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Rojas-Velázquez L, Morán P, Serrano-Vázquez A, Fernández LD, Pérez-Juárez H, Poot-Hernández AC, Portillo T, González E, Hernández E, Partida-Rodríguez O, Nieves-Ramírez ME, Magaña U, Torres J, Eguiarte LE, Piñero D, Ximénez C. Genetic Diversity and Distribution of Blastocystis Subtype 3 in Human Populations, with Special Reference to a Rural Population in Central Mexico. BIOMED RESEARCH INTERNATIONAL 2018; 2018:3916263. [PMID: 29744356 PMCID: PMC5878905 DOI: 10.1155/2018/3916263] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 02/11/2018] [Indexed: 02/01/2023]
Abstract
Blastocystis subtype 3 (ST3) is a parasitic protist found in the digestive tract of symptomatic and asymptomatic humans around the world. While this parasite exhibits a high prevalence in the human population, its true geographic distribution and global genetic diversity are still unknown. This gap in knowledge limits the understanding of the spread mechanisms, epidemiology, and impact that this parasite has on human populations. Herein, we provided new data on the geographical distribution and genetic diversity of Blastocystis ST3 from a rural human population in Mexico. To do so, we collected and targeted the SSU-rDNA region in fecal samples from this population and further compared its genetic diversity and structure with that previously observed in populations of Blastocystis ST3 from other regions of the planet. Our analyses reveled that diversity of Blastocystis ST3 showed a high haplotype diversity and genetic structure to the world level; however, they were low in the Morelos population. The haplotype network revealed a common widespread haplotype from which the others were generated recently. Finally, our results suggested a recent expansion of the diversity of Blastocystis ST3 worldwide.
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Affiliation(s)
- Liliana Rojas-Velázquez
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
- Unidad de Posgrado, Universidad Nacional Autónoma de México (UNAM), Circuito de Posgrado S/N, Coyoacán, Cd. Universitaria, 04510 Ciudad de México, Mexico
| | - Patricia Morán
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
| | - Angélica Serrano-Vázquez
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
| | - Leonardo D. Fernández
- Centro de Investigación en Recursos Naturales y Sustentabilidad (CIRENYS), Universidad Bernardo O'Higgins, Avenida Viel 1497, Santiago, Chile
| | - Horacio Pérez-Juárez
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
- Unidad de Posgrado, Universidad Nacional Autónoma de México (UNAM), Circuito de Posgrado S/N, Coyoacán, Cd. Universitaria, 04510 Ciudad de México, Mexico
| | - Augusto C. Poot-Hernández
- Departamento de Ingeniería de Sistemas Computacionales y Automatización, Sección de Ingeniería de Sistemas Computacionales, Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México (UNAM), Circuito Escolar 3000, Cd. Universitaria, Coyoacán, 04510 Ciudad de México, Mexico
| | - Tobías Portillo
- Unidad de Bioinformática, Bioestadística y Biología Computacional, Red de Apoyo a la Investigación, Coordinación de la Investigación Científica, UNAM, Instituto Nacional de Ciencias Médicas y Nutrición, Vasco de Quiroga 15, Tlalpan, 14080 Ciudad de México, Mexico
| | - Enrique González
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
| | - Eric Hernández
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
| | - Oswaldo Partida-Rodríguez
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
| | - Miriam E. Nieves-Ramírez
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
| | - Ulises Magaña
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
- Unidad de Posgrado, Universidad Nacional Autónoma de México (UNAM), Circuito de Posgrado S/N, Coyoacán, Cd. Universitaria, 04510 Ciudad de México, Mexico
| | - Javier Torres
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Siglo XXI, Instituto Mexicano del Seguro Social (IMSS), Avenida Cuauhtémoc 330, Doctores, Cuauhtémoc, 06720 Ciudad de México, Mexico
| | - Luis E. Eguiarte
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Circuito Exterior S/N, Junto al Jardín Botánico, Cd. Universitaria, Coyoacán, 04510 Ciudad de México, Mexico
| | - Daniel Piñero
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Circuito Exterior S/N, Junto al Jardín Botánico, Cd. Universitaria, Coyoacán, 04510 Ciudad de México, Mexico
| | - Cecilia Ximénez
- Unidad de Investigación en Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Dr. Balmis 148, Doctores, Cuauhtémoc, 06726 Ciudad de México, Mexico
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Barbosa CV, Barreto MM, Andrade RDJ, Sodré F, d’Avila-Levy CM, Peralta JM, Igreja RP, de Macedo HW, Santos HLC. Intestinal parasite infections in a rural community of Rio de Janeiro (Brazil): Prevalence and genetic diversity of Blastocystis subtypes. PLoS One 2018. [PMID: 29522552 PMCID: PMC5844535 DOI: 10.1371/journal.pone.0193860] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Background Intestinal parasitic infections are considered a serious public health problem and widely distributed worldwide, mainly in urban and rural environments of tropical and subtropical countries. Globally, soil-transmitted helminths and protozoa are the most common intestinal parasites. Blastocystis sp. is a highly prevalent suspected pathogenic protozoan, and considered an unusual protist due to its significant genetic diversity and host plasticity. Methodology/main findings A total of 294 stool samples were collected from inhabitants of three rural valleys in Rio de Janeiro, Brazil. The stool samples were evaluated by parasitological methods, fecal culture, nested PCR and PCR/Sequencing. Overall prevalence by parasitological analyses was 64.3% (189 out of 294 cases). Blastocystis sp. (55.8%) was the most prevalent, followed by Endolimax nana (18.7%), Entamoeba histolytica complex (7.1%), hookworm infection (7.1%), Entomoeba coli (5.8%), Giardia intestinalis (4.1%), Iodamoeba butchilii (1.0%), Trichuris trichiura (1.0%), Pentatrichomonas hominis (0.7%), Enterobius vermicularis (0.7%), Ascaris lumbricoides (0.7%) and Strongyloides stercoralis (0.7%). Prevalence of IPIs was significantly different by gender. Phylogenetic analysis of Blastocystis sp. and BLAST search revealed five different subtypes: ST3 (34.0%), ST1 (27.0%), ST2 (27.0%), ST4 (3.5%), ST8 (7.0%) and a non-identified subtype. Conclusions/significance Our findings demonstrate that intestinal parasite infection rates in rural areas of the Sumidouro municipality of Rio de Janeiro, Brazil are still high and remain a challenge to public health. Moreover, our data reveals significant genetic heterogeneity of Blastocystis sp. subtypes and a possible novel subtype, whose confirmation will require additional data. Our study contributes to the understanding of potential routes of transmission, epidemiology, and genetic diversity of Blastocystis sp. in rural areas both at a regional and global scale.
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Affiliation(s)
- Carolina Valença Barbosa
- Laboratório de Estudos Integrados em Protozoologia, Instituto Oswaldo Cruz/Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Magali Muniz Barreto
- Laboratório de Avaliação e Promoção da Saúde Ambiental, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| | - Rosemary de Jesus Andrade
- Departamento de Ginecologia e Obstetrícia, Instituto Fernandes Figueira/FIOCRUZ, Rio de Janeiro, Brazil
| | - Fernando Sodré
- Laboratório de Parasitologia, Departamento de Patologia, Hospital Universitário Antônio Pedro, Universidade Federal Fluminense, Rio de Janeiro, Brazil
| | - Claudia Masini d’Avila-Levy
- Laboratório de Estudos Integrados em Protozoologia, Instituto Oswaldo Cruz/Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Ricardo Pereira Igreja
- Departamento de Medicina Preventiva da Faculdade de Medicina, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Heloisa Werneck de Macedo
- Laboratório de Parasitologia, Departamento de Patologia, Hospital Universitário Antônio Pedro, Universidade Federal Fluminense, Rio de Janeiro, Brazil
| | - Helena Lucia Carneiro Santos
- Laboratório de Estudos Integrados em Protozoologia, Instituto Oswaldo Cruz/Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
- * E-mail:
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The intestinal protist Blastocystis is not a common member of the healthy infant gut microbiota in a Westernized country (Ireland). Parasitology 2018; 145:1274-1278. [PMID: 29397054 DOI: 10.1017/s0031182018000033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Research into the gut microbiota of human infants is necessary in order to better understand how inter-species interactions and ecological succession shape the diversity of the gut microbiota, and in turn, how the specific composition of the gut microbiota impacts on host health both during infancy and in later years. Blastocystis is a ubiquitous intestinal protist that has been linked to a number of intestinal and extra-intestinal diseases. However, emerging data show that asymptomatic carriage is common and that Blastocystis is prevalent in the healthy adult gut microbiota. Nonetheless, little is known about the prevalence and diversity of this microorganism in the healthy infant gut, including when and how individuals become colonized by Blastocystis. Here, we surveyed the prevalence and diversity of Blastocystis in an infant population (n = 59) from an industrialized country (Ireland) using Blastocystis-specific primers at three or more time-points up to 24 months old. Only three infants were positive for Blastocystis (prevalence = 5%) and this was only noted for samples collected at month 24. This rate is comparatively low relative to previously reported prevalence rates in the contemporaneous adult population. These data suggest that infants in Westernized countries that are successfully colonized by Blastocystis most likely acquire this microorganism via horizontal transfer.
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Garcia LS, Arrowood M, Kokoskin E, Paltridge GP, Pillai DR, Procop GW, Ryan N, Shimizu RY, Visvesvara G. Practical Guidance for Clinical Microbiology Laboratories: Laboratory Diagnosis of Parasites from the Gastrointestinal Tract. Clin Microbiol Rev 2018; 31:e00025-17. [PMID: 29142079 PMCID: PMC5740970 DOI: 10.1128/cmr.00025-17] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
This Practical Guidance for Clinical Microbiology document on the laboratory diagnosis of parasites from the gastrointestinal tract provides practical information for the recovery and identification of relevant human parasites. The document is based on a comprehensive literature review and expert consensus on relevant diagnostic methods. However, it does not include didactic information on human parasite life cycles, organism morphology, clinical disease, pathogenesis, treatment, or epidemiology and prevention. As greater emphasis is placed on neglected tropical diseases, it becomes highly probable that patients with gastrointestinal parasitic infections will become more widely recognized in areas where parasites are endemic and not endemic. Generally, these methods are nonautomated and require extensive bench experience for accurate performance and interpretation.
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Affiliation(s)
| | - Michael Arrowood
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of Foodborne, Waterborne, and Environmental Diseases, Waterborne Disease Prevention Branch, Atlanta, Georgia, USA
| | - Evelyne Kokoskin
- Public Health Ontario, Ottawa, Ontario, Canada
- Public Health Laboratories-Ottawa, Ottawa, Ontario, Canada
| | | | - Dylan R Pillai
- Calgary Laboratory Services, Diagnostic and Scientific Centre, Calgary, Alberta, Canada
| | - Gary W Procop
- Enterprise Test Utilization and Pathology Consultative Services, Cleveland, Ohio, USA
- Molecular Microbiology, Parasitology, and Mycology Laboratories, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, USA
| | - Norbert Ryan
- Bacteriology and Parasitology, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute, Melbourne, Victoria, Australia
| | | | - Govinda Visvesvara
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of Foodborne, Waterborne, and Environmental Diseases, Waterborne Disease Prevention Branch, Atlanta, Georgia, USA
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Forsell J, Bengtsson-Palme J, Angelin M, Johansson A, Evengård B, Granlund M. The relation between Blastocystis and the intestinal microbiota in Swedish travellers. BMC Microbiol 2017; 17:231. [PMID: 29228901 PMCID: PMC5725903 DOI: 10.1186/s12866-017-1139-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 11/30/2017] [Indexed: 01/07/2023] Open
Abstract
Background Blastocystis sp. is a unicellular eukaryote that is commonly found in the human intestine. Its ability to cause disease is debated and a subject for ongoing research. In this study, faecal samples from 35 Swedish university students were examined through shotgun metagenomics before and after travel to the Indian peninsula or Central Africa. We aimed at assessing the impact of travel on Blastocystis carriage and seek associations between Blastocystis and the bacterial microbiota. Results We found a prevalence of Blastocystis of 16/35 (46%) before travel and 15/35 (43%) after travel. The two most commonly Blastocystis subtypes (STs) found were ST3 and ST4, accounting for 20 of the 31 samples positive for Blastocystis. No mixed subtype carriage was detected. All ten individuals with a typable ST before and after travel maintained their initial ST. The composition of the gut bacterial community was not significantly different between Blastocystis-carriers and non-carriers. Interestingly, the presence of Blastocystis was accompanied with higher abundances of the bacterial genera Sporolactobacillus and Candidatus Carsonella. Blastocystis carriage was positively associated with high bacterial genus richness, and negatively correlated to the Bacteroides-driven enterotype. These associations were both largely dependent on ST4 – a subtype commonly described from Europe – while the globally prevalent ST3 did not show such significant relationships. Conclusions The high rate of Blastocystis subtype persistence found during travel indicates that long-term carriage of Blastocystis is common. The associations between Blastocystis and the bacterial microbiota found in this study could imply a link between Blastocystis and a healthy microbiota as well as with diets high in vegetables. Whether the associations between Blastocystis and the microbiota are resulting from the presence of Blastocystis, or are a prerequisite for colonization with Blastocystis, are interesting questions for further studies. Electronic supplementary material The online version of this article (10.1186/s12866-017-1139-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joakim Forsell
- Department of Clinical Microbiology, Umeå University, -901 87, Umeå, SE, Sweden.
| | - Johan Bengtsson-Palme
- Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.,Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Martin Angelin
- Department of Clinical Microbiology, Infectious Diseases, Umeå University, Umeå, Sweden
| | - Anders Johansson
- Department of Clinical Microbiology, Bacteriology, and the Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Birgitta Evengård
- Department of Clinical Microbiology, Infectious Diseases, Umeå University, Umeå, Sweden
| | - Margareta Granlund
- Department of Clinical Microbiology, Umeå University, -901 87, Umeå, SE, Sweden
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Valença Barbosa C, de Jesus Batista R, Pereira Igreja R, d'Avila Levy CM, Werneck de Macedo H, Carneiro Santos HL. Distribution of Blastocystis subtypes isolated from humans from an urban community in Rio de Janeiro, Brazil. Parasit Vectors 2017; 10:518. [PMID: 29070053 PMCID: PMC5657060 DOI: 10.1186/s13071-017-2458-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 10/06/2017] [Indexed: 12/13/2022] Open
Abstract
Background Blastocystis is a cosmopolitan protist parasite found in the human gastrointestinal tract and is highly prevalent in developing countries. Recent molecular studies have revealed extensive genetic diversity, which has been classified into different subtypes (STs) based on sequence analysis of small subunit ribosomal RNA gene. Blastocystis is one of the most common fecal parasites in Brazil, but the diversity of subtypes remains unknown in the country. This study aimed to determine the distribution of Blastocystis STs in an urban community in Duque de Caxias, Rio de Janeiro, Brazil. Methods A total of 64 stool samples positive for Blastocystis in Pavlova’s medium were subtyped by PCR and sequenced using primers targeting the small subunit rRNA gene, in addition to phylogenetic analysis and subtype-specific PCR using sequence-tagged-site (STS) primers. Results Endolimax nana (14%), Entamoeba complex (10.5%), Taenia sp. (0.6%), Trichuris trichiura (1.3%) and Enterobius vermicularis (1.3%) were detected in Blastocystis-positive samples. Of the 64 samples tested by PCR/DNA sequencing, 55 were identified as ST1 (42%), ST3 (49%), ST2 (7%) and ST4 (2%), and the presence of mixed ST (ST1 + ST3) infection was detected in nine samples (14%). Conclusions DNA sequencing and phylogenetic analysis of Brazilian Blastocystis isolates identified four different subtypes. To our knowledge, this study provided the first genetic characterization of Blastocystis subtypes in an urban area of Rio de Janeiro, Brazil. We also identified ST4 for the first time in Brazil. Further studies are necessary to determine the distribution of STs across human populations in Rio de Janeiro.
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Affiliation(s)
- Carolina Valença Barbosa
- Laboratório de Estudos Integrados em Protozoologia, Instituto Oswaldo Cruz/FIOCRUZ, Av. Brasil, 4365 Pavilhão Arthur Neiva, Rio de Janeiro, 21.045-900, Brazil
| | - Rosemary de Jesus Batista
- Departamento de Ginecologia e Obstetrícia, IFF/Fiocruz, Rio de Janeiro, Brasil, Av. Rui Barbosa, 716, Flamengo, Rio de Janeiro, 22250-020, Brazil
| | - Ricardo Pereira Igreja
- Departamento de Medicina Preventiva da Faculdade de Medicina da UFRJ , Av. Carlos Chagas Filho, 373, Edifício do Centro de Ciências da Saúde Bloco K, 2° andar, Sala 49 - Cidade Universitária - Ilha do Fundão, Rio de Janeiro, 21.941-902, Brazil
| | - Claudia Masini d'Avila Levy
- Laboratório de Estudos Integrados em Protozoologia, Instituto Oswaldo Cruz/FIOCRUZ, Av. Brasil, 4365 Pavilhão Arthur Neiva, Rio de Janeiro, 21.045-900, Brazil
| | - Heloisa Werneck de Macedo
- Laboratório de Parasitologia do Departamento de Patologia, Hospital Universitário Antônio Pedro/Universidade Federal Fluminense, Niterói, RJ, Rua Marquês do Paraná, 303. 4º andar, sala 12, Niterói, Rio de Janeiro, 24033 900, Brazil
| | - Helena Lúcia Carneiro Santos
- Laboratório de Estudos Integrados em Protozoologia, Instituto Oswaldo Cruz/FIOCRUZ, Av. Brasil, 4365 Pavilhão Arthur Neiva, Rio de Janeiro, 21.045-900, Brazil.
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Lepczyńska M, Białkowska J, Dzika E, Piskorz-Ogórek K, Korycińska J. Blastocystis: how do specific diets and human gut microbiota affect its development and pathogenicity? Eur J Clin Microbiol Infect Dis 2017; 36:1531-1540. [PMID: 28326446 PMCID: PMC5554277 DOI: 10.1007/s10096-017-2965-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 03/08/2017] [Indexed: 12/31/2022]
Abstract
Blastocystis is an enteric parasite that inhabits the gastrointestinal tract of humans and many animals. This emerging parasite has a worldwide distribution. It is often identified as the most common eukaryotic organism reported in human fecal samples. This parasite is recognized and diagnosed more often than ever before. Furthermore, some strains develop resistance against currently recommended drugs, such as metronidazole; therefore, the use of natural remedies or special diets has many positive aspects that may address this problem. The goal of this review is to compare natural treatments and various diets against the efficacy of drugs, and describe their influence on the composition of the gut microbiota, which affects Blastocystis growth and the occurrence of symptoms. This article reviews important work in the literature, including the classification, life cycle, epidemiology, pathogenesis, pathogenicity, genetics, biology, and treatment of Blastocystis. It also includes a review of the current knowledge about human gut microbiota and various diets proposed for Blastocystis eradication. The literature has revealed that garlic, ginger, some medical plants, and many spices contain the most effective organic compounds for parasite eradication. They work by inhibiting parasitic enzymes and nucleic acids, as well as by inhibiting protein synthesis. The efficacy of any specific organic compound depends on the Blastocystis subtype, and, consequently, on its immunity to treatment. In conclusion, the article discusses the findings that human gut microbiota composition triggers important mechanisms at the molecular level, and, thus, has a crucial influence on the parasitic pathogenicity.
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Affiliation(s)
- M Lepczyńska
- Department of Medical Biology, Faculty of Medical Sciences, University of Warmia and Mazury, Żołnierska 14 C, Olsztyn, 10-561, Poland.
| | - J Białkowska
- Department of Neurology and Neurosurgery, Faculty of Medical Sciences, University of Warmia and Mazury, Warszawska 30, Olsztyn, Poland
| | - E Dzika
- Department of Medical Biology, Faculty of Medical Sciences, University of Warmia and Mazury, Żołnierska 14 C, Olsztyn, 10-561, Poland
| | - K Piskorz-Ogórek
- Department of Nursing, Faculty of Medical Sciences, University of Warmia and Mazury, Żołnierska 14 C, Olsztyn, Poland
- Regional Specialized Children's Hospital in Olsztyn, Żołnierska 18A, Olsztyn, Poland
| | - J Korycińska
- Department of Medical Biology, Faculty of Medical Sciences, University of Warmia and Mazury, Żołnierska 14 C, Olsztyn, 10-561, Poland
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Blastocystis in Côte d'Ivoire: molecular identification and epidemiological data. Eur J Clin Microbiol Infect Dis 2017; 36:2243-2250. [PMID: 28674969 DOI: 10.1007/s10096-017-3053-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/20/2017] [Indexed: 10/19/2022]
Abstract
Blastocystis is an enteric protozoan infecting humans and animals in both developed and developing countries at all latitudes. Despite this, data on Blastocystis infection are not available for several geographical areas, including many African countries. In this study, a survey was conducted on Blastocystis among humans and domestic animals in rural and urban localities in Côte d'Ivoire, in order to investigate the prevalence, the subtype distribution, and the zoonotic potential in association with sociodemographic factors, seasonality, symptoms, and co-infections. A total of 110 fecal samples were collected from patients living in four localities. Molecular and phylogenetic analyses were conducted for Blastocystis detection and subtyping. Positive samples from symptomatic patients were tested by Luminex xTAG® Gastrointestinal Pathogen Panel (GPP) to evidence the presence of other common intestinal pathogens. Overall, a prevalence of 58.2% was observed in humans and subtypes ST1(50.0%), ST2 (22.0%) and ST3 (28.1%) were identified. The prevalence values varied significantly among the sites but not in relation to the subtype. The seasonal rains significantly increase the infection rate in all localities. No significant differences in the ST distribution between asymptomatic and symptomatic subjects were observed. As regard the zoonotic transmission, an additional sampling was conducted in another village where fecal samples were simultaneously collected from humans and animals. Blastocystis STs 1-3 and ST7 were identified in eight humans and four chickens, respectively. This study provides the first exhaustive data on the prevalence and molecular epidemiology of Blastocystis in Côte d'Ivoire.
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Molecular characterization of Blastocystis sp. in captive wild animals in Qinling Mountains. Parasitol Res 2017; 116:2327-2333. [PMID: 28540508 DOI: 10.1007/s00436-017-5506-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 05/07/2017] [Indexed: 01/26/2023]
Abstract
Blastocystis is one common protist inhabiting in gastrointestinal tracts of animals and humans. Examining the subtypes has important implications for assessing the zoonotic potential of Blastocystis and intestinal health of hosts. In the present study, a total of 497 fecal samples collected from 37 wild animal species in Qinling Mountains were investigated for the presence and subtypes of Blastocystis. Of them, 200 (40.2%) were positive for Blastocystis and 13 subtypes were found, including eight known subtypes (STs1-3, 5, 10, 12-14) and five possible novel subtypes (temporarily named as STs18-22), with ST10 as the predominate subtype and the subtype ST5 was detected in an ostrich for the first time. These findings indicated the wide distribution and specific subtype characteristics of Blastocystis in wild animals of Qinling Mountains.
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Identification of Blastocystis subtypes in clinical stool samples from Sao Paulo City, Brazil. ACTA ACUST UNITED AC 2017. [DOI: 10.1017/pao.2017.3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
SUMMARY
Blastocystis sp. is a protozoan commonly found in human and animal stool samples. Several pathogenic and zoonotic aspects of this organism are still unknown. The aim of the present study was to investigate Blastocystis subtypes (STs) in samples from patients of the Hospital das Clínicas of the Faculdade de Medicina at the Universidade de São Paulo (HC-FMUSP), Brazil. Blastocystis sp.-positive stool samples diagnosed at the Section of Parasitology of the Central Laboratory (HC-FMUSP) were used for DNA isolation. Polymerase chain reaction (PCR) was performed using specific primers targeting the small-subunit rRNA gene. Direct DNA sequencing of the PCR products was performed and the DNA sequences were then aligned and compared with other sequences obtained from the GenBank database. Phylogenetic analysis was used to identify STs and determine the phylogenetic relationships between the sequences. Four STs were identified: ST1 (22·5%), ST2 (12·5%), ST3 (60%) and ST6 (5%). In conclusion, ST3 was the most prevalent ST among the human isolates followed by ST1. The present study is one of the few providing STs data from the human population in South America. Determining ST prevalence in human samples may contribute to the monitoring of Blastocystis sp. infection transmission in endemic regions.
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Li C, Jin X, Li M, Wang G, Zou H, Li W, Wu S. Light and transmission electron microscopy of Cepedea longa (Opalinidae) from Fejervarya limnocharis. ACTA ACUST UNITED AC 2017; 24:6. [PMID: 28145223 PMCID: PMC5780805 DOI: 10.1051/parasite/2017006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 01/18/2017] [Indexed: 11/25/2022]
Abstract
Cepedea longa Bezzenberger, 1904, collected from Fejervarya limnocharis (Amphibia, Anura, Ranidae) from Honghu Lake, Hubei Province, China in May–July 2016, is described at both light and transmission electron microscope levels. This is the first electron microscopic study of this species. Cepedea longa possesses a developed fibrillar skeletal system, composed of longitudinal fibrillar bands and transversal fibrils as well as numerous thin microfibrils dispersed in the endoplasm, which may play an important role in morphogenesis and offer some resilience to deformations of the cell. Longitudinal microfibrils are polarizing elements of kineties, bordering the somatic kineties on the left side and possibly responsible for kinetosome alignment. Two types of vesicles exist in the somatic cortex: globular endocytotic vesicles and flattened exocytotic vesicles. As to the nuclei of C. longa, a thick microfibrillar layer was observed to attach to the cytoplasmic face of the nuclear envelope. This fact suggests no necessary connection between the presence of this microfibrillar layer and the number of nuclei. In addition, some unknown tightly-packed microtubular structures in the nucleoplasm were observed for the first time in opalinids; neither their nature nor physiological significance is known. A detailed list of all reported Cepedea species is included.
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Affiliation(s)
- Can Li
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, PR China
| | - Xiao Jin
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, PR China
| | - Ming Li
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Guitang Wang
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Hong Zou
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Wenxiang Li
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Shangong Wu
- Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, PR China
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Martin FN, Tooley PW. Phylogenetic relationships amongPhytophthoraspecies inferred from sequence analysis of mitochondrially encoded cytochrome oxidase I and II genes. Mycologia 2017. [DOI: 10.1080/15572536.2004.11833112] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | - Paul W. Tooley
- USDA-ARS, Foreign Disease-Weed Science Research Unit, 1301 Ditto Ave., Fort Detrick, Maryland 21702
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Palasuwan A, Palasuwan D, Mahittikorn A, Chiabchalard R, Combes V, Popruk S. Subtype Distribution of Blastocystis in Communities along the Chao Phraya River, Thailand. THE KOREAN JOURNAL OF PARASITOLOGY 2016; 54:455-60. [PMID: 27658597 PMCID: PMC5040084 DOI: 10.3347/kjp.2016.54.4.455] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/19/2016] [Accepted: 06/08/2016] [Indexed: 11/23/2022]
Abstract
Blastocystis is a common zoonotic enteric protozoan that has been classified into 17 distinct subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distributions of Blastocystis in villagers living along the Chao Phraya River, Ayutthaya Province, Thailand, and to assess the risk of zoonotic infection. In total, 220 stool samples were collected, and DNA was extracted. PCR and sequencing were performed with primers targeting the small-subunit ribosomal RNA (SSU rRNA) genes. Blastocystis was present in 5.9% (13/220) of samples, and ST3 (5.0%; 11/220) was the predominant subtype, followed by ST2 (0.45%; 1/220) and ST6 (0.45%; 1/220). Phylogenetic trees were constructed with the maximum-likelihood method based on the Hasegawa–Kishino–Yano + G + I model, neighbor-joining, and maximum parsimony methods. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. All the sequences of the Blastocystis-positive samples (KU051524–KU051536) were closely related to those from animals (pig, cattle, and chicken), indicating a zoonotic risk. Therefore, the villagers require proper health education, especially regarding the prevention of parasitic infection, to improve their personal hygiene and community health. Further studies are required to investigate the Blastocystis STs in the animals living in these villages.
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Affiliation(s)
- Attakorn Palasuwan
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Duangdao Palasuwan
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Aongart Mahittikorn
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Rachatawan Chiabchalard
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
| | - Valery Combes
- Faculty of Sciences, School of Life Sciences, University of Technology, Sydney, Australia
| | - Supaluk Popruk
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
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Forsell J, Granlund M, Samuelsson L, Koskiniemi S, Edebro H, Evengård B. High occurrence of Blastocystis sp. subtypes 1-3 and Giardia intestinalis assemblage B among patients in Zanzibar, Tanzania. Parasit Vectors 2016; 9:370. [PMID: 27356981 PMCID: PMC4928263 DOI: 10.1186/s13071-016-1637-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 06/10/2016] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Blastocystis is a common intestinal parasite with worldwide distribution but the distribution of Blastocystis and its subtypes in East Africa is largely unknown. In this study, we investigate the distribution of Blastocystis subtypes in Zanzibar, Tanzania and report the prevalence of intestinal parasites using both molecular methods and microscopy. METHODS Stool samples were collected from both diarrhoeic and non-diarrhoeic outpatients in Zanzibar. In addition to microscopy, real-time PCR for Blastocystis, Entamoeba histolytica and E. dispar, Giardia intestinalis, Cryptosporidium spp., and Dientamoeba fragilis was used. Blastocystis subtypes were determined by a conventional PCR followed by partial sequencing of the SSU-rRNA gene. Genetic assemblages of Giardia were determined by PCR with assemblage specific primers. RESULTS Intestinal parasites were detected in 85 % of the 174 participants, with two or more parasites present in 56 %. Blastocystis sp. and Giardia intestinalis were the most common parasites, identified by PCR in 61 and 53 % of the stool samples respectively, but no correlation between carriage of Blastocystis and Giardia was found. The Blastocystis subtype distribution was ST1 34.0 %, ST2 26.4 %, ST3 25.5 %, ST7 0.9 %, and 13.2 % were positive only by qPCR (non-typable). The Giardia genetic assemblages identified were A 6.5 %, B 85 %, A + B 4.3 %, and non-typable 4.3 %. The detection rate with microscopy was substantially lower than with PCR, 20 % for Blastocystis and 13.8 % for Giardia. The prevalence of Blastocystis increased significantly with age while Giardia was most prevalent in children two to five years old. No correlation between diarrhoea and the identification of Giardia, Blastocystis, or their respective genetic subtypes could be shown and, as a possible indication of parasite load, the mean cycle threshold values in the qPCR for Giardia were equal in diarrhoeic and non-diarrhoeic patients. CONCLUSIONS Carriage of intestinal parasites was very common in the studied population in Zanzibar. The most commonly detected parasites, Blastocystis and Giardia, had different age distributions, possibly indicating differences in transmission routes, immunity, and/or other host factors for these two species. In the Blastocystis subtype analysis ST1-3 were common, but ST4, a subtype quite common in Europe, was completely absent, corroborating the geographical differences in subtype distributions previously reported.
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Affiliation(s)
- Joakim Forsell
- Division of Clinical Bacteriology, Department of Clinical Microbiology, Umeå University, SE-901 87, Umeå, Sweden.
| | - Margareta Granlund
- Division of Clinical Bacteriology, Department of Clinical Microbiology, Umeå University, SE-901 87, Umeå, Sweden
| | - Linn Samuelsson
- Division of Clinical Bacteriology, Department of Clinical Microbiology, Umeå University, SE-901 87, Umeå, Sweden
| | - Satu Koskiniemi
- Division of Clinical Bacteriology, Department of Clinical Microbiology, Umeå University, SE-901 87, Umeå, Sweden
| | - Helén Edebro
- Division of Clinical Bacteriology, Department of Clinical Microbiology, Umeå University, SE-901 87, Umeå, Sweden
| | - Birgitta Evengård
- Division of Infectious Diseases, Department of Clinical Microbiology, Umeå University, SE-901 87, Umeå, Sweden
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65
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Stensvold CR, Clark CG. Current status of Blastocystis: A personal view. Parasitol Int 2016; 65:763-771. [PMID: 27247124 DOI: 10.1016/j.parint.2016.05.015] [Citation(s) in RCA: 216] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 05/10/2016] [Accepted: 05/27/2016] [Indexed: 12/15/2022]
Abstract
Despite Blastocystis being one of the most widespread and prevalent intestinal eukaryotes, its role in health and disease remains elusive. DNA-based detection methods have led to a recognition that the organism is much more common than previously thought, at least in some geographic regions and some groups of individuals. Molecular methods have also enabled us to start categorizing the vast genetic heterogeneity that exists among Blastocystis isolates, wherein the key to potential differences in the clinical outcome of Blastocystis carriage may lie. In this review we summarize some of the recent developments and advances in Blastocystis research, including updates on diagnostic methods, molecular epidemiology, genetic diversity, host specificity, clinical significance, taxonomy, and genomics. As we are now in the microbiome era, we also review some of the steps taken towards understanding the place of Blastocystis in the intestinal microbiota.
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Affiliation(s)
| | - C Graham Clark
- London School of Hygiene and Tropical Medicine, London, UK
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66
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Ajjampur SSR, Tan KSW. Pathogenic mechanisms in Blastocystis spp. - Interpreting results from in vitro and in vivo studies. Parasitol Int 2016; 65:772-779. [PMID: 27181702 DOI: 10.1016/j.parint.2016.05.007] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 05/04/2016] [Accepted: 05/11/2016] [Indexed: 01/20/2023]
Abstract
Blastocystis spp. are commonly reported intestinal protists but whose clinical significance remains controversial. Infections have ranged from asymptomatic carriage to non-specific gastrointestinal symptoms and have also been linked to irritable bowel syndrome and urticaria in some patient populations. In vitro studies showed that both parasite and parasite lysates have damaging effects on intestinal epithelial cells causing apoptosis and degradation of tight junction proteins occludin and ZO1, resulting in increased intestinal permeability. Adhesion of trophic forms to the intestinal epithelium and release of cysteine proteases appear to be the major triggers leading to pathogenesis. Two putative virulence factors identified are cysteine proteases legumain and cathepsin B. Blastocystis spp. also have immuno-modulatory effects including degradation of IgA, inhibition of iNOS and upregulation of proinflammatory cytokines, IL8 and GM-CSF in intestinal epithelial cells and IL1β, IL6 and TNFα in murine macrophages. Blastocystis spp. have also been reported to dampen response to LPS in intestinal epithelial cells and monocytes. Studies in rodent models and naturally infected pigs have shown that the parasite localizes to the lumen and mucosal surface of the large intestine mostly in the caecum and colon. The parasite has been found to cause mucosal sloughing, increase in goblet cell mucin, increased intestinal permeability and to induce a pro-inflammatory cytokine response with upregulation of TNFα, IFNγ and IL12. In this review, we summarize findings from in vitro and in vivo studies that demonstrate pathogenic potential but also show considerable inter and intra subtype variation, which provides a plausible explanation on the conflicting reports on clinical significance.
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Affiliation(s)
- Sitara S R Ajjampur
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology, National University of Singapore, Singapore
| | - Kevin S W Tan
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology, National University of Singapore, Singapore.
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67
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The Biological Fight Against Pathogenic Bacteria and Protozoa. NEW WEAPONS TO CONTROL BACTERIAL GROWTH 2016. [PMCID: PMC7123701 DOI: 10.1007/978-3-319-28368-5_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The animal gastrointestinal tract is a tube with two open ends; hence, from the microbial point of view it constitutes an open system, as opposed to the circulatory system that must be a tightly closed microbial-free environment. In particular, the human intestine spans ca. 200 m2 and represents a massive absorptive surface composed of a layer of epithelial cells as well as a paracellular barrier. The permeability of this paracellular barrier is regulated by transmembrane proteins known as claudins that play a critical role in tight junctions.
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68
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Lepczyńska M, Chen WC, Dzika E. Mysterious chronic urticaria caused by Blastocystis spp.? Int J Dermatol 2015; 55:259-66; quiz 263-4, 266. [PMID: 26469206 DOI: 10.1111/ijd.13064] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 03/09/2015] [Accepted: 04/08/2015] [Indexed: 01/18/2023]
Abstract
Species of the genus Blastocystis, which are single-cell, intestinal protozoan parasites of humans and animals, remain mysterious, with unclear clinical and epidemiologic significance. In recent years, many researchers have suggested a possible connection between Blastocystis spp. infection and chronic urticaria. In the present article, we review the literature and discuss the possible associations between the clinical symptomatology and pathogenicity of this organism in terms of its subtypes, morphologic forms, genetic diversity, and interactions with other intestinal microbiota.
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Affiliation(s)
- Małgorzata Lepczyńska
- Department of Medical Biology, Faculty of Medical Sciences, University of Warmia and Mazury, Olsztyn, Poland
| | - Wen-Chieh Chen
- Department of Dermatology and Allergy, Technical University of Munich, Munich, Germany.,Women's Health Center, Far Eastern Memorial Hospital, New Taipei City, Taiwan
| | - Ewa Dzika
- Department of Medical Biology, Faculty of Medical Sciences, University of Warmia and Mazury, Olsztyn, Poland
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69
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Khoshnood S, Rafiei A, Saki J, Alizadeh K. Prevalence and Genotype Characterization of Blastocystis hominis Among the Baghmalek People in Southwestern Iran in 2013 - 2014. Jundishapur J Microbiol 2015; 8:e23930. [PMID: 26587213 PMCID: PMC4644266 DOI: 10.5812/jjm.23930] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 01/30/2015] [Accepted: 02/16/2015] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Blastocystis hominis is a common globally distributed parasite. The prevalence of this parasite has been shown to vary among different countries. Molecular studies have also shown that there is a high level of genetic diversity among Blastocystis spp. isolated from humans and animals. Extensive information on parasitic genotypes will aid in devising more effective strategies for the identification and potential control of these pathogenic parasites. OBJECTIVES This study aimed to gain information on the prevalence and abundance of Blastocystis subtypes in Iran. MATERIALS AND METHODS Over a period of 3 months, 1,410 stool samples were collected and examined by microscopy. Samples found to be positive for B. hominis were concentrated and phylogenetic analysis was subsequently performed. A questionnaire was completed by all study participants. RESULTS Blastocystis hominis was found to have a prevalence of 3.33% in the study population. There was no significant association of Blastocystis infection with age (P = 0.3) or gender (P = 0.57). The Blastocystis subtypes (ST) identified in this study were ST3, ST4, ST5, and ST7 with the most prevalent being ST4 (40.9%). CONCLUSIONS The prevalence of B. hominis in the study area was lower than that reported for most developed countries, and unlike in other countries in the Middle East, ST4 was the most prevalent subtype.
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Affiliation(s)
- Saleh Khoshnood
- Parasitology Department, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran
| | - Abdollah Rafiei
- Parasitology Department, Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran
| | - Jasem Saki
- Parasitology Department, Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran
| | - Kobra Alizadeh
- Department of Occupational Health, Faculty of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran
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Casero RD, Mongi F, Sánchez A, Ramírez JD. Blastocystis and urticaria: Examination of subtypes and morphotypes in an unusual clinical manifestation. Acta Trop 2015; 148:156-61. [PMID: 25976414 DOI: 10.1016/j.actatropica.2015.05.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 04/27/2015] [Accepted: 05/04/2015] [Indexed: 01/09/2023]
Abstract
Blastocystis is a human common enteric protist that may colonize a large variety of non-human hosts linked to symptoms and diseases such as abdominal pain, constipation, diarrhea, urticaria, flatulence and irritable bowel syndrome (IBS). Blastocystis exhibits remarkable genetic diversity and multiple subtypes (STs) within the genus with no absolute associations with clinical symptomatology. Here we analyzed fecal samples from Argentinean patients (n=270) belonging to symptomatic (urticaria and non-specific gastrointestinal symptoms, n=39) and asymptomatic control (n=28). Those patients infected with Blastocystis (n=67) were submitted for morphological analysis, DNA extraction, 18S PCR, sequencing and STs identification according to DNA barcoding. Blastocystis vacuolar forms were the predominant morphotype (75%), ameboid-like forms were evidenced in 1.5% of samples. Blastocystis ST3 was detected in 71.6% (n=48), of which 71.4%, (n=35) and 28.6% (n=14) belonged to symptomatic and asymptomatic respectively. Other subtypes identified were ST1 (14.9%), ST6 (7.5%) and ST2 (5.9%). Blastocystis 18S barcoding evidenced in non-urticaria symptomatic patients and asymptomatic control group the presence of allele 134 (ST3) (p<0.0001), while allele 34 (ST3) was detected in 85.7% (18/21) of symptomatic uricaria as compared with control group (1/21) (p<0.0001). The presence of a particular allele (a34) significantly associated with urticaria patients was detected and the clinical implications of these findings are herein discussed.
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71
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Molecular epidemiology and genetic diversity of Blastocystis infection in humans in Italy. Epidemiol Infect 2015; 144:635-46. [PMID: 26194649 DOI: 10.1017/s0950268815001697] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In order to describe the molecular epidemiology of Blastocystis infection in Italy, 189 isolates, which had been collected during the years 2012-2014 from mildly symptomatic patients, or those affected by inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) or chronic diarrhoea, or otherwise immunosuppressed, were subtyped by sequence analysis of the SSU rRNA gene (536 bp). Six subtypes (STs) were detected: ST1 (15·3%), ST2 (13·8%), ST3 (46·0%), ST4 (21·7%), ST6 (3·2%) and ST8 (0·5%). They clustered in distinct clades, as inferred from Bayesian inference phylogenetic and median joining network analyses. A high genetic differentiation was found at the inter-subtype level; it ranged from Jukes-Cantor (JC) distance = 0·02 (between ST1 and ST4) to JC = 0·11 (between ST6 and ST2). At the intra-ST level, a high genetic homogeneity was registered in ST4, whereas higher genetic variation was found in isolates corresponding to ST1 and ST2. Accordingly, high values of haplotype and nucleotide diversity were observed in ST1, ST2 and ST3. No association was found between patient gender and ST, whereas ST3 and ST1 were significantly more prevalent in patients aged 15-50 years. A significant occurrence of Blastocystis ST4 in patients suffering from IBS, IBD or chronic diarrhoea was observed; in addition, a slight significant association between ST1 and ST3 and IBS patients was found. Multiple correspondence analysis showed some significant contribution of different variables (subtypes, haplotypes, age) in the observed pattern of ordination of the 189 patients in the symptom categories.
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Development and Application of a Blastocystis Subtype-Specific PCR Assay Reveals that Mixed-Subtype Infections Are Common in a Healthy Human Population. Appl Environ Microbiol 2015; 81:4071-6. [PMID: 25841010 DOI: 10.1128/aem.00520-15] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 03/31/2015] [Indexed: 01/01/2023] Open
Abstract
The human gut is host to a diversity of microorganisms, including the single-celled microbial eukaryote Blastocystis. Research has shown that most carriers host a single Blastocystis subtype (ST), which is unusual given the considerable within-host species diversity observed for other microbial genera in this ecosystem. However, our limited knowledge of both the incidence and biological significance of Blastocystis diversity within hosts (i.e., so-called mixed infections) is likely due to problems with existing methodologies. Here, we developed and applied Blastocystis ST-specific PCRs for the investigation of the most common subtypes of Blastocystis (ST1 to ST4) to a healthy human cohort (n = 50). We detected mixed infections in 22% of the cases, all of which had been identified as single-ST infections in a previous study using state-of-the-art methods. Our results show that certain STs occur predominantly as either single (ST3 and 4) or mixed (ST1) infections, which may reflect inter alia transient colonization patterns and/or cooperative or competitive interactions between different STs. Comparative analyses with other primers that have been used extensively for ST-specific analysis found them unsuitable for detection of mixed- and, in some cases, single-ST infections. Collectively, our data shed new light on the diversity of Blastocystis within and between human hosts. Moreover, the development of these PCR assays will facilitate future work on the molecular epidemiology and significance of mixed infections in groups of interest, including health and disease cohorts, and also help identify sources of Blastocystis transmission to humans, including identifying potential animal and environmental reservoirs.
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Popruk S, Udonsom R, Koompapong K, Mahittikorn A, Kusolsuk T, Ruangsittichai J, Palasuwan A. Subtype distribution of Blastocystis in Thai-Myanmar border, Thailand. THE KOREAN JOURNAL OF PARASITOLOGY 2015; 53:13-9. [PMID: 25748704 PMCID: PMC4384802 DOI: 10.3347/kjp.2015.53.1.13] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/14/2014] [Accepted: 10/23/2014] [Indexed: 11/23/2022]
Abstract
Blastocystis sp. is a common zoonotic intestinal protozoa which has been classified into 17 subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distribution of Blastocystis in villagers living on the Thai-Myanmar border, where the risk of parasitic infection is high. A total of 207 stool samples were collected and DNA was extracted. PCR and sequencing using primers targeting small-subunit ribosomal RNA (SSU rRNA) gene were performed. The prevalence of Blastocystis infection was 37.2% (77/207). ST3 (19.8%; 41/207) was the predominant subtype, followed by ST1 (11.6%; 24/207), ST2 (5.3%; 11/207), and ST4 (0.5%; 1/207). A phylogenetic tree was reconstructed using the maximum likelihood (ML) method based on the Hasegawa-Kishino-Yano + G + I model. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. Some sequences of Blastocystis positive samples (TK18, 39, 46, 71, and 90) were closely related to animals (pig and cattle) indicating zoonotic risks. Therefore, proper health education in parasitic prevention for the villagers should be promoted to improve their personal hygiene. Further longitudinal studies are required to monitor the prevalence of parasitic infections after providing health education and to investigate Blastocystis ST in animals living in these villages.
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Affiliation(s)
- Supaluk Popruk
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Bangkok, 10400, Thailand
| | - Ruenruetai Udonsom
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Bangkok, 10400, Thailand
| | - Khuanchai Koompapong
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Bangkok, 10400, Thailand
| | - Aongart Mahittikorn
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Bangkok, 10400, Thailand
| | - Teera Kusolsuk
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Bangkok, 10400, Thailand
| | - Jiraporn Ruangsittichai
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Bangkok, 10400, Thailand
| | - Attakorn Palasuwan
- Department of Clinical Microscopy, Faculty of Allied Health Sciences, Chulalongkorn University, 154 Rama I Road, Bangkok, Thailand
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Pandey PK, Verma P, Marathe N, Shetty S, Bavdekar A, Patole MS, Stensvold CR, Shouche YS. Prevalence and subtype analysis of Blastocystis in healthy Indian individuals. INFECTION GENETICS AND EVOLUTION 2015; 31:296-9. [PMID: 25701123 DOI: 10.1016/j.meegid.2015.02.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 11/17/2022]
Abstract
There is a growing interest in subtype (ST) analysis of the intestinal parasite Blastocystis due to its extensive genetic diversity that might reflect differences in pathogenicity. Although essential for reference, few studies are available on Blastocystis in healthy individuals. Moreover, molecular epidemiology data on Blastocystis in India still remain to emerge. In the present study we identified the prevalence and ST distribution of Blastocystis in healthy Indian individuals. A total of 220 stool samples were obtained; four of 100 samples from 100 adults were chosen randomly for construction of small subunit (SSU) rRNA gene clone libraries in order to elucidate micro-eukaryotic diversity in the human gut. From the SSU rDNA library, 64 sequences annotated to Blastocystis were used for ST analysis along with sequences obtained by direct sequencing of SSU rDNA PCR products amplified from the remaining samples and generated using primers targeting Blastocystis. Of 220 stool samples collected, 120 samples from 30 infants (aged 1week to 1year) were PCR-negative. Of the remaining 100 samples from 100 adults, 27 resulted in specific amplification. Out of these 27, four samples were suspected of mixed ST infection and so these samples were further analyzed by construction of clone libraries. Analysis of cloned sequences revealed that indeed 2 samples had mixed ST infection (ST1 and ST3) while the remaining two showed infection with two separate ST3 strains. ST3 was the most common ST present in our study group (100%) followed by ST1 (7.4%); ST1 was seen only in mixed infections. SSU rDNA clone library sequences generated by processing of pooled samples were identified as ST3. The majority of ST3 sequences exhibited allele 34 commonly found in the European population.
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Affiliation(s)
- Prashant Kumar Pandey
- Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India
| | - Pankaj Verma
- Marine Biotechnology Lab, National Institute of Ocean Technology, Chennai, India
| | - Nachiket Marathe
- Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India
| | - Sudarshan Shetty
- Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India
| | - Ashish Bavdekar
- Department of Paediatrics [A.V], KEM Hospital, Pune 411011, Maharashtra, India
| | - Milind Shivaji Patole
- Molecular Biology Unit, National Centre for Cell Science, Pune 411007, Maharashtra, India
| | - Christen Rune Stensvold
- Department of Microbiology and Infection Control, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark
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Belli A, Coppola MG, Petrullo L, Lettieri G, Palumbo C, Dell'Isola C, Smeraglia R, Triassi M, Spada E, Amoroso P. The current spectrum and prevalence of intestinal parasitosis in Campania (region of southern Italy) and their relationship with migration from endemic countries. Int J Infect Dis 2014; 29:42-7. [PMID: 25449234 DOI: 10.1016/j.ijid.2014.04.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Revised: 03/11/2014] [Accepted: 04/20/2014] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND In Italy, the current clinical-epidemiological features of intestinal parasitosis and the impact of recent massive migration flows from endemic areas on their distribution are not very well known. METHODS An analysis was carried out involving 1766 patients (720 natives and 1046 immigrants) observed during the period 2009-2010 (the 'current group') and 771 native patients observed during the period 1996-1997 (the 'historical group'), a time at which immigration in the area was minimal. Patients were analyzed for intestinal parasitosis at four healthcare centres in Campania. RESULTS A wide variety of intestinal parasites was detected in the study subjects. Immigrants had a significantly higher prevalence of parasitosis and multiple simultaneous infections than natives in both groups. In both study groups of natives, the detection of at least one parasite was significantly associated with a history of travel to endemic areas. Among immigrants, we found an inverse correlation between the frequency of parasite detection and the amount of time spent in Italy. No circulation of parasites was found among contacts of parasitized patients. CONCLUSIONS Intestinal parasites are still a cause of intestinal infection in Campania. Although immigrants have a significantly higher prevalence of parasitosis than natives, this does not increase the risk of infection for that population. This is likely due to the lack of suitable biological conditions in our area.
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Affiliation(s)
- Alberta Belli
- Department of Preventive Medical Sciences, University of Naples Federico II, Naples, Italy
| | - Maria Grazia Coppola
- Unit of Microbiology, Cotugno Hospital, AORN "Ospedali dei Colli", Naples, Italy
| | - Luciana Petrullo
- Unit of Microbiology, Cotugno Hospital, AORN "Ospedali dei Colli", Naples, Italy
| | - Gennaro Lettieri
- VI Division of Infectious Diseases, Cotugno Hospital, AORN "Ospedali dei Colli", Naples, Italy
| | - Cristiana Palumbo
- VI Division of Infectious Diseases, Cotugno Hospital, AORN "Ospedali dei Colli", Naples, Italy
| | - Chiara Dell'Isola
- VI Division of Infectious Diseases, Cotugno Hospital, AORN "Ospedali dei Colli", Naples, Italy
| | - Riccardo Smeraglia
- Unit of Microbiology, Cotugno Hospital, AORN "Ospedali dei Colli", Naples, Italy
| | - Maria Triassi
- Department of Preventive Medical Sciences, University of Naples Federico II, Naples, Italy
| | - Enea Spada
- Department of Infectious, Parasitic and Immuno-mediated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Pietro Amoroso
- VI Division of Infectious Diseases, Cotugno Hospital, AORN "Ospedali dei Colli", Naples, Italy.
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Scanlan PD, Stensvold CR, Rajilić-Stojanović M, Heilig HGHJ, De Vos WM, O'Toole PW, Cotter PD. The microbial eukaryote Blastocystis is a prevalent and diverse member of the healthy human gut microbiota. FEMS Microbiol Ecol 2014; 90:326-30. [PMID: 25077936 DOI: 10.1111/1574-6941.12396] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/22/2014] [Accepted: 07/24/2014] [Indexed: 12/18/2022] Open
Abstract
To date, the majority of research into the human gut microbiota has focused on the bacterial fraction of the community. Inevitably, this has resulted in a poor understanding of the diversity and functionality of other intestinal microorganisms in the human gut. One such nonbacterial member is the microbial eukaryote Blastocystis, which has been implicated in the aetiology of a range of different intestinal and extra-intestinal diseases. However, prevalence data from different studies are conflicting, and crucially, there is limited information on its incidence and diversity in healthy individuals. Here, we survey the prevalence, genetic diversity and temporal stability of Blastocystis in a group of healthy adults (n = 105) using a sensitive PCR assay. Blastocystis was present in 56% of our sample set, which is much higher than previously reported from an industrialised county (Ireland). Moreover, a diversity of different subtypes (species) were detected, and Blastocystis was present in a subset of individuals sampled over a period of time between 6 and 10 years, indicating that it is capable of long-term host colonisation. These results show that Blastocystis is a common and diverse member of the healthy gut microbiota, thereby extending our knowledge of the microbial ecology of the healthy human intestine.
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Li W, Wang C, Huang F, Li M, Nilsen F, Liu H, Xu J. Redescription of Protoopalina pingi Nie, 1935 inhabiting the recta of Hylarana guentheri and Pelophylax nigromaculatus in China. Parasite 2014; 21:46. [PMID: 25208482 PMCID: PMC4160848 DOI: 10.1051/parasite/2014021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/01/2014] [Indexed: 11/15/2022] Open
Abstract
A redescription of Protoopalina pingi Nie, 1935 is presented in this paper to complete Nie’s description at both light and scanning electron microscope levels. These organisms were collected from the recta of the frogs Hylarana guentheri Boulenger, 1882 and Pelophylax nigromaculatus Hallowell, 1861 from Jialing River, Sichuan Province and Honghu Lake, Hubei Province, respectively, in China. This is the first record of its occurrence in H. guentheri and P. nigromaculatus. The body of P. pingi is elongated and somewhat spindle-like in shape, slightly narrowed and bluntly rounded at the anterior extremity, while the posterior end is tapering or sharply pointed. The body surface is thickly flagellated, with the caudal tip being barren. The falx, located at the margin of the anterior end, is composed of a narrow band of kinetosomes. Four round or oval-shaped nuclei, usually arranged in a straight line, are situated in the middle region of the body. Comparisons are made between P. pingi and its congeners.
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Affiliation(s)
- Weidong Li
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China
| | - Chong Wang
- Institute of Hydroecology, Ministry of Water Resources & Chinese Academy of Sciences, Wuhan 430079, China
| | - Feng Huang
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China
| | - Ming Li
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China - Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen 5020, Norway - Hubei Collaborative Innovation Centre for Freshwater Aquaculture, Wuhan 430070, China
| | - Frank Nilsen
- Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen 5020, Norway
| | - Huiyu Liu
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China
| | - Jianlong Xu
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China
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Wawrzyniak I, Poirier P, Viscogliosi E, Dionigia M, Texier C, Delbac F, Alaoui HE. Blastocystis, an unrecognized parasite: an overview of pathogenesis and diagnosis. Ther Adv Infect Dis 2014; 1:167-78. [PMID: 25165551 DOI: 10.1177/2049936113504754] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Blastocystis sp. is among the few enteric parasites with a prevalence that often exceeds 5% in the general population of industrialized countries and can reach 30-60% in developing countries. This parasite is frequently found in people who are immunocompromised (patients with human immunodeficiency virus/acquired immunodeficiency syndrome or cancer) and a higher risk of Blastocystis sp. infection has been found in people with close animal contact. Such prevalence in the human population and the zoonotic potential naturally raise questions about the impact of these parasites on public health and has increased interest in this area. Recent in vitro and in vivo studies have shed new light on the pathogenic power of this parasite, suggesting that Blastocystis sp. infection is associated with a variety of gastrointestinal disorders, may play a significant role in irritable bowel syndrome, and may be linked with cutaneous lesions (urticaria). Despite recent significant advances in the knowledge of the extensive genetic diversity of this species, the identification of extracellular proteases as virulence factors and the publication of one isolate genome, many aspects of the biology of Blastocystis sp. remain poorly investigated. In this review, we investigate several biological aspects of Blastocystis sp. (diversity and epidemiology, diagnosis tools and pathophysiology). These data pave the way for the following challenges concerning Blastocystis sp. research: deciphering key biological mechanisms and pathways of this parasite and clarification of its clinical impact in humans.
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Affiliation(s)
- Ivan Wawrzyniak
- Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes, Génome et Environnement, Clermont-Ferrand and CNRS, UMR 6023, LMGE, Aubière, France
| | - Philippe Poirier
- Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes, Génome et Environnement, Clermont-Ferrand, CNRS, UMR 6023, LMGE, Aubière, Clermont Université, Université d'Auvergne, JE 2526, Evolution des bactéries pathogènes et susceptibilité de l'hôte, Clermont-Ferrand and CHU Clermont-Ferrand, Service Parasitologie Mycologie, Clermont-Ferrand, France
| | - Eric Viscogliosi
- Institut Pasteur de Lille, Centre d'Infection et d'Immunité de Lille, Inserm U1019, CNRS UMR 8204, Université Lille Nord de France, Biology and Diversity of Emerging Eukaryotic Pathogens, Lille cedex, France
| | - Meloni Dionigia
- Institut Pasteur de Lille, Centre d'Infection et d'Immunité de Lille, Inserm U1019, CNRS UMR 8204, Université Lille Nord de France, Biology and Diversity of Emerging Eukaryotic Pathogens, Lille cedex, France and Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center 3-1-1 Koyadai, Tsukuba-shi, Ibaraki, Japan
| | - Catherine Texier
- Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes, Génome et Environnement, Clermont-Ferrand and CNRS, UMR 6023, LMGE, Aubière, France
| | - Frédéric Delbac
- Clermont Université, Université Blaise Pascal, Laboratoire Microorganismes, Génome et Environnement, Clermont-Ferrand and CNRS, UMR 6023, LMGE, Aubière, France
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Blastocystis hominis infection in a post-cardiotomy patient on extracorporeal membrane oxygenation support: A case report and literature review. Int J Surg Case Rep 2014; 5:637-9. [PMID: 25160800 PMCID: PMC4200881 DOI: 10.1016/j.ijscr.2014.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 06/19/2014] [Accepted: 07/10/2014] [Indexed: 11/21/2022] Open
Abstract
The opportunistic pathogen, B. hominis, can cause severe infection in patients on ECMO support. Administration of metronidazole in the patients on ECMO support with gastrointestinal symptoms. Prophylactic administration of metronidazole in the patients on ECMO support, which live in the region with a high prevalence of B. hominis.
INTRODUCTION Opportunistic pathogens can cause severe damage leading to irreversible complications in immune-compromised patients. Here we describe a patient who sustained Blastocystis hominis infection resulting in severe sepsis while on extracorporeal membrane oxygenation (ECMO) support, and the course of treatment taken to treat him. PRESENTATION OF CASE Our case, a 34-year-old Filipino man, was hospitalized for valvular disease and received valve replacements. ECMO and an intra-aortic balloon pump (IABP) were implemented when the patient developed progressive heart failure after cardiac surgery. Unfortunately, the patient suffered from sepsis with persistent fever and diarrhea, and subsequent examinations indicated the patient was infected by B. hominis. After adequate administration of the antibiotic metronidazole, the patient's symptoms subsided and he was discharged. DISCUSSION Blastocystis hominis is a unicellular protozoa commonly found in the intestinal tract, and the prevalence of B. hominis is 1.5–10% in developed countries and 30–50% in developing countries. The patient needed the support of ECMO and IABP, was immunocompromised to a certain extent; B. hominis can be a harmful opportunistic pathogen for them and lead to severe irreversible complications such as death. CONCLUSION This is the first published article showing that the opportunistic pathogen, B. hominis, can cause severe infection in patients on ECMO support, a result that should be kept in mind when patients come from a place with a high prevalence of B. hominis. The prophylactic medication should be administered routinely when patients live in the region and extracorporeal life-support is used.
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80
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Yang R, Brice B, Ryan U. A new Caryospora coccidian species (Apicomplexa: Eimeriidae) from the laughing kookaburra (Dacelo novaeguineae). Exp Parasitol 2014; 145:68-73. [PMID: 25092438 DOI: 10.1016/j.exppara.2014.07.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/14/2014] [Accepted: 07/22/2014] [Indexed: 11/17/2022]
Abstract
A new Caryospora coccidian species is described from the laughing kookaburra (Dacelo novaeguineae). Sporulated oocysts (n=30) are ovoid in shape with a smooth, colourless, bilayered oocyst wall and measure 31.4×29.3 (30.0-32.0×28.0-31.0) μm with a shape index of 1.1. Oocysts contain one spheroidal to subspheroidal sporocyst, 21.2×20.6 (20.0-24.0×20.0-21.0) μm. A spheroidal shaped sporocyst residuum is present; micropyle, Stieda, substieda and parastieda bodies are absent. Vermiform sporozoites (n=8) are arranged either parallel or randomly in the sporocyst, measuring 17.0×4.8 (16.0-18.0×4.0-6.0) μm, with a L/W ratio of 3.5. There is a large spheroidal, posterior refractile body in the middle of the sporozoite. Morphologically, this new species is most similar to Caryospora. The prevalence of this parasite was 6.7% in birds sampled in the morning and 33.3% from those sampled after midday. Further molecular characterisation was conducted at two loci; the 18S and 28S ribosomal RNA (rRNA). At the 18S locus, the new species of Caryospora was most closely related to Besnoitia besnoiti (99.2% similarity) and Hammondia triffittae (98.8% similarity). Although, no 28S partial sequences from Caryospora were available in GenBank, the highest similarity was with B.besnoiti (91.3%). Based on morphological and molecular data, this coccidian parasite is a new species that to date has not been reported. The new coccidian parasite is named Caryospora daceloe n. sp. after its host D. novaeguineae (the laughing kookaburra).
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Affiliation(s)
- Rongchang Yang
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia.
| | - Belinda Brice
- Kanyana Wildlife Rehabilitation Centre, 120 Gilchrist Road, Lesmurdie, Western Australia 6076, Australia
| | - Una Ryan
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia 6150, Australia
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81
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Klimeš V, Gentekaki E, Roger AJ, Eliáš M. A large number of nuclear genes in the human parasite blastocystis require mRNA polyadenylation to create functional termination codons. Genome Biol Evol 2014; 6:1956-61. [PMID: 25015079 PMCID: PMC4159000 DOI: 10.1093/gbe/evu146] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Termination codons in mRNA molecules are typically specified directly by the sequence of the corresponding gene. However, in mitochondria of a few eukaryotic groups, some mRNAs contain the termination codon UAA deriving one or both adenosines from transcript polyadenylation. Here, we show that a similar phenomenon occurs for a substantial number of nuclear genes in Blastocystis spp., divergent unicellular eukaryote gut parasites. Our analyses of published genomic data from Blastocystis sp. subtype 7 revealed that polyadenylation-mediated creation of termination codons occurs in approximately 15% of all nuclear genes. As this phenomenon has not been noticed before, the procedure previously employed to annotate the Blastocystis nuclear genome sequence failed to correctly define the structure of the 3'-ends of hundreds of genes. From sequence data we have obtained from the distantly related Blastocystis sp. subtype 1 strain, we show that this phenomenon is widespread within the Blastocystis genus. Polyadenylation in Blastocystis appears to be directed by a conserved GU-rich element located four nucleotides downstream of the polyadenylation site. Thus, the highly precise positioning of the polyadenylation in Blastocystis has allowed reduction of the 3'-untranslated regions to the point that, in many genes, only one or two nucleotides of the termination codon are left.
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Affiliation(s)
- Vladimír Klimeš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
| | - Eleni Gentekaki
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, CanadaIntegrated Microbial Biodiversity Program, Canadian Institute for Advanced Research, Halifax, Nova Scotia, Canada
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
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Roberts T, Stark D, Harkness J, Ellis J. Update on the pathogenic potential and treatment options for Blastocystis sp. Gut Pathog 2014; 6:17. [PMID: 24883113 PMCID: PMC4039988 DOI: 10.1186/1757-4749-6-17] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 05/15/2014] [Indexed: 12/23/2022] Open
Abstract
Although Blastocystis is one of the most common enteric parasites, there is still much controversy surrounding the pathogenicity and potential treatment options for this parasite. In this review we look at the evidence supporting Blastocystis as an intestinal pathogen as shown by numerous case studies and several in vivo studies and the evidence against. We describe the chronic nature of some infections and show the role of Blastocystis in immunocompromised patients and the relationship between irritable bowel syndrome and Blastocystis infection. There have been several studies that have suggested that pathogenicity may be subtype related. Metronidazole is the most widely accepted treatment for Blastocystis but several cases of treatment failure and resistance have been described. Other treatment options which have been suggested include paromomycin and trimethroprim- sulfamethoxazole.
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Affiliation(s)
- Tamalee Roberts
- Department of Microbiology, St. Vincent's Hospital, Victoria St, Darlinghurst 2010, NSW, Australia ; School of Medical and Molecular Biosciences, University of Technology, Sydney, Ultimo, NSW 2007, Australia
| | - Damien Stark
- Department of Microbiology, St. Vincent's Hospital, Victoria St, Darlinghurst 2010, NSW, Australia
| | - John Harkness
- Department of Microbiology, St. Vincent's Hospital, Victoria St, Darlinghurst 2010, NSW, Australia
| | - John Ellis
- School of Medical and Molecular Biosciences, University of Technology, Sydney, Ultimo, NSW 2007, Australia
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Molecular subtyping of Blastocystis spp. using a new rDNA marker from the mitochondria-like organelle genome. Parasitology 2014; 141:670-81. [PMID: 24467909 DOI: 10.1017/s0031182013001996] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Blastocystis spp. are common anaerobic intestinal protozoa found in both human and animals. They are characterized by a high genetic diversity with at least 17 subtypes (STs) that have been described on the basis of a 600 bp 'barcoding region' from the 18S rDNA gene. However, analysis of the recently sequenced genome of a Blastocystis ST7 isolate (strain B) revealed the presence of multiple variable copies of the 18S rDNA gene, with 17 completely assembled copies. Comparison of the barcoding region from these 17 copies allowed us to classify the 18S rDNA sequences into 6 clusters, each cluster containing identical sequences. Surprisingly, 4 of these clusters had the highest homology with 18S rDNA sequences from 2 other Blastocystis ST7 isolates referred as QQ98-4 and H. These results suggest that the 18S rDNA gene is not the marker of choice to discriminate between strains within STs. In the present study, we identified a single-copy subtyping rDNA marker in the genome of the mitochondria-like organelles (MLOs). Using a partial sequence of the MLO rDNA, we successfully subtyped 66 isolates from both human and animals belonging to Blastocystis ST1 to ST10. Our results also indicate that this mitochondrial marker could be useful to detect co-infections by different isolates of a same ST.
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84
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Subtype distribution of Blastocystis isolates in Sebha, Libya. PLoS One 2013; 8:e84372. [PMID: 24376805 PMCID: PMC3869855 DOI: 10.1371/journal.pone.0084372] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 11/22/2013] [Indexed: 01/07/2023] Open
Abstract
Background Blastocystis is a genetically diverse and a common intestinal parasite of humans with a controversial pathogenic potential. This study was carried out to identify the Blastocystis subtypes and their association with demographic and socioeconomic factors among outpatients living in Sebha city, Libya. Methods/Findings Blastocystis in stool samples were cultured followed by isolation, PCR amplification of a partial SSU rDNA gene, cloning, and sequencing. The DNA sequences of isolated clones showed 98.3% to 100% identity with the reference Blastocystis isolates from the Genbank. Multiple sequence alignment showed polymorphism from one to seven base substitution and/or insertion/deletion in several groups of non-identical nucleotides clones. Phylogenetic analysis revealed three assemblage subtypes (ST) with ST1 as the most prevalent (51.1%) followed by ST2 (24.4%), ST3 (17.8%) and mixed infections of two concurrent subtypes (6.7%). Blastocystis ST1 infection was significantly associated with female (P = 0.009) and low educational level (P = 0.034). ST2 was also significantly associated with low educational level (P= 0.008) and ST3 with diarrhoea (P = 0.008). Conclusion Phylogenetic analysis of Libyan Blastocystis isolates identified three different subtypes; with ST1 being the predominant subtype and its infection was significantly associated with female gender and low educational level. More extensive studies are needed in order to relate each Blastocystis subtype with clinical symptoms and potential transmission sources in this community.
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85
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Parija SC, Jeremiah S. Blastocystis: Taxonomy, biology and virulence. Trop Parasitol 2013; 3:17-25. [PMID: 23961437 PMCID: PMC3745665 DOI: 10.4103/2229-5070.113894] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 06/24/2013] [Indexed: 11/20/2022] Open
Abstract
The unicellular protist Blastocystis has long been an unsolved puzzle for taxonomists, microbiologists and clinicians. Over the years, the organism has been bounced on and off the different branches of the tree of life due the possession of unique phenotypic characters intermediary to different organisms. The organism is polymorphic with only few of forms such as vacuolar, granular, amoeboid, and the cyst form being commonly known. However it could exist in other forms much more frequently than the widely known forms which could be missed by the unaware observer. Certain older concepts in the life cycle of Blastocystis although has been proven wrong are still being followed in various textbooks and other trustworthy internet sources. The causal role of Blastocystis in human disease has long been a subject of controversy. It is widely believed that certain subtypes of the organism are virulent. But this is not so as other factors are also involved in the clinical outcome of the infection. In these contexts, this review intends to shed light on the past misconceptions and the recent findings on the taxonomy, biology and the virulence of this organism.
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86
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Alfellani MA, Stensvold CR, Vidal-Lapiedra A, Onuoha ESU, Fagbenro-Beyioku AF, Clark CG. Variable geographic distribution of Blastocystis subtypes and its potential implications. Acta Trop 2013; 126:11-8. [PMID: 23290980 DOI: 10.1016/j.actatropica.2012.12.011] [Citation(s) in RCA: 259] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 11/29/2012] [Accepted: 12/20/2012] [Indexed: 01/23/2023]
Abstract
Blastocystis is a common intestinal micro-eukaryote found in both humans and non-human hosts and known to be genetically very diverse. It has been divided into numerous subtypes (STs), nine of which have been identified in humans to date. Surveys of ST prevalence have started to emerge over the past few years but to date no data are available for any African country except Egypt and Tanzania. In this study, we determined the prevalence of Blastocystis STs in populations from Libya, Liberia and Nigeria, as well as expanding the dataset available for the UK. A total of 356 Blastocystis STs were identified in this study, 271 from the UK, 38 from Libya, 25 from Liberia and 22 from Nigeria. SSU rRNA gene sequences revealed the presence of eight of the nine STs known from humans but at varying frequencies between countries. ST1 was the most common ST in Libya and Nigeria whereas ST3 showed the highest frequency in the other two countries, as indeed is the case in most populations around the world. ST4 was absent in Libya and ST2 in Nigeria, while no ST5, ST6, ST8 or ST9 infections were detected in any of the three African populations. The picture emerging from this and other surveys suggests that there is significant variation in ST prevalence between populations. Some of the possible reasons for and implications of this diversity are discussed.
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87
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Abstract
Blastocystis is a common parasite of the human large intestine but has an uncertain role in disease. In this review, we appraise the published evidence addressing this and its weaknesses. Genetic diversity studies have led to the identification of numerous subtypes (STs) within the genus Blastocystis and, recently, methods for studying variation within STs have been developed, with implications for our understanding of host specificity. The geographic distribution of STs is summarised and the impact this may have on investigations into the role of the organism in disease is discussed. Finally, we describe the organelle and nuclear genome characteristics and look to future developments in the field.
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88
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Pandey PK, Siddharth J, Verma P, Bavdekar A, Patole MS, Shouche YS. Molecular typing of fecal eukaryotic microbiota of human infants and their respective mothers. J Biosci 2012; 37:221-6. [PMID: 22581327 DOI: 10.1007/s12038-012-9197-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The micro-eukaryotic diversity from the human gut was investigated using universal primers directed towards 18S rRNA gene, fecal samples being the source of DNA. The subjects in this study included two breast-fed and two formula-milk-fed infants and their mothers. The study revealed that the infants did not seem to harbour any microeukaryotes in their gut. In contrast, there were distinct eukaryotic microbiota present in the mothers. The investigation is the first of its kind in the comparative study of the human feces to reveal the presence of micro-eukaryotic diversity variance in infants and adults from the Indian subcontinent. The micro-eukaryotes encountered during the investigation include known gut colonizers like Blastocystis and some fungi species. Some of these micro-eukaryotes have been speculated to be involved in clinical manifestations of various diseases. The study is an attempt to highlight the importance of micro-eukaryotes in the human gut.
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Affiliation(s)
- Prashant K Pandey
- Insect Molecular Biology Unit, National Centre for Cell Science, Pune University Campus, Ganeshkhind, Pune 411 007, Maharashtra, India
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89
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Blastocystis: past pitfalls and future perspectives. Trends Parasitol 2012; 28:327-34. [PMID: 22738855 DOI: 10.1016/j.pt.2012.05.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 05/15/2012] [Accepted: 05/16/2012] [Indexed: 02/08/2023]
Abstract
Blastocystis is a genetically heterogeneous protist found in the intestinal tract (IT) of many vertebrates, and although it is implicated in a variety of human intestinal disorders, data regarding the clinical relevance of Blastocystis is at best speculative. Several research issues, including a lack of standardization across studies, the potential for intrasubtype variation in pathogenicity, and difficulties associated with diagnostics for many idiopathic disorders of the human IT have led to conflicting reports in support of a role for Blastocystis pathogenicity. Here, several research areas and methodologies are reviewed that if integrated appropriately into a prospective study may prove useful and facilitate a better understanding of the role of Blastocystis in human health and disease.
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90
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Dunn LA, Tan KSW, Vanelle P, Juspin T, Crozet MD, Terme T, Upcroft P, Upcroft JA. Development of metronidazole-resistant lines of Blastocystis sp. Parasitol Res 2012; 111:441-50. [PMID: 22362365 DOI: 10.1007/s00436-012-2860-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2011] [Accepted: 02/07/2012] [Indexed: 01/22/2023]
Abstract
Metronidazole (MTR) is frequently used for the treatment of Blastocystis infections, but with variable effectiveness, and often with treatment failures as a possible result of drug resistance. We have developed two Blastocystis MTR-resistant (MTR(R)) subtype 4 WR1 lines (WR1-M4 and WR1-M5), with variable susceptibility to a panel of anti-protozoal agents including various 5-nitroimidazoles, nitazoxanide and furazolidone. WR1-M4 and WR1-M5 were developed and assessed over an 18-month period and displayed persistent MTR resistance, being more than 2.5-fold less susceptible to MTR than the parent isolate. The MTR(R) lines grew with a similar g time to WR1, but were morphologically less consistent with a mixture of size. All Blastocystis isolates and the MTR(R) lines were most susceptible to the 5-nitroimidazole drug ronidazole. WR1-M5 was apparently cross-resistant to satranidazole and furazolidone, and WR1-M4 was cross-resistant to nitazoxanide. These MTR(R) lines now provide a valuable tool for the continued assessment of the efficacy and mechanism of action of new and established drugs against a range of Blastocystis sp. subtypes, in order to identify a universally effective drug and to facilitate understanding of the mechanisms of drug action and resistance in Blastocystis.
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Affiliation(s)
- L A Dunn
- Queensland Institute of Medical Research, PO Royal Brisbane Hospital, 4029, Herston, Queensland, Australia.
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91
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Stensvold CR, Alfellani M, Clark CG. Levels of genetic diversity vary dramatically between Blastocystis subtypes. INFECTION GENETICS AND EVOLUTION 2011; 12:263-73. [PMID: 22116021 DOI: 10.1016/j.meegid.2011.11.002] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 11/05/2011] [Accepted: 11/07/2011] [Indexed: 11/26/2022]
Abstract
Blastocystis is a common single-celled parasite of humans and other animals comprising at least 13 genetically distinct small subunit ribosomal RNA lineages (subtypes (STs)). In this study we investigated intra-subtype genetic diversity and host specificity of two of the most common subtypes in humans, namely ST3 and ST4, by analysing and comparing over 400 complete and partial nuclear SSU-rDNAs and data from multilocus sequence typing (MLST) of the mitochondrion-like organelle (MLO) genome of 132 samples. Inferences from phylogenetic analyses of nuclear SSU-rDNA and concatenated MLST sequences were compatible. Human ST3 infections were restricted to one of four identified MLO clades except where exposure to non-human primates had occurred. This suggests relatively high host specificity within ST3, that human ST3 infections are caused predominantly by human-to-human transmission, and that human strains falling into other clades are almost certainly the result of zoonotic transmission. ST4 from humans belonged almost exclusively to one of two SSU-rDNA clades, and only five MLST sequence types were found among 50 ST4s belonging to Clade 1 (discriminatory index: 0.41) compared to 58 MLST sequence types among 81 ST3s (discriminatory index: 0.99). The remarkable differences in intra-subtype genetic variability suggest that ST4 has a more recent history of colonising humans than ST3. This is congruent with the apparently restricted geographical distribution of ST4 relative to ST3. The implications of this observation are unclear, however, and the population structure and distribution of ST4 should be subject to further scrutiny in view of the fact ST4 is being increasingly linked with intestinal disease.
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Affiliation(s)
- C Rune Stensvold
- Department of Microbiological Diagnostics, Statens Serum Institut, Orestads Boulevard 5, DK-2300 Copenhagen S, Denmark.
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92
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Coyle CM, Varughese J, Weiss LM, Tanowitz HB. Blastocystis: to treat or not to treat... Clin Infect Dis 2011; 54:105-10. [PMID: 22075794 DOI: 10.1093/cid/cir810] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Parasites in the genus Blastocystis comprise several subtypes (genotypes) and have a worldwide distribution. In some surveys, these are the most common parasites found in human stool specimens. An emerging literature suggests that the pathogenicity of Blastocystis is related to specific subtypes and parasite burden, although even individuals with small numbers of cysts may be symptomatic. Some data suggest an association between infection with Blastocystis and irritable bowel syndrome. However, there are few clinical studies demonstrating a direct relationship between the presence of this parasite and disease, few animal models to explore this relationship, and no consensus as to appropriate treatment. We recommend that asymptomatic individuals with few cysts not be treated. However, those who have gastrointestinal or dermatologic signs and symptoms and many cysts in stool specimens may require treatment. Metronidazole is the drug of choice. Additional studies are required to determine pathogenicity and appropriate therapy.
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Affiliation(s)
- Christina M Coyle
- Department of Medicine, Division of Infectious Diseases, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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93
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Petrášová J, Uzlíková M, Kostka M, Petrželková K, Huffman M, Modrý D. Diversity and host specificity of Blastocystis in syntopic primates on Rubondo Island, Tanzania. Int J Parasitol 2011; 41:1113-20. [DOI: 10.1016/j.ijpara.2011.06.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 06/13/2011] [Accepted: 06/16/2011] [Indexed: 11/25/2022]
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94
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Denoeud F, Roussel M, Noel B, Wawrzyniak I, Da Silva C, Diogon M, Viscogliosi E, Brochier-Armanet C, Couloux A, Poulain J, Segurens B, Anthouard V, Texier C, Blot N, Poirier P, Ng GC, Tan KSW, Artiguenave F, Jaillon O, Aury JM, Delbac F, Wincker P, Vivarès CP, El Alaoui H. Genome sequence of the stramenopile Blastocystis, a human anaerobic parasite. Genome Biol 2011; 12:R29. [PMID: 21439036 PMCID: PMC3129679 DOI: 10.1186/gb-2011-12-3-r29] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 01/04/2011] [Accepted: 03/25/2011] [Indexed: 01/28/2023] Open
Abstract
Background Blastocystis is a highly prevalent anaerobic eukaryotic parasite of humans and animals that is associated with various gastrointestinal and extraintestinal disorders. Epidemiological studies have identified different subtypes but no one subtype has been definitively correlated with disease. Results Here we report the 18.8 Mb genome sequence of a Blastocystis subtype 7 isolate, which is the smallest stramenopile genome sequenced to date. The genome is highly compact and contains intriguing rearrangements. Comparisons with other available stramenopile genomes (plant pathogenic oomycete and diatom genomes) revealed effector proteins potentially involved in the adaptation to the intestinal environment, which were likely acquired via horizontal gene transfer. Moreover, Blastocystis living in anaerobic conditions harbors mitochondria-like organelles. An incomplete oxidative phosphorylation chain, a partial Krebs cycle, amino acid and fatty acid metabolisms and an iron-sulfur cluster assembly are all predicted to occur in these organelles. Predicted secretory proteins possess putative activities that may alter host physiology, such as proteases, protease-inhibitors, immunophilins and glycosyltransferases. This parasite also possesses the enzymatic machinery to tolerate oxidative bursts resulting from its own metabolism or induced by the host immune system. Conclusions This study provides insights into the genome architecture of this unusual stramenopile. It also proposes candidate genes with which to study the physiopathology of this parasite and thus may lead to further investigations into Blastocystis-host interactions.
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Affiliation(s)
- France Denoeud
- Genoscope (CEA) and CNRS UMR 8030, Université d'Evry, 2 rue Gaston Crémieux, 91057 Evry, France
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95
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Molecular subtyping of Blastocystis sp. isolates from symptomatic patients in Italy. Parasitol Res 2011; 109:613-9. [PMID: 21340563 DOI: 10.1007/s00436-011-2294-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 02/09/2011] [Indexed: 10/18/2022]
Abstract
Blastocystis sp. is the most common eukaryotic parasite in the intestinal tract of humans. Due to its potential impact in public health, we determined the Blastocystis sp. subtypes (STs) and their relative frequency in symptomatic patients living in or in the vicinity of two Italian cities (Rome and Sassari). A total of 34 Blastocystis sp. isolates corresponding to 26 single and 4 mixed infections were subtyped using partial small subunit ribosomal RNA gene sequencing. From this molecular approach, the ST distribution in the present Italian population was as follows: ST3 (47.1%), ST2 (20.6%), ST4 (17.7%), ST1 (8.8%), and ST7, and ST8 (2.9%). As in almost all countries worldwide, ST3 was the most common ST reinforcing the hypothesis of its human origin. Together with a previous preliminary report, a total of seven STs (with the addition of ST5) have been found in Italian symptomatic patients. The wide range of STs identified in the Italian population suggest that Blastocystis sp. infection is not associated with specific STs even if some STs (ST1-ST4) are predominant as reported in all other countries. Since most of the STs identified in Italian patients are zoonotic, our data raise crucial questions concerning the identification of animal reservoirs for Blastocystis sp. and the potential risks of transmission to humans.
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96
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Development of a new PCR protocol to detect and subtype Blastocystis spp. from humans and animals. Parasitol Res 2011; 109:205-12. [DOI: 10.1007/s00436-010-2244-9] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 12/14/2010] [Indexed: 10/18/2022]
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97
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Yubuki N, Leander BS, Silberman JD. Ultrastructure and Molecular Phylogenetic Position of a Novel Phagotrophic Stramenopile from Low Oxygen Environments: Rictus lutensis gen. et sp. nov. (Bicosoecida, incertae sedis). Protist 2010; 161:264-78. [DOI: 10.1016/j.protis.2009.10.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2009] [Accepted: 10/11/2009] [Indexed: 11/17/2022]
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98
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Stensvold CR, Nielsen HV, Mølbak K, Smith HV. Pursuing the clinical significance of Blastocystis--diagnostic limitations. Trends Parasitol 2008; 25:23-9. [PMID: 19013108 DOI: 10.1016/j.pt.2008.09.010] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 08/11/2008] [Accepted: 09/23/2008] [Indexed: 11/17/2022]
Abstract
The clinical significance of one of the most prevalent single-celled intestinal parasites worldwide, Blastocystis, remains unsettled. A plethora of clinical and epidemiological studies have been undertaken to generate data on its prevalence in different populations and investigate the role of the parasite as a cause of gastro- and extra-intestinal disease. In this article, we pinpoint limitations of studies that seek to determine the clinical significance of Blastocystis, based on shortcomings in our understanding of Blastocystis diagnosis and biology, and identify methodologies for further studies aimed at determining the molecular epidemiology and clinical impact of this parasite.
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Affiliation(s)
- C Rune Stensvold
- Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen S, Denmark.
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99
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Boorom KF, Smith H, Nimri L, Viscogliosi E, Spanakos G, Parkar U, Li LH, Zhou XN, Ok UZ, Leelayoova S, Jones MS. Oh my aching gut: irritable bowel syndrome, Blastocystis, and asymptomatic infection. Parasit Vectors 2008; 1:40. [PMID: 18937874 PMCID: PMC2627840 DOI: 10.1186/1756-3305-1-40] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2008] [Accepted: 10/21/2008] [Indexed: 12/14/2022] Open
Abstract
Blastocystis is a prevalent enteric protozoan that infects a variety of vertebrates. Infection with Blastocystis in humans has been associated with abdominal pain, diarrhea, constipation, fatigue, skin rash, and other symptoms. Researchers using different methods and examining different patient groups have reported asymptomatic infection, acute symptomatic infection, and chronic symptomatic infection. The variation in accounts has lead to disagreements concerning the role of Blastocystis in human disease, and the importance of treating it. A better understanding of the number of species of Blastocystis that can infect humans, along with realization of the limitations of the existing clinical laboratory diagnostic techniques may account for much of the disagreement. The possibility that disagreement was caused by the emergence of particular pathogenic variants of Blastocystis is discussed, along with the potential role of Blastocystis infection in irritable bowel syndrome (IBS). Findings are discussed concerning the role of protease-activated receptor-2 in enteric disease which may account for the presence of abdominal pain and diffuse symptoms in Blastocystis infection, even in the absence of fever and endoscopic findings. The availability of better diagnostic techniques and treatments for Blastocystis infection may be of value in understanding chronic gastrointestinal illness of unknown etiology.
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Affiliation(s)
- Kenneth F Boorom
- Blastocystis Research Foundation, 5060 SW Philomath Blvd, #202, Corvallis, OR 97333, USA.
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100
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Jones MS, Whipps CM, Ganac RD, Hudson NR, Boorom K. Association of Blastocystis subtype 3 and 1 with patients from an Oregon community presenting with chronic gastrointestinal illness. Parasitol Res 2008; 104:341-5. [PMID: 18923844 DOI: 10.1007/s00436-008-1198-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Accepted: 09/10/2008] [Indexed: 11/25/2022]
Abstract
Chronic gastrointestinal illness of unknown etiology is a significant problem in the United States. Using a real-time LightCycler PCR assay we detected Blastocystis in nine patients from a metropolitan area of Corvallis, Oregon who presented with diarrhea, abdominal pain, fatigue, joint pain, skin rash and psychiatric co-morbidity. Phylogenetic analysis identified six infections with Blastocystis sp. subtype 3, and one with subtype 1, using the standard Stensvold nomenclature. Most patients with subtype 3 had previously tested negative with conventional parasitological diagnostics, had been symptomatic for over 4 years, and reported antibiotic failure.
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Affiliation(s)
- Morris S Jones
- Clinical Investigation Facility, David Grant USAF Medical Center, 101 Bodin Circle, Travis AFB, Fairfield, CA 94535, USA.
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