Diversity of Ocular Surface Bacterial Microbiome Adherent to Worn Contact Lenses and Bacterial Communities Associated With Care Solution Use.

PURPOSE: This study assessed microbiome adherent to contact lenses and defined the bacterial communities associated with use of lens care solutions. METHODS: Among 84 lenses screened for adherent ocular surface bacterial microbiome using 16S rRNA molecular amplification, 63 (75%) generated bacterial-specific amplicons processed using the Ion Torrent Personal Genome Machine workflow. Data were stratified by solution use (peroxide vs. polyhexamethylene biguanide [PHMB]-preserved multipurpose solution [MPS]). Diversity of lens-adherent microbiome was characterized using Shannon diversity index and richness index. Data were analyzed using principal components analysis and Kruskal-Wallis tests. RESULTS: We identified 19 phyla and 167 genera of bacteria adherent to the lenses. Proteobacteria was the most abundant phyla, followed by Firmicutes and Actinobacteria. The most abundant bacterial genera (>1% abundance) were Ralstonia, Enterococcus, Streptococcus, Halomonas, Corynebacterium, Staphylococcus, Acinetobacter, Shewanella, Rhodococcus, and Cobetia. Sixteen of 20 lenses (80%) negative for bacterial DNA were worn by participants using peroxide solutions while only 4 (20%) were MPS-treated lenses (P=0.004). Genera diversity of lens-adherent microbiome showed a significant increase in MPS-treated lenses compared with peroxide (P=0.038). Abundance of Corynebacterium, Haemophilus, and Streptococcus were increased 4.3-, 12.3-, and 2.7-fold, respectively, in the MPS group compared with peroxide (P=0.014, 0.006, 0.047, respectively). CONCLUSIONS: Commensal, environmental, and pathogenic bacteria known to be present in the conjunctival microbiome can be detected on worn contact lenses. Although most contact lenses worn by asymptomatic wearers harbor bacterial DNA, compared with peroxide, lenses stored in a PHMB-preserved MPS have more quantifiable, abundant, and diverse bacterial communities adherent to them.

Admission to the Intensive Care Unit is Associated With Changes in the Oral Mycobiome.

A prospective exploratory study was conducted to characterize the oral mycobiome at baseline and determine whether changes occur after admission to the intensive care unit (ICU). We found that ICU admission is associated with alterations in the oral mycobiome, including an overall increase in Candida albicans.

Silicon phthalocyanine 4 phototoxicity in Trichophyton rubrum.

Trichophyton rubrum is the leading pathogen that causes long-lasting skin and nail dermatophyte infections. Currently, topical treatment consists of terbinafine for the skin and ciclopirox for the nails, whereas systemic agents, such as oral terbinafine and itraconazole, are also prescribed. These systemic drugs have severe side effects, including liver toxicity. Topical therapies, however, are sometimes ineffective. This led us to investigate alternative treatment options, such as photodynamic therapy (PDT). Although PDT is traditionally recognized as a therapeutic option for treating a wide range of medical conditions, including age-related macular degeneration and malignant cancers, its antimicrobial properties have also received considerable attention. However, the mechanism(s) underlying the susceptibility of dermatophytic fungi to PDT is relatively unknown. As a noninvasive treatment, PDT uses a photosensitizing drug and light, which, in the presence of oxygen, results in cellular destruction. In this study, we investigated the mechanism of cytotoxicity of PDT in vitro using the silicon phthalocyanine (Pc) 4 [SiPc(OSi(CH3)2(CH2)3N(CH3)2)(OH)] in T. rubrum. Confocal microscopy revealed that Pc 4 binds to cytoplasmic organelles, and upon irradiation, reactive oxygen species (ROS) are generated. The impairment of fungal metabolic activities as measured by an XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxyanilide inner salt) assay indicated that 1.0 µM Pc 4 followed by 670 to 675 nm light at 2.0 J/cm(2) reduced the overall cell survival rate, which was substantiated by a dry weight assay. In addition, we found that this therapeutic approach is effective against terbinafine-sensitive (24602) and terbinafine-resistant (MRL666) strains. These data suggest that Pc 4-PDT may have utility as a treatment for dermatophytosis.

Efficacy of care solutions against contact lens-associated Fusarium biofilms.

PURPOSE: The aim of this study is to assess the effect of lens wear on the formation of soft contact lens-associated Fusarium biofilms and to determine the efficacy of marketed contact lens care products against such biofilms. METHODS: Using an established in vitro soft contact lens-Fusarium biofilm model, two clinical Fusarium isolates (F. solani B6914 and F. oxysporum B8996) were incubated with three different types (lotrafilcon A, etafilcon A, and balafilcon A) of worn contact lenses under conditions that facilitate biofilm formation. Unworn lenses were used as internal controls for biofilm formation. Biofilm was quantified using a tetrazolium XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide) assay. In addition, susceptibilities of the fungal biofilm growth phases to the five most common multipurpose contact lens care solutions available at the time of study (three polymeric biguanide-preserved and two polyquaternium-preserved) and two hydrogen peroxide care solutions were assessed. RESULTS: Both Fusarium strains formed dense biofilms on each of the contact lens types tested. Worn lenses showed no differences in the ability of biofilm to form compared with unworn lenses except worn etafilcon A lenses which formed more biofilm with F. oxyspourm B8996 compared with unworn controls. Lens material did not influence biofilm formation. The biofilms of F. solani on all three lens types were consistently susceptible to both hydrogen peroxide care systems (growth reduction of 84 to 97%, p ≤ 0.001) and two of the five multipurpose solutions (MPSs) (growth reduction of 62 to 85% for a biguanide-preserved MPS, p ≤ 0.05; growth reduction of 92 to 96% for a polyquaternium-myristamidopropyl dimethylamine preserved MPS, p < 0.001). The biofilms of F. oxysporum on all three lens types were consistently susceptible to both hydrogen peroxide care systems (growth reduction of 79 to 99%, p ≤ 0.001) and one of the five MPSs (growth reduction of 93 to 96% for a polyquaternium-myristamidopropyl dimethylamine preserved MPS, p ≤ 0.001). CONCLUSIONS: F. solani and F. oxysporum form biofilms on lotrafilcon A, etafilcon A, and balafilcon A worn contact lenses, which are resistant to the antifungal activity of several soft contact lens care products. Only the hydrogen peroxide care systems and one polyquaternium-myristamidopropyl dimethylamine-preserved solution consistently demonstrated effective antifungal activity against both Fusarium strains on all three lens types.

Angiogenic pretreatment to enhance myocardial function after cellular cardiomyoplasty with skeletal myoblasts.

OBJECTIVE: Improvements in ventricular function after cellular cardiomyoplasty appear to be limited by the poor survival of the cellular implants. Angiogenic pretreatment of infarcted myocardium may improve implanted cell survival and consequently myocardial function. METHODS: Fischer 344 rats underwent coronary artery ligation and injection of an adenovirus encoding vascular endothelial growth factor 121 or of saline solution at increasing intervals after ligation. Myocardial perfusion and mass preservation were assessed. On the basis of these data, four groups of animals underwent coronary ligation and adenovirus with or without syngeneic skeletal myoblast administration: (1) adenovirus at ligation and myoblasts 3 weeks later (n = 7), (2) saline solution at ligation and myoblasts 3 weeks later (n = 8), (3) saline solution at ligation and 3 weeks later (n = 8), and (4) saline solution at ligation and adenovirus with myoblasts 3 weeks later (n = 5). Left ventricular ejection fraction was analyzed by echocardiography before coronary ligation and 3 and 5 weeks later, after which cell survival was assessed in harvested tissues. RESULTS: Myocardial infarct perfusion was at least 50% greater in animals treated with adenoviral vector than with saline solution immediately after ligation (P < .02). In comparison, delayed adenovirus administration did not significantly diminish infarct perfusion but resulted in decreased myocardial preservation (P < .05). Accordingly, adenovirus administration nearly tripled implanted myoblast survival relative to saline solution-treated animals (P = .004). Left ventricular ejection fraction was improved, however, only after cell implantation with adenovirus pretreatment (P = .027). CONCLUSION: Angiogenic strategies can help to preserve myocardium jeopardized by acute coronary occlusions. Angiogenic pretreatment enhances the efficacy of cellular cardiomyoplasty.

An Egr-1 master switch for arteriogenesis: studies in Egr-1 homozygous negative and wild-type animals.

BACKGROUND: Arteriogenesis has been implicated as an important biologic response to acute vascular occlusion. The early growth response 1 (Egr-1) gene encodes an immediate-early response transcription factor that is upregulated by changes in vascular strain and that in turn upregulates a number of putative angiogenic and arteriogenic growth factors. We therefore hypothesized that early growth response 1 might be a critical arteriogenic messenger that induces revascularization in the setting of acute vascular occlusions. METHODS: Wild-type or Egr-1-/- (null) C57 BL mice, or Sprague-Dawley rats, underwent unilateral iliofemoral artery excision and subsequent analyses for angiogenesis and arteriogenesis through cell-specific immunohistochemistry. Rats were also administered an adenoviral vector encoding for Egr-1 (AdEgr group), noncoding vectors (AdNull group), or saline, after which these animals were assessed by means of serial laser Doppler perfusion imaging and morphologic examination of rat foot-pad ischemic lesions. RESULTS: Egr-1 wild-type mice demonstrated an equivalent number of capillaries but a greater number of arterioles following excision versus Egr-1 null mice. AdEgr group rats demonstrated greater distal perfusion from 7 to 21 days after excision compared with control animals (P < .02), which approximated normal perfusion at 21 days after excision. AdEgr group rats also demonstrated greater arteriolar density and less severe ischemic foot-pad lesions than control animals. CONCLUSION: These data suggest the importance of Egr-1 as a critical and potentially therapeutic mediator of revascularization after vascular occlusion and implicate arteriogenesis (collateral vessel formation) as a critical component of this process.

Angiogenic pretreatment improves the efficacy of cellular cardiomyoplasty performed with fetal cardiomyocyte implantation.

BACKGROUND: Cell implantation into areas of myocardial infarction (cellular cardiomyoplasty) may be limited in efficacy because of the lack of blood supply to these areas of myocardium, resulting in early loss of transplanted cells. We therefore tested the hypothesis that pretreatment of infarcted myocardium with angiogenic therapy, followed by cell transplant, would be more effective than the application of either strategy alone. METHODS: Fischer 344 rats underwent left coronary artery ligation and injection of an adenovirus encoding VEGF 121, an empty expression cassette control vector, or saline solution. Capillary density in the infarcted region was determined in preliminary studies. Cardiomyocytes harvested from syngeneic Fischer rat fetuses were prelabeled and then injected directly into the infarct area 3 weeks after vector administration. Exercise treadmill testing was performed 2 weeks after cell transplantation, after which a cell viability index was calculated as the number of implanted (prelabeled) nuclei divided by the number of coadministered microspheres detected in sections of implanted myocardium. RESULTS: Capillary density in the area of infarction was significantly greater in adenovirus encoding VEGF 121 compared with rats injected with saline solution (P =.001). The cell survival index was also greater in adenovirus encoding VEGF 121 compared with animals injected with empty expression cassette control or saline solution (P =.0045). Exercise tolerance was nearly doubled in animals receiving adenovirus encoding VEGF 121 3 weeks prior to cell implantation compared with animals receiving adenovirus encoding VEGF 121 or cells alone or those receiving adenovirus encoding VEGF 121 at the time of cell implantation (P <.001). CONCLUSIONS: Pretreatment of an infarcted region of the heart with angiogenic mediators such as VEGF can enhance the efficacy of cellular cardiomyoplasty, presumably by creating a more favorable environment for the survival of transplanted cells.

Adenoviral-mediated transfer of vascular endothelial growth factor 121 cDNA enhances myocardial perfusion and exercise performance in the nonischemic state.

BACKGROUND: Angiogenic gene therapy has been demonstrated to enhance perfusion to ischemic tissues, but it is unknown whether the administration of angiogenic growth factors will increase blood flow to nonischemic tissues. This study investigates whether enhanced myocardial perfusion can be mediated by adenovirus-mediated transfer of vascular endothelial growth factor 121 cDNA to nonischemic myocardium. METHODS: New Zealand White rabbits received adenovirus (5 x 10(10) particle units) encoding for vascular endothelial growth factor 121 (n = 14) or a control vector without a transgene (n = 13) or saline solution (n = 9) via direct myocardial injection. Fluorescent microsphere perfusion studies and histologic analyses were performed 4 weeks later. In a parallel study, exercise treadmill testing was performed to assess the functional effects of this therapy in Sprague-Dawley rats. RESULTS: Microsphere assessment of myocardial perfusion in rabbits 4 weeks after adenovirus-encoding vascular endothelial growth factor administration was greater than that for rats injected with control vector without a transgene or saline solution (3.2 +/- 0.5 vs 2.7 +/- 0.7 and 2.4 +/- 0.4, respectively; P <.03). The endothelial cell count per high power field was increased in animals injected with adenovirus-encoding vascular endothelial growth factor versus animals injected with control vector without a transgene or saline solution (147 +/- 27 vs 123 +/- 14 and 125 +/- 16 cells, respectively), although this did not reach statistical significance (P =.12). Rats treated with adenovirus-encoding vascular endothelial growth factor also demonstrated prolonged exercise tolerance compared with rats injected with control vector without a transgene or saline solution (exhaustion time: 26 +/- 5 minutes vs 19 +/- 2 minutes and 20 +/- 3 minutes, respectively; P =.006). CONCLUSIONS: Adenovirus encoding-mediated transfer of vascular endothelial growth factor 121 induces an enhancement in regional perfusion in nonischemic myocardium that corresponds to changes in exercise tolerance. Adenovirus-encoding vascular endothelial growth factor therapy may be useful for inducing angiogenesis in the nonischemic state, such as for prophylactic therapy of early coronary artery disease.