Comparison of Biofilm Formation Capacities of Two Clinical Isolates of Staphylococcus Epidermidis with and without icaA and icaD Genes on Intraocular Lenses.

OBJECTIVES: To compare biofilm formations of two Staphylococcus epidermidis (S. epidermidis) isolates with known biofilm formation capacities on four different intraocular lenses (IOL) that have not been studied before. MATERIALS AND METHODS: Two isolates obtained from ocular surfaces and identified in previous studies and stored at -86 °C in 15% glycerol in the microbiology laboratory of the Anadolu University Department of Biology were purified and used in the study. The isolates were S. epidermidis KA 15.8 (ICA+), a known biofilm producer isolate positive for icaA, icaD and bap genes, and S. epidermidis KA 14.5 (ICA-), known as a non-biofilm producer isolate negative for icaA, icaD and bap genes. The biofilm formation capacities of the 2 isolates on 4 different IOLs were compared. Two of the IOLs were acrylic (UD613 [IOL A], Turkey; SA60AT [IOL B], USA), and the other two were polymethyl methacrylate (PMMA) (B60130C [IOL C], India; B55125C [IOL D], India). Bacterial enumeration and optical density measurements were done from biofilms that formed on the IOLs. Biofilms were imaged using scanning electron microscopy. RESULTS: Mean bacterial counts on the IOLs were 7.1±0.4 log10 CFU/mL with the ICA+ isolate, and 6.7±0.8 log10 CFU/mL with the ICA- isolate; there were no statistically significant differences. Biofilm formation was lower with acrylic lenses than PMMA lenses with both isolates (p=0.009 and p=0.013). The highest biofilm production was obtained on IOL C (PMMA) (p<0.001) and the lowest was obtained on IOL A (hydrophilic acrylic) (p<0.001). CONCLUSION: Bacterial counts after biofilm formation were lower on acrylic lenses, especially hydrophilic acrylic with hydrophobic properties. Further animal and in vivo studies are required to support the findings of this study.

Bacillus Spp. isolated from the conjunctiva and their potential antimicrobial activity against other eye pathogens.

BACKGROUND: In this study, we attempted to screen and investigate antibacterial activity of Bacillus species, which were isolated from conjunctiva, against other eyes pathogens. METHODS: To examine predominant isolates of Bacillus subtilis, B. pumilus, B. cereus and B. mojevensis, isolated from conjunctiva for their antimicrobial activity against indicator microorganisms as Micrococcus luteus, Staphyloccocus aureus, S. epidermidis, S.hominis, S. lugdunensis, S.warneri, S. haemolyticus, B. cereus, Listeria monocytogenes, and Proteus mirabilis. Growth inhibitions of indicator microorganisms were tested using agar diffusion tests by cells and supernatants of five B. mojevensis, one B. subtilis, four B. cereus and five B. pumilus strains which were isolated from conjunctiva. RESULTS: The Bacillus isolates showed variable ability of inhibition against the tested microorganisms. Two strains of B. pumillus, 1 strain of B. subtilis, 5 strains of B. mojevensis, 1 strain of B. cereus were efficacious against the tested microorganisms. Most resistant microorganism to these bacteria was Proteus mirabilis. Two of Gram positive bacteria, S. lugdenensis (K15-9) and S. aureus (SDA48), were also found as resistant. CONCLUSIONS: In this study, Bacillus spp isolated from conjunctiva showed antimicrobial activity against Gram-positive bacteria. Human eye-derived microorganisms and their antimicrobial effects might be a useful source of natural products for the future.

Automated ribotyping and antibiotic resistance determining of Bacillus spp from conjunctiva of diabetic patients.

OBJECTIVE(S): We aimed to characterize the phenotype and genotype of Bacillus spp isolated from diabetic patients' eyes, by studying the drug sensitivity patterns with a disc-diffusion method. MATERIALS AND METHODS: Fifty eyes of 25 patients with type II diabetes mellitus, with at least 10 years of diabetes history, were included in the study. We analyzed the eyes for the presence of Bacillus spp.; presumptive isolates were identified by morphological, and biochemical tests, and confirmed by the VITEK system. Automated EcoRI ribotyping was performed with a RiboPrinter(®) Microbial Characterization System. We determined the antibiotic resistance of the isolates by the Kirby-Bauer disc diffusion test. RESULTS: Seven out of 25 patients were on insulin treatment; 7 on oral anti-diabetic medication; and 11 on combination therapy of insulin and oral medications. Among the 28 Bacillus spp isolates, 14 were B. cereus, 11 were B. pumilus, 2 were B. mojavensis and 1 was B. subtilis. Almost all the strains were either resistant or multiresistant, particularly towards cefuroxime, methicillin, and ceftazidime. CONCLUSION: Diabetic patients seem to be more prone to B. cereus infections than healthy individuals. It would be greatly beneficial to understand and recognize the prevalence of microorganisms and their resistance patterns for better outcome in ocular surgeries.

Congenital retinal macrovessel: atypical presentation using optical coherence tomography.

To describe a congenital retinal macrovessel with macular thickening. This case was investigated using fundus photography, fluorescein angiography, Spectralis optical coherence tomography and a 10-2 visual field test. A 23-year-old man was referred to our clinic with decreased vision in the right eye. Fundus examination of the right eye revealed a congenital retinal macrovessel that originated inferior to the superotemporal branch of the central retinal vein. Using fluorescein angiography, early filling and delayed emptying of the aberrant vein were observed. Spectralis optical coherence tomography demonstrated macular thickening and was supported by a 10-2 visual field test that revealed a relative scotoma corresponding to the same location. At the 18-month follow-up, visual acuity remained stable. Although rare, this case demonstrated that macular thickening can cause decreased visual acuity in the presence of a congenital retinal macrovessel.

Exophthalmometric values in a normal Turkish population living in the northeastern part of Turkey.

BACKGROUND: Exophthalmometry is a simple examination procedure used for the early diagnosis of many of the orbital pathologies. The exophthalmometric measures tend to vary with age, sex, and race. Therefore, a lot of investigators conducted researches to determine the minimum, maximum, and normal values of exophthalmometric measures in their populations. OBJECTIVE: We planned this study to gather data about the normal exophthalmometric measures in our population. DESIGN: In this study, 240 male and 240 female subjects with age ranging from 3 to 80 years were included. The results of measures from both the eyes were evaluated for the study subjects. The protrusions of both the eyes were measured simultaneously in daylight via Hertel exophthalmometry. RESULTS: The minimum and maximum measures of Hertel exophthalmometry for the male subjects were found to be 8 and 20 mm, respectively, with the mean being 13.49 +/- 2.6 mm. No statistically significant difference existed either between the eyes or between the age groups for the male subjects. The minimum and maximum measures of Hertel exophthalmometry for the female subjects were 8 and 19 mm, respectively, with the mean being 13.39 +/- 2.6 mm. Similar to the males, no statistically significant difference existed either between the eyes or between the age groups for the females. When the results of Hertel measurements for male and female subjects were compared, no significant difference could be found. CONCLUSIONS: As it provides results of exophthalmometry for the Turkish population, our study is important. However, larger, nationwide, and multisite studies examining more subjects may provide more valuable data about the Turkish population.

Chromosome and sister chromatid exchange studies in Behcet's patients.

Behcet's disease is a chronic multisystemic disease of unknown pathogenesis characterized by four major symptoms: oral aphthous ulcers, skin lesions, ocular symptoms and genital ulcerations. The disease is spread throughout the world, but it is most frequent in Turkey, Japan, Korea and China. Although HLA-Bw51 has been found to predominate in Behcet's cases, the genetic etiology has not yet been clarified. In this study, we investigated the chromosomal abnormalities and sister chromatid exchange rates in patients with Behcet's diseases. Thirty-eight patients with Behcet's disease (diagnosed for the first time) and 30 healthy subjects (as controls) were included in this study. Although numerical and structural chromosomal abnormalities were not detected in our patients, we found an increased rate of sister chromatid exchange in patients over the control groups (P < 0.01). On the basis of these results, we discuss the genetic etiology of Behcet's disease.

Corneal degeneration following bicanalicular silicone intubation.

PURPOSE: A case of bilateral arcus-like corneal degeneration in the medial limbal regions following bilateral bicanalicular silicone intubation is reported. METHODS: Case report. RESULTS: Bilateral arcus-like corneal opacifications were observed in the medial limbal regions of a 33-year-old woman 3 months after the bilateral silicone intubation with dacryocystorhinostomy. No clinical signs of infection and direct contact of the silicone tubes with those regions of the corneas were observed. Routine laboratory tests revealed no abnormalities, and serum lipoprotein composition was normal. CONCLUSIONS: Silicone tubing appeared to be the precipitating factor of the corneal opacifications that occurred in this patient.