OBJECTIVES To assess risk factors for fluoroquinolone resistance in community-onset febrile Escherichia coli urinary tract infection (UTI). METHODS A nested case-control study within a cohort of consecutive adults with febrile UTI presenting at primary healthcare centres or emergency departments during January 2004 through December 2009. Resistance was defined using EUCAST criteria (ciproflox...

Fluoroquinolone resistance is mainly caused by mutations in quinolone resistance-determining regions of DNA gyrase and topoisomerase IV in Escherichia coli. The AcrAB-TolC efflux pump contributes to resistance against fluoroquinolone and other antimicrobials. In this study, we investigated a high-level mechanism of fluoroquinolone resistance in E. coli that was isolated from human clinical samp...

We determined the prevalence of fluoroquinolone resistance among the isolates of Mycobacterium tuberculosis from 605 pulmonary tuberculosis patients in Shanghai, China. Mutations in gyrA were found in 81.5% of phenotypically fluoroquinolone-resistant isolates and were used as a molecular marker of fluoroquinolone resistance. gyrA mutations were detected in 1.9% of strains pan-susceptible to fir...

Antibiotic resistance in Streptococcus pneumoniae has increased worldwide by the spread of a few clones. Fluoroquinolone resistance occurs mainly by alteration of their intracellular targets, the type II DNA topoisomerases, which is acquired either by point mutation or by recombination. Increase in fluoroquinolone-resistance may depend on the balance between antibiotic consumption and the cost ...

The aim of this study was to determine whether alternative resistance mechanisms, other than mutation in the quinolone resistance-determining region (QRDR) of DNA gyrase, could confer fluoroquinolone resistance in Clostridium difficile. An in vitro-generated C. difficile mutant exhibiting increased fluoroquinolone resistance was isolated through antibiotic selection on ciprofloxacin. The QRDR o...

Few long-term multicenter investigations have evaluated the relationships between aggregate antimicrobial drug use in hospitals and bacterial resistance. We measured fluoroquinolone use from 1999 through 2003 in a network of US hospitals. The percentages of fluoroquinolone-resistant Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) were obtained from yearly antibiogr...

Clinicians have enthusiastically used fluoroquinolones owing to their good safety profile and wide range of indications. This article reviews fluoroquinolone pharmacology, pharmacodynamic principles, and fluoroquinolone resistance mechanisms, highlighting recent trends in the epidemiology of fluoroquinolone resistance among gram-negative organisms and Streptococcus pneumonia. Important fluoroqu...

This paper on the fluoroquinolone resistance epidemiology stratifies the data according to the different prescription patterns by either primary or tertiary caregivers and by indication. Global surveillance studies demonstrate that fluoroquinolone resistance rates increased in the past years in almost all bacterial species except S. pneumoniae and H. influenzae, causing community-acquired respi...

A spontaneous fluoroquinolone-resistant mutant (STM1) was isolated from its parent Salmonella enterica serovar Typhi (S. Typhi) clinical isolate. Unlike its parent isolate, this mutant has selective resistance to fluoroquinolones without any change in its sensitivity to various other antibiotics. DNA gyrase assays revealed that the fluoroquinolone resistance phenotype of the STM1 mutant did not...