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Affiliation(s)
| | | | - C Graham Clark
- London School of Hygiene and Tropical Medicine, London, UK
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2
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Yason JA, Liang YR, Png CW, Zhang Y, Tan KSW. Interactions between a pathogenic Blastocystis subtype and gut microbiota: in vitro and in vivo studies. Microbiome 2019; 7:30. [PMID: 30853028 PMCID: PMC6410515 DOI: 10.1186/s40168-019-0644-3] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 02/01/2019] [Indexed: 05/12/2023]
Abstract
BACKGROUND Blastocystis is a common gut eukaryote detected in humans and animals. It has been associated with gastrointestinal disease in the past although recent metagenomic studies also suggest that it is a member of normal microbiota. This study investigates interactions between pathogenic human isolates belonging to Blastocystis subtype 7 (ST7) and bacterial representatives of the gut microbiota. RESULTS Generally, Blastocystis ST7 exerts a positive effect on the viability of representative gut bacteria except on Bifidobacterium longum. Gene expression analysis and flow cytometry indicate that the bacterium may be undergoing oxidative stress in the presence of Blastocystis. In vitro assays demonstrate that Blastocystis-induced host responses are able to decrease Bifidobacterium counts. Mice infected with Blastocystis also reveal a decrease in beneficial bacteria Bifidobacterium and Lactobacillus. CONCLUSIONS This study shows that particular isolates of Blastocystis ST7 cause changes in microbiota populations and potentially lead to an imbalance of the gut microbiota. This study suggests that certain isolates of Blastocystis exert their pathogenic effects through disruption of the gut microbiota and provides a counterpoint to the increasing reports indicating the commensal nature of this ubiquitous parasite.
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Affiliation(s)
- John Anthony Yason
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore, 117545, Singapore
- Institute of Biology and Natural Sciences Research Institute, College of Science, University of the Philippines, Diliman, Quezon City, 1101, Philippines
| | - Yi Ran Liang
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore, 117545, Singapore
| | - Chin Wen Png
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore, 117545, Singapore
| | - Yongliang Zhang
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore, 117545, Singapore
| | - Kevin Shyong Wei Tan
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 5 Science Drive 2, Singapore, 117545, Singapore.
- Microbiome Otago, Department of Microbiology and Immunology, University of Otago, PO Box 56 720, Cumberland St, Dunedin, 9054, Otago, New Zealand.
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3
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Rajamanikam A, Hooi HS, Kudva M, Samudi C, Kumar S. Resistance towards metronidazole in Blastocystis sp.: A pathogenic consequence. PLoS One 2019; 14:e0212542. [PMID: 30794628 PMCID: PMC6386359 DOI: 10.1371/journal.pone.0212542] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 02/05/2019] [Indexed: 01/13/2023] Open
Abstract
Blastocsytis sp. is a protozoan parasite that has been linked to common gastrointestinal illnesses. Metronidazole, the first line therapy, was reported to show frequent inefficacy. Previously, Blastocystis sp. isolated from different population showed varying metronidazole resistance. However, the effect of metronidazole treatment on pathogenic potentials of Blastocystis sp. isolated from different populations, which is known to have different gut environment, is unclear. This study investigates the in vitro effect of metronidazole on the pathogenic potentials of Blastocystis sp. isolated from urban and orang asli individuals. Blastocystis sp. ST 3 isolated from symptomatic and asymptomatic individuals were treated with a range of metronidazole concentration. The parasites’ growth characteristics, apoptotic rate, specific protease activity and the ability to proliferate cancer cells were analyzed upon treatment with 0.001 mg/l metronidazole. The study demonstrates that Blastocystis sp. isolates showed increase in the parasite numbers especially the amoebic forms (only in urban isolates) after treating with metronidazole at the concentration of 0.001 mg/ml. High number of cells in post-treated isolates coincided with increase of apoptosis. There was a significant increase in cysteine protease of Blastocystis sp. isolates upon treatment despite the initial predominance of serine protease in asymptomatic isolates. Metronidazole resistant Blastocystis sp. also showed significant increase in cancer cell proliferation. Resistance to metronidazole did not show significant different influence on the pathogenicity between Blastocystis sp. isolated from urban and orang asli individual. However, an increase in parasite numbers, higher amoebic forms, cysteine protease and ability to proliferate cancer cells implicates a pathogenic role. The study provides evidence for the first time, the effect of metronidazole towards enhancing pathogenic potentials in Blastocystis sp. when isolated from different gut environment. This necessitates the need for reassessment of metronidazole treatment modalities.
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Affiliation(s)
- Arutchelvan Rajamanikam
- Depatment of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Ho Shiaw Hooi
- Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Madhav Kudva
- Gastroenterology and Hepatology Specialist Clinic, Pantai Hospital, Kuala Lumpur, Malaysia
| | - Chandramathi Samudi
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Suresh Kumar
- Depatment of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail:
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4
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Lee IL, Tan TC, Govind SK. Establishing a protocol for water sample processing for the detection of Blastocystis sp. Exp Parasitol 2019; 198:105-110. [PMID: 30695704 DOI: 10.1016/j.exppara.2019.01.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 11/26/2018] [Accepted: 01/20/2019] [Indexed: 11/18/2022]
Abstract
This study was aimed at establishing a protocol for water sample processing for the detection of Blastocystis sp. using distilled water spiked with Blastocystis sp. cysts. The study established a protocol involving eight technical aspects, namely, storage temperature, storage duration, minimum water sample volume, optimum relative centrifugal force, centrifugation duration, minimum number of cyst for inoculation in Jones' medium and turn-around-time for the detection of vacuolar forms of Blastocystis sp. Results showed a minimum of 1.0 L water sample should be collected and processed on the same day. Otherwise, it should be stored at 4 °C and processed within 3 days. Water sample should be centrifuged at 1400×g for 10 min. For the isolation of Blastocystis sp. cysts, parasite pellet could be layered on top of Ficoll-Paque™ PLUS, centrifuged at 1400×g for 20 min and washed twice using 0.9% saline with centrifugation at 1400×g for 10 min. A minimum of 1 × 105 cysts could then be inoculated in Jones' medium supplement with 10% horse serum, incubated at 37 °C and examined for any presence of vacuolar forms of Blastocystis sp. after 3 days of inoculation. A protocol for water sample processing for the detection of Blastocystis sp. has successfully been established. The protocol was validated using 106 various water samples. This protocol will be very useful in determining the extent of Blastocystis sp. contamination in water sources in order to identify the seriousness of contamination.
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Affiliation(s)
- Ii Li Lee
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia; Kulliyyah of Medicine and Health Sciences, Sultan Abdul Halim Mu'adzam Shah International Islamic University, 09300, Kuala Ketil, Kedah, Malaysia
| | - Tian Chye Tan
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Suresh Kumar Govind
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603, Kuala Lumpur, Malaysia.
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Tsaousis AD, Hamblin KA, Elliott CR, Young L, Rosell-Hidalgo A, Gourlay CW, Moore AL, van der Giezen M. The Human Gut Colonizer Blastocystis Respires Using Complex II and Alternative Oxidase to Buffer Transient Oxygen Fluctuations in the Gut. Front Cell Infect Microbiol 2018; 8:371. [PMID: 30406045 PMCID: PMC6204527 DOI: 10.3389/fcimb.2018.00371] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/03/2018] [Indexed: 12/12/2022] Open
Abstract
Blastocystis is the most common eukaryotic microbe in the human gut. It is linked to irritable bowel syndrome (IBS), but its role in disease has been contested considering its widespread nature. This organism is well-adapted to its anoxic niche and lacks typical eukaryotic features, such as a cytochrome-driven mitochondrial electron transport. Although generally considered a strict or obligate anaerobe, its genome encodes an alternative oxidase. Alternative oxidases are energetically wasteful enzymes as they are non-protonmotive and energy is liberated in heat, but they are considered to be involved in oxidative stress protective mechanisms. Our results demonstrate that the Blastocystis cells themselves respire oxygen via this alternative oxidase thereby casting doubt on its strict anaerobic nature. Inhibition experiments using alternative oxidase and Complex II specific inhibitors clearly demonstrate their role in cellular respiration. We postulate that the alternative oxidase in Blastocystis is used to buffer transient oxygen fluctuations in the gut and that it likely is a common colonizer of the human gut and not causally involved in IBS. Additionally the alternative oxidase could act as a protective mechanism in a dysbiotic gut and thereby explain the absence of Blastocystis in established IBS environments.
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Affiliation(s)
- Anastasios D. Tsaousis
- RAPID Group, Laboratory of Molecular & Evolutionary Parasitology, School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Karleigh A. Hamblin
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
- Biosciences, University of Exeter, Exeter, United Kingdom
| | - Catherine R. Elliott
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Luke Young
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Alicia Rosell-Hidalgo
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Campbell W. Gourlay
- Kent Fungal Group, School of Biosciences, University of Kent, Canterbury, United Kingdom
| | - Anthony L. Moore
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Brighton, United Kingdom
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6
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Prodeus TV, Fedianina LV, Frolova AA. [Morphological identification of blastocystis]. Med Parazitol (Mosk) 2014:9-13. [PMID: 24738219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The authors have attempted to systematize the currently known specific morphological features of the composition of Blastocystis spp. existing in different forms and to present this material as a reference table, by understanding the need for further data clarification. In addition, the paper describes observations of variations in the forms of human blastocysts. In particular, it depicts the species of multinucleated cysts, the identification of which may cause difficulties in diagnosing and differentiating these forms with some representative species of the genus Entamoeba.
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7
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Prodeus TV, Fedianina LV, Gritsiuk OV, Volkova IV, Begunova SV. [Blastocystis spp. culturing as a method for diagnosing the parasite]. Med Parazitol (Mosk) 2013:16-19. [PMID: 24640125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The technique for isolating blastocysts in the culture was assessed, by examining the fresh specimens from 196 patients with gastrointestinal tract (GIT) disorders and from 56 persons with an uncertain protozoological diagnosis. A set of techniques, such as triple examination of native smears, parallel inoculation of the Pavlova medium, and microscopy of obtained permanent specimens as may be required, contributes to the timely identification of protozoa, including blastocysts, in persons with GIT disorder. The efficiency of the technique for isolating blastocysts on Pavlova's medium and the native smear test averaged 34.8% and 49.4%, respectively. Among those known to be infected, the rate of parasite development in vitro was not greater than 52.9%. The culture showed amoeboids generally with the clinical manifestation of infection. The culture-based diagnostic method cannot be changed for routine microscopy techniques in detecting blastocysts, although it is essential to investigate the morphofunctional and phylogenetic properties of the parasite. The pleomorphism of cultured blastocysts with variability of growth properties was shown as a manifestation of phenotypic characteristics when isolating the parasite.
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8
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Valido EM, Rivera WL. Colony growth of Philippine isolates of Blastocystis hominis in simplified, soft agar medium. Parasitol Res 2007; 101:213-7. [PMID: 17235545 DOI: 10.1007/s00436-006-0456-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 12/22/2006] [Indexed: 10/23/2022]
Abstract
The agar-cloning technique of Blastocystis hominis has been observed in both solid and semisolid agar using Iscove's modified Dulbecco's medium. In this study, Philippine isolates of B. hominis were grown by pour-plate method in semisolid agar using Locke's solution. Inoculated plates contained 0.7% agar, 10% horse serum, and 0.1% sodium thioglycollate. Plates were incubated at 37 degrees C in a microaerophilic jar for 7-10 days. Biconvex disk-shaped colonies were seen abound at the bottom half of the medium. Colonies growing at the agar-glass interface were flat and consisted of thin layers of cells. From these colonies, large amoeboid cells were frequently seen on the periphery, whereas smaller cells were concentrated at the core. Analysis of the SSU rDNA genetically established the identity of the clones to be B. hominis. This is the first report on agar cloning of Blastocystis in a compound medium.
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Affiliation(s)
- Ezra M Valido
- Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines
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9
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Frolov AO, Chistiakova LV, Gudkov AV, Malysheva MN. [The morphological study of the cysts Pelomyxa palustris Greeff, 1874]. Tsitologiia 2007; 49:642-651. [PMID: 17926559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Pelomyxa palustris Greeff, 1874, is the only species of pelomixoid amoebas with the rest cysts in its life cycle. The morphology of the P. palustris has been studied by the light and electronic microscopy. Encystation of P. palustris under climatic conditions of North-West of Russia occurs within August-September. Rest cysts have a complex, trilaminar wall. Two inner lamina are the dense endocyst and the laminated mesocyst, thickness of each layer runs up to 0.6-0.7 microm. Thickness of the electron-dense ectocyst usually does not exceed 0.1-0.2 microm. The encystated cell of P. palustris has the unique structure. About 60 % of the cell volume are occupied by a huge vacuole placed in the center and filled up with the prokaryotic cytobionts. Different vacuoles, small vesicles of various nature, autophagosomes and lipid drops could be found inside that huge vacuole. The amoebae cytoplasm occupies the space in between endocyst's inner surface and the central vacuole. No any inclusions, prokaryotic cytobionts and most of cell organelles are absent in the cytoplasm. There are 4 large nuclei filled with relatively homogeneous karyoplasm lying in the cytoplasm. Nuclear envelope forms a lot of long tubular channels, running through the cytoplasm and lining the membrane of the central vacuole. Encysted pelomixoid stay in this state up until the beginning of excystation. Excystation of P. palustris in the studied region occurs in spring, during the latter half of April and the beginning of May. Cysts undergo complex morphofunctional changes, related to the reorganization of the wall and formation of young multinucleate amoebas. Only one wall lamina of the 3 initial ones is left up to the moment of excystation. The central vacuole endures ruination and its content penetrates into the cytoplasm. Pelomixoid nuclei divide twice. Prokaryotic cytobionts are localized in cytoplasm and in the perinuclear area. Young multinuclear species of P. palustris coming out of the cysts do not differ in their structure from the adult forms.
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10
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Abstract
Blastocystis cysts were detected in 38% (47/123) (37 Scottish, 17 Malaysian) of sewage treatment works. Fifty percent of influents (29% Scottish, 76% Malaysian) and 28% of effluents (9% Scottish, 60% Malaysian) contained viable cysts. Viable cysts, discharged in effluent, provide further evidence for the potential for waterborne transmission of Blastocystis.
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Affiliation(s)
- K Suresh
- Scottish Parasite Diagnostic Laboratory, Stobhill Hospital, 133 Balornock Road, Glasgow G21 3UW, Scotland
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Puthia MK, Vaithilingam A, Lu J, Tan KSW. Degradation of human secretory immunoglobulin A by Blastocystis. Parasitol Res 2005; 97:386-9. [PMID: 16151742 DOI: 10.1007/s00436-005-1461-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/27/2005] [Indexed: 10/25/2022]
Abstract
Microbial immunoglobulin A (IgA) proteases cleave human secretory IgA, promoting the mucosal adhesion of pathogens. To investigate if the enteric protozoan Blastocystis degrades human secretory IgA, cell lysate and conditioned medium from two species were exposed to immunoglobulin A. Secretory IgA was cleaved by both cell lysate and conditioned medium with mainly cysteine proteinase activity in B. hominis B isolate and aspartic proteinase activity in B. ratii WR1 isolate. These findings suggest that Blastocystis proteases may play a role in parasite survival in vivo.
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Affiliation(s)
- Manoj K Puthia
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597
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Sawangjaroen N, Sawangjaroen K. The effects of extracts from anti-diarrheic Thai medicinal plants on the in vitro growth of the intestinal protozoa parasite: Blastocystis hominis. J Ethnopharmacol 2005; 98:67-72. [PMID: 15763365 DOI: 10.1016/j.jep.2004.12.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 12/07/2004] [Accepted: 12/23/2004] [Indexed: 05/24/2023]
Abstract
The activities of n-hexane, dichloromethane and methanol extracts from five anti-diarrheic Thai medicinal plants, Acacia catechu (Fabaceae) resin, Amaranthus spinosus (Amaranthaceae) whole plant, Brucea javanica (Simaroubaceae) seed, Piper longum (Piperaceae) fruit and Quercus infectoria (Fagaceae) nut gall were tested against the in vitro growth of fresh isolates of the intestinal protozoan parasite, Blastocystis hominis. The extracts at concentrations that ranged from 62.5 to 2000 microg/mL, were incubated with several isolates of Blastocystis hominis for 48 h. The activities were classified as killed, inhibited, moderately inhibited and not-inhibited. Dichloromethane and methanol extracts from the Brucea javanica seed and a methanol extract from Quercus infectoria nut gall showed the highest activity. At a concentration of 2000 microg/mL, the three extracts killed 82, 75 and 67% of the Blastocystis hominis samples tested and inhibited 94, 100 and 76% of them, respectively. Metronidazole, used as a reference antiprotozoan drug, at a concentration of 40 microg/mL, killed 97% of the Blastocystis hominis isolates and inhibited all samples tested at concentrations that ranged from 1.25 to 20 microg/mL.
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Affiliation(s)
- Nongyao Sawangjaroen
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
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Yoshikawa H, Morimoto K, Nagashima M, Miyamoto N. A survey of Blastocystis infection in anuran and urodele amphibians. Vet Parasitol 2004; 122:91-102. [PMID: 15177714 DOI: 10.1016/j.vetpar.2004.03.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Revised: 03/28/2004] [Accepted: 03/31/2004] [Indexed: 11/23/2022]
Abstract
Blastocystis infection in amphibians was surveyed in three species of anuran and one species of urodele amphibians captured at two distinct locations in Japan. All three species of frogs were highly infected with Blastocystis, while 69 individual urodele newts, Cynopus pyrrhogaster, were negative for infection. Eleven Blastocystis isolates (47.8%) were recovered from 23 Rana nigromaculata leopard frogs. Twenty-three (92%) of 25 Rana catesbeiana bullfrogs and all (100%) of 24 Bufo japonicus japonicus toads were positive for Blastocystis. Two distinct populations of the toad and bullfrog showed a high prevalence (100 or 84.6%) of Blastocystis infection, while in two populations of the leopard frog only one population was positive for Blastocystis (84.6%). Three Blastocystis isolates from different species of the frogs were established. Since none of the three isolates could survive at 37 degrees C, a temperature tolerance assay was performed to assess the optimal growth temperature and to determine the range of non-lethal temperatures. During the exponential growth phase of 3- or 4-day cultures at 25 degrees C, three isolates were exposed to 4, 28, 31, or 34 degrees C for 3 days and then returned to 25 degrees C to monitor the cell growth. Based on the optimal growth temperatures and different ranges of temperature tolerance among the three new isolates from frogs and two known species, Blastocystis hominis and Blastocystis lapemi, it was established that the three isolates recovered from different species of frogs had different physiological features from B. hominis and B. lapemi.
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Affiliation(s)
- Hisao Yoshikawa
- Department of Biological Science, Faculty of Science, Nara Women's University, Kitauoya-Nishimachi, Nara 630-8506, Japan.
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14
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15
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16
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17
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Abstract
A porcine strain of Blastocystis sp. grown in LES medium was transferred to Iscove's modified Dulbecco's medium (IMDM) and encystation medium (EM). In comparison with the cells maintained in LES medium, the cells cultivated for several days in both IMDM and EM exhibited considerable differences in their morphology and ultrastructure. The central vacuole was mostly electron-opaque, usually with electron-lucent granules in its center. Mitochondrial matrix became less electron-dense and cristae were shortened and reduced in number. Two membranes of the nuclear envelope were dilated and the intramembranous space was filled with intermediately electron-dense bodies. Two or three nuclei surrounded by one joint outer membrane were often seen. In the old cultures the surface coat often disappeared and electron-dense pits on the cell surface were much more numerous than in young cultures or in the cells grown in LES medium. The possible role of the cells with peculiar ultrastructural features in the Blastocystis life cycle is discussed.
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Affiliation(s)
- M Pakandl
- Institute of Parasitology, Academy of Sciences of the Czech Republic, Ceské Budejovice.
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18
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Abstract
Colonies of Blastocystis from non-axenic cultures grown in agar medium were isolated from bacterial colonies. Axenization of human and reptilian isolates of Blastocystis was achieved using antibiotic treatment to lower bacterial numbers, followed by colony growth to isolate pure parasite colonies.
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Affiliation(s)
- G C Ng
- Department of Microbiology, Faculty of Medicine, National University of Singapore, Singapore
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19
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Chen XQ, Singh M, Ho LC, Tan SW, Yap EH. Characterization of protein profiles and cross-reactivity of Blastocystis antigens by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis. Parasitol Res 1999; 85:343-6. [PMID: 10099019 DOI: 10.1007/s004360050559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The protein profiles of Blastocystis hominis, B. lapemi, and B. ratti were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and species could be differentiated by this means as well as by Western-blot analysis with polyclonal antibodies. No intraspecies difference could be distinguished between the two B. hominis isolates or the three B. ratti isolates. Western-blot analysis showed extensive cross-reactivity of B. lapemi and B. hominis antigens with anti-B. ratti serum. Some of the cross-reactive antigens were glycoproteins as determined on the basis of their sensitivity to periodate treatment.
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Affiliation(s)
- X Q Chen
- Department of Microbiology, Faculty of Medicine, National University of Singapore, Singapore
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20
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Abstract
Cysts of Blastocystis ratti were produced in vitro by culturing the parasite in Iscove's modified Dulbecco's medium (IMDM) with increasing concentrations of horse serum. Yields up to 3 x 10(6) cysts/ml of culture medium were obtained after 72 h. Encystation efficiency was time, strain and inoculum size dependent. A viability of > 70% was determined by flow cytometry employing fluorescein diacetate and propidium iodide staining. The presence of chitin as a cyst wall component was demonstrated by Calcofluor White M2R staining with which cystic stages showed blue fluorescence. The changes in morphology during excystation were examined by transmission electron microscopy. The cyst enlarged in size and some vacuoles appeared within the condensed cytoplasm. The vacuoles were full of inclusions and small glycogen aggregates. Coalescence of the vacuoles led to central body formation. Glycogen deposits were prominent throughout the excystation process. Some cysts divided by binary fission before the completion of the excystation.
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Affiliation(s)
- X Q Chen
- Department of Microbiology, Faculty of Medicine, National University of Singapore, Singapore
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Abstract
The kinetics of in vitro encystation of Blastocystis hominis was studied over 9 days. The differentiation between trophic (TF) and cyst forms (CF) was determined by differential counts before and after treatment with distilled water. A cytochemistry study using acridine orange and Calcofluor white wet-mount preparations of CF was carried out. The growth curves of TF and CF were related because the decrease in TF was followed by an increase in CF, and vice versa. The maximum of CF counts was obtained on the 6th or 7th day. Using the differential acridine orange stain, two subpopulations of CF, yellow-orange fluorescent cells or precysts and green fluorescent cells or cysts, were detected and their curves were also related. CF was stained by Calcofluor white, which suggested the existence of beta-(1-4)-glycosyl residues in the wall cysts of B. hominis.
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Affiliation(s)
- J Villar
- Departamento de Microbiología, Facultad de Medicina, Valencia, Spain
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Krylov MV, Belova LM. [Blastocystis from primates]. Parazitologiia 1997; 31:341-5. [PMID: 9479381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A new species, Blastocystis lemuri sp. n., was found in the Lemur catta. Size of blastocysts in a culture is 10.25-35.25 mkm, the number of nuclei varies from 1 to 2. The optimum temperature for cultivation is +39 degrees.
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Singh M, Ho LC, Yap AL, Ng GC, Tan SW, Moe KT, Yap EH. Axenic culture of reptilian Blastocystis isolates in monophasic medium and speciation by karyotypic typing. Parasitol Res 1996; 82:165-9. [PMID: 8825212 DOI: 10.1007/s004360050088] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The growth of axenic reptilian isolates of Blastocystis in Iscove's modified Dulbecco's medium (IMDM) was studied and the morphology of the parasite was examined by phase-contrast microscopy. The chromosomal patterns of these reptilian isolates of Blastocystis were examined by pulsed-field gel electrophoresis (PFGE) and compared with those of B. hominis and B. lapemi, a sea snake Blastocystis. IMDM with 10% horse serum supported excellent growth of the reptilian Blastocystis isolates. The parasites from all the isolates were predominantly vacuolar, but multivacuolar and amoeboid forms were also seen. Amoeboid forms with rather elongate pseudopodia were also observed. There were some differences in size, morphology, and growth characteristics in the different reptilian isolates. The karyotypic patterns of the Blastocystis isolates from tortoise, iguana, and python were distinctly different from one another and from those obtained with B. hominis and B. lapemi. On the basis of the above-mentioned differences in chromosomal patterns, the tortoise, iguana, and python isolates are described as new species, viz., B. geocheloni sp. nov. from Geochelone carbonaria (red-footed tortoise), B. cycluri sp. nov. from Cyclura cornuta (rhino iguana), and B. pythoni sp. nov. from Python reticulatus (reticulated python).
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Affiliation(s)
- M Singh
- Department of Microbiology, National University of Singapore
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Belova LM. [The cultivation of Blastocystis (Rhizopoda: Lobosea) from hens and ducks]. Parazitologiia 1992; 26:443-7. [PMID: 1297974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The method of cultivation of Blastocystis galli from hens and Blastocystis sp. from ducks was worked out. Blastocystis grow on nutrient medium at pH 7.0 to 7.2 in a wide range of temperatures from 30 to 45 C. Optimum temperatures for cultivation are 41 to 42 C. The growth of cultures was obtained on biphase egg medium. Solid phase of the medium presents coagulated contents of the hen's egg. Liquid phase can be made of Henk's solution with the addition of 30% of fresh or lyophilizinic hen serum or horse serum. Henk's solution can be replaced by medium 199 (we observed the growth of culture on medium 199 without addition of blood serum). In all variants of medium we added antibiotics on a per--1 ml of medium basis: ampicillini--4 thousand units, streptomycini--1 thousand units. After 2 to 3 passages antibiotics can be excluded from the medium. Optimum medium is that with the addition of 30% of fresh hen serum. Passages go well at the transfer of 15-20% culture after 72 to 96 hours. The size of cultural stages varied within the limits of 2.5-56.2 x 2.5-56.2 microns and 2.5-110 x 2.5-110 microns for Blastocystis sp. and B. galli, respectively, the number of nuclei in one individual varied from 1 to 64, seldom over 100.
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Teow WL, Zaman V, Ng GC, Chan YC, Yap EH, Howe J, Gopalakrishnakone P, Singh M. A Blastocystis species from the sea-snake, Lapemis hardwickii (Serpentes: Hydrophiidae). Int J Parasitol 1991; 21:723-6. [PMID: 1757201 DOI: 10.1016/0020-7519(91)90086-m] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Observations were made on Blastocystis isolated from the sea-snake, Lapemis hardwickii. Exponential growth of the organism was observed between 2 and 4 days of culture. Vacuolated, amoeboid and granular forms were observed in cultures, similar to B. hominis. The optimal growth temperature for the sea-snake Blastocystis was 24 degrees C compared with 37 degrees C for B. hominis. The karyotypic patterns of B. hominis and the sea-snake Blastocystis were studied in the clamped homogeneous electric field (CHEF) technique and found to be different. Based on the above differences, the sea-snake Blastocystis was designated as Blastocystis lapemi sp. nov.
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Affiliation(s)
- W L Teow
- Department of Microbiology, Faculty of Medicine, National University of Singapore, Kent Ridge
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