Displaying publications 1 - 20 of 51 in total

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  1. Elevated levels of urinary hyaluronidase in humans infected with intestinal parasites
    Chandramathi S, Suresh K, Kuppusamy UR
    Ann Trop Med Parasitol, 2010 Jul;104(5):449-52.
    PMID: 20819313 DOI: 10.1179/136485910X12743554760423
    Matched MeSH terms: Blastocystis Infections/enzymology*; Blastocystis Infections/epidemiology
  2. Viable blastocystis cysts in Scottish and Malaysian sewage samples
    Suresh K, Smith HV, Tan TC
    Appl Environ Microbiol, 2005 Sep;71(9):5619-20.
    PMID: 16151162
    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.
    Matched MeSH terms: Blastocystis Infections/parasitology; Blastocystis Infections/transmission
  3. Fulltext A preliminary study of Blastocystis hominis in some development areas in Alor Gajah District Melaka
    Shafariatul Akmar Ishak, Hidayatulfathi Othman, Mazrura Sahani
    Jurnal Sains Kesihatan Malaysia, 2008;6(1):109-115.
    MyJurnal
    A descriptive study was conducted to evaluate the prevalence of Blastocystis hominis in children aged between 1-12 years old from randomly selected villages in Alor Gajah district Melaka. The sampling was carried out from 1st to 7th of July of 2006. A total of 48 faecal samples were obtained from the children in those studied villages. The faecal specimens were examined by direct saline wet moun, formalin ethyl acetate concentration and trichrome staining method. It was found that 45.8% (22 out of 48) of the examined children were infected with Blastocystis hominis . Based on the results, the cumulative prevalence of three methods used showed that Blastocystis hominis infection in female children higher compared to male children. Whilst the schooling children aged of 6 to 12 years had a higher prevalence than pre school children at the age of 1-5 years. In term of diagnosis, formalin ethyl acetate concentration method showed prevalence of detection at 60.9%. It was followed by direct saline wet mount (43.5%) and trichrome staining at 34.8%.
    Matched MeSH terms: Blastocystis Infections
  4. Fulltext High lipid storage in vacoular forms of subtype 6 Blastocystis sp. in ostrich
    Chandrasekaran H, Govind SK, Panchadcharam C, Bathmanaban P, Raman K, Thergarajan G
    Parasit Vectors, 2014;7:469.
    PMID: 25358755 DOI: 10.1186/s13071-014-0469-7
    Blastocystis sp., a widely prevalent intestinal protozoan parasite is found in a wide range of animals, including humans. The possibility of zoonotic transmission to human from birds especially ostriches led us to investigate on the cross infectivity of Blastocystis sp. isolated from the ostrich feces as well as the phenotypic and subtype characteristics. There is a need to investigate this especially with the rising number of ostrich farms due to the growing global ostrich industry.
    Matched MeSH terms: Blastocystis Infections/parasitology; Blastocystis Infections/veterinary*
  5. Fulltext Phenotypic variation in Blastocystis sp. ST3
    Ragavan ND, Govind SK, Chye TT, Mahadeva S
    Parasit Vectors, 2014;7:404.
    PMID: 25174569 DOI: 10.1186/1756-3305-7-404
    Blastocystis, is one of the most common human intestinal protozoan, which has many conflicting reports on its pathogenic role. Gut conditions which obviously varies in asymptomatic individuals, symptomatic and irritable bowel syndrome (IBS) patients in terms of gut flora, pH, osmotic pressure and water potentials could play an important role in its pathogenicity. The present study is the first study to investigate phenotypic characteristics of Blastocystis sp. ST3 isolated from asymptomatic, symptomatic and IBS isolates.
    Matched MeSH terms: Blastocystis Infections/parasitology*
  6. Fulltext Advantage of using colonic washouts for Blastocystis detection in colorectal cancer patients
    Kumarasamy V, Roslani AC, Rani KU, Kumar Govind S
    Parasit Vectors, 2014;7:162.
    PMID: 24708637 DOI: 10.1186/1756-3305-7-162
    There have been previous studies associating microorganisms to cancer and with our recent findings of Blastocytsis antigen having a higher in vitro proliferation of cancer cells strengthens the suspicion. Collecting faecal samples alone to associate this parasite with cancer may not be accurate due to the phenomenon of irregular shedding and the possible treatment administrated to the cancer patients. Hence, this become the basis to search for an alternate method of sample collection. Colonic washout is an almost complete washed up material from colon and rectum which includes various microorganisms such as Blastocystis and other lodged material within the villi. The detection of parasite in colonic washouts will give a better reflection on the association between Blastocystis and CRC.
    Matched MeSH terms: Blastocystis Infections/diagnosis; Blastocystis Infections/parasitology*
  7. Fulltext Amoebic forms of Blastocystis spp. - evidence for a pathogenic role
    Rajamanikam A, Govind SK
    Parasit Vectors, 2013;6(1):295.
    PMID: 24499467 DOI: 10.1186/1756-3305-6-295
    Blastocystis spp. are one of the most prevalent parasites isolated from patients suffering from diarrhea, flatulence, constipation and vomiting. It's pathogenicity and pathophysiology remains controversial to date. Protease activity and amoebic forms have been reported previously in symptomatic isolates but there has been no conclusive evidence provided to correlate the protease activity and any specific life cycle stage of the parasite thus far.
    Matched MeSH terms: Blastocystis Infections/parasitology*
  8. Fulltext Prevalence, predictors and clinical significance of Blastocystis sp. in Sebha, Libya
    Abdulsalam AM, Ithoi I, Al-Mekhlafi HM, Khan AH, Ahmed A, Surin J, et al.
    Parasit Vectors, 2013;6:86.
    PMID: 23566585 DOI: 10.1186/1756-3305-6-86
    BACKGROUND: Blastocystis sp. has a worldwide distribution and is often the most common human intestinal protozoan reported in children and adults in developing countries. The clinical relevance of Blastocystis sp. remains controversial. This study was undertaken to determine the prevalence of Blastocystis infection and its association with gastrointestinal symptoms among outpatients in Sebha city, Libya.
    METHODS: A total of 380 stool samples were collected from outpatients attending the Central Laboratory in Sebha, Libya for routine stool examination. The presence of Blastocystis sp. was screened comparing light microscopy of direct smears against in vitro cultivation. Demographic and socioeconomic information were collected with a standardized questionnaire.
    RESULTS: The us (OR = 2.2; 95% CI = 1.02, 4.70) as significant predictors of Blastocystis infection among this population. In those who had only Blastocystis infection but no other gastrointestinal parasitic infections, the prevalence of gastrointestinal symptoms was higher compared to those without Blastocystis infection (35.3% vs 13.2%; x² = 25.8; P < 0.001). The most common symptoms among these patients were abdominal pain (76.4%), flatulence (41.1%) and diarrhoea (21.5%).overall prevalence of Blastocystis infection was 22.1%. The prevalence was significantly higher among patients aged ≥18 years compared to those aged < 18 years (29.4% vs 9.9%; x² = 19.746; P < 0.001), and in males compared to females (26.4% vs 17.5%; x² = 4.374; P = 0.036). Univariate analysis showed significant associations between Blastocystis infection and the occupational status (P = 0.017), family size (P = 0.023) and educational level (P = 0.042) of the participants. Multiple logistic regression analysis confirmed that the age of ≥ 18 years (OR = 5.7; 95% CI = 2.21; 9.86) and occupational stat
    CONCLUSIONS: Blastocystis sp. is prevalent and associated with gastrointestinal symptoms among communities in Sebha city, Libya. Age and occupational status were the significant predictors of infection. However, more studies from different areas in Libya are needed in order to delineate the epidemiology and clinical significance of this infection.
    Matched MeSH terms: Blastocystis Infections/epidemiology*; Blastocystis Infections/parasitology; Blastocystis Infections/pathology
  9. Fulltext Blastocystis infection in Malaysia: evidence of waterborne and human-to-human transmissions among the Proto-Malay, Negrito and Senoi tribes of Orang Asli
    Anuar TS, Ghani MK, Azreen SN, Salleh FM, Moktar N
    Parasit Vectors, 2013;6:40.
    PMID: 23433099 DOI: 10.1186/1756-3305-6-40
    Blastocystis has been described as the most common intestinal parasite in humans and has an increased impact on public health. However, the transmission of this parasite has not been conclusively determined.
    Matched MeSH terms: Blastocystis Infections/epidemiology*; Blastocystis Infections/transmission*
  10. Fulltext Tongkat Ali (Eurycoma longifolia): a possible therapeutic candidate against Blastocystis sp
    Girish S, Kumar S, Aminudin N
    Parasit Vectors, 2015;8:332.
    PMID: 26082155 DOI: 10.1186/s13071-015-0942-y
    In the local Malaysian context, herbal plants such as Eurycoma longifolia (Tongkat Ali), Orthosiphon stamineus (MisaiKucing), Ficus deltoidea (Mas Cotek), Zingiber officinale (Halia Bara) and Barringtonia racemosa (Putat) are known and widely used for its therapeutic properties. The first part of this study aims to screen for the anti-protozoal activity of these herbal plant extracts against Blastocystis sp. isolate subtype (ST) 3. Herbal extract with the highest efficacy was further fractionized into water and ethyl acetate fractions and tested against ST1, ST3 and ST5 Blastocystis sp. isolates. These isolates were also exposed to allopathic drugs, Metronidazole (MTZ), Tinidazole, Trimethoprim-sulfamethoxazole(TMP-SMX), Ketoconazole and Nitazoxanide for comparison purpose.
    Matched MeSH terms: Blastocystis Infections/parasitology
  11. Fulltext Molecular epidemiology of blastocystosis in Malaysia: does seasonal variation play an important role in determining the distribution and risk factors of Blastocystis subtype infections in the Aboriginal community?
    Noradilah SA, Moktar N, Anuar TS, Lee IL, Salleh FM, Manap SNAA, et al.
    Parasit Vectors, 2017 Jul 31;10(1):360.
    PMID: 28760145 DOI: 10.1186/s13071-017-2294-2
    BACKGROUND: Alternating wet and dry seasons may play an important role in the acquisition and distribution of Blastocystis subtype infection in the tropics. This cross-sectional study was therefore conducted to provide the prevalence of Blastocystis and to determine the potential risk factors associated with each subtype during the wet and dry seasons in the Aboriginal community, Pahang, Malaysia.

    METHODS: A total of 473 faecal samples were collected: 256 (54.1%) and 217 (45.9%) samples were obtained during the wet (October-November 2014) and the dry season (June 2015), respectively. All fresh faecal samples were subjected to molecular analysis for subtype and allele identification.

    RESULTS: Of the 473 samples, 42.6% and 37.8% were positive for Blastocystis ST1, ST2, ST3 and ST4 during wet and dry seasons, respectively. Prevalence of Blastocystis ST1 was significantly higher during the wet season compared to the dry season (Z = 2.146, P 

    Matched MeSH terms: Blastocystis Infections/ethnology*; Blastocystis Infections/parasitology; Blastocystis Infections/transmission
  12. Drinking water is a significant predictor of Blastocystis infection among rural Malaysian primary schoolchildren
    Abdulsalam AM, Ithoi I, Al-Mekhlafi HM, Ahmed A, Surin J, Mak JW
    Parasitology, 2012 Jul;139(8):1014-20.
    PMID: 22444778 DOI: 10.1017/S0031182012000340
    Blastocystis infection has a worldwide distribution especially among the disadvantaged population and immunocompromised subjects. This study was carried out to determine the prevalence and the association of Blastocystis infection with the socio-economic characteristics among 300 primary schoolchildren, living in rural communities in Lipis and Raub districts of Pahang state, Malaysia. Stool samples were collected and examined for the presence of Blastocystis using direct smear microscopy after in vitro cultivation in Jones' medium. The overall prevalence of Blastocystis infection was found to be as high as 25.7%. The prevalence was significantly higher among children with gastrointestinal symptoms as compared to asymptomatic children (x2 =4.246; P=0.039). Univariate and multivariate analyses showed that absence of a piped water supply (OR=3.13; 95% CI=1.78, 5.46; P<0.001) and low levels of mothers' education (OR=3.41; 95% CI=1.62, 7.18; P<0.01) were the significant predictors of Blastocystis infection. In conclusion, Blastocystis is prevalent among rural children and the important factors that determine the infection were the sources of drinking water and mothers' educational level. Interventions with provision of clean water supply and health education especially to mothers are required.
    Matched MeSH terms: Blastocystis Infections/diagnosis; Blastocystis Infections/epidemiology*; Blastocystis Infections/physiopathology
  13. High levels of oxidative stress in rats infected with Blastocystis hominis
    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 Infections/blood; Blastocystis Infections/metabolism*; Blastocystis Infections/urine
  14. Modified fields' stain: ideal to differentiate Dientamoeba fragilis and Blastocystis sp
    Ragavan AD, Govind SK
    Parasitol Res, 2015 Mar;114(3):1163-6.
    PMID: 25614298 DOI: 10.1007/s00436-014-4296-8
    Dientamoeba fragilis, a trichomonad parasite is usually found in the gastrointestinal tract of human, and it is known to be the cause for gastrointestinal disease. The parasite is globally distributed and mostly found in rural and urban areas. The parasite is found in humans and nonhuman primates such as the macaques, baboons, and gorillas. Often, the parasite is confused with another largely found organism in stools called Blastocystis sp. especially when seen directly under light microscopy on culture samples containing both parasites. Both sometimes are seen with two nuclei with sizes tending to be similar which complicates identification. Stools were collected fresh from nine previously diagnosed persons infected with D. fragilis who also were found to be positive for Blastocystis sp. Samples were then cultured in Loeffler's medium and were stained with Giemsa, iron hematoxylin, and modified Fields' (MF) stain, respectively. D. fragilis was differentiated from Blastocystis sp. when stained with MF stain by the presence of a thinner outer membrane with clearly demarcated nuclei in the center of the cell whilst Blastocystis sp. had a darker and thicker stained outer membrane with the presence of two nuclei. The staining contrast was more evident with modified Fields' stain when compared with the other two. The simplicity in preparing the stain as well as the speed of the staining procedure make MF stain an ideal alternate. The modified Fields' stain is faster and easier to prepare when compared to the other two stains. MF stain provides a better contrast differentiating the two organisms and therefore provides a more reliable diagnostic method to precisely identify one from the other especially when cultures show mixed infections.
    Matched MeSH terms: Blastocystis Infections/diagnosis*; Blastocystis Infections/parasitology
  15. Genetic diversity of caprine Blastocystis from Peninsular Malaysia
    Tan TC, Tan PC, Sharma R, Sugnaseelan S, Suresh KG
    Parasitol Res, 2013 Jan;112(1):85-9.
    PMID: 22961236 DOI: 10.1007/s00436-012-3107-3
    Blastocystis sp. is a common intestinal parasite found in humans and animals. The possibility of zoonotic transmission to humans from livestock especially goats led us to investigate the genetic diversity of caprine Blastocystis sp. obtained from five different farms in Peninsular Malaysia. Moreover, there is a lack of information on the prevalence as well as genetic diversity of Blastocystis sp. in goat worldwide. Results showed that 73/236 (30.9 %) of the goats were found to be positive for Blastocystis infection. The most predominant Blastocystis sp. subtype was ST1 (60.3 %) followed by ST7 (41.1 %), ST6 (41.1 %), and ST3 (11.0 %) when amplified by PCR using sequenced-tagged site (STS) primers. Four farms had goats infected only with ST1 whereas the fifth showed mixed infections with multiple STs. The proximity of the fifth farm to human dwellings, nearby domesticated animals and grass land as opposed to a sterile captive environment in the first four farms may account for the multiple STs seen in the fifth farm. Since ST1, ST3, ST6 and ST 7 were previously reported in human infection worldwide in particular Malaysia, the potential of the zoonotic transmission of blastocystosis should not be disregarded. The implications of different farm management systems on the distribution of Blastocystis sp. STs are discussed.
    Matched MeSH terms: Blastocystis Infections/epidemiology; Blastocystis Infections/parasitology; Blastocystis Infections/veterinary*
  16. Predominance of Blastocystis sp. subtype 4 in rural communities, Nepal
    Lee IL, Tan TC, Tan PC, Nanthiney DR, Biraj MK, Surendra KM, et al.
    Parasitol Res, 2012 Apr;110(4):1553-62.
    PMID: 22076050 DOI: 10.1007/s00436-011-2665-0
    Blastocystis sp. is a common intestinal parasite. To date, there have been sporadic and scanty studies on Blastocystis sp. carried out in rural communities in Nepal. We surveyed the prevalence of Blastocystis sp. and its possible associated risk factors, and reported the predominant Blastocystis sp. subtype in two rural communities, Bolde Phediche and Bahunipati, in Nepal. Human faecal samples were collected from 241 participants, cultured using in vitro cultivation and examined for Blastocystis sp. The presence of Blastocystis sp. in faecal samples was further confirmed by polymerase chain reaction (PCR) and subsequently genotyped using subtype-specific sequence tagged site (STS) primers. There were 26.1% (63/241) of the participants that were infected by Blastocystis sp. We detected 84.1% (53/63) of Blastocystis sp. subtype 4 infections in these rural communities. The unusually high prevalence of Blastocystis sp. subtype 4 can be attributed to the rearing of family-owned animals in barns built close to their houses. Eighty one percent (51/63) of the Blastocystis sp. infected participants drank not boiled or unfiltered water. The present study revealed that Blastocystis sp. could pose a health concern to the communities and travellers to the hilly area in Nepal. Infection may be transmitted through human-to-human, zoonotic and waterborne transmissions. We provide recommendations to ensure good public health practices.
    Matched MeSH terms: Blastocystis Infections/epidemiology*; Blastocystis Infections/parasitology*
  17. Effects of symptomatic and asymptomatic isolates of Blastocystis hominis on colorectal cancer cell line, HCT116
    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 Infections/parasitology*
  18. Urinary hyaluronidase activity in rats infected with Blastocystis hominis--evidence for invasion?
    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 Infections/diagnosis; Blastocystis Infections/pathology; Blastocystis Infections/veterinary*
  19. Genetic variability of Blastocystis sp. isolates obtained from cancer and HIV/AIDS patients
    Tan TC, Ong SC, Suresh KG
    Parasitol Res, 2009 Oct;105(5):1283-6.
    PMID: 19603182 DOI: 10.1007/s00436-009-1551-5
    This represents the first study to determine the genetic diversity of Blastocystis sp. among cancer and HIV/AIDS patients. Forty Blastocystis sp. isolates obtained from 20 cancer and 20 HIV/AIDS patients were genotyped by PCR using seven pairs of known sequenced-tagged site primers. Out of the 40 isolates, 38 were identified as one of the known genotypes and two isolates were negative with all the STS primers. Blastocystis sp. subtype 3 which is reported to be associated with disease was found to be predominant among the study subjects.
    Matched MeSH terms: Blastocystis Infections/parasitology*
  20. Phenotypic and genotypic characterisation of Blastocystis hominis isolates implicates subtype 3 as a subtype with pathogenic potential
    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 Infections/parasitology*; Blastocystis Infections/physiopathology*
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