Abstract
Limited data are available on temocillin susceptibilities in Enterobacteriaceae from Asian countries where antimicrobial resistance is prevalent. The in vitro activities of temocillin and 15 commonly used antimicrobials against 613 non-duplicate blood (n = 310) and urine (with clinically significant bacteriuria; n = 303) isolates of Enterobacteriaceae from patients who attended 3 out of 7 clusters of public hospitals of the Hospital Authority, Hong Kong, during 2015/2016 were tested. Minimum inhibitory concentrations (MICs) were determined by Clinical and Laboratory Standards Institute (CLSI) microbroth dilution (agar dilution with fosfomycin). For temocillin, MICs were also obtained using the British Society of Antimicrobial Chemotherapy (BSAC) microbroth dilution method and interpreted using the BSAC breakpoints. Overall, 93.0% (570) isolates were susceptible to temocillin using BSAC systemic breakpoint (≤8 mg/L) and all except 2 isolates were susceptible using the urinary breakpoint (≤32 mg/L). The extended spectrum beta-lactamase (ESBL) positivity rate was 23.2% (118 out of 508 E. coli, Klebsiella spp., Proteus spp.). Temocillin resistance rate to ESBL-positive isolates was 16.1% using the systemic breakpoint of ≤8 mg/L (MIC50 and MIC90 were 8 mg/L and 16 mg/L respectively). Two isolates (1 E. coli, temocillin MIC 64 mg/L, 1 Klebsiella sp., MIC 32 mg/mL) were resistant to meropenem and possessed the NDM-5 and KPC-2 genes respectively. Other susceptibility rates were: amoxicillin/clavulanate (59.1%), trimethoprim/sulfamethoxazole (62.5%), ciprofloxacin (71.5%), ceftriaxone (75.4%), nitrofurantoin (76.4%), gentamicin (78.3%), cefepime (81.1%), ceftazidime (83.5%), piperacillin/tazobactam (86%), colistin (88.8%), tigecycline (89.4%), fosfomycin (92.8%), ertapenem (99.0%), amikacin (99.2%) and meropenem (99.7%). Temocillin may be a useful alternative for the treatment of infections caused by ESBL and multi-drug-resistant Enterobacteriaceae in Hong Kong, particularly as resistance rates to ciprofloxacin, nitrofurantoin and piperacillin/tazobactam are high.
Highlights
The global pandemic of CTX-M extended spectrum betalactamases (ESBLs) has driven rates of multi-drug-resistant Gram-negative bacteria (MDRGNB) to unprecedented levels, in Asia [1]
We 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 bacteraemia in Hong Kong hospitals. Most laboratories in this region perform antimicrobial susceptibilities based on the Clinical and Laboratory Standards Institute (CLSI) method, and as the susceptibility to temocillin had been based on the British Society of Antimicrobial Chemotherapy (BSAC)-defined Minimum inhibitory concentrations (MICs) breakpoints for Enterobacteriaceae [8], we examined and compared its activity using the microbroth dilution methods according to the CLSI and the BSAC methods
The susceptibility rates to temocillin according to the BSAC method were 93.0% (570 out of 613) and 100% using the systemic (≤8 mg/L) and urinary (≤32 mg/L) breakpoints respectively
Summary
The global pandemic of CTX-M extended spectrum betalactamases (ESBLs) has driven rates of multi-drug-resistant Gram-negative bacteria (MDRGNB) to unprecedented levels, in Asia [1] This is exemplified by recent data reporting an ESBL rate in E. coli of 66% in China [2], whereas in Hong Kong, 20% of E. coli and 15.4% of K. pneumoniae causing bacteraemia in hospitalized patients had been reported to be ESBL-positive isolates [3, 4]. We sought to evaluate the in vitro activity of temocillin and commonly used antimicrobials (including fosfomycin, tigecycline and colistin) against clinical isolates of Enterobacteriaceae in patients with urinary tract infections and/or bacteraemia in Hong Kong hospitals.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: European Journal of Clinical Microbiology & Infectious Diseases
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
