A 11-year-old boy with Blastocystis hominis infection, presents as immune thrombocytopenia

BACKGROUND

Some causes of first-line treatment failure for ITP are often closely related to infections. But parasitic infections are rarely mentioned and easily overlooked. The case is the first to describe a boy with immune thrombocytopenia associated with blastocystis hominis.

CASE PRESENTATION

The case involved a boy presenting with bleeding skin spots and ecchymosis and accompanied by intermittent epigastric pain and constipation. After a series of complete examinations, the platelet count was found to be decreased to 13 × 109/L and immune thrombocytopenia was diagnosed. After first-line treatment with gamma globulin and prednisolone, the thrombocytopenia remained unchanged. Blastocystis hominis was subsequently found in the patient's stool and then the treatment of metronidazole was provided. One week later, the patient's thrombocytopenia was completely relieved. He was followed up for six months and was found to have recovered well.

CONCLUSIONS

The screening for potential predisposing factors is very important for immune thrombocytopenia patients with poor response to first-line treatment, and the best treatment strategy should include the management of potential diseases.

Spread of Intestinal Parasites in Patients Presenting with Gastrointestinal Complaints

Objective

The aim of this study is to determine the prevalence of intestinal parasites in patients admitted to University of Health Sciences Türkiye (UHS) Van Training and Research Hospital.

Methods

A total of 300 patients between the ages of 18-90 who applied to UHS Van Training and Research Hospital with gastrointestinal complaints and were referred to the parasitology laboratory between September 2021 and December 2021, and 100 patients without any chronic disease and gastrointestinal complaints in the control group were included in the study. Stool samples taken from patients included in the study and individuals in the control group were analyzed by native-lugol and modified acid-fast staining methods.

Results

In the study, intestinal parasites were detected in 41 (13.3%) of 300 patients in the patient group and in seven (7%) of 100 individuals in the control group. The highest rate of Blastocystis species (Blastocystis spp.) (5.7%) was found in the patient group. Entamoeba coli 3%, G. intestinalis 2.7% and Cryptosporidium species (Cryptosporidium spp). 2.3% were found among the other species detected. In addition, a statistically significant correlation was found between the incidence of parasites and abdominal pain (p=0.022) and nausea (p=0.029).

Conclusion

As a result; it was concluded that intestinal parasites are still an important health problem in patients with gastrointestinal complaints and intestinal parasites should definitely be considered in this patient group.

Dientamoeba fragilis associated with microbiome diversity changes in acute gastroenteritis patients

This study examined the correlation between intestinal protozoans and the bacterial microbiome in faecal samples collected from 463 patients in New Zealand who were diagnosed with gastroenteritis. In comparison to traditional microscopic diagnosis methods, Multiplexed-tandem PCR proved to be more effective in detecting intestinal parasites. Among the identified protozoans, Blastocystis sp. and Dientamoeba fragilis were the most prevalent. Notably, D. fragilis was significantly associated with an increase in the alpha-diversity of host prokaryotic microbes. Although the exact role of Blastocystis sp. and D. fragilis as the primary cause of gastroenteritis remains debatable, our data indicates a substantial correlation between these protozoans and the prokaryote microbiome of their hosts, particularly when compared to other protists or patients with gastroenteritis but no detectable parasitic cause. These findings underscore the significance of comprehending the contributions of intestinal protozoans, specifically D. fragilis, to the development of gastroenteritis and their potential implications for disease management.

Gastrointestinal Pathogens in Multi-Infected Individuals: A Cluster Analysis of Interaction

Indigenous people live in remote areas of Colombia. Multiple infections with bacteria, protozoa and/or helminths are common, as well as colonization in various forms. This study focused on the question of whether and to what extent various pathogens interact with each other. Therefore, a mathematical approach was retrospectively applied to PCR-based data of 244 stool samples, collected in two datasets. A stable cluster solution of the pathogens assessed was determined, and a unique configuration between Blastocystis hominis/Campylobacter spp./Giardia lamblia forming cluster 1 and Dientaemoeba fragilis was verified. A pathogen density-dependent interplay appeared between the B. hominis/Campylobacter spp./G. lamblia cluster, D. fragilis and Ascaris lumbricoides. The applied mathematical approach demonstrated that co-infections with parasites of questionable pathological relevance such as B. hominis and D. fragilis can be of diagnostic relevance due to their ability to promote or repress other pathogens. With the increasing availability of highly sensitive multiplexed molecular diagnostic approaches even in resource-limited settings, where multiple colonization of infection events with enteric pathogens in parallel are common, the importance of interpreting whole pathogen patterns rather than just individual pathogen detection may become more and more relevant.

Intestinal microbiota analysis of different Blastocystis subtypes and Blastocystis-negative individuals in Taiwan

BACKGROUND

Intestinal parasitic infections are the most common infectious diseases among Southeast Asian migrant workers in Taiwan, especially for infections with Blastocystis hominis. However, little is known about the impact of Blastocystis subtypes (STs) on the gut microbiota.

MATERIAL AND METHODS

We retrospectively evaluated the prevalence of intestinal parasites in a teaching hospital in Northern Taiwan in the period of 2015 to 2019. Blastocystis-positive stool specimens were collected for ST analysis by polymerase chain reaction in 2020. Intestinal microbiota analyses of different Blastocystis STs and Blastocystis-free individuals were conducted by 16S rRNA sequencing.

RESULTS

A total of 13,859 subjects were analyzed, of which 1,802 cases (13%) were diagnosed with intestinal parasitic infections. B. hominis infections were the most prevalent (n = 1546, 85.7%). ST analysis of Blastocystis-positive samples (n=150) indicated that ST1 was the most common type, followed by ST3, ST4, ST2, ST7, and ST5. Different Blastocystis STs (ST1, ST3, and ST4) were associated with distinct richness and diversity of the microbiota. Taxonomic profiles revealed that Akkermansia muciniphila was significantly enriched for all analyzed Blastocystis STs, whereas Holdemanella biformis was more abundant in the Blastocystis-free group. Additionally, Succinivibrio dextrinosolvens and Coprococcus eutactus were specifically more abundant in ST3 carriers than in non-infected individuals.

CONCLUSIONS

This study demonstrates that A. muciniphila is positively associated with all Blastocystis STs, while H. biformis was negatively associated with them. Several bacteria were enriched in specific STs, highlighting the need for further microbiota analysis at the ST level to elucidate the pathogenicity of Blastocystis.

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.

Remission of chronic blastocystosis using ciprofloxacin

Blastocystis hominis is a controversial parasite because of its taxonomy and its treatment. In this report, an immunocompetent person with chronic blastocystosis, in whom a series of treatments were used without success, except for the use of ciprofloxaci. Ciprofloxacin could be an antibiotic of choice in chronic blastocystosis.

Investigation of Blastocystis hominis Frequency in Patients with Diabetes by Microscopy and Conventional PCR Methods

Background

We aimed to determine the frequency and subtype of B. hominis in diabetic patients.

Methods

One hundred and fifty diabetic patients and 100 healthy people without any chronic disease were included in the study. Stool samples were analyzed by native-Lugol, condensation, trichrome staining and PCR methods.

Results

İn 150 patients with diabetes; B. hominis was detected in 38 (25.3%) by PCR, in 34 (22.7%) by native-Lugol and trichrome staining. In the control group, 14 (14%) out of 100 subjects were positive by PCR, and 10 (10%) were positive by native-Lugol and trichrome staining. In the statistical evaluation, a significant difference was found between gender (P=0.023), age (P=0.045; ≤35 and >35 comparison), duration of diabetes (P=0.04), the HbA1c value (P=0.023; <8 and ≥8 comparison), and B. hominis positivity. ST1 was determined in 76.9% of patients with diabetes, and ST2 was determined in 23.07%. Considering the 3 methods, B. hominis positivity was detected in 40 patients (26.7%) in diabetic group and in 14 participants (14%) in the control group (P=0.011).

Conclusion

B. hominis is a factor to be considered in patients with diabetes. Herein, the most common subtype detected in the patients with diabetes mellitus was ST1, but this result was not considered sufficient to reveal the importance of the subtype factor in the pathogenicity of B. hominis in patients with diabetes. In this context, there is a need for more comprehensive studies in both diabetic and other immunocompromised patient groups.

Antiprotozoal activity of Boesenbergia rotunda (L.) Mansf and Ganoderma lucidum (Fr.) Kart extracts against Blastocystis hominis

Background and Aim

Blastocystis hominis is an intestinal protozoan in humans and animals. The parasite causes mild-to-severe intestinal complications, such as diarrhea, in healthy humans and immunocompromised hosts. This study aimed to determine the antiprotozoal activity of Boesenbergia rotunda (L.) Mansf and Ganoderma lucidum (Fr.) Kart extracts against B. hominis.

Materials and Methods

Antiprotozoal activity of B. rotunda and G. lucidum extracts against B. hominis subtype 3 was determined using the erythrosin B exclusion assay, confirmed by a time-kill study. The morphology of the parasite treated with the extracts was observed by a scanning electron microscope. The phytochemicals present in B. rotunda and G. lucidum extracts were identified by gas chromatography-mass spectrometry analysis.

Results

Both B. rotunda and G. lucidum extracts demonstrated strong antiprotozoal activity with similar minimum inhibitory concentration (MIC) values of 62.5 μg/mL. At 4× MIC and 8× MIC, both B. rotunda and G. lucidum extracts, and metronidazole inhibited the growth of B. hominis by up to 90% after 12 h treatment. Blastocystis hominis cells treated with B. rotunda extract, G. lucidum extract, and metronidazole were deformed and withered when compared with the control. Geraniol and versalide were found as the main compounds in B. rotunda and G. lucidum extracts, respectively.

Conclusion

These results indicate the potential medicinal benefits of B. rotunda and G. lucidum extracts in the growth inhibition of B. hominis.

Efficacy of Nitazoxanide, Nitazoxanide-Garlic Combination and Tinidazole in Treatment of Giardia duodenalis and Blastocystis hominis: Coproscopic Assessment

Background

Giardia duodenalis and Blastocystis hominis are among the most common intestinal protozoa worldwide. Treatment of infection by metronidazole (MTZ) has some limitations. The objective of this study was to detect the prevalence of Blastocystis and giardiasis among school-age children from December 2021 till March 2022 from Motoubes, Kafrelsheikh, Egypt, and determine the efficacy of nitazoxanide (NTZ), NTZ plus garlic and tinidazole (TIN) on Blastocystis and giardiasis infection.

Methods

Stool samples were collected from 390 children and microscopically examined using formalin-ethyl acetate concentration and culturing on Jones' medium for B. hominis. Those who tested positive for giardiasis (120 children, 30.7%) (Group I) or Blastocystis (180 children, 46.1%) (Group II) were equally divided into four subgroups. The first subgroup received NTZ orally, every 12 hours for three successive days. The second subgroup received NTZ in the same dose as the first subgroup plus dry garlic powder every 12 hours for three successive days. The third subgroup received TIN as a single oral dose, and a fourth control subgroup. Successful cure was considered if no Blastocystis or giardiasis stages were found in post-treatment faecal specimens.

Results

Cure rate was significantly higher in TIN treated groups (75.5% and 96.6%) than NTZ (57.7% and 40%) or NTZ plus garlic treated groups (55.5% and 43%) in both Blastocystis and giardiasis, respectively (P<0.05).

Conclusion

TIN, once, is more efficacious than NTZ or NTZ plus garlic in the treatment of Blastocystis and giardiasis in children.

[Microscopy vs. molecular biology in the diagnosis of intestinal protozoal infections, is it time for a change?]

OBJECTIVE

Microscopic examination of the intestinal parasites, from the patient's concentrated feces, has a lower sensitivity when compared to molecular diagnostic techniques. Therefore, the objective of this study has been to compare both techniques, as well as to evaluate whether there is a correlation between the microscopic examination and the threshold cycles (Ct) obtained for Blastocystis hominis.

METHODS

Retrospective study of the samples received in the Microbiology laboratory during September 2021. The MiniParasep SF® concentration test was performed for microscopic visualization and then PCR was performed with the Seegene AllplexTM Parasite Assay panel.

RESULTS

A 27% (n=74) of the samples were positive by molecular diagnosis, with a total of 87 parasites detected. 53% (n=39) were women with a mean age of 47 ± 24 years. In 76% (n=56) of the cases the service of origin was Primary Care. The most frequently found parasite was B. hominis, 85% (n=64), followed by Dientamoeba fragilis 20% (n=15) and Giardia lamblia 11% (n=8). Co-infection by two parasites was detected in 13 cases (B. hominis + D. fragilis in 6 cases, and B. hominis + G. lamblia in 7 cases). In the microscopic diagnosis, 9.5% (n=26) positivity was obtained. The most frequently found parasite was B. hominis, 84% (n=23), followed by G. lamblia, which was seen in three cases by microscopy. D. fragilis was not seen in any case. Coinfection of B. hominis + G. lamblia was observed in one sample.

CONCLUSIONS

Techniques for molecular diagnosis of intestinal parasites are fast, reliable and more sensitive than microscopic techniques, improving microbiological diagnosis and quality of care.

playing a positive role in colorectal cancer risk? A systematic review and meta-analysis

Objective

Intestinal protozoa Blastocystis hominis and Cryptosporidium spp. are two influential factors in intestinal complications and malignancies. In present study, we estimated the pooled prevalence and odds ratio (OR) of the two parasites in colorectal cancer (CRC) patients and their possible association with the deadly disease.

Method

Our systematic search was conducted for published researches between January 1, 2000 and April 30, 2022 by using four international databases include Scopus, PubMed, and Web of Science as well as Google scholar search engine. The random- and fixed-effects models were used to estimate the pooled prevalence, OR, and 95% confidence interval (CI) by comprehensive meta-analysis (V2.2, Bio stat) software. Inclusion and exclusion criteria were applied.

Results

Thirteen papers (seven case–control and six cross-sectional studies) for B. hominis/CRC and six papers (two case–control and four cross-sectional studies) for Cryptosporidium spp./CRC were eligible to include in data synthesis. Pooled prevalence of B. hominis and Cryptosporidium spp. in CRC patients was calculated to be 26.8% (95% CI 19.4–35.7%) and 12.7% (95% CI 6.8–22.5%), respectively. Based on case–control studies, significant difference was found between case and controls in both protozoa (B. hominis OR 2.10; 95% CI 1.39–3.18% vs. Cryptosporidium spp. OR 5.06; 95% CI 1.8–13.6%). Considering the Blastocystis subtypes, ST1 (5/6; 83.33% studies) and ST3 (5/6; 83.33% studies) had the highest number of reports in CRC patients. Regarding the Cryptosporidium species, only C. parvum and C. hominis were reported.

Conclusion

Given the significant prevalence of both parasites in CRC patients and their statistically significant association, there is a need to pay more attention to these two intestinal parasites in under treatment patients.

Parasitic infections among patients hospitalized in the Tropical and Parasitic Clinic of Poznan University of Medical Sciences, Poland between 2015 and 2018. Is there a relationship between protozoa infection and gastrointestinal symptoms?

Introduction

Diarrhoea is a common reason for hospitalization among travellers returning from the tropics. The aetiology is predominantly bacterial, but it can also be caused by parasites such as Giardia intestinalis, Cryptosporidium spp., and Blastocystis spp.

Aim

We analysed patients from the Poznan Tropical and Parasitic Clinic to evaluate the presence of parasitic infections and to find correlations between infections, journeys, and gastrointestinal symptoms.

Material and methods

In our study we examined 2561 stool samples obtained from patients hospitalized in the Tropical and Parasitic Department of Poznan Medical University, Poland. Microscopic examinations of samples were performed based on a direct thin smear in 0.9% NaCl, which allowed the assessment of the presence of protozoa life stages.

Results

In 106 (4.14%) of the 2561 examined samples we detected parasites, mainly from people coming back from tropical areas (61.32%). Mostly we detected Blastocystis sp. and Giardia intestinalis. Fifty percent of patients suffered from gastrointestinal symptoms, so careful microscopic stool examination should be performed in every case in which intestinal pathology occurs, and certainly in travelling individuals.

Conclusions

Traveling is a real risk factor for protozoa infection. The most common parasites detected in the stool are Blastocystis sp. and Giardia intestinalis. Parasitic coinfection should be taken into consideration as a pathologic agent in patients suffering from abdominal signs and persistent diarrhoea. Prolonged protozoa infection and its role in microbiota alterations requires further investigation.

Molecular characterization of Entamoeba, Blastocystis and Cryptosporidium species in stool samples collected from Jordanian patients suffering from gastroenteritis

Little is known about the prevalence of intestinal protozoa in patients suffering from diarrhea in Jordan. The present study aimed to detect and speciate Entamoeba, Blastocystis, and Cryptosporidium species in a total of 159 human patients with diarrhea from November 2014 to October 2016. The overall prevalence for the three parasites was 19.5% (31/159). Entamoeba spp. (Entamoeba. dispar and/or Entamoeba histolytica), Blastocystis hominis, and Cryptosporidium parvum subtype IIaA15G2R1 were detected in 12.6%, 6%, and 0.6 of samples, respectively. This is the first molecular study in Jordan to confirm the diagnosis of Entamoeba species and to discriminate between E. histolytica and E. dispar.

Prevalence of Intestinal Protozoan Infection in Patients with Ulcerative Colitis (UC) in Isfahan, Iran

Background:

Determination of the prevalence of intestinal protozoan infection is a fundamental step to set up an effective control program to improve the health status of society and to establish efficient strategies. Intestinal pathogen and even non-pathogen protozoa consider as major causes of disease in patients with gastrointestinal problems. The objective of this study is to determine the prevalence of intestinal protozoan infection in patients with ulcerative colitis (UC) in Isfahan, Iran.

Methods:

The descriptive cross-sectional study carried out from 2013 to 2018 in Isfahan, Iran. One thousand nine hundred and sixty-five samples of feces from patients with UC collected and each sample examined using direct wet mounting with normal saline and iodine and sedimentation tests such as formol-ethyl acetate concentration and trichrome-staining methods.

Results:

From 655 patients, 185 (28.2%) infected with Giardia lamblia followed by Blastocystis hominis (27.3%), Endolimax nana (14.4%), Entamoeba coli (11.5%), Iodamoba butschlii (4.7%), Entamoeba histolytica (1.4%), and Chilomastix mesnili (0.6%).

Conclusions:

This study revealed a high prevalence of infection with at least one or six non-pathogenic and pathogenic intestinal protozoa in UC patients in the Isfahan region. Intestinal protozoa are a challenging public health problem wherever health care is limited in the area. The emergence of UC in the world results in the need to study etiologic factors. In order to obtain further information about the etiology of disease, we investigated the prevalence of intestinal protozoan infection in patients with UC in Isfahan, Iran.

Infectious Proctitis in Ulcerative Colitis: The Importance of an Accurate Differential Diagnosis

The authors present the case of a 62-year-old male presenting with a relapse of ulcerative colitis. He had unprotected anal intercourse with other men and his medical record was remarkable for HIV infection. He was admitted to the emergency department with bloody diarrhea, tenesmus, urgency, and recent weight loss. Laboratory workup revealed de novo mild anemia and mild elevation of inflammation parameters. Endoscopic evaluation displayed loss of normal vascular pattern, edema, erythema, exudation, and superficial ulceration in the distal rectum. Biopsies showed chronic proctitis with mild to moderate activity. The patient was treated with intravenous glucocorticoids, but symptoms persisted. Extensive microbial study allowed the identification of multiple infectious agents with potential for infectious proctitis: cytomegalovirus, Chlamydia trachomatis, and Blastocystis hominis. This case highlights the importance of careful microbial investigation, supporting a detailed clinical history, in patients presenting with symptoms of inflammatory bowel disease flare, particularly in risk groups such as that with sexual risk.

Prevalence of Intestinal Parasites among Patients with Chronic Urticaria in Northern Iran

BACKGROUND

Chronic urticaria (CU) has a range of clinical demonstrations and causes. Parasitic infections are mentioned as one of the main causes of the CU.

OBJECTIVES

The aim of this study was to investigate the prevalence of intestinal parasites in patients with CU (with duration time of more than 6 weeks) compared healthy subjects.

METHODS

A total of 169 cases and 210 controls were included in this study. Ages ranged from 1 to 77 years old. Three samples were gathered from each patients and direct wet mount, formol-ether concentration, Ziehl-Neelsen and trichrome staining were used.

RESULTS

Out of the 379 individuals examined here, 208 were from urban areas and 171 from rural areas. Three stool samples were taken from each patient in three consecutive days. Based on parasitological tests, 7 (4.1%) cases from 169 patients with CU and 6 (2.9%) cases from 210 non- CU group individuals were positive for intestinal parasites.

CONCLUSION

The prevalence of various parasites between case and control groups was not significant.

[Study on the mechanisms of the intestinal tight-junction destruction caused by Blastocystis hominis infection in rats]

OBJECTIVE

To explore the mechanism of the intestinal barrier damage caused by Blastocystis hominis infections in rats.

METHODS

Thirty SD rats were randomly divided into the control group, and the 1-, 3-, 6- and 9-week-infection groups, of 6 rats in each group. Rats in each infection group were orally infected with B. hominis trophozoites at a density of 2 × 10⁸ parasites per rat, and the control group was given an equal volume of phosphate buffered saline solution. The 7-hour urine samples were collected 1, 3, 6 and 9 weeks post-infection for the measurement of the intestinal permeability. Then, rats were sacrificed using the cervical dislocation method, and the cecum specimens were collected for the detection of the intestinal epithelial cell permeability. The expression of tight junction-related Occludin and Claudin - 1 genes and apoptosis-related Bcl - 2 and Bax genes was quantified in cecum epithelial cells using the real-time fluorescent quantitative PCR (qPCR) assay, and cell apoptosis was detected in the rat cecum using the TdT-mediated dUTP nick-end labeling (TUNEL) assay.

RESULTS

The median urinary lactolose to mannitol ratios were 0.29, 0.72, 0.44, 0.46 and 0.38 in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 12.09, P < 0.05). B. hominis invasion and epithelial injury were observed in intestinal epithelial cells of rats infected with B. hominis, and transmission electron microscopy displayed the destruction of tight junctions between intestinal epithelial cells. The relative expression of Occludin, Claudin-1, Bcl-2 and Bax genes was 1.04, 0.62, 0.71, 0.68 and 0.96; 1.03, 0.61, 0.63, 0.76 and 0.86; 1.08, 0.70, 0.75, 0.74 and 1.03; and 1.00, 1.57, 1.33, 1.35 and 1.10 in the control group and the 1-, 3-, 6- and 9-week-infection groups, respectively, and all differences were statistically significant (F = 2.86, 2.85, 3.37 and 4.45, all P values < 0.05). The median number of positive staining cells were 1.00, 13.00, 9.00, 3.50 and 1.00 in rat cecum specimens in the control group, and the 1-, 3-, 6- and 9-week-infection groups, respectively, and the difference was statistically significant (H = 22.95, P < 0.01).

CONCLUSIONS

B. hominis infection may cause an increase in the rat intestinal permeability through triggering the apoptosis of intestinal epithelial cells to destroy the tight junction between intestinal epithelial cells, thereby destroying the intestinal barrier function.

[Progress of researches on animal models of Blastocystis hominis infections]

Blastocystis hominis is a common parasitic protozoa in human and animal intestines; however, its pathogenicity remains controversial. Construction of animal models is of great significance to investigate the pathogenicity, pathogenic mechanisms and drug screening of B. hominis. Experimental animals, mode of infections, parasite strains and host immune status are important factors affecting the successful modeling of B. hominis infections in animals. Hereby, we review the progress of researches on animal models of B. hominis infections, and summarize the influencing factors and application of animal models of B. hominis infections, in order to provides insights into the selection of animals models of B. hominis infections.

[Progress of researches on global prevalence of Blastocystis hominis human infections and its subtypes]

Blastocystis hominis is a parasite that parasitizes in the intestines of humans and animals, and is closely related to a variety of gastrointestinal diseases such as abdominal pain and diarrhea. B. hominis is distributed worldwide, and the prevalence of B. hominis infections and dominant subgenotypes vary in countries and in regions from the same country. This paper reviews the global prevalence of B. hominis human infections, its subtypes and geographical distribution, so as to provide insights into the understanding of the global epidemiology of B. hominis and the management of B. hominis infections.

[Prevalence and risk factors of Blastocystis hominis infections among AIDS patients in Nanchang City]

OBJECTIVE

To investigate the prevalence and risk factors of Blastocystis hominis infections among AIDS patients in Nanchang City.

METHODS

A cross-sectional questionnaire survey was conducted among AIDS patients in Nanchang City during the period between May and September, 2016. B. hominis infection was detected in patients'stool samples using a PCR assay, and the CD4⁺ T cell count was measured in subjects'blood samples. In addition, the risk factors of B. hominis infection in AIDS patients were identified using univariate and multivariate logistic regression analyses.

RESULTS

A survey was conducted in Nanchang City from May to September 2016. A total of 505 AIDS patients were investigated, and the prevalence of B. hominis infection was 4.16%. Univariate analysis revealed that B. hominis infection correlated with the occupation (χ² = 8.595, P = 0.049), education level (χ² = 14.494, P = 0.001), type of daily drinking water (χ² = 10.750, P = 0.020), root of HIV infections (χ² = 8.755, P = 0.026) and receiving anti-HIV therapy (χ² = 23.083, P = 0.001) among AIDS patients, and multivariate logistic regression analysis identified daily direct drinking of tap water as a risk factor of B. hominis infections [odds ratio (OR) = 7.988, 95% confidential interval (CI): (1.160, 55.004)] and anti-HIV therapy as a protective factor of B. hominis infection [OR = 0.183, 95% CI: (0.049, 0.685)].

CONCLUSIONS

The prevalence of B. hominis is 4.16% among AIDS patients in Nanchang City. Daily direct drinking of tap water is a risk factor, and anti-HIV therapy is a protective factor of B. hominis infection among AIDS patients living in Nanchang City.

In vitro Effect of Silver Nanoparticles on Blastocystis hominis

INTRODUCTION

This study aims to assess the efficacy of silver nanoparticles (Ag Nps) alone and combined with metronidazole (Ag Nps + MTZ) as potential alternative therapeutic agents for Blastocystis hominis.

METHODS

The parasites were challenged with Ag Nps, Ag Nps + MTZ and MTZ. To assess the efficacy of drugs, counting of viable parasites was done after 1, 2, and 3 hours of adding the drugs.

RESULTS

Blastocystis hominis count was reduced by 20.72%, 28.23%, and 18.92% after one hour of adding Ag Nps, Ag Nps + MTZ, and MTZ, respectively. Cysts count was further reduced by 51.49%, 61.61%, and 40.78% after 2 hours and by 71.69%, 79.67%, and 62.65% after 3 hours of adding the drugs in the same order, respectively.

CONCLUSION

There was a statistically significant difference (P<0.05) in the in vitro growth inhibition of the parasite over the different time intervals when using the tested drugs against the control drug.

Evaluation of the AllplexTM Gastrointestinal Panel-Parasite Assay for Protozoa Detection in Stool Samples: A Retrospective and Prospective Study

This study aims at evaluating the performances of the multiplex PCR Allplex^TM Gastrointestinal Panel-Parasite Assay (GIPPA), which detects G. duodenalis, Cryptosporidium spp., E. histolytica, D. fragilis, B. hominis, and C. cayetanensis, by comparison to microscopy. A retrospective evaluation was conducted on a series of positive clinical samples (n = 99) stored at -80 °C or at +4 °C. A five-month prospective study was then conducted on all samples sent to our lab for parasite detection (n = 586). In the retrospective cohort, sensitivity was 81% for both G. duodenalis (26/32) and D. fragilis (21/26) and 100% for Cryptosporidium spp. (26/26, including 6 different species), B. hominis (26/26), and C. cayetanensis (4/4). During the prospective study, 95 samples were positive by microscopy and 207 by multiplex PCR assay. The molecular assay showed a significantly higher sensitivity of PCR, especially for G. duodenalis (100% vs. 60.7%, p < 0.01), D. fragilis (97.2% vs. 14.1%, p < 0.001), and B. hominis (99.4% vs. 44.2%, p < 0.001) but also for E. histolytica (100% vs. 50.0%). The sensitivity of the Allplex^TM GIPPA on the first stool sample was equivalent to the sensitivity of microscopy on multiple stool samples but inferior to multiplex PCR on multiple stool samples. Taken together, the Allplex^TM GIPPA is suitable for the routine detection of protozoa in fecal samples.

Initial Evidences of Salt and Pepper Retinal Lesions (SPRL) in Patients with Intestinal Protozoan Infections in Iran

BACKGROUND

It is made clear that salt and pepper retinal lesion (SPRL) has subsequently associated with the infection with Giardia lamblia (G. lamblia). However, little is known regarding the prevalence of SPRL among patients suffered from parasitic infections in the world.

OBJECTIVE

This study aimed to determine the prevalence of SPRL among patients with intestinal protozoan infections, for the first time, in Sari, northern Iran.

METHODS

In this case-control study, a total of 150 subjects participated: 75 were in the patients group diagnosed to have an intestinal parasite and 75 in the control group without any intestinal infection. Fecal samples were obtained from all participants and examined with wet mount and formalin-ether methods. The retina of both groups was examined by an ophthalmologist.

RESULTS

Overall, salt and pepper retinal changes were diagnosed in 12 (16 %) patients with at least one parasitic infection (7 females and 5 males). G. lamblia was diagnosed in 6 subjects (50%), Blastocystis hominis in 5 (41.6%), and Entamoeba coli in 1 (8.3 %). Most of the patients (58.3%) had a mild infection. Bilateral retinal involvement was observed in 75% of the patients. Furthermore, macula involvement was observed in 91.7 % with SPRL.

CONCLUSION

Our findings indicated the relatively high prevalence of SPRL in subjects with giardiasis and blastocystosis. It can be concluded that not only G. lamblia but also B. hominis can cause SPRL in Sari, Iran. Further studies are needed to find other etiologic parasites able to cause retinal damages.

Improving Hashimoto's thyroiditis by eradicating Blastocystis hominis: Relation to IL-17

BACKGROUND

Hashimoto's thyroiditis (HT) is a common autoimmune disorder that causes significant morbidity. Interleukin (IL)-17 was identified as a major contributing factor in the pathogenesis of HT. Blastocystis hominis (BH) is a very common infection and has been shown to be associated with several diseases. Our aim was to determine serum IL-17 level in HT patients with and without BH infection and the effect of eradicating BH in patients with HT.

METHODS

A prospective cohort study was conducted on 20 HT patients not infected with BH (group I), 20 HT patients infected with BH (group II), and 20 healthy patients (group III). Serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibodies (anti-TPO), and IL-17 were performed by ELISA method and were repeated in group II after 6 weeks of eradication of BH.

RESULTS

Patients with HT showed a significantly higher serum IL-17 compared with controls. IL-17 was significantly higher in HT patients infected with BH compared with HT patients not BH infected (mean 6.93 ± 2.83 pg/ml versus 3.25 ± 1.55 pg/ml, p = 0.003). After BH eradication TSH, anti-TPO, and IL-17 were significantly decreased (mean 14.76 ± 11.11 µIU/ml versus 9.39 ± 7.11 µIU/ml, p < 0.001; mean 308 ± 175.6 IU/ml versus 295.4 ± 167.1 IU/ml, p = 0.006; and mean 6.93 ± 2.83 pg/ml versus 6.45 ± 2.48 pg/ml, p < 0.001), respectively. Multivariate analysis after treating BH infection showed that IL-17 was significantly negatively correlated with FT3 (adjusted p = 0.002) and significantly positively correlated with anti-TPO (adjusted p = 0.045).

CONCLUSION

Treatment of BH infection ameliorates HT through reduction in IL-17, anti-TPO, and TSH.

CLINICAL TRIAL REGISTRATION NUMBER

PACTR201909495111649.

[Prevalence and risk factors of Blastocystis hominis infection in inpatients in Jiangjin District, Chongqing City]

OBJECTIVE

To understand the prevalence and risk factors of Blastocystis hominis infection in inpatients in Jiangjin District, Chongqing City.

METHODS

A cross-sectional study was conducted in a community hospital in Jiangjin District, Chongqing City, and the inpatients were surveyed by questionnaires. After obtaining the informed consent from the inpatients or legal guardians, the stool and blood samples were collected and examined by microscopy and PCR from April 17 to May 1, 2018. The univariate analysis and logistic regression analysis were used to analyze the risk factors of the B. hominis infection.

RESULTS

A total of 198 hospitalized patients were investigated, and the infection rate of B. hominis was 10.61% (21/198), and the infection rate of the females (12.10%) was higher than that of the males (8.11%), but the difference was not statistically significant. The highest rate of infection was 19.23% in the age group of 10 to 20 years, followed by 17.74% in the age group of 60 years and above, and the lowest rate was 2.38% in the age group of 20 to 40 years. The difference in infection rates of B. hominis among the different age groups was statistically significant (P < 0.05). The infection rate of B. hominis in the people who used dry pail latrines was 33.30%, which was higher than that of the people who used water flush toilets (9.10%) (P < 0.05). The genotypes of B. hominis were ST1, ST3, ST6 and ST7, and ST6 and ST3 being the most predominant genotypes which accounted for 47.62% (10/21) and 38.10% (8/21) respectively, and among the infected males, the genotypes were only ST3 and ST6. The multiple logistic regression analysis showed that among the factors affecting B. hominis infection, only keeping pets was a risk factor [OR = 3.798, 95% CI (1.245, 11.581), P < 0.05].

CONCLUSIONS

A high prevalence of B. hominis infection is found in the inpatients in Jiangjin District, Chongqing City, the predominant genotypes are ST6 and ST3, and keeping pets may be one of the main risk factors.

[Epidemiological characteristics and risk factors of Blastocystis hominis infection among patients with HIV/AIDS in Fuyang City Anhui Province]

OBJECTIVE

To investigate the prevalence and risk factors of Blastocystis hominis infections among patients with HIV/AIDS in Fuyang City, Anhui Province.

METHODS

A cross-sectional study was conducted in Fuyang City, Anhui Province in 2016. The demographic and socioeconomic status, and the lifestyle and production style were collected using a questionnaire survey. B. hominis DNA was detected in subjects'stool samples using a PCR assay, and the CD4+ T lymphocyte count and HIV viral load were measured in the subjects' blood samples. The risk factors of B. hominis infections among patients with HIV/AIDS were identified using univariate and multivariate logistic regression analyses.

RESULTS

A total of 398 HIV/AIDS patients were enrolled in this study, with a mean age of 49.3 years, a mean body weight of 55.9 kg and a mean height of 164.4 cm. The prevalence of B. hominis infection was 6.78% in the study subjects, and no gender- (χ² = 1.589, P = 0.207), education level- (χ² =0.508, P = 0.776), marital status- (χ² = 0.419, P = 0.811) or occupation-specific prevalence (χ² = 2.744, P = 0.615) was detected. Among the patients with HIV/AIDS, there were no significant differences in the age (t = 0.370, P = 0.712), height (t = 1.587, P =0.113), body weight (t = 0.516, P = 0.606), CD4⁺ T lymphocyte count (t = 1.187, P = 0.230) or HIV viral load (t = 0.193, P =0.496) between B. hominis-infected and uninfected individuals. Dinking non-tap water [OR = 6.554, 95% CI: (1.876 to 22.903)] and keeping dogs [OR = 5.895, 95% CI: (2.017 to 17.225)] were identified as risk factors for B. hominis infection in patients with HIV/AIDS.

CONCLUSIONS

The prevalence of B. hominis infection is high in HIV/AIDS patients, and drinking non-tap water and keeping dogs are risk factors for B. hominis infection among HIV/AIDS patients.

The Prevalence of Intestinal Parasitic Infections in Ahvaz, Southwest of Iran, during 2007-2017

BACKGROUND

Intestinal parasitic infections (IPIs) are frequently considered one of the public health problems worldwide. Therefore, we aimed to evaluate the prevalence of IPIs among patients.

METHODS

In this Retrospective cross-sectional study, 50000 stool samples (24551 males) were collected among males and females referred to Naft Hospital of Ahvaz, southern Iran during 2007-2017. At first, the collected specimens were macroscopically observed for the presence of trophozoites, eggs, cysts using the procedure of direct as well as the method of formalin-ether concentration.

RESULTS

Of 50000 samples, 2878 (5.75%) cases were positive for IPIs that 1426 and 1452 cases were observed in the males and females, respectively. Giardia lamblia with 887 (1.774%) cases, Blastocystis hominis with 784 (1.568%) cases, Entamoeba histolytica/dispar with 685 (1.37%) cases, E. coli with 357 (0.714%) cases, Trichomonas hominis with 43 (0.086%) cases, Chilomastix mesnili with 40 (0.08%) cases, Hymenolepis nana with 38 (0.076%) cases, Lodamoeba butschlii with 25 (0.05%) cases, Endolimax nana with 18 (0.036%) cases, Taenia saginata proglottid with one (0.002%) case were found.

CONCLUSION

Our finding showed a relatively high prevalence of IPIs among people referred to Naft Hospital of Ahvaz, southern Iran during 2007-2017.

Frequency and genetic diversity of Blastocystis subtypes among patients attending to health centers in Mazandaran, northern Iran

Blastocystis hominis is a common intestinal protozoan with global distribution. The prevalence of B. hominis is extremely diverse in different countries. Molecular studies show that there is a great deal of genetic variation in the Blastocystis parasite isolated from humans and animals. Therefore, this study was conducted to determine B. hominis genotypes in patients attending to health centers of Sari, Mazandaran Province, north of Iran. 420 fecal specimens were collected from individuals in health centers of Sari from April to December 2017. The samples were examined by direct methods, parasite test (formalin ether) and Giemsa staining. In order to determine the genotypes of Blastocystis parasite, all positive samples in direct methods were tested by PCR using SSU rDNA gene. Eventually, seven positive molecular samples were sequenced and recorded in the gene bank. The phylogenetic analysis was done by drawing a gene tree using the neighbor-joining procedure. B. hominis was detected in 60 stool specimens by microscopic method. All these 60 samples were positive by PCR and the bands 310 bp were observed. According to the phylogenetic tree, it was revealed that B. hominis isolates of Mazandaran Province are more similar to subtype ST3 (ST type) that reported in Khorramabad in Lorestan Province (West of Iran). The present study showed that, like most studies, ST3 is the dominant genotype of protozoan in Sari. Improvement of public health awareness, relative improvement in environmental health, urban wastewater treatment, proper clothing coverage and the use of gloves during dealing with livestock and the use of domestic water treatment devices can reduce the Blastocystis infection in this area.

The hidden impact of different Blastocystis genotypes on C-3 and IgE serum levels: a matter of debate in asthmatic Egyptian children

Blastocystis hominis is highly prevalent with respiratory allergies among Egyptian children. Yet, little is known about the possible immunological relationship. Aims of this study were to measure complement-3 (C-3), total and specific IgE to intestinal allergens in patients' serum regarding the identified B. hominis genotypes. In a cross-sectional study, three hundred children (150 asthmatics and 150 non asthmatics) participated in the study from both sexes, mean age 7.5 ± SD (3-4) years after a questionnaire administration. PCR-based genotyping of B. hominis selective in vitro cultivation was performed. C-3, total and specific IgE were all measured in patients' serum utilizing ELISA. Blastocystosis was detected in 100 out of 300 children, 65 (43.3%) out of 150 asthmatics and 35 (23.3%) out of 150 non-asthmatics. Vacuolar forms were the most prevalent in both direct wet mount and stool cultures. Forty (61.5%) out 65 asthmatics and 5 (14.2%) out of 35 non-asthmatics were ≥ 5 organisms/HPF. Sex and irritable bowel disease were statistically insignificant (p value < 0.05). Urticaria was coincided in 15.4% of asthmatics and 8.6% of non-asthmatics. Of 100 cases of blastocystosis, eighty-four were genotype-3 and sixteen were genotype-4. Out of these, 55 cases of genotype-3 and 6 cases of genotype-4 were asthmatics. Positive C-3 serum levels were in 46 (54.81%) of genotype-3 and 2 (12.5%) of genotype-4. High total IgE levels in 30 (35.7%) out of 84 cases of genotype-3 and 4 (25%) out of 16 cases of genotype-4. Positive specific IgE was in 25 (29.8%) of genotype-3 and 3 (18.75%) of genotype-4. Genotype-3 was of higher infection intensity (p value = 0.0001). In conclusion, B. hominis possess a hidden allergy triggering impact that can be obscured by simultaneous high (total and specific) IgE levels towards specific common intestinal allergens. Blastocystosis induces allergy by increasing C-3 serum levels in a genotype-dependent manner being higher in genotype-3. Virulence of genotype-3 seems to stand beyond increased parasite intensity and wide absorption of intestinal allergens that indirectly elevate IgE serum levels.

Geospatial analysis and epidemiological aspects of human infections with Blastocystis hominis in Mazandaran Province, northern Iran

OBJECTIVES

Blastocystis hominis is a very common large intestinal protozoan with global prevalence in humans and non-human hosts. No precise statistics exist regarding the geographical distribution of Blastocystis that would enable the identification of high-risk communities. Therefore, the current research aimed to characterize the spatial patterns and demographic factors associated with B. hominis occurrence in northern Iran.

METHODS

The current study was performed among 4,788 individuals referred to health centers in Mazandaran Province, from whom stool samples were obtained. Socio-demographic data were gathered using a questionnaire. Samples were examined by a direct wet mount, the formalin-ethyl acetate concentration technique, and trichrome staining. Moran local indicators of spatial association and a geographically weighted regression model were utilized to analyze the results.

RESULTS

Generally, the infection rate of Blastocystis parasites was 5.2%, and was considerably higher in the age group of 10-14 years (10.6%) than in other age groups (p=0.005). Our data showed important associations between the occurrence of B. hominis and age, residence, job, contact with domestic animals, anti-parasitic drug consumption, and elevation above sea level (p<0.001).

CONCLUSIONS

The current study characterized for the first time the infection rate and risk of B. hominis in the north of Iran, and produced a prediction map. It is expected that this map will help policymakers to plan and implement preventive measures in high-risk areas and to manage already-infected patients.

Prevalence of Cryptosporidium, Blastocystis, and other opportunistic infections in patients with primary and acquired immunodeficiency

Intestinal opportunistic infections are often caused by unicellular parasites. Individuals with decreased immunity are particularly susceptible to infection by said microorganisms, and when they are infected, diarrhea can be the main clinical manifestation. However, intestinal parasites have rarely been taken into account in intestinal disorders. In our study, an investigation was conducted to determine the prevalence of intestinal micro-pathogens, such as Cryptosporidium, Giardia, Blastocystis, and microsporidia, in hospitalized patients with different immunological statuses. The study at hand indicates that protozoan parasitic infections are rare among immunodeficient patients in Poland. The overall prevalence of micro-pathogens among participants was 4.6%; it was three times higher in adults (12.5%) than in children (2.3%). Cryptosporidium and Cyclospora species (Apicomplexa) were diagnosed as the main cause of heavy diarrhea. Accordingly, adult patients were positive mainly for Blastocystis and microsporidia, while children were more often infected with the Cryptosporidium species.

Prevalence of Intestinal Parasites and Associated Risk Factors for Infection among Rural Communities of Chachoengsao Province, Thailand

Intestinal parasitic infections remain a major public health problem in many parts of Thailand, particularly in rural areas. This study aimed to determine the prevalence of intestinal parasitic infections and associated risk factors among the people living in Huai Sai sub-district, Bang Khla district, Chachoengsao Province, central Thailand. A cross-sectional survey was carried out from June 2017 to August 2017 which included a total of 224 participants. Stool samples were examined using a simple direct smear and formalin ethyl acetate concentration technique. Association between risk factors and intestinal parasitic infections was assessed using multivariate logistic regression analysis. The overall prevalence of intestinal parasitic infections was 16.1%. Soil-transmitted helminth infections (14.3%) were more common than protozoan infections (1.8%). The most common intestinal parasites were hookworms (6.7%) followed by Strongyloides stercoralis, (5.0%), Ascaris lumbricoides (1.3%) and Trichuris trichiura (1.3%). Entamoeba histolytica/dispar (1.0%), Giardia intestinalis (0.4%), and Blastocystis hominis (0.4%) were the protozoans identified. A high prevalence of infections was found in male participants of ≥40 years who raised dogs in the households and did not wear boots while working fields. Multivariate analysis showed a significant association of intestinal parasitic infections with gender with the adjusted odds ratio (OR) of 2.4 and 95% confidence interval (CI) of 1.1–5.2 (P=0.020). The results showed a high prevalence of soil-transmitted helminth infections among adults in rural communities which were particularly apparent regarding the skin-penetrating species of nematodes. A greater focus on intervention is required by improving sanitation and personal hygiene to prevent the spread of intestinal parasitic infections.

Genetic diversity of Blastocystis hominis sensu lato isolated from humans in Poland

INTRODUCTION AND OBJECTIVES

Blastocystis hominis s. l. is one of the most commonly detected protozoa in the human large intestine. The aim of the study was to determine the genetic subtypes of Blastocystis hominis s. l. occurring in humans in Poland.

MATERIALS AND METHODS

Stool samples from patients diagnosed in the Laboratory of the Department of Parasitology, National Institute of Public Health – National Institute of Hygiene (NIZP-PZH) and in the Parasitology Laboratory of the Hospital for Infectious Diseases in Warsaw were examined. Blastocystis subtypes were assayed based on the fragment of small-subunit ribosomal RNA gene sequences (SSU rDNA).

RESULTS

The examined isolates were classified into five Blastocystis subtypes (STs), fifteen of which belonged to ST3, three to ST1, two to ST2, two to ST6, and one isolate belonged to ST7. In three cases the subtype of isolate was not identified.

DISCUSSION AND CONCLUSIONS

In Poland, the subtypes ST1, ST2, ST3, ST4, ST6 and ST7 have been reported in humans so far. The ST6 and ST7 subtypes are rarely detected in humans in Europe. In Poland, the ST6 subtype was previously described in chickens. On the basis of the studies, it was found that Blastocystis isolated from humans in Warsaw show high genetic diversity. In order to determine the possible pathogenic potential of individual Blastocystis subtypes, special epidemiological studies are required.

Additional Glance on the Role of Dientamoeba fragilis & Blastocystis hominis in Patients with Irritable Bowel Syndrome

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal disease with high population prevalence. Dientamoeba fragilis and Blastocystis hominis are reported worldwide as a cause of human gastrointestinal symptoms. This study evaluated the possible link between this syndrome and the infection with D. fragilis and B. hominis in Egypt.

METHODS

Overall, 310 stool samples (160 from IBS patients and 150 from controls) were obtained from Tropical Medicine Outpatient Clinic, Faculty of Medicine, Ain Shams University, Cairo, Egypt between Mar 2015 and Feb 2016. All the stool specimens underwent direct examination and Trichrome staining. Each sample was cultivated on Jones and Robinson's media.

RESULTS

Overall, 42 cases (28%) showed B. hominis and 2 cases (1.3%) for D. fragilis infections. After performing the culture methods for B. hominis and D. fragilis, detections increased to 50 cases (33.3%) and 3 cases (2%), respectively. While among 150 controls 18 (12%) positive samples were detected as B. hominis.

CONCLUSION

There may be a possible relationship between the presentation of irritable bowel syndrome and D. fragilis and B. hominis infections, which have to be excluded first.

Asymptomatic Effluent Protozoa Colonization in Peritoneal Dialysis Patients

Currently, chronic kidney disease (CKD) is a global health problem. Considering the impaired immunity of CKD patients, the relevance of infection in peritoneal dialysis (PD), and the increased prevalence of parasites in CKD patients, protozoa colonization was evaluated in PD effluent from CKD patients undergoing PD. Overnight PD effluent was obtained from 49 asymptomatic stable PD patients. Protozoa analysis was performed microscopically by searching cysts and trophozoites in direct wet mount of PD effluent and after staining smears. Protozoa were found in PD effluent of 10.2% of evaluated PD patients, namely Blastocystis hominis, in 2 patients, and Entamoeba sp., Giardia sp., and Endolimax nana in the other 3 patients, respectively. None of these patients presented clinical signs or symptoms of peritonitis at the time of protozoa screening. Our results demonstrate that PD effluent may be susceptible to asymptomatic protozoa colonization. The clinical impact of this finding should be further investigated.

Intestinal Parasitic Infections and Environmental Water Contamination in a Rural Village of Northern Lao PDR

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.

Genomic analysis of Blastocystis hominis isolates in patients with HIV-positive using locus SSU-rDNA

Blastocystis hominis (B. hominis) is a protozoan zoonosis which clinical signs of infection with this parasite has been reported to be more severe in patients with weakened immune systems than healthy controls. So, the aim of the study was to evaluate genomic analysis of B. hominis isolates obtained from patients with HIV-positive using locus SSU-rDNA. At first, 268 stool samples were randomly collected from patients with HIV-positive referred to health centers of Khuzestan province, southwest of Iran. Formol-ether and direct smear techniques were used for the detection of parasitic agents. After extracting DNA, the samples were analyzed by the PCR method. Finally, the subtypes were determined by the sequencing and PCR methods. New samples were used for the preparation of positive control sample; they were cultured in coagulant-serum biphasic cultivation media. Of 268 stool samples, 33 (12.3%) cases were detected positive for B. hominis using Formol-Ether technique but 51 (19%) cases were positive using molecular method. The most common isolates were related to the subtype III with 29 positive cases (56.8%), then, genotype I with 11 (21.6%) cases, 6 cases (11.8%) with genotype II, 3 (5.9%) combined cases with genotypes I and III as well as 2 cases (3.9%) with genotype VI. There was a significant difference between two groups of HIV-positive patients (infected with the parasite and/or without the parasite) in the term of the mean of TCD4-positive cells. The results indicated a relatively high prevalence of B. hominis in HIV-positive patients as well as our findings may represent that the number reduction of TCD4-positive cells has an effective role in the increased risk of the parasitic infection in HIV-positive patients.

A novel genotype screening and phylogenetic analysis of Blastocystis hominis based on EF-1α

Blastocystis hominis (B. h) is a kind of intestinal parasitic protozoa with the characteristic of worldwide distribution, morphology diversity, and diarrhea induced, etc. The traditional morphological classify was difficult to distinguish the genetic difference of B. h in different population and different geological strains. Recently, based on the small subunit ribosomal DNA sequence of B. h, the sequenced-tagged site (STS) primers was design, and successfully and widely applied to the distinguish the genotype of B. h, and however several B. h strains did not distinguish. To address it, the elongation factor-1 alpha (EF-1α) gene of B. h was screened due to its conservation here, and its specific primers were designed to distinguish the genotype of B. h. After epidemiological survey, the infection rate of B. h in boys was 14.74%, and that of girls was 15.05%, and the total infection rate of B. h was 14.93%. In total of 53 infection students, with the using of 7 pairs STS primers, 31 strains was validated by polymerase chain reaction (PCR), including 4 strains of Type 1, 17 strains of Type 3, 4 strains of Type 4, 1 strains of Type 6, and 5 strains of Type 7, and did not found the Type 2, Type 5 and mixture genotype. In the 23 unknown genotype strains of B. h, 15 strains were identified by PCR using EF-1α primers, and had a higher homology in the DNA sequence (70%), and was evolutionarily closer to the EF-1α sequence of S and H strains of B. h. This study indicated that STS primers could identify the genotype of B. h, and EF-1α primers as a novel diagnosis primers could auxiliary identify the unknown genotype strain of B. h, and exhibited a wide application on the identification of the genotype strain of B. h, and provided a significant reference on the study of B. h in clinic.

Predominance and association risk of Blastocystis hominis subtype I in colorectal cancer: a case control study

Background

Blastocystis, a genetically diverse intestinal parasite with controversial pathogenic potential, has increasingly been incriminated for diarrheal illness in immunocompromised individuals including colorectal cancer (CRC) patients. The aim of the current study was to assess the possible association between Blastocystis infection and CRC condition in Makkah, Saudi Arabia (KSA).

Methods

Stool samples were collected from 80 non-cancer (NC) and 138 cancer subjects including 74 CRC patients and 64 patients with other cancers outside gastrointestinal tract (COGT). Molecularly confirmed Blastocystis isolates were genetically grouped and subtyped using multiplex polymerase chain reaction with restriction fragment length polymorphism (PCR-RFLP) and sequence-tagged site primers-based PCR (PCR-STS), respectively.

Results

Blastocystis hominis were confirmed in 29.7, 25 and 15% among CRC, COGT and NC patients, respectively. Obtained Blastocystis isolates were initially categorized into 2 groups (A and C), which were subsequently subtyped into 3 different subtypes; subtype-I (38%), subtype-II (44%) and subtype-V (22%). Interestingly, subtype-I was the most predominantly detected subtype (54.5%) among CRC patients with a significant association risk (COR 7.548; 95% CI: 1.629–34.987; P = 0.004).

Conclusion

To the best of our knowledge, the current study is the first to provide genetic insights on the prevalence of Blastocystis hominis among CRC patients in Makkah, KSA. Moreover, the study suggests for a possible association between subtype-I of Blastocystis hominis and CRC, which could indicate a potential influence of Blastocystis on CRC condition. Further studies are required to confirm this association risk and to investigate the possible underlying mechanism of postulated carcinogenic influence of Blastocystis hominis subtype-I.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-017-0131-z) contains supplementary material, which is available to authorized users.

PCR-based molecular characterization of Blastocystis hominis subtypes in southwest of Iran

Blastocystis hominis is the most common intestinal parasite found in humans and many other hosts. Pathogenicity of Blastocystis sp. remains controversial and it has been suggested that it may be associated with certain subtypes of organism. The aim of this study was to evaluate the molecular epidemiology of B. hominis and its subtype distribution in Ahvaz, southwest of Iran. During 2012-2014, a total of 481 samples were collected from patients referred to the medical laboratory centers in Ahvaz for stool examination. Samples were examined by wet mount, and genomic DNA was extracted from 50 positive samples. PCR was performed using seven primer pairs targeting the SSU rDNA gene and sequenced. 69 (14.35%) samples were found to be positive for B. hominis and the subtypes of 50 samples were identified. Five subtypes (STs) were identified, including: ST1 (22%), ST2 (6%), ST3 (40%), ST4 (2%), and ST5 (8%). 11 (22%) mixed infections were found, of which 5 were a mixture of ST3/ST4. Mixtures of ST1/ST3 and ST1/ST4 were 3, respectively. In this study people infected with ST3 showed the most gastrointestinal symptoms. This is the first study in the population of Ahvaz and indicates the high prevalence of ST3 in this area. The results suggest a possible association between this subtype and pathogenic potential of parasite.

A decade of intestinal protozoan epidemiology among settled immigrants in Qatar

Background

The World Health Organization estimates that about 3.5 billion people worldwide are affected by intestinal parasitic infections. Reports have already emphasized the role of immigrants in outbreaks of parasitic diseases in industrialized countries. With the mass influx of immigrants to Qatar, patent intestinal parasitic infections have been observed. Herein, the prevalence of intestinal protozoan infections was analysed in 29,286 records of subjects referred for stool examination at the Hamad Medical Corporation over the course of a decade (2005 to 2014, inclusive).

Results

Overall prevalence of combined protozoan infections was 5.93 % but there were significant temporal trends, age and sex effects and those arising from the region of origin of the subjects. The most common protozoan was Blastocystis hominis (overall prevalence 3.45 %). Giardia duodenalis, Chilomastix mesnili, Entamoeba coli, Entamoeba hartmanni, Endolimax nana, Iodamoeba butschlii, Entamoeba histolytica/dispar, Cryptosporidium sp. and a single case of Isospora were also detected. The prevalence of combined protozoan infections, G. duodenalis and the non-pathogenic amoebae all declined significantly across the decade. That of B. hominis varied between years but showed no directional trend across years and there was no evidence that prevalence of E. histolyitica/dispar changed significantly. Protozoan infections were observed among all regional groups, but prevalence was higher among subjects from the Arabian Peninsula, Africa and Asia compared to those from the Eastern Mediterranean and Qatar. Prevalence was higher among male subjects in all cases, but age-prevalence profiles differed between the taxa.

Conclusion

These results offer optimism that prevalence will continue to decline in the years ahead.

Nonagonal cadherins: A new protein family found within the Stramenopiles

Cadherins, a group of molecules typically associated with planar cell polarity and Wnt signalling, have been little reported outside of the animal kingdom. Here, we identify a new family of cadherins in the Stramenopiles, termed Nonagonal after their 9 transmembrane passes, which contrast to the one or seven passes found in other known cadherin families. Manual curation and experimental validation reveal two subclasses of nonagonal cadherins, depending on the number of uninterrupted extracellular cadherin (EC) modules presented. Firstly, shorter mono-exonic, unimodular, protein models, with 3 to 12 EC domains occur as duplicate paralogs in the saprotrophic Labyrinthulomycetes Aurantiochytrium limanicum and Schizochytrium aggregatum, the gastrointestinal Blastocystis hominis (Blastocystae) and as a single copy gene in the autotrophic Pelagophyte Aureococcus anophagefferens. Larger, single copy, multi-exonal, tri-modular protein models, with up to 72 EC domain in total, are found in the Oomycete genera Albugo, Phytophthora, Pythium and Eurychasma. No homolog was found in the closely related autotrophic Phaeophyceae (brown algae) or Bacillariophyceae (diatoms), nor in several genera of plant and animal pathogenic oomycetes (Aphanomyces, Saprolegnia and Hyaloperonospora). This potential absence was further investigated by synteny analysis of the genome regions flanking the cadherin gene models, which are found to be highly variable. Novel to this new cadherin family is the presence of intercalated laminin and putative carbohydrate binding in tri-modular oomycete cadherins and at the N-terminus of thraustochytrid proteins. As we were unable to detect any homologs of proteins involved in signalling pathways where other cadherin families are involved, we present a conceptual hypothesis on the function of nonagonal cadherin based around the presence of putative carbohydrate binding domains.

Prevalence and Genotype Characterization of Blastocystis hominis Among the Baghmalek People in Southwestern Iran in 2013 - 2014

BACKGROUND

Blastocystis hominis is a common globally distributed parasite. The prevalence of this parasite has been shown to vary among different countries. Molecular studies have also shown that there is a high level of genetic diversity among Blastocystis spp. isolated from humans and animals. Extensive information on parasitic genotypes will aid in devising more effective strategies for the identification and potential control of these pathogenic parasites.

OBJECTIVES

This study aimed to gain information on the prevalence and abundance of Blastocystis subtypes in Iran.

MATERIALS AND METHODS

Over a period of 3 months, 1,410 stool samples were collected and examined by microscopy. Samples found to be positive for B. hominis were concentrated and phylogenetic analysis was subsequently performed. A questionnaire was completed by all study participants.

RESULTS

Blastocystis hominis was found to have a prevalence of 3.33% in the study population. There was no significant association of Blastocystis infection with age (P = 0.3) or gender (P = 0.57). The Blastocystis subtypes (ST) identified in this study were ST3, ST4, ST5, and ST7 with the most prevalent being ST4 (40.9%).

CONCLUSIONS

The prevalence of B. hominis in the study area was lower than that reported for most developed countries, and unlike in other countries in the Middle East, ST4 was the most prevalent subtype.

Blastocystis hominis infection in a post-cardiotomy patient on extracorporeal membrane oxygenation support: A case report and literature review

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The opportunistic pathogen, B. hominis, can cause severe infection in patients on ECMO support.

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Administration of metronidazole in the patients on ECMO support with gastrointestinal symptoms.

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Prophylactic administration of metronidazole in the patients on ECMO support, which live in the region with a high prevalence of B. hominis.

INTRODUCTION

Opportunistic pathogens can cause severe damage leading to irreversible complications in immune-compromised patients. Here we describe a patient who sustained Blastocystis hominis infection resulting in severe sepsis while on extracorporeal membrane oxygenation (ECMO) support, and the course of treatment taken to treat him.

PRESENTATION OF CASE

Our case, a 34-year-old Filipino man, was hospitalized for valvular disease and received valve replacements. ECMO and an intra-aortic balloon pump (IABP) were implemented when the patient developed progressive heart failure after cardiac surgery. Unfortunately, the patient suffered from sepsis with persistent fever and diarrhea, and subsequent examinations indicated the patient was infected by B. hominis. After adequate administration of the antibiotic metronidazole, the patient's symptoms subsided and he was discharged.

DISCUSSION

Blastocystis hominis is a unicellular protozoa commonly found in the intestinal tract, and the prevalence of B. hominis is 1.5–10% in developed countries and 30–50% in developing countries. The patient needed the support of ECMO and IABP, was immunocompromised to a certain extent; B. hominis can be a harmful opportunistic pathogen for them and lead to severe irreversible complications such as death.

CONCLUSION

This is the first published article showing that the opportunistic pathogen, B. hominis, can cause severe infection in patients on ECMO support, a result that should be kept in mind when patients come from a place with a high prevalence of B. hominis. The prophylactic medication should be administered routinely when patients live in the region and extracorporeal life-support is used.

Distribution of haematological indices among subjects with Blastocystis hominis infection compared to controls

INTRODUCTION

Some studies suggest Blastocystis hominis is a potentially pathogenic protozoa. Blastocystis hominis contributed to anaemia in children aged 8-10 years old in one study.

AIM

To compare haematological indices in cases with blastocystis hominis infection with healthy controls.

MATERIAL AND METHODS

From 2001 to 2012, 97600 stool examinations were done in 4 university hospitals. Parasites were observed in 46,200 specimens. Of these cases, subjects with complete laboratory investigation (complete blood count - CBC, ferritin, total iron binding capacity - TIBC, and serum) and blastocystis hominis infection were included in this study as the case group. Of these cases, 6851 cases had only B. hominis infection. In the control group, 3615 subjects without parasite infestation were included. Age, haemoglobin (Hb), serum iron, TIBC, white blood cell (WBC), platelet (PLT), mean corpuscular volume (MCV), haematocrit (HCT) and erythrocyte sedimentation rate (ESR) were recorded for cases and controls. SPSS software version 13.0 was used for analysis. Independent sample t-test and χ(2) tests were used for comparison.

RESULTS

Erythrocyte sedimentation rate level was significantly higher in cases with B. hominis infection (p < 0.05). C-reactive protein level was positive in 1.46% of cases and 0.5% of controls, which was statistically significant (p < 0.05). Frequency of serum iron < 120 was significantly higher in cases with B. hominis infection compared to controls. Occult blood was positive in 0.93% of cases and in none of the controls (p < 0.05).

CONCLUSIONS

The ESR, CRP and occult blood was significantly higher in cases with B. hominis infection.

A cross-sectional study on intestinal parasitic infections in rural communities, northeast Thailand

Despite the existence of effective anthelmintics, parasitic infections remain a major public health problem in Southeast Asia, including Thailand. In rural communities, continuing infection is often reinforced by dietary habits that have a strong cultural basis and by poor personal hygiene and sanitation. This study presents a survey of the prevalence of intestinal parasitic infections among the people in rural Thailand. The community-based cross-sectional study was conducted in villages in Khon Kaen Province, northeastern Thailand, from March to August 2013. A total of 253 stool samples from 102 males and 140 females, aged 2-80 years, were prepared using formalin-ethyl acetate concentration methods and examined using light microscopy. Ninety-four individuals (37.2%) were infected with 1 or more parasite species. Presence of parasitic infection was significantly correlated with gender (P=0.001); nearly half of males in this survey (49.0%) were infected. Older people had a higher prevalence than younger members of the population. The most common parasite found was Opisthorchis viverrini (26.9%), followed by Strongyloides stercoralis (9.5%), Taenia spp. (1.6%), echinostomes (0.4%), and hookworms (0.4%). The prevalence of intestinal protozoa was Blastocystis hominis 1.6%, Entamoeba histolytica 0.8%, Entamoeba coli 0.8%, Balantidium coli 0.4%, Iodamoeba bütschlii 0.4%, and Sarcocystis hominis 0.4%. Co-infections of various helminths and protozoa were present in 15.9% of the people. The present results show that the prevalence of parasitic infections in this region is still high. Proactive education about dietary habits, personal hygiene, and sanitation should be provided to the people in this community to reduce the prevalence of intestinal parasite infections. Moreover, development of policies and programs to control parasites is needed.

Blastocystis: Consensus of treatment and controversies

Blastocystis is a highly controversial protozoan parasite. It has been variably regarded as a commensal and pathogen. Scientists have for decades wondered whether it is truly an enteropathogen and if it is observed in symptomatic patients whether treatment is required because patient recovery and improvement has been noted even without any treatment. Though associated with self-limiting infection, treatment is warranted in many patients due to persistence of symptoms. This particularly holds true for children and adults who are immuno compromised. Several drugs have been used to treat Blastocystis but each one of them has produced widely variable rates of clinical cure and eradication of the parasite from the feces. Based on the studies carried out in vitro and clinical responses obtained in patients, metronidazole appears to be the most effective drug for Blastocystis infection. However, the therapy is complicated due to different dosages and regimens adopted and the unresponsiveness to treatment observed in several sections of the population studied. Recently, the finding of different subsets of Blastocystis exhibiting resistance to metronidazole and associated with variable degrees of symptoms has underscored the importance of typing the subsets of the parasite in order to foretell the clinical response and the need to treat. Till date, the mode of action of the drugs used and the mechanism of resistance is not entirely known and is a topic of speculation. Other drugs with anti Blastocystis activity and used in therapy includes trimethoprim sulfamethoxazole and nitazoxanide. Several other compounds have also been evaluated for the treatment either alone or in combination with the first or second line drugs. A lot of interest has also been generated on the role of probiotics particularly Saccharomyces boularrdii and other natural food compounds on eradication of the parasite. This review provides a comprehensive overview of antimicrobials used to target Blastocystis and discusses the issues pertaining to drug resistance, treatment failure, reinfection, and the current views on treatment modalities.

Blastocystis hominis and Endolimax nana Co-Infection Resulting in Chronic Diarrhea in an Immunocompetent Male

Blastocystis hominis and Endolimax nana exist as two separate parasitic organisms; however co-infection with the two individual parasites has been well documented. Although often symptomatic in immunocompromised individuals, the pathogenicity of the organisms in immunocompetent subjects causing gastrointestinal symptoms has been debated, with studies revealing mixed results. Clinically, both B. hominis and E. nana infection may result in acute or chronic diarrhea, generalized abdominal pain, nausea, vomiting, flatulence and anorexia. We report the case of a 24-year-old immunocompetent male presenting with chronic diarrhea and abdominal pain secondary to B. hominis and E. nana treated with metronidazole, resulting in symptom resolution and eradication of the organisms. Our case illustrates that clinicians should be cognizant of both B. hominis and E. nana infection as a cause of chronic diarrhea in an immunocompetent host. Such awareness will aid in a timely diagnosis and possible parasitic eradication with resolution of gastrointestinal symptoms.

Opportunistic parasites among immunosuppressed children in Minia District, Egypt

A total of 450 stool samples were collected from inpatient and outpatient clinics of Pediatric Department, Minia University Hospital, Minia District, Egypt. Two groups of patients were studied, including 200 immunosuppressed and 250 immunocompetent children. Stool samples were subjected to wet saline and iodine mounts. A concentration technique (formol-ether sedimentation method) was carried out for stool samples diagnosed negative by wet saline and iodine mounts. Samples were stained by 2 different methods; acid fast stain (modified Ziehl-Neelsen stain) and Giemsa stain. Total 188 cases (94%) were diagnosed positive for parasitic infections among immunosuppressed children, whereas 150 cases (60%) were positive in immunocompetent children (P<0.0001). The most common protozoan infection in immunosuppressed group was Cryptosporidium parvum (60.2%), followed by Blastocystis hominis (12.1%), Isospora belli (9.7%), and Cyclospora caytenensis (7.8%). On the other hand, Entamoeba histolytica (24.6%) and Giardia lamblia (17.6%) were more common than other protozoans in immunocompetent children.