Streptomyces coelicolor A3(2) ftsI-and ftsW-null mutants produced aerial hyphae with no evidence of septation when grown on a traditional osmotically enhanced medium. This phenotype was partially suppressed when cultures were grown on media prepared without sucrose. We infer that functional FtsZ rings can form in ftsIand ftsW-null mutants under certain growth conditions. Rod-shaped bacteria that produce a peptidoglycan cell wall synthesize lateral-wall material during cell elongation and produce septa during cytokinesis. Most rod-shaped bacteria possess separate systems for these processes, each containing a protein of the SEDS (shape, elongation, division, and sporulation) family and a cognate class B penicillin-binding protein (PBP) (7, 9, 11). In Escherichia coli, the protein pairs involved in cell elongation and division are RodA-PBP2 and FtsW-FtsI (PBP3), respectively. However, some bacteria possess three protein pairs, as in Bacillus subtilis, where sporulation-specific division genes exist in addition to those for vegetative functions (15). Streptomyces coelicolor is a gram-positive, filamentous bacterium that requires cell division only for sporulation (13). Its genome possesses four homologous SEDS-PBP pairs (3).Here we report the characterization of S. coelicolor cell division genes ftsI and ftsW. We show that ftsI and ftsW are dispensable for colony formation but are required for efficient cell division. Similar to the ftsL and divIC mutants (2), the ftsIand ftsW-null mutants displayed medium-dependent phenotypic defects that are more severe on an osmotically enhanced medium. We suggest that because the ftsI and ftsW mutants are able to divide when grown on certain media, other proteins may compensate for the loss of FtsI and FtsW. Chains of spores are produced under certain growth conditions, implying that ladder-like arrays of Z rings (18) must be stably formed and function in the absence of FtsI and FtsW under certain conditions.Identification of ftsI and ftsW homologues in S. coelicolor. The S. coelicolor ftsI and ftsW homologues, ftsI Sc (StrepDB [http://streptomyces.org.uk/] accession number SCO2090) and ftsW Sc (accession number SCO2085), are located in the division and cell wall (dcw) cluster (Fig. 1). We determined the gene sequences prior to the S. coelicolor genome project. ftsI Sc is predicted to encode a 654-amino-acid, 69.5-kDa bitopic membrane protein with 26% (160/602) of its residues identical to B. subtilis PBP 2B (the FtsI homologue), 31% (188/604) identical to B. subtilis SpoVD (the sporulation-specific FtsI homologue), and 29% (175/586) identical to E. coli FtsI. ftsW Sc is predicted to encode a 456-amino-acid, 48-kDa integral membrane protein with 36% (128/351) of its residues identical to B. subtilis SpoVE (the sporulation-specific FtsW homologue), 36% (137/373) identical to B. subtilis FtsW (YlaO), and 31% (114/358) identical to E. coli FtsW. FtsW Sc lacks the unique C-terminal extension required for interaction with FtsZ in the related actinomycete Mycobacterium tuberculosis (...

PurposeThe purpose of this study is to describe the diagnosis, course, and outcome of a case of Acanthamoeba and Stenotrophomonas keratitis with a fungal keratitis in the contralateral eye.MethodsA case of Acanthamoeba and Stenotrophomonas keratitis was diagnosed with confocal microscopy and cultures with confocal diagnosis of fungal keratitis in the fellow eye.ResultsDuring the initial treatment of the Acanthamoeba and Stenotrophomonas keratitis, the contralateral eye developed a keratitis that demonstrated hyphae in the corneal stroma with confocal microscopy consistent with fungal keratitis.ConclusionsBilateral chronic keratitis cannot be assumed to be caused by the same organism and independent cultures, and confocal microscopy needs to be performed to direct appropriate therapy.

PurposeTo describe the course and outcome of treatment of advanced Acanthamoeba sclerokeratitis with intravenous pentamidine.MethodsA case of advanced Acanthamoeba sclerokeratitis was resistant to conventional therapy and was treated with intravenous pentamidine. The eye was later removed due to incapacitating pain.ResultsThe eye showed Acanthamoeba organisms within the cornea and evidence of acute and chronic inflammation throughout the remainder of the eye. The patient has survived without orbital recurrence for 2 years.ConclusionsThis case demonstrates late inflammation with active Acanthameoba keratitis following systemic pentamidine therapy.

Background/Aims: Atypical fibroxanthoma is an uncommon tumor that usually occurs in the skin of the head and neck of the elderly with significant sun exposure. We describe a unique case featuring a rare ocular surface conjunctival tumor (atypical fibroxanthoma) and provide insight on its characteristic clinical features, surgical management, and histology. Methods: A 71-year-old male fisherman with no pertinent ocular history presented to an academic center with a rapidly enlarging bulbar conjunctival mass in the right perilimbal region for the past several months. The patient underwent surgical excisional biopsy with cryotherapy, adjuvant alcohol, and amniotic membrane transplantation. Results: Pathology specimen illustrated an atypical spindle cell tumor with inflammatory cells, increased mitotic activity, cytologic atypia, and positive diffuse staining with CD163 and CD10 consistent with an atypical fibroxanthoma. Conclusion: Atypical fibroxanthoma is an extremely rare ocular surface tumor that may simulate conjunctival or ocular surface squamous neoplasia. While this lesion typically pursues a benign clinical course, it may recur or rarely metastasize. Thus it should be treated aggressively with excisional biopsy, cryotherapy, absolute alcohol, and/or amniotic membrane transplantation.

Purpose To calculate and compare cone location and magnitude index (CLMI), Kmax and other corneal measures derived from three different technologies, Placido, Scheimpflug, and a combination dual Scheimpflug-Placido device, from the same group of eyes with keratoconus and postrefractive surgery corneal ectasia. Methods Keratoconus (n = 26) eyes of (n = 19) subjects and postrefractive surgery ectasia (n = 5) eyes of (n = 5) subjects were selected to have measurements performed using the Keratron Scout, Pentacam HR and Galilei Dual Scheimpflug Analyzer. Device-generated SimK's and device-specific CLMI and Kmax indices as well as map data, were exported from each device. Index values for multiple exams were averaged. The map data were processed using The Ohio State University Corneal Topography Tool (OSUCTT) to calculate CLMI parameters, Kmax and SimK values using consistent algorithms on all three devices. Maps were averaged before calculation for multiple examinations. Repeated measures analysis of variance and post- hoc analysis were used to identify differences between devices. Results The anterior axial CLMI calculated from the Keratron data was significantly higher than CLMI for the Galilei (p = 0.0443) or Pentacam (p < 0.0004) with keratoconus, 12.23 compared with 11.20 and 11.00 diopters, respectively. Kmax was also significantly higher in the Keratron than the Galilei (p = 0.0063) or the Pentacam (p < 0.0002). Galilei and Pentacam were not significantly different from each other in either CLMI (p = 0.6287) or Kmax (p = 0.2115). The anterior CLMI values for the postrefractive surgery ectasia eyes were not significantly different between devices. Posterior CLMI values were calculated from the Galilei and Pentacam data and were −2.60 and −2.46 diopters (p = 0.1173) for keratoconus and −2.66 and −3.04 diopters (p = 0.2242) for postrefractive surgery ectasia. Conclusion The small cone Placido measured dioptric values that were greater than the pure Scheimpflug system, but the difference was only about 1 diopter, which is not relevant clinically in evaluating and managing ectasia. The combined dual Scheimpflug-Placido system produced measured dioptric values between the other two technologies. The anterior CLMI calculations accurately predicted keratoconus with all three devices. The posterior CLMI in ectasia may be a potentially valuable calculation in demonstrating asymmetric steepening. How to cite this article Mauger TF, Mahmoud AM, Roberts CJ, Chheda LV, Kuennen RA, Hendershot AJ, Lembach RG. Comparison of Placido, Scheimpflug and Combined Dual Scheimpflug-Placido Technologies in Evaluating Anterior and Posterior CLMI, SimK's as well as Kmax, in Keratoconic and Postrefractive Surgery Ectasia. Int J Keratoco Ectatic Corneal Dis 2012;1(1):44-52. • C Roberts is a Consultant for Oculus Optikgerate GmbH and Ziemer Ophthalmic Systems AG, and has an interest in the GALILEI. • A Mahmoud has an interest in the GALILEI. • T Mauger, L Chheda, R Kuennen, A Hendershot, and R Lembach have no financial interests.