Funda Dogruman-Al

A possible link between subtype 2 and asymptomatic infections of Blastocystis hominis

Blastocystis hominis is one of the most common eukaryotic organisms in the intestinal tract of humans, while its pathogenic potential is still controversial. A total of 286 stool samples obtained from adult and pediatric patients with or without gastrointestinal symptoms in two hospitals in Manisa, Turkey, were cultured to detect B. hominis infection. Forty-one and 51 isolates were obtained from the adults and children, respectively, and these isolates were subjected to subtyping by polymerase chain reaction (PCR) with the known sequence-tagged site primers. The correlation between the genotype and the symptoms was evaluated. PCR subtyping indicated that subtype 3 was the most common genotype in both symptomatic and asymptomatic groups, and the second common genotype was subtypes 1 and 2 in symptomatic and asymptomatic groups, respectively. A significant correlation between subtype 2 and the asymptomatic groups was found among both in pediatric and adult patients (χ2cal = 4.38, df = 1, p = 0.044). However, there were no significant differences between the other genotypes and the symptomatic or asymptomatic groups, as well as both the age and sex of the patients. The present study suggests that subtype 2 is a non-pathogenic genotype of B. hominis.

Comparison of methods for detection of Blastocystis infection in routinely submitted stool samples, and also in IBS/IBD Patients in Ankara, Turkey.

Background This study compared diagnostic methods for identifying Blastocystis in stool samples, and evaluated the frequency of detection of Blastocystis in patients with irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). Results and Discussion From a set of 105 stool specimens submitted for routine parasitological analysis, 30 were identified as positive for Blastocystis by the culture method. From that group of 30 positives, Lugols stain, trichrome staining, and an immunofluorescence assay identified 11, 15, and 26 samples as positive respectively. Using culture as a standard, the sensitivity of Lugols stain was 36.7%, trichrome staining was 50%, and the IFA stain was 86.7%. The specificity of Lugols stain was 91%, trichrome staining was 100%, and the IFA stain was 97.3%. In the group of 27 IBS and IBD patients, using all methods combined, we detected Blastocystis in 67% (18/27) of the patients. Blastocystis was detected in 33% (2/6) of IBD patients and 76% (16/21) of IBS patients. For comparison, trichrome staining alone, the method most frequently used in many countries, would have only identified Blastocystis infection in 29% (6/21) of the IBS patients. No parasitic co-infections were identified in the IBS/IBD patients. Most Blastocystis-positive IBS/IBD patients were over 36 with an average length of illness of 4.9 years. Conclusions Most IBS patients in this study were infected with Blastocystis. IFA staining may be a useful alternative to stool culture, especially if stool specimens have been chemically preserved.

PCR-based subtyping of Blastocystis isolates from symptomatic and asymptomatic individuals in a major hospital in Ankara, Turkey

The stool samples obtained from 94 patients with gastrointestinal symptoms and 109 asymptomatic individuals, who checked in due to other reasons, admitted at a major hospital in Ankara, Turkey were examined with native Lugol’s iodine, trichrome, and Kinyoun’s acid-fast stainings for parasitology examinations and with in vitro culture method for detection of Blastocystis. In a total of 203 stool samples tested, native Lugol’s iodine and trichrome stainings could detect 12 (5.9%) and 20 (9.9%) positive samples for Blastocystis, respectively. Conversely, culture method could detect 66 (32.5%) positive samples, and this method was more sensitive compared to the both microscopic examinations (p < 0.001). Among 66 positive samples for Blastocystis, 27 were from symptomatic patients and 39 were from asymptomatic group. Subtypes (STs) were determined by PCR using seven different sequence-tagged site primers. ST3 was the most dominant in both symptomatic and asymptomatic groups and followed by ST1 or ST2. There were mixed infections with STs 1 and 2 or STs 1 and 3 in nine isolates. There was no statistical significance of the distribution of Blastocystis sp. subtypes between symptomatic and asymptomatic individuals (p > 0.05).

Oxidative stress and tryptophan degradation pattern of acute Toxoplasma gondii infection in mice.

Toxoplasma gondii is a very common obligate single-cell protozoan parasite which induces overproduction of interferon (IFN)-gamma and of other proinflammatory cytokines. Although immunomodulatory role of IFN-gamma favors tryptophan (Trp) degradation via indoleamine-2,3-dioxygenase (IDO) activity and is related with nitric oxide (NO) synthesis, the mechanism of antitoxoplasma activity is complex. In order to characterize the Trp degradation pattern during the acute T. gondii infection, serum Trp, kynurenine (Kyn), and urinary biopterin levels of mice were measured. The possible oxidative status was evaluated by the liver, spleen, brain, and serum malondialdehyde (MDA) and NO levels. Increased free radical toxicity may cause elevation in tissue MDA in T. gondii-infected mice, while unchanged serum MDA might indicate the increased oxidative stress due to T. gondii infection restricted to intracellular area. Elevated serum NO most probably might be due to the formation of reactive nitrogen radicals. The Kyn/Trp ratio was higher in T. gondii-infected mice compared to healthy animals (p < 0.05); however, it was not correlated with urinary biopterin. These results suggested that Trp degradation might be promoted by a pathway other than IDO during T. gondii infection and the reduction of Trp concentration favors the local immunosuppression and systemic tolerance.

A possible relationship between Toxoplasma gondii and schizophrenia: A seroprevalence study

Objective. Schizophrenia is a pervasive neuropsychiatric disease of uncertain etiology. We aimed to investigate a possible association between Toxoplasma gondii infection and schizophrenia in this study. Method. We selected individuals with schizophrenia (n=88) and tested them with commercially available enzyme-linked immunosorbent assay (ELISA) for anti-Toxoplasma IgG and IgM antibodies and compared these seropositivity rate to those of controls without psychiatric disease (n=88). Results. The rate of IgG antibody in the schizophrenia patients (47.7%) was higher than the control groups (20.4%) (P<0.001). We did not find any anti-Toxoplasma IgM seropositivity in both schizophrenia patients and control group. In schizophrenic patients with and without anti-Toxoplasma IgG groups statistical analysis did not reveal any correlation between demographic variables and Toxoplasma infection. Conclusion. Our findings supported previous studies indicate that T.gondii may play a role in etiopathogenesis in some cases of schizophrenia.

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.

Airway inflammation and bronchial hyperreactivity in steroid naive children with intermittent and mild persistent asthma

Intermittent and mild persistent asthma are defined according to symptom frequency and spirometry and treated differently. To our knowledge, there is no study comparing airway inflammation between intermittent and mild persistent asthmatic children.

Cytokine profile in murine toxoplasmosis.

OBJECTIVE To investigate which cytokines are produced after acute infection of mice with Toxoplasma gondii (T. Gondii) RH strain. METHODS Mus domesticus domesticus mice in infected group were inoculated with with highly virulent T. Gondii RH strain by intraperitoneally. Serum samples were obtained from infected and non-infected mice for cytokine levels for ELISA assay. RESULTS The concentrations of tumor necrosis factor-α, interferon-γ, interleukin (IL)-10 and IL-12 in the cardiac blood sample of the infected mice were significantly higher than those in uninfected controls (P<0.05). The levels of transforming growth factor-1β decreased in mice infected with T. gondii compared to those of the controls, the decrease was statistically significant (P<0.05). No significant difference was observed in levels of IL-4 between infected and healty control groups (P>0.05). CONCLUSIONS According to our findings, immune response into T helper type 1 was predominant during acute T. gondii infection. Further characterization and purification of Toxoplasma molecule(s) implicated in the regulation of cytokines could lead to the development of new drug prospects to control Toxoplasma infection.

[Determination of anti-echinococcus IgG antibodies by ELISA in patients with suspected hydatid cyst].

OBJECTIVE Cystic echinococcosis (hydatid cyst) is one of the most important parasitic zoonoses that affect both humans and animals and has been known since prehistoric times. The cystic echinoccosis is a major health problem in our country as well as in many countries worldwide, and serological methods, in addition to imaging techniques, are used in the diagnosis of hydatid cyst. In the present study, anti- Echinococcus antibodies were investigated by ELISA in patients serum samples, which were routinely delivered to the Medical Microbiology Laboratory of Gazi University Faculty of Medicine due to suspected hydatid cyst. METHODS A total of 186 patients with suspected hydatid cysts from several outpatient clinics and departments of Gazi University Hospital were included in the present study. IgG antibodies in serum samples of patients with anti-Echinococcus were investigated by ELISA (Novalisa Echinococcus IgG, NovaTec, Germany). RESULTS Anti-Echinococcus IgG seropositivity was determined as 35.5% in patients with suspected hydatid cyst. There are no statistical differences in ELISA positive results relating to gender, adult/child age group and associated clinics. CONCLUSION Hydatid cyst seropositivity was higher among patients admitted to our hospital.

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

ABSTRACT 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.