Detection of Blastocystis sp. and Dientamoeba fragilis using conventional and molecular methods in patients with celiac disease.

Blastocystis sp. and Dientamoeba fragilis are intestinal protists, which are common worldwide, but the pathogenic role of these organisms in gastrointestinal diseases is still controversial. This study aimed to investigate the frequency of Blastocystis sp. and D. fragilis in stool samples from adult patients with celiac disease (CD) by using conventional and molecular methods. A total of 75 patients with CD and 75 healthy individuals were included in this study. Fresh stool specimens collected from each individual were analyzed by conventional and molecular methods. The overall prevalence of Blastocystis sp. and D. fragilis was 41.3% (31/75) and 24% (18/75) in patients with CD, and 46.7% (35/75) and 13.3% (10/75) in healthy controls, respectively. There was no statistically significant difference in the prevalence of Blastocystis sp. and D. fragilis between CD patients and healthy individuals. Blastocystis sp. subtypes were identified in 20 CD and 16 control patients and the overall subtype distribution was observed as ST1 13.9%, ST2 30.6%, and ST3 55.6%. The prevalence of Blastocystis sp. and D. fragilis in adults with CD is similar to the prevalence of protozoa in healthy adults. In this study, the most prevalent Blastocystis subtype was ST3 and the most frequent allele was a34 in both CD patients and healthy individuals. No significant difference was found between the two groups in terms of the detection rates of Blastocystis sp. and D. fragilis, and it is thought that both protists may be colonisers of the intestinal microbiome.

Blastocystis: A Mysterious Member of the Gut Microbiome.

Blastocystis is the most common gastrointestinal protist found in humans and animals. Although the clinical significance of Blastocystis remains unclear, the organism is increasingly being viewed as a commensal member of the gut microbiome. However, its impact on the microbiome is still being debated. It is unclear whether Blastocystis promotes a healthy gut and microbiome directly or whether it is more likely to colonize and persist in a healthy gut environment. In healthy people, Blastocystis is frequently associated with increased bacterial diversity and significant differences in the gut microbiome. Based on current knowledge, it is not possible to determine whether differences in the gut microbiome are the cause or result of Blastocystis colonization. Although it is possible that some aspects of this eukaryote's role in the intestinal microbiome remain unknown and that its effects vary, possibly due to subtype and intra-subtype variations and immune modulation, more research is needed to characterize these mechanisms in greater detail. This review covers recent findings on the effects of Blastocystis in the gut microbiome and immune modulation, its impact on the microbiome in autoimmune diseases, whether Blastocystis has a role like bacteria in the gut-brain axis, and its relationship with probiotics.

Prevalence of Blastocystis and Dientamoeba fragilis in diarrheal patients in Corum, Türkiye.

To investigate the prevalence of Blastocystis and Dientamoeba fragilis in diarrhea patients and healthy individuals in Corum, Türkiye, fecal samples from 92 diarrhea patients and 50 healthy individuals were collected and evaluated using direct microscopy and molecular methods to screen for bacteria, protozoa, and viruses. The prevalence of Blastocystis was 24.6% in total and more frequent in the healthy group (30.0%). The commonly detected STs (subtypes) were ST3 (40.0%) and ST2 (34.2%). The distribution of Blastocystis STs in the healthy and diarrheal groups did not show any difference in sex and age, but ST3 was detected more frequently in patients aged from 40 to 59 years (p < 0.05). Alleles 4 (8/12) and 2 (4/12) were present in ST1; 9 (3/5) and 12 (2/5) in ST2; 34 (9/14), 36 (3/14), and 38 (2/14) in ST3; and only allele 42 (2/2) in ST4. D. fragilis was present in 8.4% of the population. However, there was no statistically significant difference between the healthy and diarrheic groups (12.0% and 6.5%, respectively), neither with respect to age nor sex. Co-infection was 58.3% and was more frequent in healthy individuals (33.3%) than in diarrhea patients (25.0%). Blastocystis ST3 was the most common subtype detected, with D. fragilis at 33.3%. Salmonella, Shigella, or helminth eggs were not observed in all groups, but Entamoeba histolytica, Giardia intestinalis, Cryptosporidium, Rotavirus, Adenovirus, and Clostridium difficile toxin were found only in diarrhea patients. These findings support the hypothesis that Blastocystis and D. fragilis may be part of the healthy human gut microbiome.

Investigation of intestinal parasites by conventional and molecular methods in children with gastrointestinal system complaints.

Intestinal parasitic infections are a global health problem that causes morbidity and mortality, especially in children living in rural areas. In this study, stool samples of pediatric patients with gastrointestinal complaints were examined by conventional and molecular methods to determine the prevalence of intestinal parasites. A total of 100 pediatric patients with gastrointestinal complaints and 50 healthy children were included in the study. Stool samples were collected from each child and examined by direct microscopic examination (native-Lugol method), formol-ethyl acetate concentration technique, Kinyoun's acid-fast staining, and Wheatley trichrome staining methods. Real-time PCR was used for the detection of Blastocystis spp. and D. fragilis in the stool samples. Sanger sequencing was used to identify Blastocystis spp. subtypes. One or more intestinal parasites were found in 12% (n = 100) of the patient group and 1% (n = 50) of the control group using conventional techniques. By using real-time PCR, Blastocystis spp. was discovered in 14% (14/100) of the patient group and 8% (4/50) of the control group. There was no significant difference in the frequency of Blastocystis spp. between the two groups. The most prevalent Blastocystis subtype was ST1 and the most frequent allele was a2 among the samples successfully amplified and sequenced. D. fragilis was detected in 17% (17/100) of the patient group and 8% (4/50) of the control group by real-time PCR. The prevalence of D. fragilis was not significantly different between the patient and control groups, as well. Blastocystis spp. and D. fragilis were found in high prevalence in pediatric patients with gastrointestinal complaints in this study. Although the role of these protists as a pathogen in humans is still controversial, it is supposed to the presence of the parasites are associated with gastrointestinal disorders such as diarrhea, abdominal pain, nausea, and vomiting. More case-control studies are needed to understand the pathogenic or commensal role of these parasites on the intestinal microbiota, especially in both patients with gastrointestinal disorders and healthy individuals.

Potential associations between alterations in gut microbiome and obesity-related traits after the bariatric surgery.

BACKGROUND: This study aimed to examine the effects of both obesity and bariatric surgery on gut microbiome, dietary intake, as well as metabolic and inflammatory parameters. METHODS: All participants (15 with morbid obesity who had bariatric surgery, 8 with morbid obesity and 11 non-obese) were followed up for a 6-month period with interviews at baseline (M0), at the end of 3 (M3) and 6 months (M6). Dietary assessment was done, and blood and faecal samples were collected. RESULTS: Dietary energy and nutrient intakes as well as serum glucose levels, total cholesterol, low-density lipoprotein (LDL)-cholesterol and high sensitivity C-reactive protein (hs-CRP) levels decreased after surgery (p < 0.05, for each). Participants with morbid obesity had higher levels of Firmicutes and lower levels of Bacteroidetes at M0 compared to non-obese participants. The abundances of Bacteroidetes increased (p = 0.02), whereas that of Firmicutes decreased (p > 0.05) after the surgery, leading to a significant decrease in Firmicutes/Bacteroidetes ratio (p = 0.01). At sub-phylum level, the abundances of Lactobacillus and Bifidobacterium decreased, whereas those of Akkermansia increased after the surgery (p < 0.01, for each). Although participants who were morbidly obese had a distinct profile according to ß-diversity indices at M0, it became similar with the profile of non-obese participants (p > 0.05) at M3 and M6. Similarly, α-diversity indices were lower in subjects with morbid obesity at M0, but became similar to levels in non-obese controls at M6. CONCLUSION: This study confirmed that bariatric surgery has substantial impacts on gut microbiome's composition and diversity, as well as anthropometrical measurements and biochemical parameters, which were associated with the alterations in dietary intake patterns.

Metabolic Fluctuations in the Human Stool Obtained from Blastocystis Carriers and Non-Carriers.

Blastocystis is an obligate anaerobic microbial eukaryote that frequently inhabits the gastrointestinal tract. Despite this prevalence, very little is known about the extent of its genetic diversity, pathogenicity, and interaction with the rest of the microbiome and its host. Although the organism is morphologically static, it has no less than 28 genetically distinct subtypes (STs). Reports on the pathogenicity of Blastocystis are conflicting. The association between Blastocystis and intestinal bacterial communities is being increasingly explored. Nonetheless, similar investigations extending to the metabolome are non-existent.Using established NMR metabolomics protocols in 149 faecal samples from individuals from South Korea (n = 38), Thailand (n = 44) and Turkey (n = 69), we have provided a snapshot of the core metabolic compounds present in human stools with (B+) and without (B-) Blastocystis. Samples included hosts with gastrointestinal symptoms and asymptomatics. A total of nine, 62 and 98 significant metabolites were associated with Blastocystis carriage in the South Korean, Thai and Turkish sample sets respectively, with a number of metabolites increased in colonised groups. The metabolic profiles of B+ and B- samples from all countries were distinct and grouped separately in the partial least squares-discriminant analysis (PLS-DA). Typical inflammation-related metabolites negatively associated with Blastocystis positive samples. This data will assist in directing future studies underlying the involvement of Blastocystis in physiological processes of both the gut microbiome and the host. Future studies using metabolome and microbiome data along with host physiology and immune responses information will contribute significantly towards elucidating the role of Blastocystis in health and disease.

Investigation of neglected protists Blastocystis sp. and Dientamoeba fragilis in immunocompetent and immunodeficient diarrheal patients using both conventional and molecular methods.

INTRODUCTION: The clinical significance of Blastocystis sp. and Dientamoeba fragilis in patients with gastrointestinal symptoms is a controversial issue. Since the pathogenicity of these protists has not been fully elucidated, testing for these organisms is not routinely pursued by most laboratories and clinicians. Thus, the prevalence of these organisms and the subtypes of Blastocystis sp. in human patients in Turkey are not well characterized. This study aimed to determine the prevalence of Blastocystis sp. and D. fragilis in the diarrheic stool samples of immunodeficient and immunocompetent patients using conventional and molecular methods and to identify Blastocystis sp. subtypes using next generation sequencing. MATERIAL AND METHODS: Individual stool specimens were collected from 245 immunodeficient and 193 immunocompetent diarrheic patients between March 2017 and December 2019 at the Gazi University Training and Research Hospital in Ankara, Turkey. Samples were screened for Blastocystis sp. and D. fragilis by conventional and molecular methods. Molecular detection of both protists was achieved by separate qPCRs targeting a partial fragment of the SSU rRNA gene. Next generation sequencing was used to identify Blastocystis sp. subtypes. RESULTS: The prevalence of Blastocystis sp. and D. fragilis was 16.7% and 11.9%, respectively as measured by qPCR. The prevalence of Blastocystis sp. and D. fragilis was lower in immunodeficient patients (12.7% and 10.6%, respectively) compared to immunocompetent patients (21.8% and 13.5%, respectively). Five Blastocystis sp. subtypes were identified and the following subtype distribution was observed: ST3 54.4% (n = 37), ST2 16.2% (n = 11), ST1 4.4% (n = 3), ST6 2.9% (n = 2), ST4 1.5% (n = 1), ST2/ST3 11.8% (n = 8) and ST1/ST3 8.8% (n = 6). There was no statistically significant difference in the distribution of Blastocystis sp. subtypes between immunocompetent and immunodeficient patients. CONCLUSION AND RECOMMENDATION: Our findings demonstrated that Blastocystis sp. and D. fragilis are commonly present in immunocompetent and immunodeficient patients with diarrhea. This study is the first to use next generation sequencing to address the presence of Blastocystis sp. mixed subtypes and intra-subtype variability in clinical samples in Turkey.

Case Report: A Human Case of Onchocerca lupi Mimicking Nodular Scleritis.

We report a case of human ocular onchocerciasis by zoonotic Onchocerca lupi presenting as nodular scleritis. Molecular analyses were used to confirm diagnosis at species level. In addition to few existing reports of human infection by O. lupi in Turkey, this case further suggests that the pathogen might be more common than previously reported, thus requiring further attention and investigations.

Detection of enteric parasites and molecular characterization of Giardia duodenalis and Blastocystis sp. in patients admitted to hospital in Ankara, Turkey.

This epidemiological study assesses the occurrence of enteric parasites in 4303 patients attended at two public hospitals in Ankara (Turkey) during 2018-2019. Microscopy was used as a screening test. Giardia duodenalis was also identified using a commercial ELISA for the detection of parasite-specific coproantigens. Giardia-positive samples by microscopy/ELISA were confirmed by real-time PCR and characterized using a multilocus genotyping scheme. Blastocystis sp. was genotyped in a sample subset. Blastocystis sp. (11.1%, 95% CI 11.4‒14.8%) and G. duodenalis (1.56%, 95% CI 1.22‒1.96) were the most prevalent pathogens found. Cryptosporidium spp., Entamoeba histolytica and intestinal helminths were only sporadically (<0.5%) found. For G. duodenalis, sequence (n = 30) analyses revealed the presence of sub-assemblages AII (23.3%), discordant AII/AIII (23.3%) and mixed AII + AIII (6.7%) within assemblage A, and BIII (10.0%), BIV (3.3%) and discordant BIII/BIV (23.3%) within assemblage B. Two additional sequences (6.7%) were assigned to the latter assemblage but sub-assemblage information was unknown. No associations between G. duodenalis assemblages/sub-assemblages and sociodemographic and clinical variables could be demonstrated. For Blastocystis sp., sequence (n = 6) analyses identified subtypes ST1, ST2 and ST3 at equal proportions. This is the first molecular characterization of G. duodenalis based on MLG conducted in Turkey to date.

Rose Bengal-Mediated Photodynamic Antimicrobial Treatment of Acanthamoeba Keratitis.

Purpose: To evaluate the in vivo efficacy of rose bengal (RB)-mediated photodynamic antimicrobial therapy (PDAT) for treatment of Acanthamoeba castellanii keratitis (AK). Materials and Methods: An animal (rabbit) AK model was successfully achieved via intrastromal inoculation of a suspension of A. castellanii cells and trophozoites. Prior to RB-PDAT (pre-treatment, day-5), the severity of the induced corneal infection was graded numerically for epithelial defects, stromal edema, neovascularity, and stromal opacity/infiltration. The right eyes of rabbits (n = 18) were divided equally into three groups (n = 6/group): control (no treatment); 0.1% RB+518 nm irradiation (5.4 J/cm2); and 0.2% RB+518 nm irradiation (5.4 J/cm2). On post-treatment day-5, animals were euthanized, after which corneal buttons were excised and submitted for real-time polymerase chain reaction (RT-PCR) analysis. Results: Post-treatment clinical scores of the 0.1 and 0.2% RB groups indicated significant improvement compared to control group scores (pre-treatment clinical scores; 5.17 ± 0.98, 7.50 ± 0.62, and 6.17 ± 0.70 and post-treatment clinical scores; 4.50 ± 0.56, (p = .043), 3.50 ± 0.99 (p = .039), 6.83 ± 1.66 (p = .34), respectively). RT-PCR analysis revealed that the mean cycle threshold (Ct) values were significantly higher in treated-group corneas compared to control-group corneas, with no significant differences between treated-groups (Mean Ct values; 34.33, 34.5, and 29.67 for 0.1 and 0.2% RB, and control groups). There was a statistically significant negative correlation between post-treatment clinical scores and Ct values (r = -0.474, p-value 0.047). Conclusions: Our results demonstrate that RB-PDAT is effective in decreasing the parasitic load and clinical severity of AK.

[Investigation of Microsporidia prevalence with calcofluor white and uvitex 2B chemiluminescence staining methods and molecular analysis of species in diarrheal patients]. / Ishalli olgularda Microsporidia sikliginin Calcofluor beyazi ve uvitex 2B kemiluminesans boyama yöntemleriyle arastirilmasi ve türlerinin moleküler yöntemle tiplendirilmesi.

Microsporidia, obligate intracellular parasites, were first defined by Nageli in 1857. Microsporidia phylum consists of 200 genus and 1500 species. They have a wide host spectrum including insects, fish, and mammals. It has been shown that they may also infect humans and may be existed both in symptomatic and asymptomatic forms. There are eight species infecting humans, which include Anncaliia (Brachiola, Nosema), Encephalitozoon, Entrocytozoon, Microsporidium, Nosema, Pleistophora, Trachipleistophor, and Vittaforma. The species most commonly infect humans are Encephalitozoon intestinalis and Enterocytozoon bieneusi. The aim of this study was to determine the prevalence of Microsporidia by using two different chemiluminescence stains, namely uvitex 2B and calcoflour and detect species by molecular analysis in diarrheal patients. For this purpose, we studied stool samples of 200 patients with diarrhea sent to Gazi University Health Practice and Research Hospital, Microbiology Laboratory and Ankara Numune Training and Research Hospital Microbiology Laboratory between 2012-2013. The stool samples were stained with chemiluminescent stains uvitex 2B and calcoflour methods; the Microsporidia prevalence was found to be 38% (77/200) by fluorescent microscopic examination. Statistically an excellent consistency was found between the chemiluminescent stains uvitex 2B and calcoflour (Cohen's kappa= 0.881). A statistical analysis for the consistency of uvitex 2B and calcoflour in terms of numerical density (low, high) and luminescence of spores (dim, bright) showed a moderate consistency between the two stains with respect to determining numerical density of spores (Cohen's kappa= 0.354), while there was no consistency in terms of luminescence of spores (Cohen's Kappa= 0.001). No significant difference was found between the Microsporidia prevalence with respect to age group or clinics (p > 0.05). A sex-based analysis showed that Microsporidia prevalence was more common in women (50%) than men (30.8%) (p< 0.05). In 77 samples that were detected positive for Microsporidia with uvitex 2B and calcoflour stains determination of genus and species level were done by using multiplex nested polymerase chain reaction (PCR) method. With this technique, seven (9.1%) of 77 isolates were detected as E.bieneusi, and 70 (90.9%) as Encephalitozoon spp. When the Microsporidia genus was considered, the Microsporidia prevalence did not show differences with respect to age, sex, and referring clinics (p> 0.05). In our study 44 (62.9%) of 70 Encephalitozoon spp. were E.intestinalis, 22 (31.4%) were E.cuniculi, and 4 (5.7%) were E. hellem. No statistical difference was found in the distribution of Encephalitozoon spp. with age, sex, and referring clinic (p> 0.05). We concluded that examination of stool samples with the chemiluminescent stain uvitex 2B and/or calcoflour would be useful for the initial stage of Microsporidia diagnosis; furthermore, the multiplex nested PCR method was considered useful for determination of genus and species. In our country, there is a small number of molecular reports about Microsporidia prevalence in stool samples. Molecular methods should be used more commonly for the evaluation of treatment options in diarrheal patients and detection of Microsporidia epidemiology.

Effect of Riboflavin/Rose Bengal-Mediated PACK-CXL on Acanthamoeba Trophozoites and Cysts in Vitro.

PURPOSE: To evaluate the antiamoebic properties of photo-activated chromophore for keratitis (PACK)-corneal cross-linking (CXL) (PACK-CXL), in combination with riboflavin (0.1 and 0.25%) or rose bengal (0.1 and 0.2%), for treatment of Acanthamoeba trophozoites and cysts. MATERIALS AND METHODS: Cultures of Acanthamoeba castellanii were grown in a fluid medium at a concentration of 2.7 × 105 cell/ml. PACK-CXL was used on A. castellani cells in combination with either riboflavin (0.1 and 0.25%) or rose bengal (0.1 and 0.2%). Riboflavin-containing wells were irradiated with ultraviolet-A (UVA) light (365-nm wavelength). Rose bengal-containing wells were irradiated with green light (523-nm wavelength). A power density of 9 mW/cm2 for 10 min and total irradiation dose of 5.4 J/cm2 was used for both riboflavin and rose bengal. After UVA and green light irradiation, cell viabilities were evaluated, and percentage of dead cells calculated. RESULTS: No significant amoebicidal activity was observed following PACK-CXL/riboflavin at either concentration. PACK-CXL/rose bengal, however, was observed to be highly effective in eradicating Acanthamoeba cells at either concentration, with no significant difference observed between the two concentrations. The percentage of dead cells was 63% following treatment at either rose bengal concentration. CONCLUSION: PACK-CXL with rose bengal demonstrated pronounced antiamoebic activity against A.castellanii. Further in vitro and in vivo studies are needed to confirm this finding.

Demodex spp. as a possible aetiopathogenic factor of acne and relation with acne severity and type.

INTRODUCTION: Acne is a very common skin disease in adolescents and young adults, but it also affects adults. However, its aetiology is not yet fully understood. Demodex appears to be associated with multiple skin disorders, but controversy persists. Some reports indicate a connection between acne vulgaris and demodicosis. AIM: To confirm the association between Demodex infestation and acne vulgaris. MATERIAL AND METHODS: A total of 108 patients were enrolled in the acne group. Acne severity was calculated as GASS and acne type (adolescent and post adolescent) was recorded. An age-sex matched healthy control group comprising 65 individuals were included in the study. Dermatological examinations were performed and an SSSB was used to determine the presence of Demodex. RESULTS: In our study, Demodex positivity was seen in 46 (42.6%) patients in the acne group and 8 (12.3%) in the control group; this difference was statistically significant (p < 0.001). A multivariate Backward Step-By-Step Logistic Regression analysis identified the most effective factors for acne development such as Demodex positivity (OR = 5.565, 95% CI: 2.384-12.99 and p < 0.001) and age under 25 years (OR = 2.3 and 95% CI: 1.183-4.473 and p = 0.014). Alcohol consumption was related to Demodex positivity (p = 0.019) in post adolescent acne. CONCLUSIONS: Our study is the first one to evaluate acne severity, acne type and the relationship to Demodex prevalence. We suggest that Demodex infestation should be considered when the classical therapies are ineffective especially in cases of post adolescent acne.

Subtype distribution of Blastocystis spp. isolated from children in Eskisehir, Turkey.

Blastocystis spp. is the most common enteric protist found in human feces. The pathogenic role of Blastocystis remains controversial and it has been suggested that the symptomatology of Blastocystis is associated with its subtypes (ST). However, only few studies have investigated the relationship between the symptomatology and subtypes of Blastocystis in children. This study aimed to investigate the prevalence of Blastocystis in children aged 3 to 13years with or without gastrointestinal complaints and determine the distribution of the subtypes of Blastocystis. A total of 303 stool samples obtained from symptomatic (n=84) and asymptomatic (n=219) children were included in the study. The presence of Blastocystis was investigated using native-lugol examination, trichrome staining and real-time PCR method. Using the real-time PCR method, 115 samples were found positive for Blastocystis. Subtyping was successfully performed on 46 samples using sequenced-tagged site (STS) primers and PCR. The remaining 69 samples could not be subtyped. The most frequently detected subtype was ST3 (43.4%) followed by ST1 (26.1%), ST4 (10.9%) and ST2 (8.7%). The mixed subtypes were identified in five samples (10.9%) as; ST1+ST3 (n=3), ST1+ST2 (n=1) and ST2+ST3 (n=1). None of the samples had ST5, ST6 or ST7. No statistically significant difference was found between the symptomatic and asymptomatic groups in terms of the Blastocystis positivity and the distribution of subtypes (p>0.05). To our knowledge, this is the first study to investigate the subtype distribution of Blastocystis in children in Turkey and the results are in agreement with the related data available in Turkey.

Association of Enteric Protist Blastocystis spp. and Gut Microbiota with Hepatic Encephalopathy.

BACKGROUND AND AIMS: Hepatic encephalopathy (HE) is a serious neuropsychiatric sequela emerging in the advanced stages of cirrhosis. The gut microbiota plays an important role in the development of HE. The aim of the study was to analyze the dynamic interplay between microbiota and Blastocystis in cirrhotic patients with or without encephalopathy. METHODS: The study was designed as cross-sectional study. A total of 37 patients from the Ankara city, admitted to the University Hospital within a 6-month period prior to enrolment into the study were included in the study. After the regular health checks, clinical histories, clinical examinations, and Psychometric HE Score (PHES) points, patients' MELD and CTP scores were recorded. The fecal microbiota configurations were characterized by targeting hypervariable regions V3 and V4 of the 16S rRNA gene using Illumina MiSeq System. RESULTS: Blastocystis spp. were detected in 21.6% (n = 8) of all cirrhotic patients. When those were analyzed by subgroups, four of them were subtype 2, three were subtype 3 and one was subtype 1. Blastocystis spp. were not found in any of the patients with HE; however, they were detected in 38.1% of the patients without HE. Also the increase in the bacterial diversity was observed along with the absence of Blastocystis. It was suggested that there was an inverse relationship between Blastocystis spp. and advanced stages of HE and the structure and composition of gut microbiota. CONCLUSION: The absence of Blastocystis spp. is associated with the HE severity and dysbiosis in the gut microbiota.

Eradication of Blastocystis in humans: Really necessary for all?

Blastocystis (initially named as Blastocystis hominis) has long been known as a protist without any clinical significance. However, there is now a huge pile of case reports where Blastocystis is blamed for the symptoms and the infection described in the patients. Introduction of the presence of as many as 17 Blastocystis subtypes while many infected individuals are non-symptomatic initially brought about the correlation between the subtypes and pathogenicity; however, the outcomes of these trials were not consistent and did not explain its pathogenicity. Today, it is mostly acknowledged that Blastocystis may colonize many individuals but the infection's onset depends on the interaction between the virulence of parasites and host's immune competence. Eradication of Blastocystis is essential in some cases where it is the only infectious agent and patient is suffering from some symptoms. In such cases, metronidazole is the drug of choice but its efficacy is relatively low in some cases. Other agents used include trimethoprim-sulfamethoxazole, paromomycin, and furazolidone. Recent studies on the interactions between human health and the role of gut microbiota introduces new data which may significantly change our point of view against some protists, which we tend to see as "parasites requiring urgent eradication for cure". May the presence or absence of some Blastocystis subtypes necessary for human health, or is the absence or presence of certain Blastocystis subtypes in human gut is associated with certain diseases/infections? The answers of these questions will surely guide us to select patients requiring treatment against Blastocystis infection in future.

Prevalence of microsporidia in healthy individuals and immunocompetent patients with acute and chronic diarrhea.

BACKGROUND: Previously published studies of microsporidial infections have primarily focused on immunodeficient or immunocompromised patients. Data regarding infections caused by this microorganism in immunocompetent subjects are lacking. In the present study, we investigated the prevalence of microsporidia in healthy individuals and immunocompetent patients with acute and chronic diarrhea. METHODS: The study included stool samples from 74 patients with acute diarrhea, 41 patients with chronic diarrhea, and 88 healthy volunteers. Slides were prepared after concentration with a formalin-ethyl acetate technique and were stained with modified trichrome, calcofluor white, and Uvitex 2B stains. The number of spores observed in each magnification field (×1000) was scored as follows: 1+, 1-10; 2+, 11-20; 3+, > 20. RESULTS: The prevalence of microsporidia was 27.0% in patients with acute diarrhea, 34.1% in patients with chronic diarrhea, and 45.5% in healthy volunteers. The parasite score was 1 + in all positive samples. The rate of microsporidia positivity was higher in solid stools (51.4%), and the rate of positivity increased with advancing age. CONCLUSION: Unexpectedly, a high prevalence of microsporidia was found in immunocompetent individuals in our region. There was no relationship between positivity for microsporidia and the presence of symptoms, due to higher rates both in solid stools and in healthy subjects. The parasite score was the same in all groups. Our results indicate that there is high exposure to microsporidia in immunocompetent subjects in our region. Natural reservoirs and environmental sources of microsporidia should be determined to design strategies for effective prevention of transmission.

The effect of two artificial salivas on the adhesion of Candida albicans to heat-polymerized acrylic resin.

PURPOSE: Xerostomia can diminish the quality of life, leads to changes in normal chemical composition of saliva and oral microbiata, and increases the risk for opportunistic infections, such as Candida albicans. Various artificial salivas have been considered for patients with xerostomia. However, the knowledge on the antifungal and antiadhesive activity of artificial saliva substitutes is limited. The aim of the present study was to evaluate influence of two artificial salivas on the adhesion of Candida albicans to the polymethylmethacrylate disc specimens. MATERIALS AND METHODS: Two commercial artificial salivas (Saliva Orthana and Biotene Oral Balance Gel) were selected. 45 polymethylmethacrylate disc specimens were prepared and randomly allocated into 3 groups; Saliva Orthana, Biotene-Oral Balance gel and distilled water. Specimens were stored in the artificial saliva or in the sterile distilled water for 60 minutes at 37℃. Then they were exposed to yeast suspensions including Candida albicans. Yeast cells were counted using ×40 magnification under a light microscope and data were analysed. RESULTS: Analysis of data indicated statistically significant difference in adhesion of Candida albicans among all experimental groups (P=.000). Findings indicated that Saliva Orthana had higher adhesion scores than the Biotene Oral Balance gel and distilled water (P<.05). CONCLUSION: In comparison of Saliva Orthana, the use of Biotene Oral Balance Gel including lysozyme, lactoferrin and peroxidase may be an appropriate treatment method to prevent of adhesion of Candida albicans and related infections in patients with xerostomia.