Vol.52 No.10 October 2004

Antimicrobial activity of antimicrobials against extended-spectrum β -lactamase (ESBL) in Escherichia coli

Tetsuro Muratani^1,2), Tomoko Kobayashi²⁾, Ryoko Gotoh²⁾, Akiko Wada²⁾, Suminori Arima²⁾, Masanori Ohkuma²⁾, Hiroko Yakushiji²⁾, Yuko Odahara²⁾, Masayuki Shigetaka²⁾, Kohei Ohkubo²⁾, Yoji Yamada¹⁾ and Tetsuro Matsumoto¹⁾

¹⁾Department of Urology, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Japan
²⁾Hibiki Research Group for Clinical Microbiology

Abstract

We studied the antimicrobial activity of 42 antimicrobial agents against 143 Escherichia coli isolates identified structural gene of extended-spectrum β -lactamase. The 143 isolates were from 133 patients who visited 31 hospitals in northern Kyushu and Yamaguchi. ESBL items were UOE-2 (CTX-M-14 or -18) type 34, CTX-M-2 type 43, CTX-M-3 type 17, UOE-1 type (CTX-M-15) 24, CTX-M-12 type 3, SHV-12 type 20, and TEM type 2. Against UOE-2 and CTX-M-2 ESBL producing isolates ceftazidime, cefepime, and aztreonam showed comparatively low MIC, and against TEM and SHV type ESBL producing isolates cefotaxime, cefpirome, and cefepime showed comparatively low MIC. Against all ESBL producing isolates, most cephalosporins and penicillins showed high MIC. Carbapenems (imipenem and meropenem) were the most active of all agents tested. The growth of all isolates was inhibited at 0.25 μ g/mL of meropenem and 0.5 μ g/mL of imipenem. Cephamycins, which have methoxy substitute at position 8, also have good activity against ESBL producing E. coli. Cefmetazole had a resistant, and latamoxef and flomoxef were susceptible against all isolates. Regarding β -lactam combined with β -lactamase inhibitor, against CTX-M type ESBL producing isolates piperacillin/tazobactam showed good activity than cefoperazone/sulbactam, while against TEM and SHV type ESBL producing isolates cefoperazone/sulbactam showed good activity than piperacillin/tazobactam. Although the activity of ampicillin/sulbactam and amoxicillin/clavulanic acid improved compared to ampicillin and amoxicillin alone, the improved MIC was not less than the breakpoint MIC. Regarding non-β -lactams, quinolones (ciprofloxacin, levofloxacin, and gatifloxacin), tetracycline, gentamicin, and cotrimoxazole showed less activity, while minocycline and fosfomycin were susceptible more than 75% against ESBL producers except UOE-2 producers. Early detection of ESBL producers and early infection control are vital importance to preventing ESBL producer outbreaks.

Key word

Extended-spectrum β-lactamase (ESBL), Antimicrobial susceptibility, Escherichia coli

Received

July 29, 2004

Accepted

September 1, 2004

Jpn. J. Chemother. 52 (10): 556-567, 2004