Ceftibuten

OBJECTIVES: In Japan, the isolation rate of group B Streptococcus (GBS) with reduced penicillin susceptibility (PRGBS) was 2.3% between 2005 and 2006. However, no data on this have been available since then; moreover, the isolation rate of MDR-PRGBS has never been reported. The aim of this study was to obtain recent data on the PRGBS isolation rate and to investigate, for the first time, the isolation rate of MDR-PRGBS.

Enterobacteriaceae causing community-acquired urinary tract infections were examined in selected outpatient clinics and hospitals in Belgium, Germany and Spain using EUCAST breakpoints for susceptibility. A total of 1190 isolates were collected. Escherichia coli isolates were resistant to amoxicillin-clavulanic acid (28.1%), ciprofloxacin (23.4%) and trimethoprim-sulfamethoxazole (21.4%) compared with fosfomycin and nitrofurantoin (each, <1.5%). Ceftibuten (MIC50/90 0.25/0.5 mg/L) and ceftriaxone activity (MIC50/90 ≤0.25 mg/L) was comparable. Ceftibuten (MIC90 ≤0.25 mg/L) was also active against Proteus mirabilis and Klebsiella spp. Extended-spectrum β-lactamase phenotypes were 7.1% for E. coli, 5.6% for Klebsiella pneumoniae and 0.4% for P. mirabilis. Resistance was common among men and elderly women.

Fosfomycin trometamol (fosfomycin tromethamine) [Monuril(®), Monurol(®), Monural(®)] is approved in numerous countries worldwide, mainly for the treatment of uncomplicated urinary tract infections (UTIs). Fosfomycin has good in vitro activity against common uropathogens, such as Escherichia coli (including extended-spectrum β-lactamase-producing E. coli), Proteus mirabilis, Klebsiella pneumoniae and Staphylococcus saprophyticus, and the susceptibility of uropathogens to fosfomycin has remained relatively stable over time. A single oral dose of fosfomycin trometamol 3 g (the approved dosage) achieves high concentrations in urine. Results of recent randomized trials indicate that single-dose fosfomycin trometamol had similar clinical and/or bacteriological efficacy to 3- to 7-day regimens of ciprofloxacin, norfloxacin, cotrimoxazole or nitrofurantoin in women with uncomplicated lower UTIs. In addition, single-dose fosfomycin trometamol had similar bacteriological efficacy to a 5-day course of cefuroxime axetil or a 7-day course of amoxicillin/clavulanic acid in pregnant women with asymptomatic bacteriuria, and similar clinical and/or bacteriological efficacy to a 5-day course of cefuroxime axetil or amoxicillin/clavulanic acid or a 3-day course of ceftibuten in pregnant women with a lower UTI.

Inadequate and delayed antibiotic treatment of extended spectrum beta-lactamase (ESBL)-producing isolates have been associated with increased mortality of affected patients. The purpose of this study was to compare the host response of human renal epithelial cells and polymorphonuclear leucocyte (PMN) cells when infected by ESBL-producing uropathogenic Escherichia coli (UPEC) isolates in the presence or absence of ineffective antibiotics. The renal epithelial cell line A498 and PMN cells were stimulated with ESBL-producing UPEC isolates in the presence or absence of three different antibiotics (trimetoprim, ceftibuten and ciprofloxacin). Host cell responses were evaluated as release of cytokines (IL-6, IL-8), reactive oxygen species (ROS), ATP and endotoxins. Bacterial morphology and PMN phagocytosis were evaluated by microscopy. In the presence of ceftibuten, 2 out of 3 examined ESBL-isolates changed their morphology into a filamentous form.