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In view of the significant negative impact of biofilm-mediated infection on patient health and the necessity of a reliable phenotypic method to detect biofilm producers, this study aimed to demonstrate phenotypic and molecular biofilm formation in coagulase-negative staphylococci (CoNS) isolated from catheter related infections and to compare the methods used with each other. The study was also aimed to determine the biofilm eradication effect of vancomycin in order to guide for the treatment. For the detection of biofilm formation, a total of 154 CoNS clinical isolates of which 30 being causative agents of catheter related bloodstream infection (CRBSI) (isolated from both the catheter tip and blood cultures of 15 patients), 89 being isolated from peripheral blood cultures of patients without a central venous catheter (CVC) (13 of them were bloodstream infection agents, 76 of them were contaminant), and 35 being isolated as catheter colonizer, were screened by tissue culture plate (TCP), Congo red agar (CRA) method and polymerase chain reaction (icaA, icaD and IS256). Vancomycin minimum inhibitory concentration (MIC) and minimum biofilm eradicating concentration (MBEC) values were determined. The pulsed field gel electrophoresis (PFGE) method was used to show the clonal relationship between CoNS isolated from the catheter tips and peripheral blood of patients with CRBSI. Of the 154 CoNS isolates included in the study, 38.9% were Staphylococcus epidermidis (n= 60), 34.4% were Staphylococcus haemolyticus (n= 53), 20.7% were Staphylococcus hominis (n= 32), and 3.8% were detected as Staphylococcus capitis (n= 6). In our study, biofilm formation was shown in 31.8% with the CRA method and in 68.1% with the TCP method. By TCP method, 22% (n= 34) were determined as weak, 31.2% (n= 48) medium and 14.9% (n= 23) strong biofilm producers. While the sensitivity of the CRA method was found to be low for isolates that were determined as weak positive in the microplate method, the high sensitivity of the CRA method for isolates with medium and strong positivity was found remarkable. The positivity rates of icaA, icaD and IS256 genes in a total of 154 CoNS isolates were found to be 40 (25.9%), 57 (37%) and 77 (50%), respectively. In total, at least one gene positivity was detected in 107 (69.5%) isolates. Single gene positivity was detected in 55 (35.7%), two gene positivity in 35 (22.7%) and three gene positivity was detected in 17 (11%) of the included CoNS. Biofilm formation (four weak, four medium, two strong) was detected by microplate method in 10 of 47 CoNS isolates (five S.epidermidis, three S.hominis, one S.haemolyticus and one S.capitis) in which no genes were detected. Vancomycin MBEC/ MIC values were found to be high and it was observed that as the biofilm forming power of the isolates increased, the MBEC/MIC ratio also increased. The CoNS isolated from the catheter samples and blood of patients diagnosed with CRBSI had a 100% similar profile with PFGE except for one unevaluable isolate. The tissue culture plate (TCP) method was found to be most sensitive, accurate and reproducible screening method for detection of biofilm formation by staphylococci and has the advantage of being a quantitative model to study the adherence of staphylococci. The presence of the icaAD and IS256 gene is not always associated with in vitro biofilm formation. For this reason, it is more appropriate to use more than one method together for the evaluation of biofilm formation. It was thought that the use of reliable methods to specifically detect biofilms could be helpful in diseases that are difficult to treat. Considering the high rates of biofilm and antimicrobial resistance of biofilm-forming isolates in biomedical device associated infections, it was determined that it would not be sufficient to evaluate only the MIC results for susceptibility results.

Candida infections are gaining more attention for the last few decades so diagnostic tools are very important for early diagnosis. Conventional identification of yeasts is time-consuming, molecular methods are more complicated and relatively expensive gold-standard methods. Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) was put into the market due to its speed and high accuracy. The aim of this study was to evaluate the performance of corn meal tween-80 agar (CMTA), CHROMagar Candida medium, and MALDI-TOF MS and to compare the obtained results with DNA sequencing.The CHROMagar Candida medium, CMTA, and MALDI-TOF MS Biotyper System were used to test 416 isolates. The isolates with discrepant results by at least one of the three methods were subjected to sequence analysis.The identification results of the 351 (%84.4) were compatible with all three methods. When compared to the sequencing results, the most accurate results were obtained by the MALDI-TOF MS, especially for rare Candida species.MALDI-TOF MS is found to be the most accurate identification tool for clinically important Candida strains. CMTA alone should not be used for the final identification of Candida species and the chromogenic medium should always be considered presumptive.

Background Coagulase-negative staphylococci, which belong to the normal microbiota of the skin and mucous membranes, are opportunistic pathogens. sasX, a newly described protein, is thought to play an important role in nasal colonization and methicillin-resistant Staphylococcus aureus virulence, and it may be acquired from coagulase-negative staphylococci by horizontal gene transfer. It has been considered that understanding the function of sasX gene may help clarify the relevance of the different adhesion mechanisms in the pathogenesis of infections associated with biofilm. Aims To investigate the sasX gene presence, staphylococcal cassette chromosome mec types, and antimicrobial resistance patterns of invasive and noninvasive coagulase-negative staphylococci isolates. Study design Cross-sectional study. Methods The study included a total of 180 coagulase-negative staphylococci strains. Non-invasive isolates (n=91) were obtained from the hands of healthy volunteers who do not work at the hospital (n=30), the nasal vestibule of healthy volunteer hospital workers (n=26), and central venous catheter (n=35). Invasive isolates (n=89) were isolated from peripheral blood cultures of inpatients who do not have catheters. All isolates were identified by conventional microbiological methods, automated systems, and, if needed, with matrix-assisted laser desorption/ionization-time of flight. Staphylococcal cassette chromosome mec typing, sasX and mec gene detection, antibiotic susceptibility, and sasX gene sequence analysis were performed. Results Peripheral blood, central venous catheter colonization, and nasal vestibule isolates were positive for the sasX gene, whereas hand isolates were negative. sasX gene was present in 17 isolates, and no statistical significance was found between invasive and noninvasive isolates (p=0.173). Sequence analysis of the sasX genes showed high homology to related proteins of Staphylococcus phage SPbeta-like and Staphylococcus epidermidis RP62A. staphylococcal cassette chromosome mec type V was the most prevalent regardless of species. staphylococcal cassette chromosome mec type II was more frequent in invasive isolates and found to be statistically important for invasive and noninvasive S. epidermidis isolates (p=0.029). Staphylococcus haemolyticus isolates had the overall highest resistance rates. Resistance to ciprofloxacin, trimethoprim-sulfamethoxazole, and erythromycin was found to be higher in isolates from catheter and blood culture. Staphylococcus hominis isolates had the highest rate for inducible clindamycin resistance. None of the isolates were resistant to vancomycin, teicoplanin, and linezolid. Conclusion The sasX gene is detected in 9.44% of the isolates. There is no statistical difference between the sasX-positive and -negative isolates in terms of antibacterial resistance and the presence of sasX and SCCmec types. Further studies about the role of sasX at virulence in coagulase-negative staphylococci, especially from clinical samples such as tracheal aspirate and abscess isolates, and distribution of staphylococcal cassette chromosome mec types are needed.

Aims: Heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) could be misinterpreted as “susceptible” with routine susceptibility testing procedures, and the subpopulations with reduce...

Aims: The emergence of multidrug-resistant and carbapenem-resistant Klebsiella pneumoniae has became a major public health threat. In this study, we describe the characteristics of isolates coprodu...

Purpose: To evaluate the role of viral infections in the pathogenesis of primary acquired nasolacrimal duct obstruction. Methods: The study included 48 patients diagnosed with primary acquired nasolacrimal duct obstruction undergoing dacryocystorhinostomy surgery. Prior to dacryocystorhinostomy surgery, nasal swab sample was taken from the inferior meatus at the same side. During dacryocystorhinostomy, tissue biopsy sample (2 × 2 mm) was taken from the junction area of the lacrimal sac and nasolacrimal duct. Following nucleic acid extraction, polymerase chain reaction was performed. Results: The patients consisted of 9 (18.8%) men and 39 (81.2%) women with a mean age of 51.0 ± 14.3 years. Qualitative polymerase chain reaction showed viral genome in the nasal swabs of 10 (20.8%) patients, including coronavirus 229E (three cases), coronavirus HKU1 (two cases), respiratory syncytial virus (two cases), coronavirus OC43 (one case), coronavirus NL63 (one case), and adenovirus (one case). In the dacryocystorhinostomy samples, viral genomes were detected in four (8.3%) cases, including respiratory syncytial virus (two cases), coronavirus HKU1 (one case), and adenovirus (one case). There was a statistically significant agreement between nasal mucosal swab and dacryocystorhinostomy biopsy samples in terms of respiratory syncytial virus positivity (kappa = 1.000, p = 0.001). Conclusion: Although the viral genome was detected in the samples, a direct relationship between viruses and pathogenesis of primary acquired nasolacrimal duct obstruction could not be revealed because of the low number of positive results. However, considering the profibrotic characteristics of specific viruses such as respiratory syncytial virus and adenovirus, viral infections may be one of the many predisposing factors of primary acquired nasolacrimal duct obstruction.

BK virus (BKV) infection has been shown to be related to hemorrhagic cystitis (HC) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). There are conflicting data regarding the association between BKV titers in plasma and clinical disease as well as the risk factors for BKV-related HC. Our aim is to study the risk factors and relationship with plasma BK viral load for development of HC in a prospective analysis.We prospectively evaluated 59 patients who received allo-HSCT between 2014 and 2016 by quantitative BK virus polymerase chain reaction (PCR) (Altona Diagnostics, Germany) from blood samples at days 0, 30, 60, and 90 after allo-HSCT. The patients were monitored for signs and symptoms of HC.HC was diagnosed in 22 patients (37%) at a mean of 100 days (range: 0-367 days). In multivariate analysis, the usage of cyclophosphamide (sub-distribution hazard ratio [sdHR]: 7.82, confidence interval [CI]: 1.375-39.645, p=0.02), reactivated CMV (sdHR: 6.105, CI: 1.614-23.094, p=0.008), and positive BKV viremia (sdHR: 2.15, CI: 1.456-22.065, p=0.01) significantly increased the risk of developing HC. Patients with higher viral loads at day 30 and day 60 were diagnosed with more severe HC (p0.001). Median BK viral loads of101.5 copies/mL at day 0 (sensitivity 0.727, specificity 0.875),98.5 copies/mL at day 30 (sensitivity 0.909, specificity 0.875), and90.0 copies/mL at day 60 (sensitivity 0.909, specificity 0.875) were indicative of HC.Our study showed that administration of cyclophosphamide, CMV reactivation, and BK virus positivity were associated with HC. Plasma BK virus PCR titers at days 0, 30, and 60 after transplant were sensitive tools for predicting clinically proven HC.BK virüs (BKV) enfeksiyonun allojeneik hematopoietik kök hücre naklinde (allo-HKHN) hemorajik sistit (HC) ile ilişkili olduğu gösterilmiştir. Literatürdeki çalışmalarda plazmadaki BKV titresi ile klinik hastalık arasında ve BKV ilişkili HC risk faktörleri açısından çelişkili veriler mevcuttur. Amacımız, prospektif olarak HC gelişimi risk faktörleri ile plazma BK viral yükü arasındaki ilişkinin gösterilmesidir.2014-2016 yılları arasında 59 allo-HKHN alıcısının 0, 30, 60 ve 90. günlerdeki kan örneklerinden kantitatif olarak BK virüs polimeraz zincir reaksiyonu (PCR) (Altona Diagnostics, Almanya) değerlendirilmiştir. Hastalar HC belirtileri ve semptomaları açısından izlenmiştir.Yirmi iki hastada (%37) nakil sonrası ortalama 100. günde (0-367 gün) HC tanısı konmuştur. Çok değişkenli analizde (siklosfosfamid alan [SdHR]: 7,82, güven aralığı [GA]: 1,375-39,645, p=0,02), CMV reaktivasyonu geçiren (SdHR: 6,105, GA: 1,614-23,094, p=0,008) ve BK virüs pozitifliği (SdHR: 2,15, GA: 1,456-22,065, p=0,01) olan hastalarda artmış HC riski saptanmıştır. Viral yükleri 30. ve 60. günlerde yüksek tespit edilen hastalarda daha ciddi HC görülmüştür (p0,001). Ortanca BK virüs yükü 0. günde101,5 kopya/mL (sensitivite 0,727, spesifite 0,875), 30. günde98,5 kopya/mL (sensitivite 0,909, spesifite 0,875), 90. günde90,0 kopya/mL (sensitivite 0,909, spesifite 0,875) ise bu durumlar HC göstergesi olabilir.Çalışmamızda siklofosfamid, CMV reaktivasyonu ve BK virüs pozitifliği HC ile ilişkili olduğu gösterilmiştir. Plazma BK virüs PCR titleri transplant sonrası 0, 30, 60. günlerde klinik olarak kanıtlanmış HC için hassas araçlardır.

The worldwide spread of carbapenemase producing Enterobacteriaceae isolates has become a major threat of public health. This worrisome situation leads the development of new methods for carbapenemase screening, detection, prevention of spread and epidemiological data collection as mandatory. In this study, it was aimed to investigate existence and distribution of carbapenemase-encoding genes (CEGs) among carbapenem-resistant Enterobacteriaceae isolated from various clinical samples in Ankara University Faculty of Medicine, Ibni Sina Hospital, Central Microbiology Laboratory between June 2010-May 2014 and detect their clonal relationship. A total of 112 non-repetitive Enterobacteriaceae isolates which were intermediate or resistant to ertapenem were identified by using Phoenix (BD Diagnostic Systems, Sparks, USA) automated microbiology system. After DNA extraction from the isolates, 11 carbapenemase-encoding genes (CEGs) (blaIMP, blaVIM, blaSPM, blaKPC, blaNDM, blaOXA-48, blaGIM, blaSIM, blaAIM, blaDIM ve blaBIC) were detected with PCR. The clonal relationship among the isolates was determined by PFGE method following digestion with Xbal DNA macrorestriction endonuclease. Among 112 isolates Klebsiella pneumoniae was the most frequent (n= 79, 70.5%) bacteria followed by Escherichia coli (n= 15, 13.4%), Enterobacter cloacae (n= 10, 8.9%), Enterobacter aerogenes (n= 4, 3.6%) and Klebsiella oxytoca (n= 4, 3.6%) respectively. blaOXA-48 was the most frequent gene detected. Among 83 (74.1%) isolates blaOXA-48 was detected alone and in 7 (6.3%) of the isolates it was identified with blaVIM gene coexistence. blaVIM gene was identified as the second most frequent CEG among the isolates. blaVIM gene was detected positive in 9 (8%) isolates. blaNDM gene was identified in 2 (1.8%) isolates. Ten of the K.pneumoniae isolates with identical PFGE pattern were named as pulsotype B. These isolates were found to be similar in terms of isolate location, isolation dates, antibiotic resistance patterns and the carbapenemase genes they carry, and are considered to be potential outbreak isolates originated from intensive care units. On the other hand CEGs were found in the clinical samples obtained from five out-patients suggesting that community-acquired infections may also arise due to carbapenemase producing Enterobacteriaceae in our country where blaOXA-48 producers are endemic. According to this study, blaOXA-48 producing gram negative bacteria were frequent in our hospital. The prevalance of blaVIM gene among metallo-beta-lactamases and coexistence with blaOXA-48 gene was remarkable. The frequency of blaNDM producing isolates in our hospital was not detected as high yet. In this study, the identification of carbapenemase producing bacteria as outbreak strains in our hospital indicated that cross-sectional surveillance for carbapenemase-producing bacteria from each patient was valuable in terms of early diagnosis of outbreaks.

Background Community respiratory viruses (CRVs) are associated with upper respiratory viral infections (URI), pneumonia or life-threatening respiratory disease in patients with allogeneic haematopoietic stem cell transplantation (allo-HSCT). Our aim is to demonstrate our URI experience related to CRVs after allo-HSCT. Methods From January 2013 to November 2015, 39 post allo-HSCT patients with acute URI symptoms were included in the study. We evaluated CRVs by multiplex PCR from nasopharyngeal wash and throat swabs. Results The median age of the patients was 39 (range 20–67 years). A total of 25 patients (64%) had viral panel positivity at a median 140 days post-transplant (range 3–617 days). The most common agents detected were respiratory syncytial virus (32%) and parainfluenza (32%). The patients with viral panel positivity had significantly lower lymphocyte count (1.05x109/l versus 3.09x109/l; P=0.013). During follow-up, 20 patients (80%) were diagnosed with pneumonia. Patients with concurrent bacterial or fungal infections were more likely to have pneumonia (100% versus 68%; P=0.023). 10 patients (40%) died due to pneumonia and related complications. Lower lymphocyte counts and higher C-reactive protein levels at the time of viral panel positivity were risk factors for mortality (1.5x109/l versus 0.39x109/l, P=0.007; 74.2 versus 199.7, P=0.006). Conclusions The viral panel was positive in 64% of patients with acute URI symptoms. Lower lymphocyte count was detected in CRV-positive patients. The onset of concomitant bacterial or fungal infections increased the risk of lower respiratory infection disease. Indeed, prospective studies should be designed for risks and outcomes of CRVs in allo-HSCT recipients.

Coagulase-negative staphylococci (CNS) are one of the primer agents of blood stream infections (BSI) and catheter-related bloodstream infections (CR-BSI) which are associated mostly with the usage of central venous catheters and, important causes of morbidity and mortality despite the usage of antibacterial and supportive treatment. It is important to determine the properties of these causative microorganisms in order to make appropriate treatment of such infections. The aims of our study were to evaluate the biofilm formation of coagulase negative staphylococci (CNS) which were causative agents of bloodstream (BSI) and catheter related bloodstream infections (CR-BSI), to determine the minimum inhibitory concentration (MIC) of planktonic forms and minimal biofilm eradication concentration (MBEC) of sessile forms for vancomycin and daptomycin and to evaluate the efficacy of these antibiotics in infections with biofilm-forming isolates in vitro. A total of 65 CoNS (n= 26 catheter colonizers, n= 28 CR-BSI, n= 11 BSI agents) were identified by conventional methods and also with BD Phoenix (Becton Dickinson, USA) and Bruker Microflex MS (Bruker Daltonics, Germany) systems. Methicillin resistance was determined by the presence of mecA gene with PCR. MIC values of vancomycin and daptomycin were investigated by broth microdilution, for daptomycin medium containing 25 and 50 μg/ml Ca++ were used. Assessment of biofilm formation and detection of MBEC were determined by microplate method. The clonal relationship was investigated by the PFGE method. A total of 65 isolates; 26 catheter colonizers, 28 CR-BSI agents and 11 BSI agents were evaluated and identified as Staphylococcus epidermidis (n= 33), Staphylococcus haemolyticus (n= 16), Staphylococcus hominis (n= 15), and Staphylococcus capitis (n= 1). 81.5% of the isolates were found to be methicillin resistant and all of them were found to be sensitive to vancomycin (MIC= 0.125-4 μg/ml) and daptomycin (MIC= 0.062-0.25 μg/ml in 25 μg/ml Ca++ and MIC= 0.031-0.50 μg/ml in 50 μg/ml Ca++ containing medium). MIC values were lower in medium containing 50 μg/ml Ca++ for daptomycin. As it is known that the efficacy of daptomycin depends on the physiological levels of Ca++, which causes conformational changes in the structure of these antibacterials. Our findings also suggested that high levels of Ca++ are needed to ensure the efficacy of daptomycin. All of the isolates produced biofilm at different strengths of positivity (n= 12/18.5% weak, n= 35/%53.8 moderate, n= 18/%27.7 strong). MBEC and MBEC/MIC values for vancomycin were found to be higher than daptomycin (p< 0.001). Strong biofilm producers had higher MBEC and MBEC/MIC, MBEC50/MIC50 ve MBEC90/MIC90 values (p< 0.05). Especially in infections with biofilm forming isolates, the detection of only MIC values are not always sufficient in the treatment of biofilm-related infections as they reflect the sensitivity of planktonic bacteria. The inconsistency between the MIC and MBEC values and the high rates of MBEC/MIC found in our study supported this prediction.The lower detection of MBEC and MBEC/MIC values of daptomycin compared to the same values of vancomycin suggested that daptomycin might be effective at lower doses than vancomycin in the treatment of biofilm infections.

We described a health care–associated Serratia marcescens outbreak of wound and soft tissue infection lasting approximately 11 months at Ankara University Ibni Sina Hospital. After identification of S marcescens strains from the clinical and environmental samples, and their susceptibility testing to antimicrobial agents, pulsed-field gel electrophoresis (PFGE) was performed to detect molecular epidemiologic relationships among these isolates. The strains which were isolated from the saline bottles used for wound cleansing in the wound care unit were found to be 100% interrelated by PFGE to the strains from the samples of the outbreak patients. Reuse of the emptied bottles has no longer been allowed since the outbreak occurred. Besides, more efficient and frequent infection control training for hospital staff has been conducted.

Biofilm production is an important virulence factor which allows staphylococci to adhere to medical devices. The principal component of biofilm is a "polysaccharide intercellular adhesin (PIA)" which is composed of a beta-1,6-N-acetylglucosamine polymer synthesized by an enzyme (N-acetylglucosamine transferase) encoded by the ica operon found on the bacterial chromosome. This operon is composed of four genes (A, B, C, and D), and a transposable element IS256. In this study, we aimed to determine the biofilm production characteristics of invasive/non-invasive staphylococcus isolates and different staphylococcus species. Biofilm production of 166 staphylococci was phenotypically investigated on Congo Red Agar (CRA); the presence of icaA, icaD and IS256 genes were investigated by polymerase chain reaction (PCR). 74 of the isolates (44.6%) were identified as methicillin resistant Staphylococcus aureus (MRSA), 25 (15.1%) as methicillin sensitive S.aureus (MSSA), 25 (37.3%) as Staphylococcus hominis, 20 (12%) as S.epidermidis, ten (15%) as Staphylococcus haemolyticus, nine (13.4%) as Staphylococcus capitis, two (3%) Staphylococcus saprophyticus and one (1.5%) as Staphylococcus warnerii. Of the MRSA strains, 52 were isolated from blood and 22 from nose; all MSSA strains were isolated from nose cultures. Coagulase-negative staphylococci (CoNS) strains were composed of invasive and non-invasive strains isolated from nose, catheter tip and blood cultures from patients with catheter. Production with CRA method was found to be statistically significant in invasive isolates (p< 0.001). It is concluded that; as the biofilm formation capacity of invasive isolates can cause refractory infections and the importance of carriage and hospital infections of these bacteria, it is important to prevent the spread of these isolates. A combination of phenotypic and genotypic tests is recommended for the investigation of biofilm formation in staphylococci. 40.3% of the CoNS isolates, and 85.8% of S.aureus isolates produced biofilm on CRA (p< 0.001) and with PCR method the ratio of carrying three genes was found to be statistically important in S.aureus when compared with CoNS. Carriage of three genes and biofilm formation capacity of invasive isolates can cause refractory infections and the importance of carriage and hospital infections of these bacteria, it is important to prevent the spread of these isolates. A combination of phenotypic and genotypic tests is recommended for the investigation of biofilm formation in staphylococci.

Aim:Rapid and accurate detection of carbapenemase producing Enterobacteriaceae isolates plays an important role in preven-ting the spread and defining treatment strategies.The modified Hodge test (MHT) is an easy and inexpensive tool that can be used to detect carbapenemase activity. Another method used for the same purpose are inhibitor-based tests (IBTs). The aim of this study is to compare the performances of these two phenotypic methods in the detection of carbapenemases in Enterobac-teriaceae isolates.Materials and Methods:A total of 112 non-repeat Enterobacteriaceae strains isolated from various clinical samples at Ibni Sina Hospital Central Microbiology Laboratory between 2010-2014 that showed decreased sensitivity and resistance to ertapenem by Kirby-Bauer disk diffusion method were included in the study.Results:When 1:10 dilution [0,05 McFarland (McF)] was performed, out of 94 isolates positive for carbapenemase-encoding genes (CEGs), false negativity was detected in seven isolates, whereas out of 18 isolates negative for CEGs, false positivity was detected in 16 isolates; so the sensitivity of MHT for carbapenemase detection was found to be 92,6%. Without dilution (0.5 McF) the number of false negative isolates decreased to three and the sensitivity of MHT increased to 96,8%, (p

The worldwide spread of carbapenemase producing Enterobacteriaceae isolates has become a major threat of public health. This worrisome situation leads the development of new methods for carbapenemase screening, detection, prevention of spread and epidemiological data collection as mandatory. In this study, it was aimed to investigate existence and distribution of carbapenemase-encoding genes (CEGs) among carbapenem-resistant Enterobacteriaceae isolated from various clinical samples in Ankara University Faculty of Medicine, Ibni Sina Hospital, Central Microbiology Laboratory between June 2010-May 2014 and detect their clonal relationship. A total of 112 non-repetitive Enterobacteriaceae isolates which were intermediate or resistant to ertapenem were identified by using Phoenix (BD Diagnostic Systems, Sparks, USA) automated microbiology system. After DNA extraction from the isolates, 11 carbapenemase-encoding genes (CEGs) (bla

Karbuz A, Karahan ZC, Aldemir-Kocabas B, Tekeli A, Ozdemir H, Guriz H, Gokdemir R, Ince E, Ciftci E. Evaluation of antimicrobial susceptibilities and virulence factors of Staphylococcus aureus strains isolated from community-acquired and health-care associated pediatric infections. Turk J Pediatr 2017; 59: 395-403. The aim of this study was to investigate the enterotoxins and Panton-Valentine leukocidin (PVL) gene as virulence factor, identification if antimicrobial sensitivity patterns, agr (accessory gene regulator) types and sequence types and in resistant cases to obtain SCCmec (staphylococcal cassette chromosome mec) gene types which will be helpful to decide empirical therapy and future health politics for S. aureus species. Total of 150 isolates of S. aureus were isolated from the cultures of the child patients in January 2011 and December 2012. In this study, the penicillin resistance was observed as 93.8%. PVL and mecA was detected positive in 8.7% and in 6% of all S. aureus strains, respectively. Two MRSA (methicillin resistant S.aureus) strains were detected as SCCmec type III and SCCmec type V and five MRSA strains were detected as SCCmec type IV. SET-I and SET-G were the most common detected enterotoxins. In both community-associated and healthcare-associated MRSA strains, agr type 1 was detected most commonly. The most common sequence types were ST737 in 13 patients than ST22 in eight patients and ST121 in six patients. This study highlights a necessity to review the cause of small changes in the structural genes in order to determine whether it is a cause or outcome; community-acquired and healthcare associated strains overlap.

From the four known isoforms of the staphylococcal exfoliative toxins (ETs), only ETA and ETB are the major causative agents. General knowledge is that the gene for ETA is located on the chromosome, whereas that for ETB is located on a large plasmid. Yoshizawa and co-workers (2000, Microbiol. Immunol. 44(3): 189–191) isolated, for the first time, a temperate phage (φETA) that carried the structural gene for ETA from an ETA-producing strain of Staphylococcus aureus. In this study, we presented eta gene encoding temperate phages isolated from methicillin-resistant S.aureus (MRSA) isolates obtained from patients in a Turkish hospital. Molecular analysis of the phage genome revealed that the eta gene is located upstream to amidase and holin genes, the same as in the φETA genome. However, partial sequence analysis of amidase and holin genes revealed polymorphic variation. In addition to polymorphic variation, restriction fragment length polymorphism (RFLP) analysis of all of the phage genomes showed that the ETA-containing phage is different from the rest of the phage genomes. The phylogenetic dendrogram of pulsed field gel electrophoresis (PFGE) analysis showed that the ETA-carrying MRSA is quite different from the rest of the MRSA strains. This is the first report showing that a MRSA strain carries an ETA-encoding phage.

The aim of this study was to investigate the in vitro activities of polymyxin B (PB) and rifampin (RIF) in combination with ampicillin/sulbactam (AS) or cefoperazone/sulbactam (CS) against 20 multidrug-resistant Acinetobacter baumannii (MDR-AB) isolates by the checkerboard and E-test methods. Fractional inhibitory concentration index (FICI) values were defined as synergy, FICI ≤ 0.5; additivity, 0.5FICI ≤ 1.0, indifference, 1.0FICI4.0; and antagonism, FICI ≥ 4. Synergistic interaction was detected only for the RIF + AS and RIF + CS combinations. While the most frequently detected interaction type for PB + AS or PB + CS combinations was indifference, some showed antagonistic interactions. The detection rate of synergy was significantly higher by the checkerboard than by the E-test method, and the detection rate of indifference was significantly higher by the E-test than by the checkerboard method for RIF + AS combination (P ≤ 0.0001). In addition, no statistically significant difference was detected between the checkerboard and E-test methods for the detection rates of interaction types for any of the other combinations (P0.05), except for PB + CS combination for the detection of additivity (P = 0.018). Owing to the high percentage of synergistic interactions between RIF and AS, we considered this combination as an effective therapeutic option for MDR-AB infections.

Sir,In the present journal, an association of high vancomycin minimal inhibitory concentration (MIC) with mortality in patients with methicillin-susceptible Staphylococcus aureus bacteremia was rec...

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens in the hospital environment. Monitoring of this pathogen by molecular characterization and phenotypic methods is important for the development of suitable infection control measures and proper therapy design. In this study, our aim was to investigate the molecular epidemiological characteristics of MRSA bloodstream isolates obtained from patients hospitalized at Ankara University Ibn-i Sina Hospital in a 10-year period (2002-2012) and monitor the possible changes. A total of 134 isolates were characterized according to their antimicrobial susceptibility profiles, biofilm formation capabilities, accessory gene regulator (agr) locus types, presence of genes encoding Panton-Valentine leukocidin (PVL), staphylococcal enterotoxins A-J (SEs A-J), toxic shock syndrome toxin, sasX, and genes associated with biofilm formation (icaD, icaA, IS256) by polymerase chain reaction. The staphylococcal cassette chromosome mec (SCCmec) types of isolates were also defined and their clonal relationships were investigated by pulsed-field gel electrophoresis (PFGE) analysis and multilocus sequence typing was performed for representative isolates obtained by PFGE.The majority of the isolates were resistant to rifampin (100%), ciprofloxacin (97%), tetracycline (97.7%), and gentamicin (94.7%); 100% carried type-III SCCmec and 89.5% were agr type-1. All the isolates were negative for PVL, and sasX genes while all of them carried the icaD, icaA, and IS256 genes. The most common SE was enterotoxin A (97%). Four major PFGE patterns with the dominance of one pattern and seven unique patterns were obtained. All the representative PFGE isolates (n = 11) belonged to sequence type 239.We have documented the characteristics of the dominant MRSA clone in our hospital, which was a PVL (-), sasX (-) ST239 clone carrying sea (+) with type-III SCCmec, and type-1 agr locus.

In January,2004 an explosive epidemic of pharyngitis occured among the staff working atIntensive Care Units and Operation Rooms of Türkiye Yüksek İhtisas Teaching Hospital, The symptoms were indistinguishable from those of group A streptococcal pharyngitis. Sore throat and weakness were the prominent symptoms in (91% and 87%, of patients respectively). In a two-day period, throat cultures were taken from 377 personnel and 121 (32%) of them were found to be positive for group-G beta-hemolytic streptococci. The configuration of the epidemic curve suggested a common source of exposure. Respiratory spread of streptococci in such a rapid fashion would be unlikely. Sixteen of the 121 positive throat cultures were obtained from the staff of the catering firm which provided the food services for the hospital staff. Most of these catering firm personnel were serving the departments where the epidemic occured. With these data, the outbreak was considered to be foodborne. PFGE analysis of randomly selected 40 (including the 16 strains isolated from the catering firm personnel) strains showed only one digestion pattern. Prompt treatment with penicillin was given to all the sick personnel and a 9-day religious holiday approaching consequently terminated the outbreak. Control cultures were negative for all the subjects.

Objective: Cross-resistance is an important issue for macrolide, lincosamide and streptogramin B (MLSB) antibiotics. The erm genes alter their ribosomal binding site by encoding ribosomal methylases. Phenotypic presentation of erm-mediated resistance can be inducible (iMLS(B)) or constitutive (cMLS(B)). Expression of msr genes which encode active efflux pumps confers the MSB phenotype. In this study, we investigated the frequency of MLSB resistance phenotypes and the presence of erm and msr genes in clinical Staphylococcus isolates. Material and Methods: The frequency of MLSB resistance phenotypes were investigated using D-zone test in 731 clinical Staphylococcus strains. The presence of erm and msr genes was investigated by polymerase chain reaction in macrolide-resistant strains. Results: Of the investigated isolates, 37.3% had iMLS(B), 35.8% had cMLSB, and 26.9% had MSB phenotypes. Among studied, 45.9% of the strains carried ermC, 15.5% carried ermA, and 4.2% carried ermA and ermC genes. Phenotypic presentation of 51.4% of the erm gene carriers were iMLS(B) and 48.6% were cMLS(B). Of the MSB phenotype strains, 73.3% carried the msrA+msrB gene combination and 3.3% carried msrB alone. Various erm and msr gene combinations were determined in 13.7% of the isolates of which 54.3% expressed iMLS(B) or cMLS(B) phenotypes and 45.7% expressed the MSB phenotype. MSB phenotype and gene combination frequencies were more in coagulase-negative staphylococci (CoNS). Conclusion: Investigating genes conferring resistance to lincosamides is important for reducing the risk of treatment failure especially for erythromycin resistant, clindamycin susceptible strains. Due to the increasing resistance problem in staphylococcal infections, clinicians must be aware of resistance development while prescribing MLSB antibiotics.

Biofilms consist of a cell-multilayer embedded in a slime matrix and they are the basis for produc-tion of polysaccharide adhesion by ica- operon-encoded enzymes is currently the best understood mechanism of biofilm development in staphylococci. The insertion sequence IS256, a mobile ele-ment frequently associated to transposons has the capacity to influence expression of the ica operon and subsequent biofilm formation by reversible insertion into the ica operon. We aimed to elucidate the role of insertion sequence IS256 in biofilm formation among various Staphylococcus aureus isolates from clinical specimens of hospitalized patients at Ankara and Hacettepe Universi-ties. A total of 207 S. aureus strains isolated between 1998 and 2004 from clinical specimens were included in the study. A total of 28 of the S. aureus isolates studied were methicillin-susceptible S. aureus (MSSA), 133 were methicillin-resistant S. aureus (MRSA), and 46 were vancomycin-interme-diate S. aureus (hetero-VISA) isolates. Genomic DNA was extracted from staphylococcal cultures and used as an amplification template with the primers in simplex PCRs for detection of biofilm genes (icaA, icaD), IS256. Of all S. aureus isolates studied 185 (89.4%) were positive for icaA, 201 (97.1%) were positive for icaD, 184 (88.9%) were positive for both whereas 18 (8.7%) strains were positive for only one of them. We found the positivity rates of biofilm genes (ica genes) among MRSA and hetero-VISA isolates were significantly higher than those among MSSA isolates (p< 0.001). IS256 positivity among MRSA and hetero-VISA isolates were also significantly higher than those among MSSA isolates (p

Ica (intersellüler adezyon) operonunu kodlayan enzimler tarafından polisakkarit intersellüler adezin (PIA) üretimi, stafilokoklardaki biofilm gelişiminin şu ana kadar en iyi anlaşılmış mekanizmasıdır. IS256, ica operonuna geri dönüşümlü olarak eklenmek suretiyle ica operonu ekspresyonunu ve sonrasında da biyofilm oluşumunu etkileme kapasitesine sahip mobil bir elemandır. Bu çalışmanın amacı 1998-2004 yılları arasında çeşitli klinik örneklerden elde edilen 207 Staphylococcus aureus izolatında insersiyon sekansı IS256’nın biofilm oluşumu üzerine etkisini araştırmaktır. 1998-2004 yılları arasında Ankara ve Hacettepe Üniversitelerinde yatan hastalara ait çeşitli klinik örneklerden elde edilen 207 S. aureus izolatı (kan, kateter, solunum yolu örnekleri, steril vucut sıvıları, yara, balgam, idrar, püy) çalışmaya dahil edildi. Çalışılan suşların 28’i (%13.5) metisilin duyarlı (MSSA),133’ü (%64.2) metisilin dirençli (MRSA), 46’sı (%22.2) ise hetero-VISA (vankomisine heterojen olarak orta duyarlı S. aureus) suşlarını içeren izolatlar idi. Stafilokok kültürlerinden genomik DNA ekstrakte edildikten sonra amplifikasyon kalıbı olarak kullanıldı. Biyofilm genleri (icaA, icaD) ve IS256 yı saptamak amacıyla simpleks PCR lar yapıldı. 207 suş içinde icaA pozitifliği %89.4 (185 izolat), icaD pozitifliği %97.1 (201 izolat), biofilm genlerinin her ikisinin de pozitifliği: %88.9 (184 izolat), sadece birinin pozitifliği %8.7 (18 izolat) oranında bulundu.Biyofilm genleri (ica) MRSA ve hVISA izolatlarında, MSSA izolatlarına göre daha yüksek oranda saptandı(p< 0.001). IS256 pozitifliği hVISA suşlarında MRSA’dan, MRSA suşlarında ise MSSA’dan daha yüksek oranda tesbit edildi (p < 0.001) Biyofilm pozitiflik prevalansı IS256 içeren suşlarda anlamlı derecede yüksek bulundu (p < 0.001), bu da S. aureus’un klinik izolatlarında IS256’nın ica operonu ekspresyonunu etkileyerek biyofilm oluşumuna yol açtığını düşündürdü.

Panton-Valentine leukocidin (PVL) is an important virulence determinant of Staphylococcus aureus. The aim of this study was to investigate the prevalence of PVL genes in clinical S. aureus isolates and to determine the staphylococcal chromosomal cassette mec (SCCmec) types of methicillin-resistant S. aureus (MRSA) strains obtained from inpatients and outpatients of two hospitals in Turkey. Of the 304 S. aureus strains (230 hospital acquired [HA] and 74 community-onset [CO]), 261 were MRSA and 43 were methicillin-sensitive S. aureus (MSSA). PVL positivity was determined in 12 (1 HA and 11 community acquired) strains. Eight were MRSA, and four were MSSA. Seven of the PVL-positive strains were isolated from wound specimens, four from urine, and one from synovial fluid. SCCmec type III (93.78%) was more prevalent among HA-MRSA strains, and SCCmec type IIIB (41.18%) was more prevalent among CO-MRSA strains. Pulsed-field gel electrophoresis patterns of the PVL-positive isolates were different. Our results indicate that PVL-positive strains are able to cause infection in nearly every system without the need for additional risk factors. Our PVL-positive CO-MRSA strains carry SCCmec types other than types IV and V. Due to the presence of PVL-positive strains in the hospitals, it is important to establish appropriate infection control measures to prevent their spread in the community and in hospitals.

Background: Recent reports have demonstrated that refrigerated bevacizumab can be stored for up to 3 weeks at 4 °C without loss of efficacy. There have been no previous reports addressing bevacizumab's sterility when stored and used as multiple doses from a single-use vial. Objective: To evaluate the sterility of bevacizumab when used as multiple doses from a single-use vial. Methods: Four groups of vials were used to simulate the storage and use conditions for bevacizumab. Each group contained 11 doses of 0.2 mL of bevacizumab. One sample from each group was cultured once each day at 37 °C for 10 days; one sample from each group was left for 15 days. MacConkey agar, blood agar, thioglycollate broth, and Sabouraud medium were used to assess bacterial and fungal growth. Results: A total of 44 samples of bevacizumab were included in this study. Each sample was placed on 4 growth media for microbial readings. All samples were found to be negative for microbial growth. No significant differences were observed among the groups. Possible limitations of this study included the number of samples for each group and in vitro design of the study, which might have affected the growth of bacterial organisms. Conclusions: Storage and multiple use of bevacizumab from single-use vials does not seem to result in microbial contamination.

Three clusters of Chryseobacterium meningosepticum infections in a tertiary health center in July 2006 and January 2007 involving 8 newborns and 5 older children were investigated. The index patient was from the neonatal intensive care unit, and the older patients were from other pediatric wards. Cultures were obtained from the environment and from health care workers' hands as part of an outbreak investigation. C meningosepticum was isolated from hand cultures obtained from a senior resident and from environmental cultures obtained from powdered infant formula, an electrical button, a computer keyboard, phone, a doorknob, and an Ambu bag. Antibiogram typing and enterobacterial repetitive intergenic consensus sequence polymerase chain reaction indicated that all of the isolates were epidemiologically related. Nine patients improved on antimicrobial treatment, and 4 premature infants died after the infection. C meningosepticum is a well-known etiologic agent for nosocomial infections involving newborns and immunocompromised patients. Wet and dry environmental surfaces and equipment may act as a source or play a role in disseminating the microorganism. Outbreaks may be controlled with strong emphasis on infection control measures.

Helicobacter pylori exists in two morphologic forms: spiral shaped and coccoid. The nonculturable coccoid forms were believed to be the morphologic manifestations of cell death for a long time. However, recent studies indicate the viability of such forms. This form of H. pylori is now suspected to play a role in the transmission of the bacteria and is partly responsible for relapse of infection after antimicrobial treatment. Urease activity of H. pylori is an important maintenance factor. Determination of urease activity and possible mutations in the DNA sequences of coccoid bacteria will hence contribute to the understanding of pathogenesis of infections, which these forms might be responsible for. In this study, our aim was to analyze the urease activity and investigate the urease gene sequences of coccoid H. pylori forms induced by different factors with respect to the spiral form. For this purpose, the urease activities of H. pylori NCTC 11637 standard strain and two clinical isolates were examined before and after transformation of the cells to coccoid forms by different methods such as exposure to amoxicillin, aerobiosis, cold starvation, and aging. The effects of these conditions on the urease gene were examined by the amplification of 411-bp ureA gene and 115-bp ureB gene regions by PCR technique and sequencing of the ureA gene. The urease activities of coccoid cells were found to be lower than those of the spiral form. ureA and ureB gene regions were amplified in all coccoid cells by PCR. Inducing the change to coccoid form by different methods was found to have no effect on the nucleotide sequence of the ureA gene. These results show that the urease gene region of coccoid H. pylori is highly protected under various mild environmental conditions.

Aim: The aim of this study was to genotype C. albicans strains isolated from blood cultures of sepsis patients (invasive isolates) and from oral rinse samples of healthy adults and HIV-positive patients (non-invasive isolates) by using two different primer sets targeting the same gene.Materials and Methods: 42 C. albicans invasive isolates obtained from sepsis patients and 68 oral non-invasive isolates obtained from oral rinse samples of healthy adults (n=30) and HIV-positive patients (n=38) were included in this study. C. albicans identification was made by conventional microbiological tests and confirmed by polymerase chain reaction (PCR). 25S intron genotyping was performed by using CaLSU-F and CaLSU-R primers and by using CA-INT-L and CA-INT-R pri-mers.Results: Twelve of the 42 C. albicans isolates from blood samples were genotype A (28.5%), 17 were genotype B (40.5) and 13 were genotype C (31%). In the noninvasive group, genotype distri-bution of the HIV-positive patients and healthy controls were as follows: 15 (39.5%) of the 38 oral isolates obtained from HIV-positive patients were found as genotype A, 7 (18.4) genotype B, and 16 (42.1%) genotype C. Among the 30 oral isolates obtained from healthy adults, 9 (30%) were genotype A, 12 (40%) were genotype B, and 9 (30%) were genotype C. The results obtained by using both of the primers were in correlation with each other.Conclusion: No statistical significant difference was observed between the genotype distributi-ons of invasive and noninvasive isolates.

Summary Candida dubliniensis which was first recognized in 1995 can be easily misidentified because of its phenotypic similarities with Candida albicans. In this study blood samples of patients from various departments of Ankara University Medical Faculty between January 2001–June 2004 were investigated for the distribution of Candida spp. and the presence of C. dubliniensis. Culture positive 67 fungi were included to the study. Phenotypic tests such as chlamydospore formation, colony morphology on Staib agar, growth at 45 °C, carbohydrate assimilation profiles were investigated for identification and differentiation of C. dubliniensis from C. albicans. To confirm the results polymerase chain reaction were used for suspected C. albicans and C. dubliniensis isolates. Among 38 germ tube and chlamydospore forming isolates, 37 of them were found as C. albicans and one as C. dubliniensis. The incidence of C. dubliniensis in our hospital is still low, this is the first C. dubliniensis isolate as an agent of candidaemia reported from Turkey.

Ankara Turkiye Yuksek Ihtisas Egitim ve Araștirma Hastanesi Yogun Bakim Kliniklerinde ve Ameliyathanelerinde calișan personel arasinda Ocak 2004’de bir farenjit salgini gelișmiștir. Hastalarin semptomlari A grubu streptokok farenjiti bulgulariyla ortușmekte olup, hastalarin %91’inde bogaz agrisi, %87’sinde ise genel halsizlik izlenmiștir. Iki gun icerisinde 377 personelden bogaz kulturu alinmiș, bu hastalarin 121’inin (%32) kulturunde G-grubu beta hemolitik streptokok uremiștir. Salgin egrisi incelendiginde, streptokoklarin solunum yolu ile bu șekilde hizla yayilmasi mumkun olmadigi, bu hastalarin ayni enfeksiyon kaynagina maruz kaldiklari dușunulmuștur. 121 pozitif kultur orneginin 16’sinin, salginin ortaya ciktigi kliniklere hastane personeli yemeklerini dagitan yemek firmasi elemanlarina ait oldugunun anlașilmasi uzerine, salginin gida kaynakli oldugu dușunulmuștur. Yemek firmasi personelinden izole edilen 16 ornek dahil olmak uzere, rastgele secilen 40 ornegin PFGE analizi sonuclari, tek bir kesim paternini ortaya koymuștur. Tum hastalanan personele penisilin tedavisi bașlanmiș, salgini takiben bașlayan dokuz gunluk bayram tatili esnasinda salgin sona ermiș, kontrol kulturlerinde ureme gozlenmemiștir.

Amaç: Tüberküloz, günümüzde giderek artan bir toplum sağlığı sorunu haline gelmiştir. İnfeksiyon dinamiklerini incelemek ve uygun tedavi ve infeksiyon kontrol stratejileri belirleyebilmek için etkenin moleküler tiplendirmesi önemlidir. Mycobacterium tuberculosis genotiplemesinde altın standart IS6110 RFLP analizi olmakla birlikte, yöntemle ilgili zorluklar nedeniyle son yıllarda Polimeraz Zincir Reaksiyonuna (PZR) dayalı yöntemler de kullanılmaktadır. Bu çalışmada, akciğer tüberkülozlu 39 farklı hastadan izole edilen M. tuberculosis izolatının, PZR yöntemi ile genotiplendirilmesi amaçlanmıştır. Gereç ve Yöntem: Löwenstein-Jensen besiyerinde üretilen suşların hücre duvarları cam boncuklarla parçalanarak DNA elde edilmiştir. PZR ile genotiplendirme için, IS6110 insersiyon dizisinin iki ucuna yönelik hazırlanan IS–1 (5’CAA GAA CCT TTC CTA CCC CA 3’) ve IS–2 (5’GGC TGA GGT CTC AGA TCA G 3’) primerleri kullanılmıştır. Elde edilen bant paternleri bilgisayar ortamına aktarılarak, suşlar arası genetik yakınlık, Syngene Gene Directory 1.02.0 (Syngene, Cambridge, İngiltere) programında UPGMA metodu ile Dice katsayısı kullanılarak belirlenmiştir.Bulgular ve Sonuç: Çalışma sonucunda izolatların hepsinin genotipik olarak birbirinden farklı olduğu tespit edilmiş, yöntem kolay uygulanabilir, hızlı, ucuz ve tekrarlanabilir bulunmuştur.

Amac: Bu calismada, sepsisli hastalarin kanindan izole edilen invaziv C. albicans izolatlari ile, saglikli ve Human-Immunodeficiency Virus (HIV) ile infekte kisilerin bogazlarindan izole edilen invaziv olmayan C. albicans izolatlarinin genotip dagilimlarinin belirlenmesi ve ayni bolgeyi hedef alan iki ayri primer cifti kullanilarak elde edilen sonuclarin karsilastirilmasi amaclanmistir. Gerec ve Yontem: Calismaya, kandan izole edilen 42 adet C. albicans susu (invaziv izolatlar) ile HIV pozitif hastalarin bogaz calkanti sularindan elde edilen 38, saglikli eriskinlerin bogaz calkanti sularindan izole edilen 30 adet C. albicans susu (invaziv olmayan izolatlar) dahil edilmistir. C. albicans identifikasyonu konvansiyonel mikrobiyolojik yontemlerle gerceklestirilmis ve polimeraz zincir reaksiyonu (PZR) yontemi ile dogrulanmistir. 25S intron genotiplendirmesi, CaLSU-F ve CaLSU-R ile CA-INT-L ve CA-INT-R primerleri kullanilarak gerceklestirilmistir. Bulgular: Kandan izole edilen 42 adet C. albicans susunun 12’si genotip A (%28.5), 17’si genotip B (%40.5) ve 13’u genotip C (%31) olarak bulunurken, saglikli kontrollerden izole edilen 30 adet C. albicans susunun 9’unun genotip A (% 30), 12’sinin genotip B (% 40) ve 9’unun genotip C (%30) dagiliminda oldugu gosterilmistir. HIV pozitif bireylerden elde edilen 38 adet C. albicans susunun 15’i genotip A (%39.5), 7’si genotip B (%18.4) ve 16’si genotip C (%42.1) olarak bulunmustur. Her iki primer ile de elde edilen sonuclar birbirleriyle uyumlu bulunmustur. Sonuc: Invaziv ve non-invaziv orneklerin genotip dagilimlari birbirleriyle karsilastirildiklarinda istatistiksel olarak anlamli bir fark gorulmemistir.

Chatter vibrations in milling, which develop due to dynamic interactions between the cutting tool and the workpiece, result in reduced productivity and part quality. Various numerical and analytical stability models have been considered in the previous publications, where mostly the stability limit of axial depth of cut is emphasized for chatter-free cutting. In this paper an analytical stability model is used, and a simple algorithm to determine the stability limit of radial depth of cut is presented. It is shown that, for the maximization of chatter-free material removal rate, radial depth of cut is of equal importance with the former. A method is proposed to determine the optimal combination of depths of cut, so that chatter-free material removal rate is maximized. The application of the method is demonstrated on a pocketing example where significant reduction in the machining time is obtained using the optimal parameters. The procedure can easily be integrated to a CAD/CAM or virtual machining environment in order to identify the optimal milling conditions automatically.

Chatter vibrations in milling, which develop due to dynamic interactions between the cutting tool and the workpiece, result in reduced productivity and part quality. Several stability models have been considered in previous publications, where mostly the stability limit in terms of axial depth of cut is emphasized for chatter free machining. In this paper, it is shown that, for the maximization of chatter free material removal rate, radial depth of cut is of equal importance. A method is proposed to determine the optimal combination of depths of cut, so that chatter free material removal rate is maximized. The application of the method is demonstrated on a pocketing example where significant reduction in the machining time is obtained using the optimal depths. The procedure can easily be integrated to a CAD/CAM system or a virtual machining environment in order to identify the optimal milling conditions.

Summary The carriage of Candida dubliniensis in the oral cavities of type-1 diabetic patients were investigated. Of 230 patients 81 (35%) had Candida spp. in their oral cavity; C. albicans was the most frequently isolated species (58%). No C. dubliniensis was found in the study population. Zusammenfassung Die Candida-Besiedlung und das Vorkommen von Candida dubliniensis im Mund-Rachenraum wurde bei Typ 1-Diabetikern untersucht. Bei 81 von 230 Patienten (35%) konnte Candida spp. nachgewiesen werden; C. albicans war die am haufigsten isolierte Art (58%). Im untersuchen Patientenkollektiv konnte C. dubliniensis nicht isoliert werden.

The biodegradation of BTEX compounds (benzene, toluene, ethyl benzene, and o,m,p-xylenes) by a mixed culture obtained from the formation of water, produced from the petroleum wells of the Turkish Petroleum Corporation (TPAO) in the Adiyaman region (southeast Turkey), and the effect of biomass concentration on the biodegradation rate of BTEX compounds, both alone and as a mixture, were investigated. The mixed culture, identified as Pseudomanas stutzeri and Vibrio mimicus, was grown on a brain heart infusion enriched medium at 30°C before its use in the biodegradation experiments. The biodegradation experiments were carried out using nonadapted, benzene-adapted, and toluene-adapted microorganisms. It was found that the mixed culture obtained degraded all BTEX compounds, both alone and as a mixture, and the overall specific biodegradation rates of BTEX compounds individually were higher with toluene-adapted microorganisms (both benzene and toluene: 4.27 mg/g biomass-day) than with the nonadapted (benzene: 0....

Candida dubliniensis is one of the Candida species which was first recognised in 1995. C. dubliniensis was misidentified because of its phenotypic similarities with Candida albicans. In this study positive blood cultures of patients from various clinics of Ankara University Medical Faculty between January 1996-September 2000 were investigated for the distribution of Candida spp. and the presence of C. dubliniensis. Culture positive 98 fungi were included in the study. Phenotypic tests for identification of C. dubliniensis and tests for differentiation of the yeast from C. albicans, such as colony morphology on Staib agar, growth at 42°C and 45°C, ß-glucosidase activity and carbonhydrate assimilation tests were investigated. These results confirm other studies which demonstrate the presence of C. dubliniensis in oral flora.

PURPOSE: Prospective, randomized studies have shown that bowel preparation may adversely affect infectious complications following colonic resections. However, very little is known about the effects of bacterial translocation on these infectious complications. The aim of this prospective, randomized study was to assess the effects of bowel preparation on bacterial translocation. METHODS: A total of 82 consecutive patients undergoing elective abdominal operations were randomly assigned to four groups: control (I; n=20), mechanical (II; n=21), mechanical plus oral metronidazole (III; n=20), and polyethylene glycol preparation (IV; n=21). Patients with intra-abdominal infection, those receiving preoperative antibiotics for any reason, and those having lower gastrointestinal tract disease were excluded from the study. Peritoneal swab, ileocecal and pericolic mesenteric lymph nodes, liver wedge biopsy, portal venous blood, and peripheral blood samples were taken for culture. Patients were followed up for postoperative infectious complications. Groups were matched according to age, gender, body surface area, and Acute Physiology and Chronic Health Evaluation II scores. RESULTS: Bacterial translocation was identified by a positive culture in one patient in Group I, two in Group II, one in Group III, and three in Group IV, respectively. Differences in number of positive cultures among the groups were not statistically significant. Nine patients had major infectious complications. Only two had bacterial translocation, and the same micro-organisms grew in both patients, in one at the wound site and in the other at the cyst abscess. CONCLUSION: This study demonstrated that mechanical bowel preparation does not enhance the spontaneous occurrence of bacterial translocation in patients without any clinical signs of lower gastrointestinal tract disease.

Human natural killer (NK) cells comprise 4% to 15% of peripheral blood mononuclear cells and have important role in immune responses against tumors and viral infections. NK cells originate in bone marrow but their progenitors and lineage development have not been completely characterized. These lymphocytes do not rearange immunoglobulins or T cell antigen receptors (TCR). They are CD16- and/or CD56+ and CD3- cells in man. In this paper the literature about NK cells are reviewed.

Thirty eight vancomycin resistant enterococci (VRE) were isolated in one year surveillance study for hospital infection control programme in a state hospital in Ankara, Turkey. All isolates were identified as Enterococcus faecium by VITEK2 system (bioMerieux, France). Vancomycin and teicoplanin resistant 30 strains were defined as vanA phenotype while vancomycin-resistant teicoplanin-susceptible eight strains were defined as vanB phenotype. vanA genes were found in 30 strains while vanB genes were found in five strains by using PCR method. Those five strains were the first vanB positive E.faecium strains in our country. VRE strains revealed six different band patterns by PFGE, while six isolates could not be classified. All isolates with vanB type resistance were found in the same cluster. Source of vanB positive strains was considered as the hemodialysis unit. When the previous national reports related to vancomycin-resistant enterococci were considered, this was the first report of vanB positive E.faecium isolates in our country. This emphasized that both the diversity of VRE and the isolation rate was increasing. In order to eliminate the spread of VRE, effective surveillance studies should be performed and protective measures should be established promptly.