Browsing by Author "Sener, AG"

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    Investigation of the dual cascade algorithm in the diagnosis of antinuclear antibodies
    Ecemis, T; Farasat, VT; Dugan, Y; Sener, AG; Ece, GT; Dündar, PE; Sanlidag, T
    Background: The dual cascade algorithm which involves screening and confirmation of antinuclear antibodies (ANAs) by further reflex testing is widely used in the detection of ANAs. We aimed to investigate this algorithm which is commonly used in many laboratories. Methods: A total of 475 sera obtained from patients with a clinical suspicion of systemic autoimmune rheumatic diseases (SARDs) upon which three expert assessors agreed for interpretation in the indirect immunofluorescence (IIF) test were determined and tested by the line immunoassay (LIA) containing 16 antigens. The results of the tests were statistically compared and evaluated. Results: In 141 of the sera (29.7%), there was an agreement between ANA-IIF(+) and LIA(+) results. The overall agreement rate between the two tests for positivity and negativity only was 85.5% with a Cohen's lc coefficient of 0.69. In 118 of these 141 sera (83.7%), pattern and associated ANA agreement was detected with an overall agreement rate of 80.6% and a Cohen's kappa coefficient of 0.57. The highest agreement between the pattern and associated ANAs was seen in centromere, dense fine speckled (DFS) and cytoplasmic reticular patterns. In these patterns, the rate of anti-centromere-associated protein B (CENP-B), anti-DFS and anti-antimitochondrial antibody M2 (anti-AMA-M2) antibodies were 93.4%, 92.3% and 66.7%, respectively. Conclusions: We found an overall moderate agreement between IIF screening and LIA confirmation tests. However, the level of agreement varies according to the pattern type. The discrepancy in agreement rates may cause false reflex test requests. Our results highlight the need for collaboration between clinical and laboratory professionals in selected cases instead of the reflex testing approach.
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    A Multicenter Analysis of Subjectivity of Indirect Immunofluorescence Test in Antinuclear Antibody Screening
    Farasat, VT; Ecemis, T; Dogan, Y; Sener, AG; Ece, GT; Dündar, PE; Sanlidag, T
    Objectives: This study aims to evaluate the interpretation of the antinuclear antibody (ANA)-indirect immunofluorescence (IIF) test results based on the interpreter-related subjectivity and to examine the inter-center agreement rates with the performance of each laboratory. Patients and methods: The ANA-IIF testing was carried out in a total of 600 sera and evaluated by four laboratories. The inter-center agreement rates were detected. The same results given by the four centers were accepted as gold standard and the predictive values of each center were calculated. Results: The inter-center agreement was reported for ANA-IIF test results from 392 of 600 (65.3%) sera, while 154 of 392 results were positive. Four study centers reported 213 (35.5%), 222 (37.0%), 266 (44.3%), and 361 (60.2%) positive test results, respectively. In terms of the patterns, the highest and lowest positive predictive values were 72.3% and 42.7%, respectively, while the highest and lowest negative predictive values were 99.6% and 61.5%, respectively. The agreement for semi-quantitative evaluation at three levels of fluorescence intensity stated by four centers was detected in 100 sera at 87% 3(+), while the other two levels were 6% and 7%. The highest predictive value for the highest fluorescence intensity of 3(+) was found to be 71.9%. Conclusion: Significant differences may be observed among laboratories in terms of qualitative results, patterns, and semi-quantitative determination of the fluorescence intensity in the ANA-IIF testing, particularly at low fluorescence intensity levels and in those with speckled patterns. In case of any discrepancy between ANA-IIF test and clinical prediagnosis, the test should be repeated in another laboratory, if necessary.
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    t030 is the Most Common spa Type Among Methicillin-Resistant Staphylococcus aureus Strains Isolated from Turkish Hospitals
    Bozdogan, B; Yildiz, O; Oryasin, E; Kirdar, S; Gülcü, B; Aktepe, O; Arslan, U; Bayramoglu, G; Çoban, AY; Coskuner, SA; Güdücüoglu, H; Karabiber, N; Öncü, S; Otkun, MT; Özkütük, N; Özyurt, M; Sener, AG
    Staphylococcus aureus is one of the most frequent agents causing hospital infections. S.aureus has a great ability to adapt itself to variety of conditions and successful clones can be epidemic and even pandemic by its ability spread from one continent to another. The aims of this study were to detect spa types of 397 methicillin-resistant S.aureus (MRSA) strains isolated from 12 centers in different geographical regions of Turkey from 2006 to 2008, and to investigate their clonality by PFGE and MLST typing. Additionally, 91 MRSA from four of those 12 centers isolated during 2011 were also studied for their spa types. PFGE profiles indicated the presence of a major pulsotype, namely pulsotype A with a rate of 91.4% (363/397), followed by pulsotype B (n = 18, 4.5%) and pulsotype C (n = 11, 2.8%). Among isolates tested 363 (91.4%) were SCCmec type III, 30 (7.6%) were SCCmec type IV. Sequence analysis of representative isolates revealed that ST239 (85.1%) was the most common MLST type followed by two MLST types ST737 (4%), and ST97 (2.8%), both SCCmec type IV. Two isolates were ST80 with SCCmec type IV. Of 397 isolates, 338 (85.1%) were t030, followed by t005 (2.5%) and t632 (2%). Among MRSA isolated during 2011, 64 (70.3%) of 91 were t030, 4 (4.4%) were t005, 2 (2.2%) were t015, and 2 (2.2%) were t1094. Among centers the t030 prevalence of 2006-2008 isolates ranged from 59-100%. The highest t030 prevalence was found in Ankara (100%) and lowest in Trabzon (59%) provinces which are located at central and northestern Anatolia, respectively. In Istanbul province, the prevalence of t030 was 94.5% among 2006-2008 isolates which decreased to 55.5% among 2011 isolates. Also a decrease in t030 rates was observed among samples from Konya and Trabzon but not from Aydin. Our results showed that the most common MRSA clone in Turkey is ST 239-SCCmec type III, t030 which persisted during the six years of the study period. Presence of PVL toxin gene was tested by PCR and 5 (3%) isolates found to be positive, of them two were SCCmec Type IV-ST80 and three were SCCmec Type III-ST239. This study is the largest epidemiological survey ever done in Turkey which showed presence of a hospital Turkish clone TR09 (ST239-SCCmecIII-t030) and a community clone TR10 (ST737-SCCmecIV-t005) largely disseminated in Turkey.
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    Antimicrobial susceptibility and resistance mechanisms of methicillin resistant Staphylococcus aureus isolated from 12 Hospitals in Turkey
    Yildiz, Ö; Çoban, AY; Sener, AG; Coskuner, SA; Bayramoglu, G; Güdücüoglu, H; Özyurt, M; Tatman-Otkun, M; Karabiber, N; Özkütük, N; Aktepe, O; Öncü, S; Arslan, U; Bozdogan, B
    Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important nosocomial pathogens and is also emerging in Turkish hospitals. The aim of this study was to determine the antimicrobial susceptibility profiles of MRSA isolated from Turkish hospitals. Materials and methods: A total of 397 MRSA strains isolated from 12 hospitals in Turkey were included to present study. Antimicrobial susceptibilities were tested using agar dilution method. Presence of ermA, ermB, ermC, msrA, tetM, tetK, linA and aac-aph genes were studied by PCR. Results: All strains were susceptible to vancomycin and linezolid. The susceptibility rates for fusidic acid, lincomycin, erythromycin, tetracyclin, gentamycin, kanamycin, and, ciprofloxacin were 91.9%, 41.1%, 27.2%, 11.8%, 8.5%, 8.3% and 6.8%, respectively. Lincomycin inactivation was positive for 3 isolates. Of 225 erythromycin resistant isolates 48 had ermA, 20 had ermC, and 128 had ermA-C. PCR was negative for 15 strains. Of 3 isolates with lincomycin inactivation one had linA and msrA. Of 358 gentamycin resistant isolates 334 had aac-aph and 24 were negatives. Among 350 tetracyclin resistant isolates 314 had tetM. Of 36 tetM negative isolates 10 had tetK. Conclusion: MRSA isolates from Turkish hospitals were multiresistant to antimicrobials. Quinolone and gentamycin resistance levels were high and macrolide and lincosamide resistance were relatively low. Susceptibility rates for fusidic asid were high. Linezolide and vancomycin resistance are not emerged. The most common resistance genes were ermA, tetM and aac-aph. Evolution of antimicrobial susceptibilities and resistance genes profiles of MRSA isolates should be surveyed at regional and national level for accurate treatment of patients and to control dissemination of resistance genes.