Yazar "Aslantas, Ozkan" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • Küçük Resim
    Öğe
    Investigation of the antibiotic resistance and biofilm-forming ability of Staphylococcus aureus from subclinical bovine mastitis cases
    (ELSEVIER SCIENCE INC, 2016) Aslantas, Ozkan; Demir, Cemil
    A total of 112 Staphylococcus aureus isolates obtained from subclinical bovine mastitis cases were examined for antibiotic susceptibility and biofilm-forming ability as well as genes responsible for antibiotic resistance, biofilm-forming ability, and adhesin. Antimicrobial susceptibility of the isolates were determined by disk diffusion method. Biofilm forming ability of the isolates were investigated by Congo red agar method, standard tube method, and microplate method. The genes responsible for antibiotic resistance, biofilm-forming ability, and adhesion were examined by PCR. Five isolates (4.5%) were identified as methicillin-resistant Staph. aureus by antibiotic susceptibility testing and confirmed by mecA detection. The resistance rates to penicillin, ampicillin, tetracycline, erythromycin, trimethoprim-sulfamethoxazole, enrofloxacin, and amoxicillin-clavulanic acid were 45.5, 39.3, 33, 26.8, 5.4, 0.9, and 0.9%, respectively. All isolates were susceptible against vancomycin and gentamicin. The blaZ (100%), tetK (67.6%), and ermA (70%) genes were the most common antibiotic-resistance genes. Using Congo red agar, microplate, and standard tube methods, 70.5, 67, and 62.5% of the isolates were found to be biofilm producers, respectively. The percentage rate of icaA, icaD, and bap genes in Staph. aureus isolates were 86.6, 86.6, and 13.4%, respectively. The adhesion molecules fnbA, can, and clfA were detected in 87 (77.7%), 98 (87.5%), and 75 (70%) isolates, respectively. The results indicated that Staph. aureus from sublinical bovine mastitis cases were mainly resistant to beta-lactams and, to a lesser extent, to tetracycline and erythromycin. Also, biofilm- and adhesion-related genes, which are increasingly accepted as an important virulence factor in the pathogenesis of Staph. aureus infections, were detected at a high rate.
  • Küçük Resim Yok
    Öğe
    Investigation of toxin genes in Staphylococcus aureus strains isolated in Mustafa Kemal University Hospital
    (Nisan 2011) Demir Cemil; Aslantas, Ozkan; Duran, Nızamı; Ocak, S; Özer, Burcın
    Aim: The aim of this study was to investigate the presence of genes encoding staphylococcal enterotoxins (SEs), exfoliative toxins (ETAs, ETBs), and toxic shock syndrome toxin-1 (TSST-1) by polymerase chain reaction (PCR) in Staphylococcus aureus strains isolated from various clinical samples from the Mustafa Kemal University Hospital. In addition, PCR-based restriction fragment length polymorphism (RFLP) analysis of the coa gene was employed to genotype the isolates. Materials and methods: A total of 120 S. aureus strains isolated from various clinical samples (blood, wounds, urine, conjuctival swabs, and tracheal aspirate) over a 1 year period, 2007-2008, were used in this study. Results: Almost 65.8% of the isolates possessed at least one toxin gene. The genes most frequently found were seg-sei (40.8%), followed by sea (30%) and eta (19.2%). Overall, 35 toxin genotypes were observed, among which the genotypes seg-sei, sea-seg-sei, and sea-see predominated at the rate of 8.3%, 5.8%, and 5%, respectively. Four coagulase genotype patterns were observed, with molecular sizes ranging from 570 to 970 bp. Coo-based RFLP analysis revealed 7 different patterns using Conclusion: Our results have revealed that toxin genes were very prevalent among S. aureus isolates, and the toxigenic isolates were independent of the genotypes obtained by PCR-RFLP of the coa gene (P > 0.05).
  • Küçük Resim
    Öğe
    Isolation and Molecular Characterization of Methicillin-Resistant Staphylococci from Horses, Personnel and Environmental Sites at an Equine Hospital in Turkey
    (JAPAN SOC VET SCI, 2012) Aslantas, Ozkan; Turkyilmaz, Suheyla; Yilmaz, Mehmet Ali; Erdem, Zeynep; Demir, Cemil
    The present study was carried out to assess the frequency of methicillin-resistant staphylococci (MRS) among racehorses (n=209) and veterinary personnel (n=13) as well as environmental surfaces (n=14) at an equine hospital in Adana, Turkey. In addition, species distribution, antimicrobial susceptibility, resistance genes, staphylococcal chromosomal cassette mec (SCCmec) type and clonality of these isolates were also investigated. MRS were identified by 16S rRNA sequencing, and typed by pulsed-field gel electrophoresis (PFGE). As a result, MRS was isolated in horses (48.3%), clinic staff (92.3%) and environmental samples (71.4%). Of the 123 MRS isolates, 118 isolates were identified as Staphylococcus lentus, and the remaining ones were found to be S. sciuri (n=3), S. intermedius (n=1) and S. fleuretti (n=1). All isolates were found to be susceptible against vancomycin, quinupristin-dalfopristin and rifampicin. Additionally, single or various combinations of resistance genes were detected among MRS isolates. SCCmec type II was identified in all isolates. Similar PFGE patterns were observed among MRS isolated from horses, humans, and environmental samples. Since MRS were concurrently isolated from horses and humans it is suggested that cross-transmission of MRS between horses and humans might occur. However, it cannot be ruled out that transmission is human to animal or animal to human.