Zeynep Senses

Publications of Zeynep Senses

• Platelet Aggregation in Children With Helicobacter Pylori Infection.

  Authors: Orhan Gursel, Avni Atay, Emin Kurekci, Ferit Avcu, Oral Nevruz, Zeynep Senses, Emel Ozturk, Adnan Hasimi, Okan Ozcan

  Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis. 07/2009;

  This study was performed to investigate the platelet aggregation alterations in platelet-rich plasma (PRP) samples of children with Helicobacter pylori (H pylori) infection. Platelet aggregationThis study was performed to investigate the platelet aggregation alterations in platelet-rich plasma (PRP) samples of children with Helicobacter pylori (H pylori) infection. Platelet aggregation induced by adenosine diphosphate (ADP), collagen, ristocetin, or epinephrine was studied with photometric aggregometry in 30 patients before and after eradication therapy and in a control group including 15 children. The pretreatment mean maximum aggregation values and slope were significantly lower (P < .0001) in the study group at 10 micromol/L concentrations of ADP (ADP-like defect). The maximum aggregation values and slope revealed no significant differences (P > .05) between the study group after therapy and the control group. We concluded that H pylori infection may cause dysfunction of platelets in children and can be reversed by H pylori eradication therapy. Further studies should be carried out to determine the mechanisms of platelet dysfunction in children with H pylori infection.

• A rare pathogen causing endocarditis: Streptococcus constellatus.

  Authors: Zeynep Senses, Mehmet Yokuşoğlu, Bilgehan Savaş Oz, Aylin Usküdar Güçlü, Hakan Erdem, Oben Baysan, Mehmet Baysallar

  Anadolu kardiyoloji dergisi : AKD = the Anatolian journal of cardiology. 09/2008; 8(4):315-6.

• Staphylococcal cassette chromosome mec (SCCmec) characterization and panton-valentine leukocidin gene occurrence for methicillin-resistant Staphylococcus aureus in Turkey, from 2003 to 2006.

  Authors: Abdullah Kilic, Aylin Guclu, Zeynep Senses, Orhan Bedir, Hakan Aydogan, A Basustaoglu

  Antonie van Leeuwenhoek. 09/2008;

  Methicillin-resistant Staphylococcus aureus (MRSA) cause serious community-acquired and nosocomial diseases all over the world. We determined the SCCmec types and occurrence of the PVL gene by usingMethicillin-resistant Staphylococcus aureus (MRSA) cause serious community-acquired and nosocomial diseases all over the world. We determined the SCCmec types and occurrence of the PVL gene by using TaqMan real-time PCR method, and correlated these with phenotypic antibiotic susceptibility patterns for MRSA strains collected from Gulhane Military Medical Academy Hospital (GMMAH) during 4 years study period. To our knowledge, this is the first report from Turkey of molecular SCCmec typing analysis of MRSA stains. A total of 385 clinical MRSA isolates collected in the clinical and Microbiology Laboratory at GMMAH between 2003 and 2006 were included in the study. Overall, SCCmec types-I, II, III, IV, V, nontypeable and PVL occurrence were detected in 11 (2.8%), 3 (0.8%), 316 (82.1%), 20 (5.1%), 20 (5.1%), 15 (3.9%) and 5 (1.3%) isolates, respectively. A total of 330 (85.5%) were SCCmec-I/II/III and 40 (10.3%) were SCCmec IV/V. SCCmec-I/II/III isolates were recovered more from patients with serious infections in surgical departments especially those with intensive care units than the SCCmec-IV/V isolates (chi(2) = 13.560, P < 0.001). SCCmec-I/II/III MRSA strains were predominantly recovered from blood stream (53.0%, P = 0.014), while SCCmec-IV/V strains were predominately isolated from skin and soft tissue and abscess (55.0%, P < 0.001). The PVL gene was detected in 10.0% of SCCmec-IV/V isolates in contrast to 0.3% in SCCmec-I/II/III (chi(2) = 25.164, P < 0.001). SCCmec-I/II/III MRSA strains were more resistant to clindamycin (chi(2) = 5.078, P = 0.024), amoxicillin-clavulanate (chi(2) = 84.912, P < 0.001), erythromycin (chi(2) = 4.651, P = 0.031), gentamicin (chi(2) = 24.869, P < 0.001), and rifampin (chi(2) = 18.878, P < 0.001) than SCCmec-IV/V MRSA strains. This data indicates that SCCmec-III MRSA strains that do not carry the PVL gene are the predominant MRSA strains in our hospital setting in Ankara, capital of Turkey and that SCCmec-I/II/III MRSA strains may cause serious infections in surgical departments especially those with intensive care units.

• Molecular characterization of methicillin-resistant Staphylococcus aureus nasal isolates from Turkey.

  Authors: Abdullah Kilic, Gurkan Mert, Zeynep Senses, Orhan Bedir, Hakan Aydogan, A Basustaoglu, Peter Appelbaum

  Antonie van Leeuwenhoek. 09/2008;

  Methicillin-resistant Staphylococcus aureus (MRSA) colonize most frequently in the anterior nares of the nose and cause serious infections all over the world. The aim of this study was to determineMethicillin-resistant Staphylococcus aureus (MRSA) colonize most frequently in the anterior nares of the nose and cause serious infections all over the world. The aim of this study was to determine the nasal carriage rate of S. aureus and MRSA strains in Turkish elementary school children. We also analyzed molecular characterizations of MRSA strains by using pulse field gel electrophoresis (PFGE), multi locus sequence typing (MLST), staphylococcal chromosomal cassette mec (SCCmec) typing, and detection of the Panton-valentine leucocidin (PVL) gene. The nasal swabs were obtained from 4,050 children during a 4 month period in Ankara. In vitro antimicrobial susceptibility testing to 1 mug oxacillin and 30 mug cefoxitin was determined by a disk diffusion method. We found that the 1,001 of 4,050 (24.7%) children were colonized with S. aureus. Three S. aureus strains were resistant to oxacillin and cefoxitin. The rate of MRSA among all children was 0.07%. The MRSA strains revealed three different PFGE pattern. All MRSA isolates by harbored the SCCmec type IV element, but not the PVL gene. The two MRSA isolate belonged to sequence type (ST) 30, whereas the other one was a unique type. The results of this study demonstrated that S. aureus nasal carriage rate was consistent with previous studies. However, MRSA carriage rate was low. This study also indicated that the ST30-type IV without PVL gene MRSA clone may be expected to spread in Turkish community.

• Acinetobacter septicus sp. nov. association with a nosocomial outbreak of bacteremia in a neonatal intensive care unit.

  Authors: Abdullah Kilic, Haijing Li, Alexander Mellmann, Ahmet C Basustaoglu, Mustafa Kul, Zeynep Senses, Hakan Aydogan, Charles W Stratton, Dag Harmsen, Yi-Wei Tang

  Journal of clinical microbiology. 04/2008; 46(3):902-8.

  Acinetobacter species other than Acinetobacter baumannii have rarely been reported to be associated with nosocomial outbreaks of bloodstream infections. Within a period of 1 week, sevenAcinetobacter species other than Acinetobacter baumannii have rarely been reported to be associated with nosocomial outbreaks of bloodstream infections. Within a period of 1 week, seven Acinetobacter-like isolates were recovered from peripheral blood and catheter specimens of five patients at a neonatal intensive care unit (NICU) in a tertiary hospital in Turkey. All five patients had placement of central venous catheters and had received total parenteral nutrition before the onset of bacteremia. Two of the five patients died. Medical devices, tap water, aerators, water samples, various surfaces, intravenous fluids, and the hands of health care workers in the NICU were sampled and were culture negative for the bacterium. All seven of the isolates had identical biochemical reactions, antimicrobial susceptibility results, and pulsed-field gel electrophoresis patterns, indicating a clonal nosocomial outbreak. A panel of standard biochemical reaction profiles and three phenotypic commercial identification systems failed to identify these isolates. Phenotypically, the isolate differed from Acinetobacter ursingii by its hemolysis on sheep blood agar and its negative citrate utilization. Sequences of the full 16S rRNA gene, which contained at least three different gene copies with polymorphic sequences between nucleotide positions 70 and 206, were determined from the first recovered isolate. The complete 1,529- to 1,531-bp 16S rRNA gene sequences and partial 801-bp rpoB gene sequences had similarities of 99.5% and 97.2%, respectively, to an A. ursingii isolate. The DNA-DNA similarities of the strain against the type strain of A. ursingii were 64.7 and 68.7%, which were lower than the recommended threshold value of 70% for the definition of bacterial species. These data indicate that a novel Acinetobacter organism caused the nosocomial outbreak of bacteremia in the NICU unit. We propose the designation of Acinetobacter septicus sp. nov. for these isolates, with isolate AK001 as the type strain.

• Nosocomial outbreak of Sphingomonas paucimobilis bacteremia in a hemato/oncology unit.

  Authors: Abdullah Kilic, Zeynep Senses, A Emin Kurekci, Hakan Aydogan, Kenan Sener, Erol Kismet, A Celal Basustaoglu

  Japanese journal of infectious diseases. 12/2007; 60(6):394-6.

  Nosocomial Sphingomonas paucimobilis infections can arise from contaminated water and the contaminated hands of hospital staff. Within a 1-month period, we isolated six S. paucimobilis strains,Nosocomial Sphingomonas paucimobilis infections can arise from contaminated water and the contaminated hands of hospital staff. Within a 1-month period, we isolated six S. paucimobilis strains, including four from blood cultures of four patients and two from hospital environment specimens including tap water and a bathtub in a hemato/oncology unit. We described here these strains' molecular epidemiological analyses by pulsed-field gel electrophoresis (PFGE) and antibiotic susceptibilities by E-test. Although clinical and environmental isolates yielded three different antibiotic resistances and PFGE patterns, all four clinical strains had an identical pattern by both methods. Thus, the isolated clinical strain clone could be traced neither to health care workers nor to environmental samples. It was concluded that S. paucimobilis strains can cause outbreaks in hemato/oncology units. We did not demonstrate genetic relatedness between clinical and environmental isolates by PFGE, but did find PFGE a useful identification technique for epidemiological investigation.

• Bacterial reduction by extensive versus conservative root canal instrumentation in vitro.

  Authors: Cumhur Aydin, Yasar Meric Tunca, Zeynep Senses, Mehmet Baysallar, Guven Kayaoglu, Dag Ørstavik

  Acta odontologica Scandinavica. 06/2007; 65(3):167-70.

  OBJECTIVE: This study aimed to test the hypothesis that aggressive dentin removal through greater-tapered instrumentation reduces the intracanal bacteria more effectively than conservative dimensionOBJECTIVE: This study aimed to test the hypothesis that aggressive dentin removal through greater-tapered instrumentation reduces the intracanal bacteria more effectively than conservative dimension instrumentation. MATERIAL AND METHODS: Twenty extracted human lower premolar teeth were used. After extirpation of the pulps, the teeth were autoclaved and immersed in a broth inoculated with Enterococcus faecalis and incubated for 7 days to allow infection of the dentinal tubules. The teeth were divided into 2 experimental groups, each comprising 10 teeth. The teeth were instrumented either with ProTaper or with Hero Shaper nickel-titanium rotary instrumentation techniques. It was calculated that ProTaper theoretically has the potential to remove at least twice the dentin volume compared with Hero Shaper. The apical preparation was standardized to file size 30. Saline solution was used for irrigation. Bacteriological samples were taken before and after instrumentation and plated onto tryptic soy agar, and the reduction in numbers was calculated. RESULTS: Both instrumentation techniques significantly reduced the number of bacteria in the root canal (p<0.05). Reduction in absolute bacterial numbers was up to 98%. There was no statistically significant difference between the two techniques. CONCLUSIONS: Preparation with an instrumentation technique removing substantial amounts of dentin did not reduce the intracanal bacteria more effectively than a more conservative instrumentation technique.

• [Molecular analysis of vancomycin-resistant enterococci isolated from clinical samples]

  Authors: Abdullah Kiliç, Zeynep Senses, Hakan Aydoğan, Ahmet Başustaoglu

  Mikrobiyoloji bülteni. 11/2006; 40(4):295-9.

  Enterococcus species are the inhabitants of gastrointestinal flora and can cause endocarditis, urinary tract infections, and bacteremia. In recent years, infections caused by vancomycin-resistantEnterococcus species are the inhabitants of gastrointestinal flora and can cause endocarditis, urinary tract infections, and bacteremia. In recent years, infections caused by vancomycin-resistant enterococci (VRE) have increased in our country. The infections caused by VRE are treated with glycopeptide antibiotics like vancomycin and teicoplanin. Although seven different resistant genes have been described in VRE, VanA is the most frequently detected one in Turkey. The aim of this study was (i) to genotype four vancomycin-resistant Enterococcus faecium strains isolated in our hospital, by using pulsed field gel electrophoresis (PFGE); and (ii) to detect the type of Van gene by using polymerase chain reaction. Three of the strains were isolated from blood cultures and one from cerebrospinal fluid of the hospitalized patients between the years 2000-2004, and identified by both conventional methods and commercial kits. By using PFGE, we detected that isolates were different according to Tenover criteria and they had VanA genes. As a result, VanA carrying VRE cause sporadic infections in our hospital. The molecular epidemiologic investigation of resistant microorganisms is important in terms of infection control and epidemiology.

• Evaluation of the BacT/ALERT and BACTEC 9240 automated blood culture systems for growth time of Brucella species in a Turkish tertiary hospital.

  Authors: Mehmet Baysallar, Hakan Aydogan, Abdullah Kilic, Ayten Kucukkaraaslan, Zeynep Senses, Levent Doganci

  Medical science monitor : international medical journal of experimental and clinical research. 08/2006; 12(7):BR235-8.

  BACKGROUND: The isolation of Brucella species from blood may be achieved by using classic culture techniques, but detection of the organism is difficult due to its slow growth. The time-to-detectionBACKGROUND: The isolation of Brucella species from blood may be achieved by using classic culture techniques, but detection of the organism is difficult due to its slow growth. The time-to-detection of Brucella can take up to 30 days using the Castaneda blood culture method. Automated blood culture systems have reduced the growth time of Brucella. MATERIAL/METHODS: In this report we would like to contribute our experience on detection time in the isolation of Brucella species from 33,039 blood culture sets using BacT/ALERT between 1995 and 2000 (13 isolates) and thereafter using both the BACTEC and BacT/ALERT systems (17 isolates). RESULTS: Thirty Brucella spp. (17 by both systems and 13 by BacT/ALERT only) were isolated from 33,039 blood culture sets between 1995 and 2002. Brucellae were recovered between 1.8 and 3.7 days (mean: 2.5 days) in the BacT/ALERT blood culture system and between 2.1 and 3.8 days (mean: 2.8 days) in BACTEC 9240 system. CONCLUSIONS: We concluded that the mean time-to-detection could be <or=3 days, which is considered rapid enough for starting appropriate evidence-based treatment in an endemic setting.

• A case of ventricular drainage infection with a rare pathogen in cerebrospinal fluid: vancomycin-resistant Enterococcus faecium.

  Authors: Mehmet Baysallar, Yusuf Izci, Abdullah Kilic, Ismail Yasar Avci, Zeynep Senses, Levent Doganci

  Microbial drug resistance (Larchmont, N.Y.). 02/2006; 12(1):59-62.

  The purpose of this study was to describe a patient, 7-month-old child with ventriculoperitoneal shunts for hydrocephalus with ventriculitis caused by vancomycin-resistant Enterococcus faecium. TwoThe purpose of this study was to describe a patient, 7-month-old child with ventriculoperitoneal shunts for hydrocephalus with ventriculitis caused by vancomycin-resistant Enterococcus faecium. Two ventriculoperitoneal shunts were inserted just after birth and on the second month. On the sixth month, both shunts were removed because of dysfunction, and external drainage was inserted. The child developed fever, and lumbar puncture revealed a high leukocyte count and protein concentration after external drainage. Cerebrospinal fluid (CSF) cultures yielded E. faecium, which was resistant to ampicillin, erythromycin, gentamicin, penicillin G, vancomycin, and teicoplanin and was susceptible to chloramphenicol, ciprofloxacin, streptomycin, levofloxacin, and rifampin, as determined by the disk diffusion method. As a result of the antimicrobial susceptibility tests, multidrug antibiotic therapy was changed from vancomycin and ceftazidime to chloramphenicol, rifampin, and meropenem. In addition, a rifampin-clindamycin-impregnated shunt (The Codman Hakim Bactiseal, Raynham, MA) was inserted. The patient became afebrile, and CSF cultures were sterile after 15 days of yielding E. faecium. Implantation of the rifampin-clindamycin-impregnated shunt and timely use of appropriate antibiotics for 10 days according to antimicrobial susceptibility testing seem to be important in the resolution of vancomycin-resistant enterococci infections, especially in countries where linezolid and quinupristin-dalfopristin are not in use yet.

• Is there a relationship between childhood Helicobacter pylori infection and iron deficiency anemia?

  Authors: A E Kurekci, A A Atay, S U Sarici, Ediz Yesilkaya, Zeynep Senses, Vedat Okutan, Okan Ozcan

  Journal of tropical pediatrics. 07/2005; 51(3):166-9.

  An association between Helicobacter pylori infection and iron deficiency anemia has been reported in children, and it has been proposed that H. pylori infection needs to be eradicated to treatAn association between Helicobacter pylori infection and iron deficiency anemia has been reported in children, and it has been proposed that H. pylori infection needs to be eradicated to treat absolutely iron deficiency anemia (IDA). We investigated whether there was any correlation between H. pylori infection and iron deficiency (ID) and IDA in children, and whether the eradication of H. pylori infection without iron treatment would lead to the resolution of ID. Hemoglobin and ferritin levels, H. pylori stool antigen test and (14)C urea breath test were measured in 140 children aged 6--16 years (median 9.5 years). Children with H. pylori infection were divided into three groups on the basis of hemoglobin, mean corpuscular volume (MCV), and serum ferritin levels: groups of IDA, ID, and control. All the children received anti-H. pylori combination therapy consisting of amoxicillin, clarithromycin, and lansoprazole. Hemoglobin and MCV values rose significantly compared with baseline values after H. pylori eradication without iron supplementation in children with IDA (p=0.002 and p=0.003, respectively). Ferritin values increased significantly after H. pylori eradication in children with ID (p<0.001). We conclude that complete recovery of ID and IDA can be achieved with H. pylori eradication without iron supplementation in children with H. pylori infection.

• [Investigation of the in-vitro effectiveness of ertapenem against Pseudomonas aeruginosa strains isolated from intensive care unit patients]

  Authors: Abdullah Kiliç, Ayten KÜÇÜKKARAASLAN, Zeynep Senses, Mehmet Baysallar, Levent Doğanci

  Mikrobiyoloji bülteni. 11/2004; 38(4):355-62.

  Pseudomonas aeruginosa is one of the important cause of infections in intensive care unit (ICU) patients. The aim of this study was to investigate the effectiveness of ertapenem prior to its use inPseudomonas aeruginosa is one of the important cause of infections in intensive care unit (ICU) patients. The aim of this study was to investigate the effectiveness of ertapenem prior to its use in Turkey, against multiple-resistant P. aeruginosa strains isolated from ICUs. Susceptibility tests were performed by using Kirby-Bauer disk diffusion method and MicroScan MERCH MIC 8 panel (MicroScan 96, Dade Behring, USA). While the resistance rates of ertapenem, imipenem and meropenem were 59.2%, 50% and 48.1% by disk diffusion method, they were 57.4%, 46.2% and 42.5% by MicroScan, respectively. Ertapenem was found less effective against multiple-resistant P. aeruginosa isolates by both of the methods when compared with imipenem and meropenem. Piperacillin/tazobactam was detected as the most effective agent against these isolates by both of the methods. As a result, although carbapenems are frequently used for infections caused by P. aeruginosa, ertapenem, which is a new carbapenem, is not effective as much as the others. In case of confirmation of our results by larger scale studies, the empiric treatment of ICU infections caused by P. aeruginosa with ertapenem, should be carefully evaluated.

• [Macrolide antibiotic resistance rates and phenotypes of group A beta hemolytic streptococci isolated between the years 1999-2000 and 2001-2002]

  Authors: Zeynep Senses, Mehmet Baysallar, Deniz Gür, Levent Doğanci

  Mikrobiyoloji bülteni. 11/2003; 37(4):225-34.

  Macrolide resistance in group A beta hemolytic streptococci (GABHS) have been reported with increasing frequency from various geographic regions in the world, and for the respective treatmentMacrolide resistance in group A beta hemolytic streptococci (GABHS) have been reported with increasing frequency from various geographic regions in the world, and for the respective treatment alternatives and epidemiologic studies, macrolide resistance rates and phenotypes have been determined. In this study erythromycin, clarithromycin and azithromycin were tested with disc diffusion method against 560 GABHS, isolated from the throat samples collected between 1999-2002. NCCLS guidelines were followed for the susceptibility tests and MIC values were obtained by E-Test in resistant isolates. For determining the resistance phenotype, erythromycin and clindamycin discs were used. Only one isolate (0.27%) was found intermediately resistant to erythromycin, and clarithromycin, and resistant to azithromycin between May 1999-January 2000, whereas in the period between January 2001-June 2002, one isolate (%0.5) was found susceptible to erythromycin and clarithromycin, but intermediately resistant to azithromycin. In each period three isolates (0.83% and 1.5%, respectively) were found to be resistant to all the tested macrolides. There was no statistically significant difference between the resistance rates in these periods. Three of the resistant isolates had inducible type, and the other five isolates had M phenotype macrolide resistance. Testing for macrolide susceptibilities and screening the resistance phenotypes have crucial importance in case of GABHS infections, since these can be taken into consideration for epidemiological issues as well as a guide for empirical treatment protocols in any geographical setting, as well as in our country.