Yazar "Ay S." seçeneğine göre listele
Listeleniyor 1 - 3 / 3
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Investigation of hydrophobic characteristics of biofilm producer and non-producer staphylococcus aureus clinical isolates(2010) Ay S.; Güldür T.; Tekereko?lu M.S.; Otlu B.The ability of staphylococcus to adhere certain structures and to form biofilm (slime) layer plays an important role in the pathogenesis of staphylococcal infections. Hydrophobic interactions and hydrogen bonds are important factors that play role in adherence. This study was designed to compare the hydrophobic properties of slime positive and negative Staphylococcus aureus strains isolated from blood cultures. Ten methicillin-resistant S.aureus isolates (five of them being slime positive) obtained from blood cultures of patients at intensive care unit of a university hospital, between May 2006 and June 2007, were included in the study. Slime production of the isolates was determined by Christensen's method. Methicillin resistance was determined by cefoxitin disc test and oxacillin salt agar test. It was determined that the test strains did not exhibit any autoaggregation. The adherence of strains to the three different hydrocarbons as solid phases (butyl-sepharose, octyl-sepharose and phenyl-sepharose; Amersham Bioscience, Sweden) were studied by using hydrophobic interaction chromatography (HIC) method. After butyl- and octyl-sepharose chromatography, it was determined that slime negative S.aureus strains were separated into three fractions eluted with phosphate buffered saline (PBS), 40% and 96% ethanol, while slime positive strains were separated into two fractions eluted with 40% and 96% ethanol, respectively. By phenyl-sepharose chromatography analysis; both slime negative and positive strains were separated into two fractions eluted in 40% and 96% ethanol. Hydrophobicity tests were repeated at 4°C and pH 6-9 to evaluate the effect of changing conditions on hydrophobicity. However, no changes were observed at these temperature and pH values. According to these analysis it was concluded that; (a) S.aureus strains consist heterogeneous fractions with distinct hydrophobic binding strengths; (b) hydrophobic surface protein secretion may be different in heterogeneous groups, and (c) slime positive S.aureus strains were more hydrophobic than non-slime producing strains. Further research is required in order to characterise the eluted fractions and to evaluate their pathogenic capacities.Öğe Molecular epidemiology of methicillin-resistant Staphylococcus aureus isolates from clinical specimens of patients with nosocomial infection: Are there unnoticed silent outbreaks?(2007) Tekerekoglu M.S.; Ay S.; Otlu B.; Çiçek A.; Kayabaş Ü.; Durmaz R.Bacteriological and epidemiological studies were carried out on 90 isolates of methicillin-resistant Staphylococcus aureus (MRSA) at lurgut Özal Medical Center of Inönü University, (Malatya/Turkey). MRSA isolates were obtained from patients with nosocomial infections. Staphylococcus aureus clinical isolates were collected between May 2004-May 2005. Isolates were tested for resistance to methicillin. Antimicrobial susceptibility testing and slime production evaluation was performed. Genotype studies were carried out by arbitrarily primed polymerase chain reaction (AP-PCR) and consequent cluster analysis. All of the isolates were mecA-positive in a PCR-based assay; all exhibited resistance to oxacillin, by agar dilution (MICs ?4mg/L) and disc diffusion methods, and multiple antibiotics. Most MRSA isolates were collected in intensive care units. Of 90 samples, 53 were found to be unrelated to the others while the remaining 37 strains were either identical or closely related. Dendrogram analysis identified nine major clusters. These data support the opinion that MRSA are significant nosocomial pathogens in intensive care units and that resistant clones may be transmitted between patients. Molecular epidemiological tools are helpful for understanding transmission patterns and sources of infection, and are useful for measuring outcomes of intervention strategies implemented to reduce nosocomial MRSA.Öğe A pneumonia case caused by Cedecea Lapagei(2008) Yetkin G.; Ay S.; Kayabaş Ü.; Gedik E.; Güçlüer N.; Çalişkan A.Cedecea spp. which are the members of Enterobacterioceae family, are mostly isolated from sputum and their clinical importance is not yet demonstrated. This report presents a pneumonia case caused by Cedecea lapagei. A 38-years-old male patient admitted to Inonu University Faculty of Medicine Emergency department with prediagnosis of subarachnoid haemorrhage was operated and transferred to Intensive Care Unit of Reanimation where he underwent artificial ventilation. On the third day of hospitalization his temperature was 39°C, white blood cell count was 27.000/ml and he was still unconscious. He had a history of chronic obstructive pulmonary disease. Chest X-ray revealed opacities in the right lower lobe and mucoid tracheal secretion ensued following tracheal entubation performed after operation. Direct microscopic examination of bronchoalveolar lavage (BAL) fluid yielded abundant number of leukocytes and gram-negative bacilli. Bacteria isolated from BAL specimen were identified as Clopagei y Phoenix 100 (Becton Dickinson, USA) automated system and also by API 20E kit (Biomerieux, France). Upon the initiation of intravenous amikacin (1 × 1 g) and meropenern (3 × 1 9), the signs of infection decreased in intensity, however, the patient was lost due to subarachnoid hemorrhage on the 12th day of hospitalization. In this case it was estimated that C.lapagei pneumonia originated from the aspiration of upper airway secretion owing to unconsciousness of the patient. Although there were reports of Cedecea infections in the literature, this was 14 first documented case of C.lapagei pneumonia when the accessible related literature was concerned.
