Karahan, Zeynep CerenSalman, Emrah2022-08-122022-08-122015http://hdl.handle.net/20.500.12575/83101Clostridium difficile infection is one of the most common hospital-acquired infections. Hypervirulent strains of C. difficile which produce toxins at high levels (PCR ribotype 027) and are characterized by a high sporulation ratio and higher resistance rates for fluoroquinolones. Infections caused by C. difficile PCR ribotype 027 also have higher morbidity and mortality, more complications and relapses. If highly pathogenic strains of C. difficile such as ribotype 027 arise in a country, it should be identified before causing a severe outbreak. Otherwise it can lead to the serious morbidities such as colectomies, increase in mortalities and remarkable costs in health services. To reduce the risk in the unaffected countries and mitigate the consequences of future outbreaks, surveillance activities should be implemented in order to investigate the factors thorough evidence based medicine. In this study fecal samples were collected from inpatients hospitalized at different hospitals in Ankara (Ankara University School of Medicine and Hacettepe University School of Medicine) and from who applied to a Private Laboratory (Düzen Laboratory Groups) in Ankara. After isolating C. difficile from fecal samples, DNA of the isolates were extracted. Antimicrobial susceptibility and presence of toxin genes were investigated. All of the strains were found to be susceptible to vancomycin and metronidazole. Three strains had a minimum inhibitory concentration (MIC) of >4 µg/ml and were resistant to moxifloxacin. One strain had a minimum inhibitory concentration (MIC) of >256 µg/ml and was resistant to clindamycin also two strains had a minimum inhibitory concentration (MIC) of >256 µg/ml and were resistant to erythromycin. Seventeen isolates had a minimum inhibitory concentration (MIC) of 2-8 µg/ml and were intermediate to clindamycin also five strains had a minimum inhibitory concentration (MIC) of 2-8 µg/ml and were intermediate to erythromycin. All of the strains were found to carry tcdA and tcdB genes. On the other hand, only one C. difficile strain (1.6%) was found to carry the "binary" toxin (cdtA and cdtB) genes in 61 strains. Bi-directional DNA sequence analysis was performed on the amplified tcdC gene in order to investigate the presence of deletion which defines the PCR ribotype 027 strains and other rare single nucleotide polymorphisms. One C. difficile strain was found to carry a 54 bp deletion also 12 strains were found to carry various single nucleotide polymorphisms. In the evaluated strains, PCR ribotype 027 wasn't detected but there was the first hypervirulent strain in Turkey.trClostridium difficileantimikrobiyal dirençgradyent testMedicalThesis