Session: P059 Activity of newer and older antimicrobials against Gram-negative organisms Category: 3b. Resistance surveillance & epidemiology: Gram-negatives 24 April 2017, 12:30 - 13:30 P1275 Antimicrobial susceptibilities of temocillin and other agents against Enterobacteriaceae in Hong Kong Margaret Ip*1, Peter M. Hawkey2, Sebastien Van de Velde3, Koon Chi Christoper Lai4, Kitty Fung5, Tak Wong6, Chendi Zhu6, Dominic N.C. Tsang4 1Chinese University of Hong Kong; Microbiology 2Public Health England; Public Health Laboratory 3Eumedica Pharmaceuticals 4Queen Elizabeth Hospital 5United Christian Hospital 6Chinese University of Hong Kong Background: Temocillin (TMO), a narrow spectrum penicillin with intrinsic stability to extended spectrum, AmpC beta-lactamases, Klebsiella pneumoniae carbapenemases, is increasingly used in European countries for the treatment of Gram negative infections including those caused by ESBL- producing Enterobacteriaceae, thus sparing the use of broad-spectrum antibiotics such as carbapenems. Except for a published report from Korea, no data is available on temocillin susceptibilities in Asian countries where antimicrobial resistance is prevalent. We thus sought to evaluate the in vitro activity of temocillin and commonly used antimicrobials against clinical isolates of Enterobacteriaceae in patients with urinary tract infections and/or bacteremia in Hong Kong hospitals. Material/methods: A total of 613 isolates of Enterobacteriaceae from participating hospitals between Jan15-Jan16 was tested. Non-duplicate isolates were obtained from blood (n=310) or urine (with clinically significant bacteriuria) (n=303) specimens from patients who attended three of seven clusters of public hospitals of the Hospital Authority, Hong Kong. The MICs of 16 antibiotics: temocillin, ceftriaxone (CFT), ceftazidime (CAZ), cefepime (CPE), ertapenem (ETP), meropenem (MEP), gentamicin (G), amikacin (AN), ciprofloxacin (CIP), piperacillin/tazobactam (PTZ), amoxicillin/clavulanate (AMC), trimethoprim/sulfamethoxazole (SXT), nitrofurantoin (NIT), fosfomycin (FOS), colistin (CL), and tigecycline (TGC) were tested by CLSI microbroth dilution method. For temocillin, MICs according to CLSI and BSAC methods were performed and were interpreted using the BSAC systemic and urinary breakpoints. Results: Overall, 93.0% (570) of 613 isolates were susceptible to temocillin using BSAC systemic breakpoint (≤8 mg/L) and all were susceptible using the urinary breakpoint (≤32 mg/L). The susceptibility rates were 91.9% (285/310) for blood and 100% (303/303) for urine isolates according to their respective systemic and urinary breakpoints (Figure). ESBL positivity rate was 23.2% (118/508 of E. coli, K spp, P. spp). Temocillin MIC50 and MIC90 against ESBL positive isolates were 8 mg/L and 16 mg/L respectively. Two isolates (1 E. coli (TMO MIC 64 mg/L), 1 Klebsiella species (TMO MIC 32 mg/mL) were resistant to meropenem and possessed the NDM-5 and KPC-2 genes respectively. Conclusions: Temocillin may be a useful alternative for the treatment of infections caused by ESBL- and MDR-Enterobacteriaceae in Hong Kong, particularly as resistance rates are high to agents such as ciprofloxacin, nitrofurantoin and piperacilllin/tazobactam. Figure. *breakpoints according to BSAC, TMO*Bl, blood (n=310), TMO*Ur, urine (n=303) #performed according to CLSI with glucose-6-phosphate suppl., ##breakpoints according to CLSI for non-fermenters (Pseudomonas aeruginosa), **interpreted with EUCAST breakpoints, ++ESBL testing inc. E.coli, Klebsiella spp, Proteus spp only.