Besifloxacin: a novel anti-infective for the treatment of bacterial conjunctivitis

Bacterial conjunctivitis, commonly known as pink eye, is demographically unbiased in its prevalence and can be caused by a variety of aerobic and anaerobic bacteria. Timely empiric treatment with a broad-spectrum anti-infective, such as a topical fluoroquinolone, is critical in preventing potentially irreversible ocular damage. However, the rise in ocular methicillin- resistant Staphylococcus aureus isolates and the patterns of fluoroquinolone resistance for patients with other ocular bacterial infections mandate the need for new agents targeted for ocular use. Besifloxacin, a novel broad-spectrum fluoroquinolone, is approved for the treatment of bacterial conjunctivitis. It has a uniquely balanced dual-targeting activity that inhibits both DNA gyrase and topoisomerase IV and is associated with a lower incidence of resistance development. Besifloxacin is not marketed in other formulations, ensuring that its exposure is limited to bacterial populations in and around the eye. This specifically precludes any bacterial exposure to besifloxacin resulting from systemic use, which further reduces the likelihood of emergence of bacterial resistance. In vitro, besifloxacin has demonstrated equivalent or superior activity compared with other commonly used topical antibiotics. In clinical trials, besifloxacin has consistently demonstrated efficacy and safety in the treatment of patients with bacterial conjunctivitis. Besifloxacin is considered safe and is well tolerated with no observed contraindications

Post-cataract outcomes in patients with noninfectious posterior uveitis treated with the fluocinolone acetonide intravitreal implant

PURPOSE: To describe visual acuity (VA) and inflammation following cataract surgery in eyes with noninfectious posterior uveitis (NIPU) that were being treated with a fluocinolone acetonide (FA) intravitreal implant compared with those that were not. DESIGN: Post hoc, subgroup analysis of data from a 3-year, dose-masked, randomized, multicenter trial evaluating the FA implant for the treatment of NIPU. PARTICIPANTS AND CONTROLS: The subset of eyes that underwent cataract surgery during the 3-year trial. Eyes were either implanted with a 0.59- or a 2.1-mg FA implant, or, in the case of affected fellow eyes, received standard-of-care local treatment. MAIN OUTCOME MEASURES: VA, anterior and posterior chamber inflammation at 1 and 3 months after surgery, and rate of uveitis recurrence and serious postoperative ocular adverse events. RESULTS: Of 278 patients enrolled in the main trial, 132/142 phakic implanted eyes and 39/186 phakic non-implanted eyes underwent cataract surgery. Mean improvement in VA was significantly greater in implanted than non-implanted eyes at 1 (P = 0.0047) and 3 months (P = 0.0015) postoperatively; significantly fewer anterior chamber cells were seen in implanted than non-implanted eyes at 1 (P = 0.0084) and 3 months (P = 0.0002). Severity of vitreous haze was less in implanted than non-implanted eyes at 3 months postoperatively (P = 0.0005). The postsurgical uveitis recurrence rate was lower in implanted than non-implanted eyes (26.5% vs 44.4%; P = 0.0433). Glaucoma was reported in 19.7% of implanted eyes and no non-implanted eyes (P = 0.0008) postoperatively. CONCLUSION: In this post hoc subgroup analysis, eyes with NIPU treated with the FA intravitreal implant demonstrated better vision and less intraocular inflammation following cataract surgery than non-implanted eyes. Recurrent uveitic inflammation did not appear to be triggered by cataract surgery. Glaucoma occurred more frequently in implanted eyes

Safety and efficacy of loteprednol etabonate ophthalmic ointment 0.5% for the treatment of inflammation and pain following cataract surgery

Timothy L Comstock1 Michael R Paterno1 Angele Singh1 Tara Erb1 Elizabeth Davis21Bausch and Lomb Inc., Rochester, NY, USA; 2Minnesota Eye Consultants, Bloomington, MN, USABackground: To compare the safety and efficacy of loteprednol etabonate ophthalmic ointment 0.5% (LE ointment), a new topical ointment formulation, with vehicle for the treatment of inflammation and pain following cataract surgery.Methods: Two randomized, multicenter, double-masked, parallel-group, vehicle-controlled studies were conducted. Patients aged ≥18 years with a combined postoperative anterior chamber cells and flare (ACI) ≥ Grade 3 following uncomplicated cataract surgery participated in seven study visits. Patients self-administered either topical LE ointment or vehicle four times daily for 14 days. Efficacy outcomes included the proportion of patients with complete resolution of ACI and the proportion of patients with no (Grade 0) pain at postoperative day 8. Safety outcomes included the incidence of adverse events, ocular symptoms, changes in intraocular pressure and visual acuity, and biomicroscopy and funduscopy findings.Results: Data from the two studies were combined. The integrated intent-to-treat population consisted of 805 patients (mean [standard deviation] age 69.0 [9.2] years; 58.0% female and 89.7% white). Significantly more LE ointment-treated patients than vehicle-treated patients had complete resolution of ACI (27.7% versus 12.5%) and no pain (75.5% versus 43.1%) at day 8 (P < 0.0001 for both). Fewer LE ointment-treated patients required rescue medication (27.7% versus 63.8%), and fewer had an ocular adverse event (47.2% versus 78.0%, P < 0.0001) while on study treatment. The most common ocular adverse events with LE ointment were anterior chamber inflammation, photophobia, corneal edema, conjunctival hyperemia, eye pain, and iritis. Mean intraocular pressure decreased in both treatment groups. Four patients had increased intraocular pressure ≥10 mmHg (three LE ointment and one vehicle) prior to rescue medication. Visual acuity and dilated funduscopy results were similar between the treatment groups, with the exception of visual acuity at visits 5 and 6, which favored LE ointment.Conclusion: LE ointment was efficacious and well tolerated in the treatment of ocular inflammation and pain following cataract surgery.Keywords: loteprednol etabonate, ophthalmic ointment, postoperative inflammation, postoperative pain, cataract surgery, intraocular pressur

Reducing the Activity and Secretion of Microbial Antioxidants Enhances the Immunogenicity of BCG

BACKGROUND:In early clinical studies, the live tuberculosis vaccine Mycobacterium bovis BCG exhibited 80% protective efficacy against pulmonary tuberculosis (TB). Although BCG still exhibits reliable protection against TB meningitis and miliary TB in early childhood it has become less reliable in protecting against pulmonary TB. During decades of in vitro cultivation BCG not only lost some genes due to deletions of regions of the chromosome but also underwent gene duplication and other mutations resulting in increased antioxidant production. METHODOLOGY/PRINCIPAL FINDINGS:To determine whether microbial antioxidants influence vaccine immunogenicity, we eliminated duplicated alleles encoding the oxidative stress sigma factor SigH in BCG Tice and reduced the activity and secretion of iron co-factored superoxide dismutase. We then used assays of gene expression and flow cytometry with intracellular cytokine staining to compare BCG-specific immune responses in mice after vaccination with BCG Tice or the modified BCG vaccine. Compared to BCG, the modified vaccine induced greater IL-12p40, RANTES, and IL-21 mRNA in the spleens of mice at three days post-immunization, more cytokine-producing CD8+ lymphocytes at the peak of the primary immune response, and more IL-2-producing CD4+ lymphocytes during the memory phase. The modified vaccine also induced stronger secondary CD4+ lymphocyte responses and greater clearance of challenge bacilli. CONCLUSIONS/SIGNIFICANCE:We conclude that antioxidants produced by BCG suppress host immune responses. These findings challenge the hypothesis that the failure of extensively cultivated BCG vaccines to prevent pulmonary tuberculosis is due to over-attenuation and suggest instead a new model in which BCG evolved to produce more immunity-suppressing antioxidants. By targeting these antioxidants it may be possible to restore BCG's ability to protect against pulmonary TB

Host-Adaptation of Francisella tularensis Alters the Bacterium's Surface-Carbohydrates to Hinder Effectors of Innate and Adaptive Immunity

The gram-negative bacterium Francisella tularensis survives in arthropods, fresh water amoeba, and mammals with both intracellular and extracellular phases and could reasonably be expected to express distinct phenotypes in these environments. The presence of a capsule on this bacterium has been controversial with some groups finding such a structure while other groups report that no capsule could be identified. Previously we reported in vitro culture conditions for this bacterium which, in contrast to typical methods, yielded a bacterial phenotype that mimics that of the bacterium's mammalian, extracellular phase.SDS-PAGE and carbohydrate analysis of differentially-cultivated F. tularensis LVS revealed that bacteria displaying the host-adapted phenotype produce both longer polymers of LPS O-antigen (OAg) and additional HMW carbohydrates/glycoproteins that are reduced/absent in non-host-adapted bacteria. Analysis of wildtype and OAg-mutant bacteria indicated that the induced changes in surface carbohydrates involved both OAg and non-OAg species. To assess the impact of these HMW carbohydrates on the access of outer membrane constituents to antibody we used differentially-cultivated bacteria in vitro to immunoprecipitate antibodies directed against outer membrane moieties. We observed that the surface-carbohydrates induced during host-adaptation shield many outer membrane antigens from binding by antibody. Similar assays with normal mouse serum indicate that the induced HMW carbohydrates also impede complement deposition. Using an in vitro macrophage infection assay, we find that the bacterial HMW carbohydrate impedes TLR2-dependent, pro-inflammatory cytokine production by macrophages. Lastly we show that upon host-adaptation, the human-virulent strain, F. tularensis SchuS4 also induces capsule production with the effect of reducing macrophage-activation and accelerating tularemia pathogenesis in mice.F. tularensis undergoes host-adaptation which includes production of multiple capsular materials. These capsules impede recognition of bacterial outer membrane constituents by antibody, complement, and Toll-Like Receptor 2. These changes in the host-pathogen interface have profound implications for pathogenesis and vaccine development

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Advances in Corticosteroid Therapy for Ocular Inflammation: Loteprednol Etabonate

Topical corticosteroids are effective in reducing anterior segment inflammation but are associated with adverse drug reactions (ADRs) including elevation of intraocular pressure (IOP) and cataract formation. Retrometabolic drug design has advanced the development of new corticosteroids with improved therapeutic indices. Engineered from prednisolone, loteprednol etabonate (LE) has a 17α-chloromethyl ester, in lieu of a ketone group, and a 17β-etabonate group. LE is highly lipophilic and binds with high affinity to the glucocorticoid receptor; any unbound LE is metabolized to inactive metabolites. LE has been studied in several anterior segment inflammatory conditions (giant papillary conjunctivitis, allergic conjunctivitis, anterior uveitis, and keratoconjunctivitis sicca), and in postoperative ocular inflammation and pain. Combined with tobramycin, it is effective in blepharokeratoconjunctivitis. Elevations in IOP are infrequent with LE, and the absence of a C-20 ketone precludes formation of Schiff base intermediates with lens proteins, a common first step implicated in cataract formation with ketone steroids