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Revista Do Instituto de Medicina... Sep 2020Intestinal mucins are the first line of defense against microorganisms. Although knowledge about the mechanisms involved in the establishment of intestinal protozoa is...
Intestinal mucins are the first line of defense against microorganisms. Although knowledge about the mechanisms involved in the establishment of intestinal protozoa is limited, there is evidence that these parasites produce lectin-like molecules and glycosidases, that exert both, constitutive and secretory functions, promoting the establishment of these microorganisms. In the present review, we analyse the main interactions between mucins of the host intestine and the four main protozoan parasites in humans and their implications in intestinal colonization. There are lectin-like molecules that contain complex oligosaccharide structures and N-acetylglucosamine (GlcNAc), mannose and sialic acid as main components, which are excreted/secreted by Giardia intestinalis, and recognized by the host using mannose-binding lectins (MBL). Entamoeba histolytica and Cryptosporidium spp. express the lectin galactose/N-acetyl-D-galactosamine, which facilitates their adhesion to cells. In Cryptosporidium, the glycoproteins gp30, gp40/15 and gp900 and the glycoprotein lectin CpClec are involved in protozoan adhesion to intestinal cells, forming an adhesion-attack complex. G. intestinalis and E. histolytica can also produce glycosidases such as β-N-acetyl-D-glucosaminidase, α-d-glucosidase, β-d-galactosidase, β-l-fucosidase, α-N-acetyl-d-galactosaminidase and β-mannosidase. In Blastocystis, α-D-mannose, α-D-glucose, GlcNAc, α-D-fucose, chitin and sialic acid that have been identified on their surface. Fucosidases, hexosaminidases and polygalacturonases, which may be involved in the mucin degradation process, have also been described in the Blastocystis secretoma. Similarly, symbiotic coexistence with the intestinal microbiota promotes the survival of parasites facilitating cell invasion and nutrients obtention. Furthermore, it is necessary to identify and characterize more glycosidases, which have been only partially described by in silico analyses of the parasite genome.
Topics: Animals; Cryptosporidiosis; Cryptosporidium; Entamoeba; Glycoproteins; Glycoside Hydrolases; Humans; Intestines; Lectins; Mucins; Parasites
PubMed: 32901761
DOI: 10.1590/S1678-9946202062064 -
Veterinary Medicine and Science May 2023In safari parks and zoos, wild animals are kept mainly for recreational purposes. Animals in these enclosures are also crucial for the education, research, and...
In safari parks and zoos, wild animals are kept mainly for recreational purposes. Animals in these enclosures are also crucial for the education, research, and conservation aspect. To ensure better management and good health of wild animals in captivity, it is essential to monitor the occurrence of gastrointestinal (GI) parasitic (helminths and protozoa) infections. The current investigation was undertaken to investigate the prevalence of GI parasitic infections in wild mammals at Bangabandhu Sheikh Mujib (BSM) safari park and Chattogram (CTG) zoo of Bangladesh. A total of 72 individual faecal samples were collected from 25 species of wild mammals. Routine qualitative (e.g. direct smear, sedimentation, and flotation) and quantitative (e.g. McMaster technique) tests were performed to identify the eggs or oocysts of helminths and protozoa. Results demonstrated that wild mammals of both BSM safari park and CTG zoo were infected with a total of 17 genera/species of helminths and protozoa. The overall prevalence of GI parasitic infections in wild mammals of both zoological parks was 65.3% (95% confidence interval [CI]: 53.14-76.12), whereas it was 72.4% (95% CI: 52.76-87.27) in the BSM safari park and 60.5% (95% CI: 44.41-75.02) in the CTG zoo. In both zoological parks, infection with nematodes was more frequent compared to other helminth into the wild mammals. The herbivores were more infected with GI parasites than carnivores and omnivores of both BSM safari park and CTG zoo. The mean eggs/oocysts per gram of faeces was the highest in the carnivores compared to herbivores and omnivores of both enclosures. The findings of the current study demonstrated that wild mammals of both BSM safari park and CTG zoo suffered from various GI parasitic infections. Regular monitoring along with proper therapeutic measures may reduce the severe consequences of GI parasitic infections in captive wild animals.
Topics: Animals; Parasites; Prevalence; Bangladesh; Mammals; Intestinal Diseases, Parasitic; Helminths; Animals, Wild; Gastrointestinal Diseases
PubMed: 36745465
DOI: 10.1002/vms3.1093 -
Journal of Clinical Microbiology Jun 2000Within the last several years, the protozoan parasites Cyclospora cayetanensis, Cryptosporidium parvum, and microsporidia have become recognized as important, rapidly...
Within the last several years, the protozoan parasites Cyclospora cayetanensis, Cryptosporidium parvum, and microsporidia have become recognized as important, rapidly emerging human pathogens in immunocompromised and immunocompetent individuals. Since the early 1990s, many of the reported outbreaks of enteric illness caused by these microorganisms have been attributed to food- and water-borne contamination. Many inherent obstacles affect the success of current surveillance and detection methods used to monitor and control levels of contamination by these pathogens. Unlike methods that incorporate preenrichment for easier and unambiguous identification of bacterial pathogens, similar methods for the detection of parasitic protozoa either are not currently available or cannot be performed in a timely manner. We have developed an extraction-free, filter-based protocol to prepare DNA templates for use in PCR to identify C. cayetanensis and C. parvum oocysts and microsporidia spores. This method requires only minimal preparation to partially purify and concentrate isolates prior to filter application. DNA template preparation is rapid, efficient, and reproducible. As few as 3 to 10 parasites could be detected by PCR from direct application to the filters. In studies, as few 10 to 50 Encephalitozoon intestinalis spores could be detected when seeded in a 100-microliter stool sample and 10 to 30 C. cayetanensis oocysts could be detected per 100 g of fresh raspberries. This protocol can easily be adapted to detect parasites from a wide variety of food, clinical, and environmental samples and can be used in multiplex PCR applications.
Topics: Animals; Apicomplexa; Coccidia; Coccidiosis; Cryptosporidiosis; Cryptosporidium parvum; DNA, Protozoan; Encephalitozoon; Encephalitozoonosis; Feces; Fruit; Humans; Microsporida; Microsporidiosis; Nepal; Polymerase Chain Reaction; Protozoan Infections; Sensitivity and Specificity; Sputum; Time Factors; Urine
PubMed: 10834988
DOI: 10.1128/JCM.38.6.2271-2277.2000 -
International Journal of Infectious... Aug 2013Visceral leishmaniases are vector-borne parasitic diseases caused by protozoa belonging to the genus Leishmania. The heterogeneity of clinical manifestations and... (Review)
Review
Visceral leishmaniases are vector-borne parasitic diseases caused by protozoa belonging to the genus Leishmania. The heterogeneity of clinical manifestations and epidemiological characteristics of the disease reflect the complex interplay between the infecting Leishmania species and the genetic and immunologic characteristics of the infected host. The clinical presentation of visceral leishmaniasis depends strictly on the immunocompetency of the host and ranges from asymptomatic to severe forms. Conditions of depression of the immune system, such as HIV infection or immunosuppressive treatments, impair the capability of the immune response to resolve the infection and allow reactivation and relapses of the disease.
Topics: Animals; Disease Vectors; Host-Parasite Interactions; Humans; Immunocompromised Host; Leishmania donovani; Leishmaniasis, Visceral
PubMed: 23380419
DOI: 10.1016/j.ijid.2012.12.024 -
Parasitology Research Dec 2022Reptiles are frequently kept as pet animals. They are considered as important reservoirs of protozoa with veterinary-medical significance. At a reptile farm in Ireland,...
Reptiles are frequently kept as pet animals. They are considered as important reservoirs of protozoa with veterinary-medical significance. At a reptile farm in Ireland, fecal samples were collected from 98 captive reptiles, representing 43 species of three orders (Squamata, Testudines, and Crocodylia). After DNA extraction, all samples were screened by conventional PCRs, targeting the ribosomal small subunit (SSU) RNA and alpha-tubulin genes of trichomonads and SSU RNA gene of Acanthamoeba spp. One leopard gecko (Eublepharis macularius) was positive for a not yet reported species/genotype of the genus Monocercomonas, different from M. colubrorum. Various Acanthamoeba genotypes were detected in six reptilian species, i.e., Acanthamoeba genotype T11 in Eunectes notaeus and Heloderma suspectum/horridum; genotype T4 in Varanus exanthematicus, Chlamydosaurus kingii, and Macrochelys temminckii; and the genotype T13 in Iguana iguana. Some of these amoeba species might have clinicopathological significance in both humans and animals. Our findings highlight the importance to monitor pathogenic protozoa in pet as well as wildlife reptiles, as a source of possible infection for animals and humans living nearby.
Topics: Humans; Animals; Acanthamoeba; Amoeba; Reptiles; Genotype; Feces; Trichomonadida; RNA
PubMed: 36184660
DOI: 10.1007/s00436-022-07677-3 -
PLoS Neglected Tropical Diseases Jun 2016Handheld light microscopy using compact optics and mobile phones may improve the quality of health care in resource-constrained settings by enabling access to prompt and...
BACKGROUND
Handheld light microscopy using compact optics and mobile phones may improve the quality of health care in resource-constrained settings by enabling access to prompt and accurate diagnosis.
METHODOLOGY
Laboratory technicians were trained to operate two handheld diagnostic devices (Newton Nm1 microscope and a clip-on version of the mobile phone-based CellScope). The accuracy of these devices was compared to conventional light microscopy for the diagnosis of Schistosoma haematobium, S. mansoni, and intestinal protozoa infection in a community-based survey in rural Côte d'Ivoire. One slide of 10 ml filtered urine and a single Kato-Katz thick smear from 226 individuals were subjected to the Newton Nm1 microscope and CellScope for detection of Schistosoma eggs and compared to conventional microscopy. Additionally, 121 sodium acetate-acetic acid-formalin (SAF)-fixed stool samples were examined by the Newton Nm1 microscope and compared to conventional microscopy for the diagnosis of intestinal protozoa.
PRINCIPAL FINDINGS
The prevalence of S. haematobium, S. mansoni, Giardia intestinalis, and Entamoeba histolytica/E. dispar, as determined by conventional microscopy, was 39.8%, 5.3%, 20.7%, and 4.9%, respectively. The Newton Nm1 microscope had diagnostic sensitivities for S. mansoni and S. haematobium infection of 91.7% (95% confidence interval (CI) 59.8-99.6%) and 81.1% (95% CI 71.2-88.3%), respectively, and specificities of 99.5% (95% CI 97.0-100%) and 97.1% (95% CI 92.2-99.1%), respectively. The CellScope demonstrated sensitivities for S. mansoni and S. haematobium of 50.0% (95% CI 25.4-74.6%) and 35.6% (95% CI 25.9-46.4%), respectively, and specificities of 99.5% (95% CI 97.0-100%) and 100% (95% CI 86.7-100%), respectively. For G. intestinalis and E. histolytica/E. dispar, the Newton Nm1 microscope had sensitivity of 84.0% (95% CI 63.1-94.7%) and 83.3% (95% CI 36.5-99.1%), respectively, and 100% specificity.
CONCLUSIONS/SIGNIFICANCE
Handheld diagnostic devices can be employed in community-based surveys in resource-constrained settings after minimal training of laboratory technicians to diagnose intestinal parasites.
Topics: Animals; Cell Phone; Cote d'Ivoire; Humans; Intestinal Diseases, Parasitic; Microscopy; Protozoan Infections; Schistosoma haematobium; Schistosoma mansoni; Schistosomiasis; Sensitivity and Specificity; Soil
PubMed: 27348755
DOI: 10.1371/journal.pntd.0004768 -
Current Gastroenterology Reports Aug 2006This paper discusses the most important parasites that inhabit the human small intestine. Beginning with the protozoa and proceeding through the various species of... (Review)
Review
This paper discusses the most important parasites that inhabit the human small intestine. Beginning with the protozoa and proceeding through the various species of cestodes, nematodes, and trematodes that inhabit the human small bowel, the most important organisms are presented. Possible future developments are discussed along with pathophysiology and treatment in this phylogenic approach. Zoonotic illnesses, those diseases that by their rarity are of little import, and diseases without significant clinical or social implications are beyond the scope of this article and are not discussed.
Topics: Animals; Global Health; Humans; Intestinal Diseases, Parasitic; Intestine, Small; Parasites; Prevalence
PubMed: 16836943
DOI: 10.1007/s11894-006-0052-2 -
The Korean Journal of Parasitology Oct 2009Zoonotic parasites are animal parasites that can infect humans. The major zoonotic protozoa in the Republic of Korea are Babesia bovis, Chilomastix mesnili,... (Review)
Review
Zoonotic parasites are animal parasites that can infect humans. The major zoonotic protozoa in the Republic of Korea are Babesia bovis, Chilomastix mesnili, Cryptosporidium parvum, Endolimax nana, Entamoeba coli, Entamoeba hitolytica, Giardia lamblia, Iodamoeba bütschlii, Pneumocystis carinii, Sarcocystis cruzi, and Toxoplasma gondii. The major zoonotic helminths in Korea include trematodes, cestodes, and nematodes. Trematodes are Clonorchis sinensis, Echinostoma hortense, Echinostoma spp., Fasciola hepatica, Heterophyes nocens, Metagonimus yokogawai, and Paragonimus westermani. Cestodes are Diphyllobothrium latum, Dipylidium caninum, Echinococcus granulosus, Hymenolepis nana, Raillietina tetragona, sparganum (Spirometra spp.), Taenia saginata, T. solium, and T. asiatica. Nematodes are Ancylostoma caninum, Brugia malayi, Capillaria hepatica, Dirofilaria immitis, Gnathostoma dololesi, Gnathostoma spinigerum, Loa loa, Onchocerca gibsoni, Strongyloides stercoralis, Thelazia callipaeda, Trichinella spiralis, Trichostrongylus orientalis, Trichuris trichiura, and Trichuris vulpis. The one arthropod is Sarcoptes scabiei. Many of these parasites have disappeared or were in decline after the 1990's. Since the late 1990's, the important zoonotic protozoa have been C. parvum, E. nana, E. coli, E. hitolytica, G. lamblia, I. buetschlii, P. carinii and T. gondii. The important zoonotic helminths have been C. sinensis, H. nocens, M. yokogawai, P. westermani, D. latum, T. asiatica, sparganum, B. malayi, T. orientalis, T. callipaeda and T. spiralis. However, outbreaks of these parasites are only in a few endemic areas. The outbreaks of Enterobius vermicularis and head lice, human parasites, have recently increased in the kindergartens and primary schools in the Republic of Korea.
Topics: Animals; Humans; Parasites; Parasitic Diseases; Parasitic Diseases, Animal; Republic of Korea; Zoonoses
PubMed: 19885329
DOI: 10.3347/kjp.2009.47.S.S133 -
International Journal of Environmental... Mar 2010Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and... (Review)
Review
Leishmaniasis is a protozoan disease caused by the genus Leishmania transmitted by female phlebotomine sand flies. Surveillance of the prevalence of Leishmania and responsive vector species in endemic and surrounding areas is important for predicting the risk and expansion of the disease. Molecular biological methods are now widely applied to epidemiological studies of infectious diseases including leishmaniasis. These techniques are used to detect natural infections of sand fly vectors with Leishmania protozoa and are becoming powerful tools due to their sensitivity and specificity. Recently, genetic analyses have been performed on sand fly species and genotyping using PCR-RFLP has been applied to the sand fly taxonomy. In addition, a molecular mass screening method has been established that enables both sand fly species and natural leishmanial infections to be identified simultaneously in hundreds of sand flies with limited effort. This paper reviews recent advances in the study of sand flies, vectors of leishmaniasis, using molecular biological approaches.
Topics: Animals; Diptera; Disease Vectors; Leishmaniasis; Molecular Epidemiology
PubMed: 20617005
DOI: 10.3390/ijerph7030814 -
BMC Ophthalmology Oct 2016The repertoire of free-living protozoa in contact lens solutions is poorly known despite the fact that such protozoa may act as direct pathogens and may harbor...
BACKGROUND
The repertoire of free-living protozoa in contact lens solutions is poorly known despite the fact that such protozoa may act as direct pathogens and may harbor intra-cellular pathogens.
METHODS
Between 2009 and 2014, the contact lens solutions collected from patients presenting at our Ophthalmology Department for clinically suspected keratitis, were cultured on non-nutrient agar examined by microscope for the presence of free-living protozoa. All protozoa were identified by 18S rRNA gene sequencing.
RESULTS
A total of 20 of 233 (8.6 %) contact lens solution specimens collected from 16 patients were cultured. Acanthamoeba amoeba in 16 solutions (80 %) collected from 12 patients and Colpoda steini, Cercozoa sp., Protostelium sp. and a eukaryotic more closely related to Vermamoeba sp., were each isolated in one solution. Cercozoa sp., Colpoda sp., Protostelium sp. and Vermamoeba sp. are reported for the first time as contaminating contact lens solutions.
CONCLUSION
The repertoire of protozoa in contact lens solutions is larger than previously known.
Topics: Acanthamoeba; Amoebida; Bacteria; Contact Lens Solutions; Contact Lenses; Female; Fungi; Humans; Keratitis; Male; Phylogeny; Prospective Studies; Protozoan Infections; RNA, Protozoan; RNA, Ribosomal, 18S
PubMed: 27793130
DOI: 10.1186/s12886-016-0370-6