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    Assessment of methicillin and clindamycin resistance patterns in staphylococcus aureus isolated from a tertiary hospital in Turkey
    (2013) Tekin A.; Dal T.; Deveci O.; Tekin R.; Atmaca S.; Dayan S.
    In order to detect the methicillin susceptibility and determine the prevalence of constitutive and inducible clindamycin resistance in Staphylococcus aureus strains, a total of 254 S. aureus isolates, including 139 (54.7%) methicillin-sensitive and 115 (45.3%) methicillin-resistant, were tested for clindamycin and erythromycin by Kirby-Bauer's disk diffusion method. The disk diffusion induction test or D-test was performed on erythromycin-resistant and clindamycin-sensitive strains using the disk diffusion method. The erythromycin-resistant and clindamycin-sensitive strains with a D-shaped zone around the clindamycin disk were considered positive for inducible clindamycin resistance. If a strain was found to be both erythromycin-resistant and clindamycin-resistant, it was considered to have constitutive clindamycin resistance. Overall, ten (3.9%) strains, including two methicillin-resistant S. aureus and eight methicillin-sensitive S. aureus, were found to be erythromycin-resistant and clindamycin-sensitive according to the disk diffusion method and all of these strains showed inducible clindamycin resistance by the D-test method. Constitutive clindamycin resistance was detected in 100 of all MRSA strains. In conclusion, the presence of inducible clindamycin-resistant strains may lead to clindamycin treatment failure in patients with S. aureus infection. The D-test method should be used for antimicrobial susceptibility testing of clindamycin.
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    Brucellosis seroprevalence in southeast Turkey (Diyarbakir)
    (2004) Atmaca S.; Özekinci T.; Akpolat N.; Elçi S.; Suay A.; Arikan E.
    This study was conducted to determine brucellosis seropositivity in patients suspected of having brucellosis who sought treatment at the Central Laboratory of Dicle University Medical Faculty Hospital in southeast Turkey (Diyarbakir). 20,663 serum samples were collected during the study (1 August 2001-31 December 2002), and 14,480 sera were tested in a 12-month period on a seasonal basis by Rose-Bengal slide agglutination (RBSA), and positive sera were titrated by standard tube agglutination (STA). Titration values of 1/160 and above were considered positive. Of the 20663 sera, 463 (2.2%) tested positive on RBSA. Of these 463 sera, 267 (57.6%) tested positive on STA, with titers of 1/160 and higher. Seasonally, hospital attendance was highest in the summer and lowest in the winter. On STA tests done on RBSA-positive samples, the highest concentration of titers of 1/160+ was in the spring. In order to eliminate brucellosis in southeast Turkey, an endemic region for the disease, precautions must be increased, the unregulated slaughtering and consumption of animals must be prevented, and the consumption of raw, unpasteurized milk and of dairy products made from such milk must be halted.
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    Comparison of the susceptibility of Pseudomonas aeruginosa and Escherichia coli, isolated from clinical specimens to ticarcillin, ticarcillin/clavulanic acid and piperacillin/tazobactam
    (1997) Atmaca S.; Gul K.
    In this study, the susceptibilities of 50 Pseudomonas aeruginosa and 50 Escherichia coli strains isolated from clinical specimens, against ticarcillin, ticarcillin/clavulanic acid and piperacillin/tazobactam were investigated by disk diffusion method. Of pseudomonas aeruginosa isolates, 54% were found to be sensitive to ticarcillin, 74% to ticarcillin/clavulanic acid, whereas 24% of Escherichia coli isolates were sensitive to ticarcillin (susceptible + moderately susceptible), and 94% to ticarcillin/clavulanic acid. It was determined that 23% of P. aeruginosa and 4% of E. coli isolates brought about a zone diameter equal to or below 15 mm against piperacillin/tazobactam. As a result, P. aeruginosa and E. coli isolates were found to be susceptible to both of the beta-lactam/beta-lactamase inhibitor combinations.
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    Effect of iron limitation on the amount of slime produced by strains of Staphylococcus epidermidis.
    (1995) Elçi S.; Atmaca S.; Gül K.
    To investigate the effect of iron limitation on the amount of slime production by most strains of Staphylococcus epidermidis, ethylenediamine-di-o-hydroxyphenol acetic acid (EDDA), was added to the growth medium and twenty clinically relevant strains were assayed for slime production during growth in standard tryptic soy broth (TSB) and iron-limited TSB. Findings revealed that the density of the biofilm which formed on the base of microtitre plates was dependent on the degree of iron limitation, characteristics of the test strains and the stage of the growth cycle.
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    Effect of Mg+2 concentration in Mueller-Hinton agar on the susceptibility of pseudomonas aeruginosa to levofloxacin
    (2001) Akpolat N.; Özekinci T.; Atmaca S.
    [No abstract available]
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    Effect of microwaves on survival of some bacterial strains
    (Akademiai Kiado Rt., 1996) Atmaca S.; Akdag Z.; Dasdag S.; Celik S.
    While the inhibitory effect of microwave radiation on microorganisms is being researched intensively, how microwave radiation brings about this effect has been a matter of discussion. Some researchers support that this effect is of a thermal character, whereas some others maintain a non-thermal effect. In this work, 1 ml suspensions of Pseudomonas aeruginosa, Pseudomonas acidovorans, Staphylococcus aureus and Staphylococcus epidermidis bacteria were subjected to microwave radiation at 2450 MHz and 550 Watts for periods of 5, 6, 7, 8, 10, 12, 14, 16, 18, 20, 25 and 30 seconds. When each result was compared with the CFU/ml results obtained from unradiated control group bacterial suspensions derived from stock cultures, significant conclusions were attained (P<0.001). The same experiments were repeated with the application of conventional heating. The difference between the CFU/ml values of similar bacterial suspensions subjected to microwave radiation and conventional heating was significant (P<0.001). Concurrently, the fact that the effect was exacerbated upon increasing of liquid volume during the application of microwave radiation was established via the results obtained through the application of microwave radiation to 1 ml and 5 ml bacterial suspensions (P<0.001).
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    Evaluation of the Ehrlich-Ziehl-Neelsen (EZN) and amplified Mycobacterium tuberculosis direct test according to the BACTEC method in respiratory and nonrespiratory samples
    (2007) Özekinci T.; Meşe S.; Atmaca S.; Akpolat N.; Gül K.
    Aim: Tuberculosis remains a significant and threatening disease, particularly in developing countries. Mycobacterium tuberculosis should be detected and identified as soon as possible to ensure the prevention of the spread of the disease. For this purpose, use of fast and reliable laboratory diagnostic methods with high sensitivity and specificity was initiated in recent years. Materials and Methods: In this study, 107 respiratory and 198 nonrespiratory (305 in total) samples submitted to Dicle University Faculty of Medicine Clinical Microbiology Laboratory were examined using the Ehrlich-Ziehl-Neelsen (EZN), BACTEC 460 TB (Becton and Dickinson Diagnostic Instrument System, Towson, MD), and MTD (Amplified Mycobacterium tuberculosis Direct Test, Gen-Probe, USA) methods. Results: In respiratory samples, sensitivity of EZN was found as 83.33%, specificity as 95.04%, positive predictive value as 50%, and negative predictive value as 98.96%, whereas in nonrespiratory samples these values were 18.18%, 98.39%, 40%, and 95.37%, respectively. In respiratory samples, sensitivity of MTD was found as 83.33%, specificity as 94.05%, positive predictive value as 45.45%, and negative predictive value as 98.95%, whereas in nonrespiratory samples these values were 54.54%, 88.23%, 21.42%, and 97.05%, respectively. Conclusions: In view of the above, the pre-diagnostic EZN test and the MTD method based on nucleic acid amplification should be applied together with the BACTEC 460 system, which is considered as a gold standard, and the evaluation should be made accordingly. Furthermore, MTD should not be used as a screening test due to its high cost, and should rather be preferred in smear-positive samples. © TÜBİTAK.
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    Fusidic acid susceptibilities of methicillin-sensitive and methicillin-resistant staphylococcus aureus strains
    (2001) Atmaca S.; Özekinci T.; Özerdem N.
    In this study, the activity of fusidic acid to methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains was investigated by disk diffusion method. For methicillin susceptibility testing, 1 ?g oxacillin disks were used, and of 103 S.aureus strains isolated from clinical samples (pus, urine, blood, throat, ear, sputum), 53 (51.4%) were found to be methicillin resistant whereas 48 (46.6%) were methicillin sensitive. Resistance to fusidic acid was detected in 10 (18.9%) of methicillin-resistant and in 2 (4.2%) of methicillin-sensitive S.aureus isolates.
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    Influence of zinc on imipenem susceptibility of Pseudomonas aeruginosa
    (1996) Atmaca S.; Gul K.; Ulak G.; Cicek R.; Atmaca M.
    The influence of zinc on imipenem susceptibility of Pseudomonas aeruginosa was investigated. In this study, two different amounts of zinc containing media were used, the first of which was Oxoid MHA containing 0.45 ?g/ml zinc, and the second Oxoid MHA supplemented with zinc-acetate, 64 times as much zinc as the first media. The percentage of P. aeruginosa isolates resistant to imipenem significantly increased (P < 0.001) in zinc-supplemented media, whereas the activity of ceftazidime against P. aeruginosa isolates was similar in both media.
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    Investigation of autoantibody, anti-HCV and anti-HIV seropositivities in "anti-HBc alone" positive samples
    (2006) Meşe S.; Özekinci T.; Yilmaz Ş.; Atmaca S.; Arikan E.
    "Anti-HBc alone" which is an unusual serologic pattern of hepatitis B virus (HBV) infections, may be detected in the seropositive samples for hepatitis C virus (HCV), human immunodeficiency virus (HIV) infections and in the presence of autoantibodies due to cross reactions. In this study, 20 serum samples with isolated antibody to hepatitis B core antigen, which were detected in May 2005, have been investigated by means of the presence of some autoantibodies (anti-nuclear antibody; ANA and rheumatoid factor; RF), anti-HCV and anti-HIV, in the Central Laboratory of Dicle University Medical School. All of the "anti-HBc alone" samples were negative for HBV-DNA by real-time polymerase chain reaction (PCR), and liver enzyme (ALT and AST) levels were normal except for three patients. As a result, a total of six (30%) samples were found positive. Four of them were positive for ANA and two were positive for anti-HCV, while one serum yielded positivity for both ANA and anti-HCV. Anti-HCV positive samples were searched for the presence of HCV-RNA by real-time PCR, and none were found positive. Of three patients with increased AST and ALT levels, one was anti-HCV positive, one was ANA positive, while the other was negative for all parameters. In conclusion, possible presence of autoantibodies and anti-HCV should be taken into consideration during the evaluation of isolated anti-HBc IgG positive test results.
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    Lamivudine and Adefovir Motif Variants Detected in chronic Hepatitis B patients
    (2014) Özekinci T.; Mese S.; Ozbek E.; Atmaca S.
    Background and Aims: Chronic hepatitis B is an important health problem worldwide. Lamivudine, adefovir, entecavir and telbivudine are the oral drugs licensed for the treatment of patients with chronic hepatitis B. Implementation of antiviral therapy leads to the emergence of mutant strains during the treatment in chronic hepatitis B. Primary antiviral resistance may be rarely encountered. The aims of this study were to detect the resistance patterns of Hepatit B Virus strains in treatment-naive chronic hepatitis B patients Materials and Methods: A total of 147 CHB patients were included to this study which was carried on between January 2007-December 2010. HBV DNA levels were detected by using the Real time PCR (COBAS Ampli-Prep/COBAS TaqMan HBV Test). HBV-DNA was extracted from the sera of the patients by using extraction kit (Invisorb, Instant Spin DNA/RNA Virus Mini Kit, Germany). A line prob assay (Inno-Lipa HBV DR v2, Innogenetics N.V, Ghent, Belgium) was used to determine motif variants at viral polymerase gene fragment in HBVDNA samples of these patients and evaluated colorimetrically. Results. In 147 patients antiviral resistance rate was found 17% (25/147) for lamivudin, 5.44% (8/147) adefovir, 0.68%(1/147) lamivudin and adefovir. Various mutations were detected. This mutations; responsible for lamivudine resistance YMDD+YVDD (n=10), YMDD+YIDD (n=12), YIDD (n=2), YVDD (=1); responsible for adefovir resistance N236T (n=3), A181T (n=5); responsible for lamivudine and adefovir resistance YMDD+YIDD+N236T (n=1). Conclusions: As a conclusion, it is thought that drug resistance should be followed up regularly, the determination of HBV drug resistance as immediate as possible period may be instructive for the treatment and follow-up in CHB patients. Although determination of known mutations with Inno Lipa DR v2 method is disadvantage, because of ease of application and the determination of both lamivudinadefovir resistance in a short time, it can be used for the treatment and follow-up in CHB patients. © Societá Editrice Universo (SEU).
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    Short communication: Evaluation of the correlation between hepatitis D virus (HDV) RNA positivity and HDV antibodies
    (2005) Özekinci T.; Atmaca S.; Akpolat N.; Temiz H.; Arikan E.
    The objective of this study was to evaluate the correlation between serum hepatitis D -delta- virus (HDV) RNA detection and anti-HDV IgG and IgM antibodies, in the serodiagnosis of delta hepatitis. A total of 153 HBsAg positive sera were screened for the presence of anti-HBc IgM, anti-HDV IgG and anti-HDV IgM by commercial enzyme immunoassays and HDV-RNA by real time polymerase chain reaction (PCR). Of 153 sera, 86 (56.2%) were found positive for HDV antibodies. Although isolated anti-HDV IgG was present in 35 and isolated anti-HDV IgM was present in 11 patients, IgG and IgM were present concurrently in 40 additional patients. HDV-RNA was detected in 21.5% (33/153) of the patients. Four of the 33 HDV-RNA positive patients were positive only for anti-HDV IgG, 8 were positive only for anti-HDV IgM, and 19 were positive for both anti-HDV IgG and IgM antibodies. Twenty seven of 51 (53%) anti-HDV IgM positive patients were also found positive for HDV-RNA, while 27 of 33 (82%) HDV-RNA positive patients exhibited anti-HDV IgM positivity. Increased serum ALT levels were detected approximately in 85% (28/33) of viremic patients. As all of the HDV-RNA positive patients were found negative for anti-HBc IgM, superinfection with delta virus were considered. In conclusion, PCR is a sensitive and useful method for the detection of viremic patients as well as for the monitorization of antiviral therapy, anti-HDV IgM positivity together with increased ALT levels appear to be good markers for the prediction of hepatitis delta viremia, especially in the countries with limited economical sources as Turkey.
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    Three cases of chronic suppurative otitis media (CSOM) caused by kerstersia gyiorum and a review of the literature
    (EDIMES Edizioni Medico Scientifiche, 2018) Özcan N.; Saat N.; Baylan M.Y.; Akpolat N.; Atmaca S.; Gül K.
    New identification techniques such as gene sequencing and mass spectrometry have increased the incidence of novel agents such as Kerstersia gyiorum. As a new member of the Alcaligenaceae family, K. gyiorum was isolated from wounds, respiratory tract, urine specimens and most frequently from chronic suppurative otitis media (CSOM). We isolated three K. gyiorum strains from three CSOM cases over a one-year period. The strains were analyzed by mass spectrometry and identified by Bruker Biotyper 3.1 (Bruker Daltonics, USA). The cases were young patients without chronic diseases and immuno-deficiencies. Two strains were resistant to ciprofloxacin. © 2018, EDIMES Edizioni Medico Scientifiche. All rights reserved.