Gur, D.Hascelik, G.Aydin, N.Telli, M.Gultekin, M.Ogunc, D.Yaman, G.2025-05-102025-05-1020091120-009X1973-947810.1179/joc.2009.21.4.3832-s2.0-70349210187https://doi.org/10.1179/joc.2009.21.4.383https://hdl.handle.net/20.500.14720/9943Kibar, Filiz/0000-0003-2983-2399; Gur, Deniz/0000-0002-7504-8450; Telli, Murat/0000-0003-2648-881XResistance rates to amikacin, ciprofloxacin, ceftazidime, cefepime, imipenem, cefoperazone/sulbactam and piperacillin/tazobactam in Escherichia coli (n = 438), Klebsiella pneumoniae (n = 444), Pseudomonas aeruginosa (n = 210) and Acinetobacter baumanni (n =200) were determined with E-test in a multicenter surveillance study (HITIT-2) in 2007. ESBL production in Escherichia coli and K. pneumoniae was investigated following the CLSI guidelines. Overall 42.0% of E.coli and 41.4% of K. pneumoniae were ESBL producers. In E. coli, resistance to imipenem was not observed, resistance to ciprofloxacin and amikacin was 58.0% and 5.5% respectively. In K. pneumoniae resistance to imipenem, ciprofloxacin and amikacin was 3.1%, 17.8% 12.4% respectively. In P. aeruginosa the lowest rate of resistance was observed with piperacillin/tazobactam (18.1%). A. baumanni isolates were highly resistant to all the antimicrobial agents, the lowest level of resistance was observed against cefoperazone/sulbactam (52.0%) followed by imipenem (55.5%). This study showed that resistance rates to antimicrobials are high in nosocomial isolates and show variations among the centers.eninfo:eu-repo/semantics/closedAccessAntimicrobial ResistanceEsblGram-Negative BacteriaBeta-Lactamase InhibitorE.ColiK. PneumoniaeP. AeruginosaA. BaumanniiArticle214Q4Q338338919622455WOS:000269414100003