Cumulative clinical experience from over a decade of use of levofloxacin in urinary tract infections: critical appraisal and role in therapy

Biotransformation of the Fluoroquinolone, Levofloxacin, by the White-Rot Fungus Coriolopsis gallica

The wastewater from hospitals, pharmaceutical industries and more generally human and animal dejections leads to environmental releases of antibiotics that cause severe problems for all living organisms. The aim of this study was to investigate the capacity of three fungal strains to biotransform the fluoroquinolone levofloxacin. The degradation processes were analyzed in solid and liquid media. Among the three fungal strains tested, Coriolopsis gallica strain CLBE55 (BRFM 3473) showed the highest removal efficiency, with a 15% decrease in antibiogram zone of inhibition for Escherichia coli cultured in solid medium and 25% degradation of the antibiotic in liquid medium based on high-performance liquid chromatography (HPLC). Proteomic analysis suggested that laccases and dye-decolorizing peroxidases such as extracellular enzymes could be involved in levofloxacin degradation, with a putative major role for laccases. Degradation products were proposed based on mass spectrometry analysis, and annotation suggested that the main product of biotransformation of levofloxacin by Coriolopsis gallica is an N-oxidized derivative.

Robust antibacterial activity of functionalized carbon nanotube- levofloxacine conjugate based on in vitro and in vivo studies

A new nano-antibiotic was synthesized from the conjugation of multi-walled carbon nanotubes with levofloxacin (MWCNT-LVX) through covalent grafting of drug with surface-modified carbon nanotubes in order to achieve an effective, safe, fast-acting nano-drug with the minimal side effects. This study is the first report on the evaluation of in vitro cell viability and antibacterial activity of nano-antibiotic along in addition to the in vivo antibacterial activity in a burn wound model. The drug-loading and release profile at different pH levels was determined using an ultraviolet–visible spectrometer. MWCNT-LVX was synthesized by a simple, reproducible and cost-effective method for the first time and characterized using various techniques, such as scanning electron microscope, transmission electron microscopy, and Brunauer–Emmett–Teller analysis, and so forth. The noncytotoxic nano-antibiotic showed more satisfactory in vitro antibacterial activity against Staphylococcus aureus compared to Pseudomona aeruginosa. The novel synthetic nano-drug possessed high loading capacity and pH-sensitive release profile; resultantly, it exhibited very potent bactericidal activity in a mouse S. aureus wound infection model compared to LVX. Based on the results, the antibacterial properties of the drug enhanced after conjugating with surface-modified MWCNTs. The nano-antibiotic has great industrialization potential for the simple route of synthesis, no toxicity, proper drug loading and release, low effective dose, and strong activity against wound infections. In virtue of unique properties, MWCNTs can serve as a controlled release and delivery system for drugs. The easy penetration to biological membranes and barriers can also increase the drug delivery at lower doses compared to the main drug alone, which can lead to the reduction of its side effects. Hence, MWCNTs can be considered a promising nano-carrier of LVX in the treatment of skin infections.

Melt-extrusion 3D printing of resorbable levofloxacin-loaded meshes: Emerging strategy for urogynaecological applications

Current surgical strategies for the treatment of pelvic floor dysfunctions involve the placement of a polypropylene mesh into the pelvic cavity. However, polypropylene meshes have proven to have inadequate mechanical properties and have been associated to the arising of severe complications, such as infections. Furthermore, currently employed manufacturing strategies are unable to produce compliant and customisable devices. In this work, polycaprolactone has been used to produce resorbable levofloxacin-loaded meshes in two different designs (90° and 45°) via melt-extrusion 3D printing. Drug-loaded meshes were produced using a levofloxacin concentration of 0.5% w/w. Drug loaded meshes were successfully produced with highly reproducible mechanical and physico-chemical properties. Tensile test results showed that drug-loaded 45° meshes possessed a mechanical behaviour close to that of the vaginal tissue (E ≃ 8.32 ± 1.85 MPa), even after 4 weeks of accelerated degradation. Meshes released 80% of the loaded levofloxacin in the first 3 days and were capable of producing an inhibitory effect against S. Aureus and E. coli bacterial strains with an inhibition zone equal to 12.8 ± 0.45 mm and 15.8 ± 0.45 mm respectively. Thus, the strategy adopted in this work holds great promise for the manufacturing of custom-made surgical meshes with antibacterial properties.

Antimicrobial Resistance Gene Prevalence in a Population of Patients with Advanced Dementia Is Related to Specific Pathobionts

Long-term care facilities are significant reservoirs of antimicrobial-resistant organisms, and patients with advanced dementia are particularly vulnerable to multidrug-resistant organism (MDRO) acquisition and antimicrobial overuse. In this study, we longitudinally examined a group of patients with advanced dementia using metagenomic sequencing. We found significant inter- and intra-subject heterogeneity in microbiota composition, suggesting temporal instability. We also observed a link between the antimicrobial resistance gene density in a sample and the relative abundances of several pathobionts, particularly Escherichia coli, Proteus mirabilis, and Enterococcus faecalis, and used this relationship to predict resistance gene density in samples from additional subjects. Furthermore, we used metagenomic assembly to demonstrate that these pathobionts had higher resistance gene content than many gut commensals. Given the frequency and abundances at which these pathobionts were found in this population and the underlying vulnerability to MDRO of patients with advanced dementia, attention to microbial blooms of these species may be warranted.

Draft Genome Sequence of Uropathogenic Escherichia coli Strain NB8

Escherichia coli NB8 is a clinical pyelonephritis isolate. Here, we report the draft genome sequence of uropathogenic E. coli NB8, which contains drug resistance genes encoding resistance to beta-lactams, aminoglycosides, quinolones, macrolides, colistin, sulfonamide-trimethoprim, and tetracycline. NB8 infects the kidney and bladder, making it an important tool for studying E. coli pathogenesis.

Antibiotic prescription by general practitioners for urinary tract infections in outpatients

In July 2008, in France, guidelines for antibiotic prescriptions for urinary tract infections (UTIs) were amended. As general practitioners (GPs) treat numerous UTIs, we wanted to evaluate whether they followed these guidelines. In order to do this, we performed a prospective study. The point of call was urinalyses. Using this selection method together with criteria diagnostic for urinalysis, we confirmed that patients presented a UTI. Each GP was contacted. Prescriptions were analysed and compared to the 2008 French guidelines for UTIs. Our study included 185 urinalyses. UTIs diagnosed by GPs were as follows: acute cystitis: 72.4 %, prostatitis: 13.5 %, nephritis: 8.7 % and asymptomatic bacteriuria: 5.4 %. The principal antibiotics used were: quinolone (59.5 %), furan (17.8 %) and cotrimoxazole (6.5 %). Only 20 % of the prescriptions were compliant with the guidelines. The correct antibiotic but not the dose or the duration of prescription was selected in 8.1 % of the prescriptions. For cystitis, inappropriate prescription was associated with an extra cost of 694 <euro>, namely, 7.4 <euro> per treatment. GP prescriptions for UTIs do not follow the guidelines. Even if GPs assert that they are aware of the emergence of resistant strains, it seems that they do not take into account the objective of quinolone restriction, which was one of the backbones of these guidelines.