
Parasite (Paris, France) 2017Parasitic diseases of camels are major causes of impaired milk and meat production, decreases in performance or even death. Some camel parasites also represent a threat... (Review)
Review
Parasitic diseases of camels are major causes of impaired milk and meat production, decreases in performance or even death. Some camel parasites also represent a threat to human health. About 171,500 one-humped camels (Camelus dromedarius) and 100-300 two-humped camels (Camelus bactrianus) live in Iran. Knowledge of the biodiversity of their parasites is still limited. The present review covers all information about camel parasitic diseases in Iran published as dissertations and in both Iranian and international journals from 1931 to February 2017. Ten genera of Protozoa (Trypanosoma, Eimeria, Cryptosporidium, Toxoplasma, Neospora, Sarcocystis, Besnoitia, Theileria, Babesia and Balantidium), 48 helminth species detected in the digestive system, including three species of Trematoda, four species of Cestoda, and 41 species of Nematoda, as well as helminths from other organs - Echinococcus spp., Dictyocaulus filaria, Thelazia leesei, Dipetalonema evansi and Onchocerca fasciata - have so far been described in Iranian camels. Furthermore, 13 species of hard ticks, mange mites, the myiasis flies Cephalopina titillator and Wohlfahrtia magnifica, and immature stages of the Pentastomida Linguatula serrata have also been reported from camels of Iran. Camel parasitic diseases are a major issue in Iran in terms of economics and public health. The present review offers information for an integrated control programme against economically relevant parasites of camels.
Topics: Animals; Camelus; Ectoparasitic Infestations; Iran; Parasitic Diseases, Animal
PubMed: 28617666
DOI: 10.1051/parasite/2017024 -
The Pediatric Infectious Disease Journal Sep 2018Intestinal protozoa are common opportunistic infections in HIV patients. Longitudinal studies on either the clinical relevance or the effect of immune reconstitution by...
Multiplex Real-time PCR Detection of Intestinal Protozoa in HIV-infected Children in Malawi: Enterocytozoon Bieneusi Is Common and Associated With Gastrointestinal Complaints and May Delay BMI (Nutritional Status) Recovery.
BACKGROUND
Intestinal protozoa are common opportunistic infections in HIV patients. Longitudinal studies on either the clinical relevance or the effect of immune reconstitution by antiretroviral therapy on intestinal protozoan infections in children are lacking however. This study investigates prevalence and clinical relevance of intestinal protozoa in HIV-infected Malawian children before and during their first year of antiretroviral treatment (ART).
METHODS
Stool samples collected at enrolment and during follow-up were tested for nonopportunistic (Giardia lamblia, Dientamoeba fragilis, Entamoeba histolytica) and opportunistic protozoa (Enterocytozoon bieneusi, Encephalitozoon spp., Cryptosporidium spp. and Cystoisospora belli) using multiplex real-time polymerase chain reaction. Associations between infections and clinical symptoms were evaluated using univariate methods.
RESULTS
Nonopportunistic and opportunistic protozoa were detected in 40% (14/35) and 46% (16/35) of children at baseline, respectively. E. bieneusi was the most prevalent protozoa (37%, 13/35) and associated with gastrointestinal complaints (43% in positive (10/13) versus 18% (4/22) in E. bieneusi-negative children, P = 0.001. Body mass index recovery during 12 months of ART was more commonly delayed in E. bieneusi-positive children (+0.29 +standard deviation 0.83) than E. bieneusi-negative children (+1.03 +standard deviation 1.25; P = 0.05). E. bieneusi was not detected after 12 months of ART.
CONCLUSIONS
E. bieneusi was the most prevalent opportunistic intestinal protozoa, present in over a third of study participants before initiation of ART. Although all children cleared E. bieneusi after 12 months of ART, E. bieneusi was associated with gastrointestinal complaints and may delay body mass index recovery. Trials to assess effect of treatment of E. bieneusi on nutritional status should be considered in HIV-infected African children.
Topics: AIDS-Related Opportunistic Infections; Anti-Retroviral Agents; Body Mass Index; Child; Enterocytozoon; Feces; Female; HIV; HIV Infections; Humans; Intestines; Malawi; Male; Multiplex Polymerase Chain Reaction; Nutritional Status; Prevalence; Prospective Studies
PubMed: 29762365
DOI: 10.1097/INF.0000000000001924