Comparison of antibiotic drops placed in the conjunctival cul-de-sac to antibiotic ointment applied to the lid margin in reduction of bacterial colonization on the lid margin.

PURPOSE: To compare the efficacy of antibiotic drops placed in the conjunctival cul-de-sac to antibiotic ointment applied to the lid margin in reduction of bacterial colonization on the lid margin. METHODS: A randomized, prospective, single-masked study was conducted on 19 patients with culture-proven colonization of bacteria on the lid margins. Ophthalmic eligibility criteria included the presence of > or =50 colony-forming units/mL (CFU/mL) of bacteria on both right and left lids. Each patient received one drop of ofloxacin in one eye every night for one week, followed by one drop once a week for one month. In the same manner, each patient received bacitracin ointment (erythromycin or gentamicin ointment if lid margin bacteria were resistant to bacitracin) to the lid margin of the fellow eye. Quantitative lid cultures were taken at initial visit, one week, one month, and two months. Fifteen volunteers (30 lids) served as controls. Lid cultures were taken at initial visit, one week, and one month. RESULTS: Both antibiotic drop and ointment reduced average bacterial CFU/mL at one week and one month. Average bacterial CFU/mL reestablished to baseline values at two months. There was no statistically significant difference between antibiotic drop and ointment in reducing bacterial colonization on the lid margin. CONCLUSION: Antibiotic drops placed in the conjunctival cul-de-sac appear to be as effective as ointment applied to the lid margins in reducing bacterial colonization in patients with > or =50 CFU/mL of bacteria on the lid margins.

Analysis of significant factors influencing visual acuity in ocular syphilis.

BACKGROUND: The aim of this study is to determine whether statistical associations can be demonstrated in ocular syphilis between baseline clinical and laboratory parameters with visual acuity at presentation and with any change in visual acuity after treatment. METHODS: Charts of 26 patients (42 eyes) with ocular syphilis presenting to the Uveitis clinic of the Jules-Gonin Eye Hospital were reviewed. A baseline cross-sectional analysis was performed in order to identify any association between visual acuity at presentation and demographic, clinical or laboratory parameters. After treatment, any analogy between these parameters and a change in visual acuity was subsequently assessed in a series of univariate comparisons. RESULTS: The following factors were associated with worse initial visual acuity: severity of visual field impairment at presentation (p=0.012), macular oedema (p=0.004) and optic neuropathy (p=0.031). There was a borderline association with the presence of vasculitis on fluroangiography (p=0.072). Improvement in best corrected visual acuity after treatment was significantly associated with the presence of vasculitis on fluroangiography (p=0.005), neurosyphilis, according to lumbar puncture findings (p=0.037) and marginally with anterior uveitis (p=0.070). Inflammation relapse was associated with the coexistence of pain as presenting sign (p<0.001) and with a longer duration of symptoms prior to the initial visit (p=0.023). CONCLUSIONS: Severe ocular inflammation associated with vasculitis, vitritis or anterior uveitis in ocular syphilis would appear to be a reversible phenomenon that responds well to appropriate antibiotic treatment, resulting in improvement in visual acuity. Prompt treatment enables a good visual prognosis, while any delay in therapy increases the risk of subsequent relapse.

Fluorescein and indocyanine-green angiography in ocular syphilis: an exploratory study.

BACKGROUND: Fluorescein (FA) and indocyanine-green angiography (ICGA) may offer valuable information concerning disease severity and prognosis in ocular syphilis. The aim of the present study is to describe angiographic patterns encountered in the context of ocular syphilis, and to explore the associations between specific angiographic manifestations and severity of disease presentation, as well as disease evolution after treatment. METHODS: We performed a retrospective institutional study with the inclusion of 23 patients with ocular syphilis presenting to the uveitis clinic of the Jules-Gonin Eye Hospital in a 10-year period. FA and ICGA were performed following a standard protocol for posterior uveitis. Patterns of fluorescence were noted, and statistical associations between each angiographic pattern and any demographic, clinical, or laboratory parameter at baseline and after treatment were sought. RESULTS: The presence of any dark dots in ICGA was significantly associated with anterior uveitis (p = 0.031). The presence of hot spots in ICGA was significantly associated with longer duration of symptoms prior to initial visit (p = 0.032) and with male gender (p = 0.012). Weak non-significant trends were found associating vascular staining in FA with anterior uveitis (p = 0.066), vitritis (p = 0.069), and younger age (p = 0.061), as well as disc hyperfluorescence in FA with seropositivity for HIV (p = 0.089) and macular edema in FA with longer disease duration (p = 0.061). The presence of any dark dots in ICGA exhibited a weak trend of association with anterior uveitis and/or vitritis (p = 0.079). CONCLUSIONS: Out of the several associations identified implicating specific angiographic features, we underline the possible role of the presence of dark dots in ICGA for identifying active inflammation, and the role of hot spots in ICGA as markers of long-standing disease. Vascular staining in FA appears to be more common in patients with severe ocular inflammation with presence of anterior uveitis and/or vitritis.

Macrophage migration inhibitory factor and host innate immune defenses against bacterial sepsis.

Macrophages are essential effector cells of innate immunity that play a pivotal role in the recognition and elimination of invasive microorganisms. Mediators released by activated macrophages orchestrate innate and adaptive immune host responses. The cytokine macrophage migration inhibitory factor (MIF) is an integral mediator of the innate immune system. Monocytes and macrophages constitutively express large amounts of MIF, which is rapidly released after exposure to bacterial toxins and cytokines. MIF exerts potent proinflammatory activities and is an important cytokine of septic shock. Recent investigations of the mechanisms by which MIF regulates innate immune responses to endotoxin and gram-negative bacteria indicate that MIF acts by modulating the expression of Toll-like receptor 4, the signal-transducing molecule of the lipopolysaccharide receptor complex. Given its role in innate immune responses to bacterial infections, MIF is a novel target for therapeutic intervention in patients with septic shock.

Anti-TNF-alpha therapy in patients with chronic non-infectious uveitis: the experience of Jules Gonin Eye Hospital.

BACKGROUND: The purpose of this study is to describe the experience of Jules Gonin Eye Hospital on the long-term outcome of anti-TNF-alpha therapy in chronic non-infectious uveitis. PATIENTS AND METHODS: We identified and followed those patients with chronic non-infectious uveitis who received systemic anti-TNF-alpha therapy. Anti-TNF-alpha therapy was administered when no response had been obtained with classical immunosuppressive therapies or in the presence of severe rheumatoid disease. RESULTS: Fifteen patients (28 eyes), 7 male and 8 female (mean age, 43 years; range: 7 to 70 years) were identified. Diagnoses included HLA-B27-associated anterior uveitis (n = 4), sarcoidosis (n = 2), juvenile idiopathic arthritis (n = 2), idiopathic retinal vasculitis with uveitis (n = 2), pars planitis (n = 2), Adamantiades-Behçet disease (n = 1), birdshot retinochoroidopathy (n = 1), and Crohn's disease (n = 1). Mean duration of ocular disease was 8 years (range: 1 to 29 years). Treatment with infliximab (n = 11), etanercept (n = 2), or adalimumab (n = 2) was initiated. One patient with etanercept was switched to infliximab due to lack of clinical response. Clinical and angiographic regression of uveitis was observed within the first two months of therapy in all patients, and was maintained throughout the entire follow-up period (mean 18 months; range: 3 - 72 months). Recurrence was observed in 3 patients, and resolved after adjustment of therapy. Adverse events were recorded in only one patient (arterial hypotension). CONCLUSIONS: In this series of patients with chronic non-infectious uveitis, anti-TNF-alpha therapy was effective and safe. Further clinical studies are needed to determine an adequate duration of therapy.

Dexamethasone intravitreal implant for noninfectious intermediate or posterior uveitis.

OBJECTIVE: To evaluate the safety and efficacy of 2 doses of dexamethasone intravitreal implant (DEX implant) for treatment of noninfectious intermediate or posterior uveitis. METHODS: In this 26-week trial, eyes with noninfectious intermediate or posterior uveitis were randomized to a single treatment with a 0.7-mg DEX implant (n = 77), 0.35-mg DEX implant (n = 76), or sham procedure (n = 76). MAIN OUTCOME MEASURE: The main outcome measure was the proportion of eyes with a vitreous haze score of 0 at week 8. RESULTS: The proportion of eyes with a vitreous haze score of 0 at week 8 was 47% with the 0.7-mg DEX implant, 36% with the 0.35-mg DEX implant, and 12% with the sham (P < .001); this benefit persisted through week 26. A gain of 15 or more letters from baseline best-corrected visual acuity was seen in significantly more eyes in the DEX implant groups than the sham group at all study visits. The percentage of eyes with intraocular pressure of 25 mm Hg or more peaked at 7.1% for the 0.7-mg DEX implant, 8.7% for the 0.35-mg DEX implant, and 4.2% for the sham (P > .05 at any visit). The incidence of cataract reported in the phakic eyes was 9 of 62 (15%) with the 0.7-mg DEX implant, 6 of 51 (12%) with the 0.35-mg DEX implant, and 4 of 55 (7%) with the sham (P > .05). CONCLUSIONS: In patients with noninfectious intermediate or posterior uveitis, a single DEX implant significantly improved intraocular inflammation and visual acuity persisting for 6 months. Application to Clinical Practice Dexamethasone intravitreal implant may be used safely and effectively for treatment of intermediate and posterior uveitis. Trial Registration clinicaltrials.gov Identifier: NCT00333814.

CD14 expression on monocytes and TNF alpha production in patients with septic shock, cardiogenic shock or bacterial pneumonia.

OBJECTIVES: In patients with septic shock, circulating monocytes become refractory to stimulation with microbial products. Whether this hyporesponsive state is induced by infection or is related to shock is unknown. To address this question, we measured TNF alpha production by monocytes or by whole blood obtained from healthy volunteers (controls), from patients with septic shock, from patients with severe infection (bacterial pneumonia) without shock, and from patients with cardiogenic shock without infection. MEASUREMENTS: The numbers of circulating monocytes, of CD14+ monocytes, and the expression of monocyte CD14 and the LPS receptor, were assessed by flow cytometry. Monocytes or whole blood were stimulated with lipopolysaccharide endotoxin (LPS), heat-killed Escherichia coli or Staphylococcus aureus, and TNF alpha production was measured by bioassay. RESULTS: The number of circulating monocytes, of CD14+ monocytes, and the monocyte CD14 expression were significantly lower in patients with septic shock than in controls, in patients with bacterial pneumonia or in those with cardiogenic shock (p < 0.001). Monocytes or whole blood of patients with septic shock exhibited a profound deficiency of TNF alpha production in response to all stimuli (p < 0.05 compared to controls). Whole blood of patients with cardiogenic shock also exhibited this defect (p < 0.05 compared to controls), although to a lesser extent, despite normal monocyte counts and normal CD14 expression. CONCLUSIONS: Unlike patients with bacterial pneumonia, patients with septic or cardiogenic shock display profoundly defective TNF alpha production in response to a broad range of infectious stimuli. Thus, down-regulation of cytokine production appears to occur in patients with systemic, but not localised, albeit severe, infections and also in patients with non-infectious circulatory failure. Whilst depletion of monocytes and reduced monocyte CD14 expression are likely to be critical components of the hyporesponsiveness observed in patients with septic shock, other as yet unidentified factors are at work in this group and in patients with cardiogenic shock.

Rapid detection of bacterial resistance to antibiotics using AFM cantilevers as nanomechanical sensors.

The widespread misuse of drugs has increased the number of multiresistant bacteria, and this means that tools that can rapidly detect and characterize bacterial response to antibiotics are much needed in the management of infections. Various techniques, such as the resazurin-reduction assays, the mycobacterial growth indicator tube or polymerase chain reaction-based methods, have been used to investigate bacterial metabolism and its response to drugs. However, many are relatively expensive or unable to distinguish between living and dead bacteria. Here we show that the fluctuations of highly sensitive atomic force microscope cantilevers can be used to detect low concentrations of bacteria, characterize their metabolism and quantitatively screen (within minutes) their response to antibiotics. We applied this methodology to Escherichia coli and Staphylococcus aureus, showing that live bacteria produced larger cantilever fluctuations than bacteria exposed to antibiotics. Our preliminary experiments suggest that the fluctuation is associated with bacterial metabolism.

New and emerging treatment of Staphylococcus aureus infections in the hospital setting.

Methicillin-resistant Staphylococcus aureus (MRSA), both hospital-acquired and community-acquired, is a dangerous pathogen that is involved in an increasing number of serious infections with high risk for morbidity and mortality. Community-acquired MRSA strains have epidemic potential and can be particularly virulent. Vancomycin has been the standard hospital treatment for the past 40 years, but vancomycin-resistant isolates of S. aureus have emerged in the USA, and vancomycin-intermediate isolates are increasingly being reported worldwide. New antimicrobial agents with activity against multidrug-resistant S. aureus and other resistant pathogens are urgently needed. Despite great strides, further advances in our understanding of the molecular and biochemical mechanisms responsible for antimicrobial resistance are still required. Several agents have been recently approved for the treatment of serious Gram-positive infections, including linezolid, daptomycin, and tigecycline. The novel investigational cephalosporin, ceftobiprole, is one of the first penicillinase-resistant agents to target penicillin-binding protein 2a (or PBP2a), an acquired PBP with low beta-lactam-affinity that confers intrinsic beta-lactam resistance to S. aureus and other staphylococci. This mechanism of PBP binding, including inhibition of PBP2a, confers broad-spectrum activity against clinically important Gram-negative and Gram-positive pathogens, including MRSA. Phase III clinical trials comparing ceftobiprole with vancomycin alone and in combination with ceftazidime for the treatment of complicated skin and skin structure infections showed ceftobiprole to have efficacy similar to the efficacy of these comparators as evidenced by non-inferior clinical cure and microbiological eradication rates.

Role of the immune response induced by superantigens in the pathogenesis of microbial infections.

Superantigens (SAgs) are microbial proteins which have potent effects on the immune system. They are presented by major histocompatibility complex (MHC) class II molecules and interact with a large number of T cells expressing specific T cell receptor V beta domains. Encounter of a SAg leads initially to the stimulation and subsequently to the clonal deletion of reactive T cells. SAgs are expressed by a wide variety of microorganisms which use them to exploit the immune system to their own advantage. Bacterial SAgs are exotoxins which are linked to several diseases in humans and animals. A classical example is the toxic shock syndrome in which the massive release of cytokines by SAg-reactive cells is thought to play a major pathogenic role. The best characterized viral SAg is encoded by mouse mammary tumour virus (MMTV) and has proved to have a major influence on the viral life cycle by dramatically increasing the efficiency of viral infection. In this paper, we review the general properties of SAgs and discuss the different types of microorganisms which produce these molecules, with a particular emphasis on the role played by the SAg-induced immune response in the course of microbial infections.

Colite à Clostridium difficile: nouvelles recommandations de prise en charge [Clostridium difficile infections: update on new European recommendations].

Clostridium difficile infections: update on new European recommandations While metronidazole and vancomycin have been the only drug options to date for the treatment of C. difficile infection, new therapeutic approaches with promising results have recently emerged for the treatment of the first episode and relapses. Fidaxomicin is a new macrocyclic antibiotic more active against C. difficile and with a narrow spectrum allowing preservation of the intestinal microbiota. While having the same efficacy as vancomycin for the treatment of the first episode, this agent is associated with a lower rate of relapse. The highest relapse-free cure rate is achieved through fecal microbiota transplantation, which should be considered for patients with multiple relapses.

Clinical consensus conference: survey on Gram-positive bloodstream infections with a focus on Staphylococcus aureus.

The increased incidence over the past decade of bloodstream infections (BSIs) caused by gram-positive bacteria, particularly methicillin-resistant Staphylococcus aureus, highlights the critical need for a consistent approach to therapy. However, there is currently no international consensus on the diagnosis and management of gram-positive BSIs. The Clinical Consensus Conference on Gram-Positive Bloodstream Infections was convened as a session at the 9th International Symposium on Modern Concepts in Endocarditis and Cardiovascular Infections held in 2007. Participants discussed various aspects of the practical treatment of patients who present with gram-positive BSI, including therapeutic options for patients with BSIs of undefined origin, the selection of appropriate empirical therapy, and treatment of complicated and uncomplicated BSIs. The opinions of participants about these key issues are reflected in this article.