Low-level resistance to the cephalosporin 3'-quinolone ester Ro 23-9424 in Escherichia coli.
نویسندگان
چکیده
Four spontaneous, single-step mutants of Escherichia coli K-12 resistant to low levels of the cephalosporin 3'-quinolone ester Ro 23-9424 were isolated at a frequency of 10(-10) to 10(-11) mutants per CFU plated. The mutants were cross-resistant to both cephalosporin (cefotaxime) and quinolone (fleroxacin) components. Accordingly, they had altered porins and replicative DNA biosynthesis resistant to fleroxacin. There was no increase in beta-lactamase activity when tested with nitrocephin, and the penicillin-binding protein profiles were normal.
منابع مشابه
Escherichia coli resistant to cephalosporins and quinolones is still susceptible to the cephalosporin-quinolone ester Ro 23-9424.
Ro 23-9424 is a broad-spectrum antibacterial agent consisting of a cephalosporin (desacetylcefotaxime) linked through an ester bond to a fluoroquinolone (fleroxacin). Its activity against mutants of Escherichia coli TE18 resistant to both antibacterial components was examined. E. coli TE18 overproduces the AmpC beta-lactamase and is resistant to several cephalosporins, including desacetylcefota...
متن کاملPharmacokinetics of Ro 23-9424, a dual-action cephalosporin, in animals.
Ro 23-9424 is a dual-action cephalosporin with an aminothiazolylmethoxyimino-type side chain at the 7 position and fleroxacin esterified at the 3' position. The new compound has broad and potent antibacterial activity in vitro and in vivo, reflecting contributions from both the beta-lactam moiety and the quinolone moiety. In animals, the ester bond potentially could be hydrolyzed enzymatically ...
متن کاملHigh frequency of mutations in gyrA gene associated with quinolones resistance in uropathogenic Escherichia coli isolates from the north of Iran
Objective(s): Regarding the global burden of uropathogenic Escherichia coli (UPEC) infections, prevention and treatment of such infections play a significant role in healthcare management. The inordinate use of fluoroquinolones led to a worldwide spread of quinolone-resistant strains. Therefore, this study aimed to investigate mutations in codons 83 and 106 of gyrA gene in UPEC isolates in the ...
متن کاملThe involvement of mutation in the serine 83 of quinolone resistant determining regions of the GyrA Gene in resistance to ciprofloxacin in Escherichia coli .
Appearance of bacteria resistant to antibacterial agents puts physicians in trouble and threatens the health of the world. The rapid development of bacterial resistance in Escherichia coli to ciprofloxacin makes difficult the treatment of infectious diseases. So, detection of the locations of possible mutations in gyrase A gene ( gyrA ) in these mutants is very important to determine the mech...
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Background: Avian pathogenic Escherichia coli (APEC), which is the causative agent of colibacillosis, harbors several putative virulence genes. An important trait of APEC for both poultry and public health is antibiotic resistance. Objectives: In the present study, some potential virulence genes of APECs isolated from Northeast of Iran and their resistance to the quinolones antibiotics were stu...
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ورودعنوان ژورنال:
- Antimicrobial agents and chemotherapy
دوره 39 2 شماره
صفحات -
تاریخ انتشار 1995