Yazar "Tokman, Hrisi Bahar" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • [ X ]
    Öğe
    Enterotoksijenik bacteroides fragilis ve fusobacterium nucleatum bağırsak kolonizasyonunun kolorektal kanser ile ilişkisi: kolon biyopsileri ile yapılan bir olgu kontrol çalışması
    (2023) Öztürk Bakar, Yeşim; Demiryas, Süleyman; Kılınçarslan, Ayşe Ceylan; Demirci, Mehmet; Kepil, Nuray; Bakar, Murat Tuğberk; Taner, Zeynep; Tokuç, Edip; Ziyad, Muhuyedin Abdırahman; Taşkı, İhsan; Kocazeybek, Bekir Sami; Tokman, Hrisi Bahar
    In recent years, it has been shown that some bacteria may be associated with colorectal cancer (CRC). In this study, it was aimed to investigate the role of Fusobacterium nucleatum and enterotoxigenic Bacteroides fragilis (ETBF) in the etiology of CRC by comparing the amounts of these bacteria in colon biopsy tissues of patients with CRC and healthy individuals. The amounts of F.nucleatum and ETBF were determined by quantitative polymerase chain reaction (qPCR) in colon biopsy samples taken from 35 CRC and 35 healthy individuals, and the results were compared in the patient and control groups. The detection rate and amounts of F.nucleatum were found to be statistically significantly higher in tissues of female patients with CRC compared to male patients (p= 0.003, p= 0.013, respectively). There was no statistically significant difference between the tissues of female and male patients with CRC in terms of detection rate and amount of ETBF (p= 0.521, p= 0.515, respectively). It was found that in the 50-74 age group, the amount of ETBF was statistically significantly higher in women and men with CRC compared to the controls (p= 0.005, p= 0.047, respectively), while the amount of F.nucleatum was statistically significantly higher in female patients compared to controls. However, no difference was found between male patients and controls (p= 0.009, p= 0.083). It was determined that the detection rate and amount of F.nucleatum in the tissues of patients with CRC, regardless of age and gender, were not statistically different from the controls (p= 0.473, p= 0.995, respectively), however, the detection rate of ETBF and the amount of ETBF were found to be statistically significantly higher (p= 0.002, p= 0.004, respectively). It has been determined that ETBF can play a role in the etiology of CRC in both men and women, and F.nucleatum only in women, in the age range of 50-74 years, when routine screenings for CRC are performed.
  • [ X ]
    Öğe
    Prevalence and antimicrobial susceptibilities of anaerobic bacteria isolated from perforated corneal ulcers by culture and multiplex PCR: An evaluation in cases with keratitis and endophthalmitis
    (Clin Lab Publ, 2014) Tokman, Hrisi Bahar; İskeleli, Güzin; Dalar, Zeynep Güngördü; Kangaba, Achille Aime; Demirci, Mehmet; Akay, Hatice K.; Kiraz, Nuri; Borsa, Barış Ata
    Background: Anaerobic bacteria play an important role in eye infections; however, there is limited epidemiologic data based on the the role of these bacteria in the etiology of keratitis and endophthalmitis. The aim of this research is to determine the prevalence of anaerobic bacteria in perforated corneal ulcers of patients with keratitis and endophthalmitis and to evaluate their antimicrobial susceptibilities. Methods: Corneal scrapings were taken by the ophthalmologist using sterile needles. For the isolation of anaerobic bacteria, samples were inoculated on specific media and were incubated under anaerobic conditions obtained with Anaero-Gen (Oxoid & Mitsubishi Gas Company) in anaerobic jars (Oxoid USA, Inc. Columbia, MD, USA). The molecular identification of anaerobic bacteria was performed by multiplex PCR and the susceptibilities of anaerobic bacteria to penicillin, chloramphenicol, and clindamycin were determined with the E test (bioMerieux). Results: 51 strains of anaerobic bacteria belonging to four different genuses were detected by multiplex PCR and only 46 strains were isolated by culture. All of them were found susceptible to chloramphenicol whereas penicillin resistance was found in 13.3% of P.anaerobius strains, clindamycin resistance was found in 34.8% of P.acnes and 13.3% of P.anaerobius strains. Additionnaly, one strain of P.granulosum was found resistant to clindamycin, one strain of B.fragilis and one strain of P.melaninogenica were found resistant to penicillin and clindamycin. Conclusions: Routine analyses of anaerobes in perforated corneal ulcers is inevitable and usage of appropriate molecular methods, for the detection of bacteria responsible from severe infections which might not be determined by cultivation, may serve for the early decision of the appropriate treatment. Taking into account the increasing antimicrobial resistance of anaerobic bacteria, alternative eye specific antibiotics effective against anaerobes are needed to achieve a successful treatment.
  • Küçük Resim
    Öğe
    Similar bacterial signatures in the gut microbiota of type 1 and type 2 diabetes patients and its association with G protein-coupled receptor 41 and 43 gene expression
    (Springer Science and Business Media Deutschland GmbH, 2022) Demirci, Mehmet; Taner, Zeynep; Keskin, Fatma E.; Ozyazar, Mucahit; Kiraz, Nuri; Kocazeybek, Bekir S.; Tokman, Hrisi Bahar
    Purpose: There are conficting reports regarding the abundance of short-chain fatty acids producing bacteria in the gut microbiota in patients with type 1 and type 2 diabetes. We aimed to determine the amount of Akkermansia muciniphila, Anaerobutyricum hallii, Bifdobacterium adolescentis, Bifdobacterium longum, Collinsella aerofaciens, Faecalibacterium prausnitzii, Lacticaseibacillus rhamnosus, and Parabacteroides distasonis in the gut microbiota in patients with type1 and type2 diabetes, compared with the healthy controls and analyze the correlation between the gene expression levels of two short-chain fatty acids receptors GPR41 and GPR43. Methods: Forty type 1, 40 type 2 stool and blood samples of diabetes patients, and 40 healthy control samples were studied. DNA and RNA were extracted, and bacteria were detected using a Microbial DNA qPCR Assay kit. Gene expressions were detected with GPR41 and GPR43 primers via in-house qPCR. Results: Compared with healthy controls, B.longum and F.prausnitzii abundance were signifcantly decreased in patients with type1 and type2 diabetes, A.hallii abundance was increased in patients with type1 and decreased in type2 diabetes contrarily A.muciniphila abundance was decreased in patients with type1 and increased in type2 diabetes. GPR43 gene expression was upregulated in both patients group, however GPR41 was upregulated only in patients with type2 diabetes. Conclusions: Elevated B. longum and F. prausnitzii abundances were detected in the gut microbiota of patients with type1 and type2 diabetes and compared with healthy controls. B. longum and F.prausnitzii abundances were also correlated with the GPR43 gene expression level in type1 diabetes patients. Extensive studies determining bacteria producing short-chain fatty acids in gut microbiota, and their contribution in the pathogenesis of diabetes, are needed to understand better the mechanism of these diseases.
  • [ X ]
    Öğe
    The relationship between bifidobacteria and allergic asthma and/or allergic dermatitis: A prospective study of 0-3 years-old children in Turkey
    (Elsevier Sci Ltd, 2014) Akay, Hatice Kubra; Tokman, Hrisi Bahar; Hatipoğlu, Nevin; Hatipoğlu, Huseyin; Siraneci, Rengin; Demirci, Mehmet; Kocazeybek, Bekir S.; Borsa, Barış Ata
    Bifidobacteria are beneficial bacteria for humans. These bacteria are particularly effective at protecting against infectious diseases and modulating the immune response. It was shown that in newborns, the fecal distribution of the colonizing Bifidobacterium species influences the prevalence of allergic diseases. This study aimed to compare the faecal Bifidobacterium species of allergic children to those of healthy children to detect species level differences in faecal distribution. Stool samples were obtained from 99 children between 0 and 3 years of age whose clinical symptoms and laboratory reports were compatible with atopic dermatitis and allergic asthma. Samples were also obtained from 102 healthy children who were similar to the case group with respect to age and sex. Bifidobacteria were isolated by culture and identified at the genus level by API 20 A. In addition, 7 unique species-specific primers were used for the molecular characterization of bifidobacteria. The McNemar test was used for statistical analyses, and p < 0.05 was accepted as significant. Bifidobacterium longum was detected in 11(11.1%) of the allergic children and in 31 (30.3%) of the healthy children. Statistical analysis revealed a significant difference in the prevalence of B. longum between these two groups (X-2: 11.2, p < 0.001). However, no significant differences in the prevalence of other Bifidobacterium species were found between faecal samples from healthy and allergic children. (p > 0.05). The significant difference in the isolation of B. longum from our study groups suggests that this species favors the host by preventing the development of asthma and allergic dermatitis. Based on these results, we propose that the production of probiotics in accordance with country-specific Bifidobacterium species densities would improve public health. Thus, country-specific prospective case control studies that collect broad data sets are needed. (C) 2014 Elsevier Ltd. All rights reserved.