Osman Aktaş

Prof. Osman Aktaş

orcid

Research Focus & Metrics

Academic Career Length

40Years (1987-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2019 in Minerva Pediatrica
Verified
Journal Article
Closed access
OAOsman Aktaş
Osman Aktaş
HAHakan Aydin
Hakan Aydin
MTMehmet O. Timurkan
Mehmet O. Timurkan
Viral gastroenteritides are among the causes of higher morbidity and mortality in the childhood period, especially in infants. Although viral-induced diarrheal diseases are important problems in Erzurum, there have been no studies on the molecular prevalence of viral gastroenteritis agents in this region's children. The aim of the prospective study is to determine the molecular prevalence of the most commonly seen viral etiologic agents and their coinfection rates in children under 5 years of age with gastroenteritis in Erzurum, Turkey. Stool samples from 375 children between 0 and 5 years of age who suffered from acute diarrhea were investigated for the presence of Rotavirus, Norovirus, Astrovirus and Adenovirus by reverse transcriptase polymerase chain reaction, followed by conventional PCR techniques. The presence of Rotavirus, Norovirus, Astrovirus and Adenovirus in the specimens was detected by amplification of the VP6, RdRp, ORF-1b and Hexon regions, respectively. Stool samples were also investigated non-viral enteropathogens by conventional techniques. At least one viral pathogen was detected in 59.2% of the stool samples. Rotavirus was the most frequently observed agent (32.3%), followed by Norovirus (20.3%), Adenovirus (9.6%) and Astrovirus (5.6%). All specimens were negative for bacterial pathogens. Twenty seven (7.2%) specimens were positive for intestinal helminths and protozoan. A total of 39 coinfection (10.4%) including 38 dual and 1 triple were detected. The most frequent coinfections were observed between Norovirus plus Rotavirus and Norovirus plus Adenovirus. Single infections or coinfections of the enteropathogenic viruses occur at a significant rate in Erzurum's children. This study draws attention to the necessity of taking account of multiple viral infections in studies on combined vaccines and the treatment of gastroenteritis.

1 January 2004 in Scandinavian Journal of Infectious Diseases
Verified
Journal Article
Closed access
MBMustafa Buyukavci
Mustafa Buyukavci
ICIbrahim Caner
Ibrahim Caner
SESuat Eren
Suat Eren
OAOsman Aktaş
Osman Aktaş
RARecep Akdag
Recep Akdag
Primary hepatic actinomycosis is extremely rare in children. Although the infection has the capability of extension to surrounding tissues or organs, involvement of the abdominal wall is infrequently reported even in adults. We present a childhood case of primary hepatic actinomycosis infiltrating the anterior abdominal wall and spontaneously draining through the skin.

1 April 2003 in Journal of International Medical Research
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Journal Article
Closed access
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AOA Ozbek
A Ozbek
OAOsman Aktaş
Osman Aktaş
The cellular fatty acid profiles of 67 strains belonging to three different species of the genus Mycobacterium were determined by gas chromatography of the fatty acid methyl esters, using the MIDI Sherlock® Microbial Identification System (MIS). The species M. tuberculosis, M. xenopi and M. avium complex were clearly distinguishable and could be identified based on the presence and concentrations of 12 fatty acids: 14:0, 15:0, 16:1ω7c, 16:1ω6c, 16:0, 17:0, 18:2ω6,9c, 18:1ω9c, 18:0, 10Me-18:0 tuberculostearic acid, alcohol and cyclopropane. Fatty acid analysis showed that there is great homogeneity within and heterogeneity between Mycobacterium species. Thus the MIS is an accurate, efficient and relatively rapid method for the identification of mycobacteria.

25 March 2025 in Medicina
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Journal Article
Open access
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NTNecip gökhan Taş
Necip gökhan Taş
OAOsman Aktaş
Osman Aktaş
HTHakan Gökalp Taş
Hakan Gökalp Taş
SZSelim ZIRH
Selim ZIRH
NKNezahat Kurt
Nezahat Kurt
HUHakan Uslu
Hakan Uslu
Background and Objective: Probiotics have been shown to be effective in controlling various adverse health conditions such as antibiotic-associated diarrhea, inflammatory bowel disease, obesity, and neurological diseases. However, to our knowledge, there is no research on the preventive effect of probiotics on heart damage caused by infections. This study examined the preventive benefits of probiotics against sepsis-related heart injury using a rat model caused by lipopolysaccharide (LPS). Materials and Methods: Four groups of twenty-four male Wistar albino rats, each with six rats, were set up. For 14 days, Group 1 (Sham Group) was given oral normal saline, intraperitoneal Escherichia coli O111-B4 lipopolysaccharide (LPS Group) was given to Group 2, and oral probiotics were given to Group 3 (Probiotic Group). Escherichia coli O111-B4 lipopolysaccharide was injected intraperitoneally after Group 4 (Probiotic + LPS) received oral probiotics containing Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB-12 (109 CFU/day). Blood samples were taken twenty-four hours following the administration of LPS. The animals were then euthanized by cervical dislocation, and samples of cardiac tissue were taken in order to assess any damage to the heart. The following serum values were measured: C-reactive protein (CRP), creatine kinase-myocardial band (CK-MB), cardiac troponin subunit I (cTn-I), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6). The TNF-α, IL-1β, IL-6, glutathione (GSH), malondialdehyde (MDA), Total Oxidant Status (TOS), Total Antioxidant Status (TAS), Oxidative Stress Index (OSI), CRP, CK-MB, and cTn-I levels were assessed in tissue samples. Additionally, staining techniques were used to analyze histopathological alterations in tissues. Results: With the exception of serum IL-6 (p = 0.111), tissue and serum cytokine levels were considerably greater in the sepsis group (Group 2) than in the other groups (p < 0.05 to <0.001). The TAS, GSH, and SOD levels were significantly lower (p < 0.05 to <0.001) in septic rats, although the tissue levels of TOS, OSI, and MDA were significantly higher. With the exception of serum CRP in Group 3 (p = 0.328), the CK-MB, CRP, and cTn-I levels were considerably higher in Group 2 than in the other groups (p < 0.01 to <0.001). When compared to the other groups, histopathological examination showed significant alterations in the LPS group. Conclusions: Probiotics showed positive effects on oxidative stress markers and dramatically decreased sepsis-induced cardiac damage in the LPS-induced sepsis model. These results imply that probiotics could be used as a therapeutic approach to lessen the cardiac damage brought on by sepsis.

1 December 2022 in GERMS
Verified
Journal Article
Open access
BÇBahar Çimen
Bahar Çimen
OAOsman Aktaş
Osman Aktaş
Diarrheal diseases have existed since antiquity, resulting in high morbidity and mortality rates, particularly among children in developing countries. To eradicate these diseases, it is crucial to identify the pathogens that cause them and immediately initiate appropriate treatment. This retrospective study aims to investigate the incidence of childhood gastroenteritis and the epidemiological features of its causative agents. During an 11-year period (2010–2020), as many as 51159 stool samples were obtained from children aged 0-17 years. These samples were examined for the presence of parasitic, bacterial, and/or viral gastroenteritis agents and evaluated retrospectively. The records obtained from the "ENLIL Hospital Information Management System Modules" were used to collect patient-related information. The most frequently observed pathogens were rotavirus (22.4%), adenovirus (2.2), Giardia lamblia (1.6%), and Campylobacter spp. (3.0%), considering the number of samples examined for each organism. The total incidence of viruses was about 25%, parasites 5% and the rate of pathogenic bacteria was 2%. In one-way ANOVA analysis, pathogen positivity was found to be significantly higher in children aged 3-5 years compared to those aged 15-17 and 0-2 [F (5, 51153, 17,588, p<0.001)]. The highest demand for the investigation of GE factors from stool samples was made in August, September and July. According to the number of samples examined, the highest pathogen positivity was in February, October, May, December and March, respectively. The most common pathogens involved in coinfections, occurring in 0.04% of the studied cases, were rotavirus and Giardia lamblia. Parasitic, viral, and bacterial gastroenteritis maintain their current status with a high prevalence in children under 18 years of age, especially in children aged 0-4 years in Erzurum, Turkey.

1 January 2016 in The Eurasian Journal of Medicine
Verified
Journal Article
Open access
HUHakan Uslu
Hakan Uslu
OAOsman Aktaş
Osman Aktaş
MUMuhammet Hamidullah Uyanik
Muhammet Hamidullah Uyanik
Objective: Entamoeba histolytica is indistinguishable from Entamoeba dispar in direct microscopic examination. A definitive diagnosis of E. histolytica is important in terms of the treatment of the patient and to avoid unnecessary costs. This study’s aim is to determine the prevalence of E. histolytica and to make a comparison of the different diagnostic tests in the patients specimens defined as E. histolytica/E. dispar infection. Materials and Methods: Faecal and serum specimens of 90 patients defined as E. histolytica/E. dispar with microscopy (wet mount examination with 0.85% saline and Lugol’s iodine) were examined. Stool samples were examined by trichrome staining for trophozoites and cysts and by immunoassay methods for specific adhesin antigens (Wampole ® E. histolytica II antigen testing) and for specific serine-rich 30 kD membrane protein (Serazym® E. histolytica antigen testing). Anti-E. histolytica antibodies were investigated using a latex slide test and indirect hemagglutination methods in serum specimens. Results: Presence of E. histolytica was not confirmed in 31.1% cases with trichrome staining, 62.2% of the Wampole antigen test, 64.4%, of the Serazym antigen test, 73.3% of the indirect hemagglutination test and 75.6%. of the latex agglutination. Considering the common results from Wampole and Serazym antigen testing as a reference standard, the specificity/sensitivity is 100/53.85% for trichrome staining, 75.00/98.11% for the latex agglutination test and 78.57/96.77% for the indirect hemagglutination test. Conclusion: It has been shown that investigation of E. histolytica in stools by direct wet-smear microscopy alone can cause significant false positive results. To obtain a reliable diagnosis for E. histolytica and to avoid unnecessary treatment for this parasite, at least one more specific assay, particularly an antigen testing and microscopy, is required.