Displaying publications 1 - 20 of 24 in total

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  1. Chandramathi S, Suresh KG, Mahmood AA, Kuppusamy UR
    Parasitol Res, 2010 May;106(6):1459-63.
    PMID: 20358228 DOI: 10.1007/s00436-010-1825-y
    The fact whether Blastocystis hominis can invade has always been in question. Apart from a few sporadic studies such as that done on gnotobiotic guinea pigs which showed surface invasion and mucosal inflammation of the host's intestine caused by B. hominis infection, no real documentation of invasion has been proven. Studies have shown that hyaluronidase is secreted during the penetration into the host's skin and gut by nematode parasites. Hyaluronidase activity in protozoa namely Entamoeba histolytica has also been described previously. This study attempts to determine hyaluronidase in urine samples of B. hominis-infected rats. The presence of hyaluronidase in urine provides an indirect evidence of invasion by B. hominis into colonic epithelium causing the degradation of extracellular matrix proteins namely hyaluronic acid (HA). HA is depolymerized by hyaluronidase which may be used by organisms to invade one another. In this study, the levels of urinary hyaluronidase of Sprague-Dawley rats infected with B. hominis were monitored for 30 days. Hyaluronidase levels in the infected rats were significantly higher on days 28 and 30 compared to the day before inoculation (P < 0.01 and P < 0.05, respectively). During this stage, parasitic burden in infected stools was also at a high level. Proinflammatory cytokines, interleukin-6 and interleukin-8, were also significantly higher (P < 0.05) in the serum of infected rats. The study demonstrates that since no other pathogen was present and that amoeboid forms of the parasites have been shown to exist previously, the elevated levels of hyaluronidase in this preliminary finding suggests that the organism is capable of having invasion or penetration activity in the hosts' intestine.
    Matched MeSH terms: Blastocystis hominis/enzymology*
  2. Chandramathi S, Suresh K, Sivanandam S, Kuppusamy UR
    PLoS One, 2014;9(5):e94567.
    PMID: 24788756 DOI: 10.1371/journal.pone.0094567
    Stress alters the oxidant-antioxidant state and immune cell responses which disrupts its function to combat infection. Blastocystis hominis, a common intestinal protozoan has been reported to be opportunistic in immunocompromised patients namely cancer. B. hominis infectivity in other altered immune system conditions especially stress is unknown. We aimed to demonstrate the stress effects towards the susceptibility and pathogenicity of B. hominis infection.
    Matched MeSH terms: Blastocystis hominis/pathogenicity*; Blastocystis hominis/physiology
  3. Chandramathi S, Suresh K, Kuppusamy UR
    Parasitol Res, 2010 Mar;106(4):941-5.
    PMID: 20165878 DOI: 10.1007/s00436-010-1764-7
    Blastocystis hominis is one of the most common intestinal protozoan parasites in humans, and reports have shown that blastocystosis is coupled with intestinal disorders. In the past, researchers have developed an in vitro model using B. hominis culture filtrates to investigate its ability in triggering inflammatory cytokine responses and transcription factors in human colonic epithelial cells. Studies have also correlated the inflammation by parasitic infection with cancer. The present study provides evidence of the parasite facilitating cancer cell growth through observing the cytopathic effect, cellular immunomodulation, and apoptotic responses of B. hominis, especially in malignancy. Here we investigated the effect of solubilized antigen from B. hominis on cell viability, using peripheral blood mononuclear cells (PBMCs) and human colorectal carcinoma cells (HCT116). The gene expressions of cytokines namely interleukin 6 (IL-6), IL-8, tumor necrosis factor alpha, interferon gamma, nuclear factor kappa light-chain enhancer of activated B cells (a gene transcription factor), and proapoptotic genes namely protein 53 and cathepsin B were also studied. Results exhibited favor the fact that antigen from B. hominis, at a certain concentration, could facilitate the growth of HCT116 while having the ability to downregulate immune cell responses (PBMCs). Therefore, there is a vital need to screen colorectal cancer patients for B. hominis infection as it possesses the ability to enhance the tumor growth.
    Matched MeSH terms: Blastocystis hominis/chemistry*
  4. Rajah S, Suresh K, Vennila GD, Khairul Anuar A, Saminathan R
    JUMMEC, 2002;7:77-79.
    Matched MeSH terms: Blastocystis hominis
  5. Init I, Foead AL, Fong MY, Yamazaki H, Rohela M, Yong HS, et al.
    PMID: 18613539
    Genomic DNA of Blastocystis isolates released into 0.1% Triton X-100 was suitable for amplification and yielded similar results as the genomic DNA extracted with standard kit. The specific B. hominis primers (BH1: GCT TAT CTG GTT GAT CCT GCC AGT and BH2: TGA TCC TTC CGC AGG TTC ACC TAC A) successfully produced the PCR product of about 1,770 bp with all the 7 Blastocystis isolates tested. The restriction fragment length polymorphism (RFLP) patterns yielded by 13 out of 25 restriction endonucleases showed that the 7 isolates could be grouped into 4 subgroups: subgroup-1 consisted of isolate C; subgroup-2 of isolates H4 and H7; subgroup-3 of isolates KP1, Y51 and M12; and subgroup-4 of isolate 27805. The differences between subgroups manifested as clear-cut RFLP patterns. A common band of 230 bp was revealed by Eco R1 in all the Blastocystis isolates tested. The band of about 180 bp was revealed by Alu I, differentiated symptomatic from asymptomatic isolates of this parasite, and might indicate the pathogenicity of this parasite.
    Matched MeSH terms: Blastocystis hominis/genetics*; Blastocystis hominis/isolation & purification
  6. Tan TC, Suresh KG
    Parasitol Res, 2006 Feb;98(3):189-93.
    PMID: 16323025
    Blastocystis hominis is one of the most common human parasites that inhabit the intestinal tract. Conflicting reports continue to exist regarding the existence and the functional role of the amoeboid forms in the life cycle of the parasite. The present study investigates the presence of these forms in 20 isolates obtained from ten symptomatic and asymptomatic patients respectively. A total of 10,000 parasite cells per ml from each isolate were inoculated into three culture tubes each containing 3 ml of Jones' medium supplemented with 10% horse serum, incubated at 37 degrees C. The contents were examined daily for 10 days. Irregular and polymorphic amoeboid forms with multiple extended pseudopodia were observed in all isolates from symptomatic patients, while none of the isolates from asymptomatic patients showed the presence of the amoeboid forms. The amoeboid forms were initially noted on day 2 and the percentages increased from 2% to 28%, with peak percentages from day 3 to day 6. Transmission electron microscopy revealed two types of amoeboid forms; one containing a large central vacuole completely filled with tiny electron-dense granules, and the other which revealed multiple small vacuoles within the central body. The cytoplasm contained strands of electron-dense granules resembling rough endoplasmatic reticulum, which is suggestive of active protein synthesis. The surface coat of the amoeboid form surrounding the parasite showed uneven thickness. Acridine orange stained the central body yellow and the periphery orange, indicating activity at the level of nucleic acids. The amoeboid form could either be an indicator of pathogenicity of B. hominis, or the form likely to contribute to pathogenicity and be responsible for the symptoms seen in patients.
    Matched MeSH terms: Blastocystis hominis/cytology*; Blastocystis hominis/physiology*
  7. Init I, Mak JW, Top S, Zulhainan Z, Prummongkol S, Nissapatorn V, et al.
    PMID: 15115079
    The objective of this study was to characterize the polypeptides associated with cysts of Blastocystis hominis. This form is believed to be infective and plays a role in parasite resistance to anti-B. hominis drugs currently used for treatment of Blastocystis associated diarrhea. Cysts were induced through in vitro culture of the parasite in complete medium supplemented with bacterial extract with trypticase, metronidazole or doxycycline. SDS-PAGE analysis showed almost similar polypeptide patterns of parasite extracts obtained from in vitro cultured parasites before and after exposure with the three supplements. Polypeptide bands at 76, 58.5, 48, 45, 40, 38, 32, 25 and 22 kDa were constantly seen in all antigenic preparations and no specific cyst-associated polypeptide was present. However, on immunoblot analysis, 3 out of 16 blastocystosis human sera identified a cyst-associated polypeptide at 60 kDa in all parasite extracts prepared from cultures with the three supplements. In addition, there were associated morphological changes detected in these parasites stained with acridine orange and observed under fluorescence microscopy. Metronidazole induced cyst forms (reddish cells) as early as 12 hours post-exposure; more cyst production (with stronger immunoblot bands) occurred after 24 hours exposure. However, cysts rupture with release and destruction of B. hominis daughters cells occurred after 48 hours exposure. Doxycycline induced less cyst-like forms at 24 hours (weaker 60 kDa band) and less destruction of the cysts (60 kDa band still present at 72 hours post exposure). Bacterial extract and trypticase also induced cysts at 12 hours with increasing numbers up to 72 hours exposure (corresponding increase in intensity of 60 kDa band from samples harvested at 12 to 72 hours post exposure) without any sign of deleterious effect on the parasite.
    Matched MeSH terms: Blastocystis hominis/drug effects; Blastocystis hominis/physiology*
  8. Tan TC, Suresh KG, Smith HV
    Parasitol Res, 2008 Dec;104(1):85-93.
    PMID: 18795333 DOI: 10.1007/s00436-008-1163-5
    Despite frequent reports on the presence of Blastocystis hominis in human intestinal tract, its pathogenicity remains a matter of intense debate. These discrepancies may be due to the varying pathogenic potential or virulence of the isolates studied. The present study represents the first to investigate both phenotypic and genotypic characteristics of B. hominis obtained from symptomatic and asymptomatic individuals. Symptomatic isolates had a significantly greater size range and lower growth rate in Jones' medium than asymptomatic isolates. The parasite cells of symptomatic isolates exhibited rougher surface topography and greater binding affinity to Canavalia ensiformis (ConA) and Helix pomatia (HPA). The present study also identifies further phenotypic characteristics, which aided in differentiating the pathogenic forms from the non-pathogenic forms of B. hominis. Blastocystis subtype 3 was found to be correlated well with the disease.
    Matched MeSH terms: Blastocystis hominis/classification*; Blastocystis hominis/genetics; Blastocystis hominis/isolation & purification; Blastocystis hominis/pathogenicity*
  9. Dib JR, Fernández-Zenoff MV, Oquilla J, Rudelli M, Lazarte S, González SN
    Trop Biomed, 2015 Dec 01;32(4):800-804.
    PMID: 33557474
    The prevalence of intestinal parasitic infections among schoolchildren in Colalao del Valle, a high-altitude community in Tucumán province, Argentina, was investigated. The data revealed a high prevalence of parasitism (79.7%) with no significant differences in distribution by sex or age. Protozoa infections were the most common with Blastocystis hominis being the most prevalent (62.5%), followed by Giardia lamblia (29.7%), Endolimax nana (15.6%), Entamoeba coli (12.5%) and Iodamoeba bütschlii (3.1%). Interestingly, there was an absence of soil-transmitted helminths among the studied population which could be related to climate (variable temperatures, moderate rainfall) and soil type (clay).
    Matched MeSH terms: Blastocystis hominis
  10. Farnaza A, Baha L
    Malays Fam Physician, 2010;5(3):148-150.
    PMID: 25606208 MyJurnal
    A 27-year-old man presented with a two-week history of central colicky abdominal pain associated with loose stools. Further history revealed that he had been exposed to contaminated waters. Stool investigation by direct wet stool smears revealed the presence of Entamoeba histolytica and Blastocystis hominis cysts. A diagnosis of amoebiasis secondary to E. histolytica and concurrent B. hominis infestation was made. We would like to emphasise the importance of clinical history including recent travel to endemic areas. Any suspicion of parasitic infection should prompt the clinician to investigate. Early diagnosis and management would prevent serious complications associated with E. Histolytica infection.
    Matched MeSH terms: Blastocystis hominis
  11. Tan TC, Suresh KG, Thong KL, Smith HV
    Parasitol Res, 2006 Sep;99(4):459-65.
    PMID: 16628457
    Genomic DNA from 16 Blastocystis hominis isolates comprising of eight asymptomatic isolates (A1-A8) and eight symptomatic isolates (S1-S8) was amplified by arbitrarily primed polymerase chain reaction (AP-PCR) using 38 arbitrary 10-mer primers. Six primers (A10, B5, C20, D1, F6, and F10) generated reproducible DNA fingerprints. AP-PCR amplification revealed similar DNA fingerprints among all symptomatic isolates (S1-S8) with common bands at 850 bp using primer A10, 920 bp using primer B5, and 1.3 kbp using primer D1. Isolates A1, A3, A4, A5, A6, and A7 showed similar DNA banding patterns and all asymptomatic isolates (A1-A8) shared a major band at 1 kbp using primer B5. Isolates A2 and A8 showed distinct DNA banding patterns that differed from the remainder of the isolates. The results of the phylogenetic analyses showed that all symptomatic isolates (S1-S8) formed a clade with >70% similarity among the isolates and which were clearly separate from asymptomatic isolates A1, A3, A4, A5, A6, and A7. Asymptomatic isolates A2 and A8 formed two distinct and separate clades. AP-PCR revealed higher genetic variability within the asymptomatic isolates than within the symptomatic isolates. The present study suggests that AP-PCR can be a valuable method for differentiating between isolates of B. hominis and our results support the hypothesis that our asymptomatic and symptomatic B. hominis isolates may represent two different strains/species with varying pathogenic potential.
    Matched MeSH terms: Blastocystis hominis/classification; Blastocystis hominis/genetics; Blastocystis hominis/isolation & purification*
  12. Haresh K, Suresh K, Khairul Anus A, Saminathan S
    Trop Med Int Health, 1999 Apr;4(4):274-7.
    PMID: 10357863
    Isolates of Blastocystis hominis from infected immigrant workers from Indonesia, Bangladesh and infected individuals from Singapore and Malaysia were assessed for growth pattern and degree of resistance to different concentrations of metronidazole. Viability of the cells was assessed using eosin-brillian cresyl blue which stained viable cells green and nonviable cells red. The Bangladeshi and Singaporean isolates were nonviable even at the lowest concentration of 0.01 mg/ml, whereas 40% of the initial inoculum of parasites from the Indonesian isolate at day one were still viable in cultures with 1.0 mg/ml metronidazole. The study shows that isolates of B. hominis of different geographical origin have different levels of resistance to metronidazole. The search for more effective drugs to eliminate th parasite appears inevitable, especially since surviving parasites from metronidazole cultures show greater ability to multiply in subcultures than controls.
    Matched MeSH terms: Blastocystis hominis/drug effects*; Blastocystis hominis/growth & development
  13. Chandramathi S, Suresh K, Anita ZB, Kuppusamy UR
    Trans R Soc Trop Med Hyg, 2012 Apr;106(4):267-9.
    PMID: 22340948 DOI: 10.1016/j.trstmh.2011.12.008
    Chemotherapy can cause immunosuppression, which may trigger latent intestinal parasitic infections in stools to emerge. This study investigated whether intestinal parasites can emerge as opportunistic infections in breast and colorectal cancer patients (n=46 and n=15, respectively) undergoing chemotherapy treatment. Breast cancer patients were receiving a 5-fluorouracil/epirubicin/cyclophosphamide (FEC) regimen (6 chemotherapy cycles), and colorectal cancer patients were receiving either an oxaliplatin/5-fluorouracil/folinic acid (FOLFOX) regimen (12 cycles) or a 5-fluorouracil/folinic acid (Mayo) regimen (6 cycles). Patients had Blastocystis hominis and microsporidia infections that were only present during the intermediate chemotherapy cycles. Thus, cancer patients undergoing chemotherapy should be screened repeatedly for intestinal parasites, namely B. hominis and microsporidia, as they may reduce the efficacy of chemotherapy treatments.
    Matched MeSH terms: Blastocystis hominis/immunology; Blastocystis hominis/pathogenicity*
  14. Suresh K, Venilla GD, Tan TC, Rohela M
    Parasitol Res, 2009 Jun;104(6):1373-80.
    PMID: 19238443 DOI: 10.1007/s00436-009-1340-1
    Blastocystis from infected stools of a person who showed chronic symptoms of abdominal discomfort and diarrhea were examined over a 6-month period, using transmission electron microscopy, for the ultrastructural changes from vacuolar to cystic stage. The study confirms the irregular shedding phenomenon of the organism previously reported, and for the first time, records sequential changes in encystation in stools collected over a time period. The study also confirms the existence of a precystic stage which has an immature cell wall consisting of a layer of a homogenous electron-dense mass surrounding the cell which acts as a intermediatory stage between the vacuolar and cystic stage.
    Matched MeSH terms: Blastocystis hominis/growth & development*; Blastocystis hominis/isolation & purification; Blastocystis hominis/ultrastructure*
  15. Suresh K, Rajah S, Khairul Anuar A, Anuar Zaini MZ, Saminathan R, Ramakrishnan S
    JUMMEC, 1998;3:62-63.
    One hundred seventy three stool samples were obtained from workers from Indonesia, Bangladesh, Myanmar, Pakistan and others. The stool samples were examined for Ascaris, Trichuris, Hookworm, Schistosomes, trematodes and cestodes. The protozaon parasites included Bnlantidiirrir coli, Blastocystis honlinis, Cyclospora cryptosporidium, Microsporidiirin, Entamoeeba histolytica, Giardia lamblia, lodamoeba butschilli. Of these 21.9%, 17% and 1% of the population studied had hookworm, Trichuris trichiura and Ascaris lumbricoides infections respectively. There was only one Indonesian reported to have Hymenolepis nana infections. The most common protozoan seen in the faecal sample is Blastocystis hominis (36%) followed by Giardia lamblia (4%). Most of the stools positive with these faecal pathogens were semisolid especially the ones positive for the protozoan. We have also shown Blastocystis from the Indonesian workers show very small forms almost 3-5 in size compared to the normal size of 10-15 pm in the other nationalities. These forms show a distinct growth profile in cultures and appears to be more resistant to temperature changes than Blastocystis seen in the other two nationalities. The high incidence of Hookworm and Trichuris infections is suggestive that if these workers are left unheated their productivity will be hampered by other possible serious complications such as anaemia, weight loss, abdominal pain with diarrhoea1 stools and nausea. There are increasing reports that Blastocystis hominis is pathogenic. Flatulence, abdominal discomfort and the increase in the frequency of the passing watery stool has been noted in patients infected with the parasite. Since most of the workers are generally housed in crowded rooms it is highly likely that this will facilitate transmission through the faecal-oral route of both Giardia and Blastocystis possibly increasing the incidences of these infections among workers.
    Matched MeSH terms: Blastocystis hominis
  16. Chandramathi S, Suresh K, Shuba S, Mahmood A, Kuppusamy UR
    Parasitology, 2010 Apr;137(4):605-11.
    PMID: 19961647 DOI: 10.1017/S0031182009991351
    Numerous studies have revealed the presence of oxidative stress in parasitic infections. However, such studies were lacking in the Malaysian population. Previously, we have provided evidence that oxidative stress is elevated in Malaysians infected with intestinal parasites. Stool examinations revealed that about 47.5% of them were infected with the polymorphic protozoa, Blastocystis hominis. However, they were found to have mixed infection with other intestinal parasites.
    Matched MeSH terms: Blastocystis hominis*
  17. Suresh K, Init I, Reuel PA, Rajah S, Lokman H, Khairul Anuar A
    Parasitol Res, 1998;84(4):321-2.
    PMID: 9569099
    Matched MeSH terms: Blastocystis hominis/physiology*
  18. Tan TC, Suresh KG
    Parasitol Res, 2007 Nov;101(6):1521-5.
    PMID: 17701428
    Blastocystis hominis has been regarded as an enigmatic parasite as many aspects of its basic biology remain uncertain. Many reproductive processes have been suggested for the organism; however, to date, only the binary fission has been proven. Plasmotomy is one of the modes of reproduction previously suggested to be seen in in vitro cultures. The present study provides trichrome and acridine orange staining evidence for the existence of nucleic acid suggestive of division of nucleus into multinucleate forms with the respective cytoplasm dividing giving rise to two or three progeny B. hominis. Transmission electron micrographs further confirmed that these daughter cells had respective surrounding surface coat, mitochondria, and vacuoles.
    Matched MeSH terms: Blastocystis hominis/physiology*; Blastocystis hominis/ultrastructure
  19. Chan KH, Chandramathi S, Suresh K, Chua KH, Kuppusamy UR
    Parasitol Res, 2012 Jun;110(6):2475-80.
    PMID: 22278727 DOI: 10.1007/s00436-011-2788-3
    The pathogenesis of Blastocystis hominis in human hosts has always been a matter of debate as it is present in both symptomatic and asymptomatic individuals. A recent report showed that B. hominis isolated from an asymptomatic individual could facilitate the proliferation and growth of existing cancer cells while having the potential to downregulate the host immune response. The present study investigated the differences between the effects of symptomatic and asymptomatic derived solubilized antigen of B. hominis (Blasto-Ag) on the cell viability and proliferation of colorectal cancer cells. Besides that, the gene expression of cytokine and nuclear transcriptional factors in response to the symptomatic and asymptomatic B. hominis antigen in HCT116 was also compared. In the current study, an increase in cell proliferation was observed in HCT116 cells which led to the speculation that B. hominis infection could facilitate the growth of colorectal cancer cells. In addition, a more significant upregulation of Th2 cytokines observed in HCT116 may lead to the postulation that symptomatic Blasto-Ag may have the potential in weakening the cellular immune response, allowing the progression of existing tumor cells. The upregulation of nuclear factor kappa light chain enhancer of activated B cells (NF-κB) was observed in HCT116 exposed to symptomatic Blasto-Ag, while asymptomatic Blasto-Ag exhibited an insignificant effect on NF-κB gene expression in HCT116. HCT116 cells exposed to symptomatic and asymptomatic Blasto-Ag caused a significant upregulation of CTSB which lead to the postulation that the Blasto-Ag may enhance the invasive and metastasis properties of colorectal cancer. In conclusion, antigen isolated from a symptomatic individual is more pathogenic as compared to asymptomatic isolates as it caused a more extensive inflammatory reaction as well as more enhanced proliferation of cancer cells.
    Matched MeSH terms: Blastocystis hominis/isolation & purification; Blastocystis hominis/pathogenicity*; Blastocystis hominis/chemistry
  20. Mohamed Kamel Abd. Ghani, Hartini Yusof
    Sains Malaysiana, 2011;40:1123-1127.
    Blastocystis hominis merupakan antara protozoa yang paling biasa ditemui di dalam sampel feses manusia di seluruh dunia. Prevalens infeksi protozoa ini adalah lebih tinggi di kalangan mereka yang tinggal di negara membangun berbanding negara maju. Seramai 71 orang kanak-kanak Orang Asli dari Pos Lenjang, Pahang telah menjadi subjek dalam kajian ini. Bagi kajian yang lebih terperinci, kumpulan kanak-kanak ini telah dibahagikan menurut jantina dan umur. Sampel feses dikumpul dan setiap sampel diperiksa dengan menggunakan 3 teknik diagnostik iaitu teknik apusan langsung, konsentrasi formalin-eter dan perwarnaan trikrom bagi tujuan pengesanan dan pengenalpastian Blastocystis hominis. Prevalens infeksi Blastocystis hominis di kalangan kanak-kanak Orang Asli adalah sangat tinggi iaitu 93%. Kanak-kanak perempuan didapati lebih ramai terinfeksi (97.5%) berbanding kanak-kanak lelaki (87.1%) walaupun secara statistiknya tidak signifikan (p>0.05). Protozoa ini juga telah menginfeksi kesemua kanak-kanak prasekolah (100%) manakala kanak-kanak yang bersekolah turut menunjukkan prevalens infeksi yang tinggi iaitu 86.5%. Daripada segi diagnosis, teknik perwarnaan trikrom didapati paling sensitif dan ia dapat mengenalpasti kesemua (66) sampel feses yang positif dengan Blastocystis hominis. Ini diikuti dengan teknik konsentrasi formalin-eter (43 sampel) dan teknik apusan langsung (18 sampel) (p<0.05). Prevalens infeksi Blastocystis hominis yang tinggi di kalangan kanak-kanak Orang Asli adalah berhubungkait dengan pelbagai faktor termasuk status sosioekonomi yang rendah, budaya, kekurangan kemudahan asas dan tahap pengetahuan mengenai penjagaan kesihatan serta kebersihan diri yang rendah. Selain itu, peningkatan prevalens infeksi dalam kajian ini menunjukkan pentingnya penggunaan teknik diagnostik yang lebih berkesan di dalam pemeriksaan rutin bagi memperolehi hasil diagnosis yang lebih tepat.
    Matched MeSH terms: Blastocystis hominis
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