ICU-Associated Gram-Negative Bloodstream Infection: Risk Factors Affecting the Outcome Following the Emergence of Colistin-Resistant Isolates in a Regional Greek Hospital oleh Marios Karvouniaris, Garyphallia Poulakou, Konstantinos Tsiakos, Maria Chatzimichail, Panagiotis Papamichalis, Anna Katsiaflaka, Katerina Oikonomou, Antonios Katsioulis, Eleni Palli, Apostolos Komnos