Fluoroquinolones are a group of synthetic antibiotics with a broad activity spectrum against mycoplasma, Gram-positive, and Gram-negative bacteria. Due to the extensive use of fluoroquinolones in farming and veterinary science, there is a constant need in the analytical methods able to efficiently monitor their residues in food products of animal origin, regulated by Commission Regulation (Euro...

ABSTRACT: Resistance to the various classes of antimicrobials continues to increase in virtually all clinically significant gram-negative and gram-positive bacteria. In particular, rates of resistance to -lactam and macrolide antimicrobial agents are on the rise among the most common bacterial pathogens, including Streptococcus pneumoniae and Haemophilus influenzae. In the bacterial cell, the f...

Recent evidence strongly suggests an association between the use of fluoroquinolones and Clostridium difficile infection (CDI). Resistance to fluoroquinolones has been described not only in the hypervirulent strain 027, but also in other important PCR ribotypes circulating in hospital settings. In a European prospective study conducted in 2005, strains resistant to moxifloxacin represented 37.5...

We compared the activities of ciprofloxacin and levofloxacin with those of the newer fluoroquinolones grepafloxacin, moxifloxacin, sparfloxacin and trovafloxacin against Clostridium difficile isolates. As there is good evidence of marked clonal spread of C. difficile, we studied both genotypically distinct (n = 26) and indistinguishable (n = 28) isolates as determined by random amplified polymo...

In recent decades, fluoroquinolones have been broadly used to treat health care-associated Gram-negative bacterial infections. Ciprofloxacin is the most commonly used fluoroquinolone for treatment of UTIs as it exists in oral and intravenous preparations (Schaeffer, 2002). However, resistance to fluoroquinolones has become prevalent due to this widespread use (Ena et al.,1998). Mutation in DNA ...

The mode of action of sulfanilyl fluoroquinolones (NSFQs) was investigated with NSFQ-104, NSFQ-105, and some structurally related compounds. Evidence arising from interactions with p-aminobenzoic acid and trimethoprim suggested that a sulfonamidelike mechanism of action makes little or no contribution to the in vitro activity of NSFQs. NSFQ-105 showed an activity that inhibits gyrase-catalyzed ...

The activities of six fluoroquinolones were determined for 117 separate strains of Shigella sonnei. The order of increasing activity (MICs for 90% of strains tested) was enoxacin (0.25 micrograms/ml), temafloxacin (0.032 micrograms/ml), sparfloxacin (0.016 micrograms/ml), CI-960 (0.008 micrograms/ml), ciprofloxacin (0.008 micrograms/ml), and PD-131628-2 (0.008 micrograms/ml). These data, along ...

In a previous study, we reported that two kaempferol glycosides isolated from Laurus nobilis L., kaempferol-3-O-alpha-L-(2'',4''-di-E-p-coumaroyl)-rhamnoside (C2) and kaempferol-3-O-alpha-L-(2''-E-p-coumaroyl-4''-Z-p-coumaroyl)-rhamnoside (C3), showed strong antibacterial activities against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci. Thereafter we fo...

Most Escherichia coli resistant to quinolones are not haemolytic. The objective of this study was to determine the phylogroup, clonal relationship, mechanism of quinolone resistance and virulence factors in 70 haemolytic E. coli resistant to nalidixic acid. Sixty-six isolates contained the hlyA gene, belonged to phylogroup B2, and 61 of them presented low-level resistance to fluoroquinolones. F...