Association of Blastocystis hominis with colorectal cancer:A systematic review of in vitro and in vivo evidences

BACKGROUND Recently,there have been several findings that showed intestinal colonisation of Blastocystis hominis(Blastocystis)as a risk factor to the worsening of colorectal cancer(CRC).However,studies have shown controversial results in the pathogenicity of Blastocystis.AIM To review systematically the evidence available on the association between CRC and Blastocystis and the prevalence of Blastocystis in CRC patients and to investigate cytopathic and immunological effects of Blastocystis in in vitro and in vivo studies.METHODS PRISMA guidelines were utilised in conducting this systematic review.Original articles published before February 2,2020 were included.PubMed,Science Direct,Scopus and Google scholar databases were searched.Manual searching was carried out to find articles missed during the online search.RESULTS Out of 12 studies selected for this systematic review,seven studies confirmed the prevalence of Blastocystis and found it to be between 2%-28%in CRC patients,whereby subtype 1 and subtype 3 were predominantly seen.A total of four studies employing in vitro human colorectal carcinoma cell line study models showed significant cytopathic and immunological effects of Blastocystis.In addition,one in vivo experimental animal model study showed that there was a significant effect of infection with Blastocystis on exacerbation of colorectal carcinogenesis.CONCLUSION Blastocystis is a commonly identified microorganism in CRC patients.These studies have provided supportive data that Blastocystis could exacerbate existing CRC via alteration in host immune response and increased oxidative damage.Future studies of CRC and Blastocystis should attempt to determine the various stages of CRC that are most likely to be associated with Blastocystis and its relationship with other intestinal bacteria.

Case report:pre tibial myxedema combined with hyperthyroidism and blastocystis hominis infection

The patient is a 37-year-old male with a right anterior tibial mass for more than one year and a left anterior tibial mass for more than one month.There was a history of hyperthyroidism.Histopathology of the lesions showed epidermal hyperkeratosis of the skin tissue,thickening of the spinous layer,extensive collagen fibrillation in the superficial dermis and reticular layer,and numerous linear and granular mucoprotein deposits in the lower and middle dermis.Blastocystis hominis was routinely detected in the stool.Diagnosis:1.Pretibial myxedema 2.intestinal parasitosis(Blastocystis hominis infection).

Impact factors of Blastocystis hominis infection in persons living with human immunodeficiency virus:a large-scale,multi-center observational study from China

Background Blastocystis hominis(Bh)is zoonotic parasitic pathogen with a high prevalent globally,causing opportunistic infections and diarrhea disease.Human immunodeficiency virus(HIV)infection disrupts the immune system by depleting CD4^(+)T lymphocyte(CD4^(+)T)cell counts,thereby increasing Bh infection risk among persons living with HIV(PLWH).However,the precise association between Bh infection risk and HIV-related biological markers and treatment processes remains poorly understood.Hence,the purpose of the study was to explore the association between Bh infection risk and CD4^(+)T cell counts,HIV viral load(VL),and duration of interruption in antiviral therapy among PLWH.Methods A large-scale multi-center cross-sectional study was conducted in China from June 2020 to December 2022.The genetic presence of Bh in fecal samples was detected by real-time fluorescence quantitative polymerase chain reaction,the CD4^(+)T cell counts in venous blood was measured using flowcytometry,and the HIV VL in serum was quantified using fluorescence-based instruments.Restricted cubic spline(RCS)was applied to assess the non-linear association between Bh infection risk and CD4^(+)T cell counts,HIV VL,and duration of interruption in highly active antiretroviral therapy(HARRT).Results A total of 1245 PLWH were enrolled in the study,the average age of PLWH was 43 years[interquartile range(IQR):33,52],with 452(36.3%)being female,50.4%(n=628)had no immunosuppression(CD4^(+)T cell counts>500 cells/μl),and 78.1%(n=972)achieved full virological suppression(HIV VL<50 copies/ml).Approximately 10.5%(n=131)of PLWH had interruption.The prevalence of Bh was found to be 4.9%[95%confidence interval(CI):3.8-6.4%]among PLWH.Significant nonlinear associations were observed between the Bh infection risk and CD4^(+)T cell counts(Pfor nonlinearity<0.001,L-shaped),HIV VL(Pfor nonlinearity<0.001,inverted U-shaped),and duration of interruption in HARRT(Pfor nonlinearity<0.001,inverted U-shaped).Conclusions The study revealed that VL was a better predictor of Bh infection than CD4^(+)T cell counts.It is crucial to consider the simultaneous surveillance of HIV VL and CD4^(+)T cell counts in PLWH in the regions with high level of socioeconomic development.The integrated approach can offer more comprehensive and accurate understanding in the aspects of Bh infection and other opportunistic infections,the efficacy of therapeutic drugs,and the assessment of preventive and control strategies.

Two-day enema antibiotic therapy for parasite eradication and resolution of symptoms

BACKGROUND Blastocystis hominis(B.hominis)and Dientamoeba fragilis(D.fragilis)are two protozoan parasites of human bowel that are found throughout the world.There is still debate about the pathogenicity of these protozoans,despite them being commonly associated with gastrointestinal symptoms and can cause health issue in both children and adults.These parasites are usually transmitted through faecal-oral contact particularly under poor hygiene conditions or food/water contamination.Once a person is infected,the parasites live in the large intestine and are passed in the faeces.AIM To investigate the effect of triple antibiotic therapy using enema infusion in the treatment of B.hominis and D.fragilis infections.METHODS This retrospective longitudinal study was conducted in a single medical centre,which included fifty-four patients(≥18 years)who were positive for D.fragilis,B.hominis or both between 2017 and 2018.The treatment consisted of triple antibiotics that were infused over two consecutive days through rectal enema.Faecal samples were collected from participants pre-and post-treatment and were tested for parasites using microscopy and polymerase chain reaction.Patients’symptoms were recorded prior and after the treatment as well as patient demographic data.RESULTS Patients(n=54),were either positive for B.hominis(37%),D.fragilis(35%)or both(28%).All patients completed the two-day treatment and no serious adverse effect was reported.The most common side effect experienced by the patients during the treatment was urine discolouration which was cleared by six weeks of followup.Common symptoms reported prior to treatment were diarrhoea,abdominal pain,constipation and fatigue.Other symptoms included abdominal discomfort,dizziness and blood in the stool.Eighty-nine percent of patients completed a final stool test post-treatment.At six weeks post-treatment,79%of patients cleared the parasites from their faeces.Symptoms such as abdominal discomfort,dizziness and blood in the stool decreased significantly at both seven days and six weeks post-treatment(P<0.040).The enema retention time,bowel preparation,previous antibiotic treatment or previous gastrointestinal problems had no significant effect on parasite eradication.CONCLUSION Overall,eradication of parasites and improvement of clinical outcomes were observed in treated patients,showing the efficacy of this combination to eradicate the parasites and provide positive clinical outcome.