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Purpose: To report a case of endophthalmitis associated with Legionella Pneumophila . Case Report: A 46-year-old, highly myopic male with a complex history of recurrent retinal detachments, macular hole, cataract surgery and an infected scleral buckle in the left eye, presented with pain, redness, hypopyon and vision loss in the left eye, 14 days following blunt head trauma. Empirical treatment for endophthalmitis with intravitreal injections of Vancomycin and Ceftazidime afforded minimal improvement. He developed recurrent hypopyon and underwent vitrectomy surgery with intravitreal antibiotic injections at the time of surgery and had improvement. Intraoperative culture was positive for Legionella Pneumophila. He had continued episodes of recurrent inflammation which were quelled by intravitreal moxifloxacin injections performed every 3-10 days. He developed a recurrent RD with proliferative vitreoretinopathy (PVR) and underwent vitrectomy with silicone oil. The retina was reattached but had no light perception vision in the affected eye. Conclusion: When endophthalmitis is contracted in a work-place setting, a culture for L. pneumophila should be considered. A combination of intravitreal moxifloxacin and oral azithromycin may be effective.

R-type bacteriocins are minimal contractile nanomachines that hold promise as precision antibiotics1–4. Each bactericidal complex uses a collar to bridge a hollow tube with a contractile sheath loaded in a metastable state by a baseplate scaffold1,2. Fine-tuning of such nucleic acid-free protein machines for precision medicine calls for an atomic description of the entire complex and contraction mechanism, which is not available from baseplate structures of the (DNA-containing) T4 bacteriophage5. Here we report the atomic model of the complete R2 pyocin in its pre-contraction and post-contraction states, each containing 384 subunits of 11 unique atomic models of 10 gene products. Comparison of these structures suggests the following sequence of events during pyocin contraction: tail fibres trigger lateral dissociation of baseplate triplexes; the dissociation then initiates a cascade of events leading to sheath contraction; and this contraction converts chemical energy into mechanical force to drive the iron-tipped tube across the bacterial cell surface, killing the bacterium. The authors report near-atomic resolution structures of the R-type bacteriocin from Pseudomonas aeruginosa in the pre-contraction and post-contraction states, and these structures provide insight into the mechanism of action of molecular syringes.

The EMDataBank Validation Challenge was a challenging task for students newly introduced to the cryoEM and molecular modeling fields. However, the competition provided an effective space for student modelers to discover and explore the potentials of atomic modeling and refinement by practicing on published atomic structures. Here, by employing manual molecular modeling programs such as Coot, Phenix, and Chimera, we have regularized and improved three targets. The T20S proteasome and TRPV1 ion channel allowed us to broaden our understanding of these modeling techniques while the 70S ribosome served as a challenge to test the limits of our abilities. We were successful in our efforts to improve each of the models and provide here our cohesive methodology for de novo modeling with and without homology models, which may serve as a starting point for other undergraduates and researchers just entering the realm of cryoEM. Additionally, we provide some constructive criticism to facilitate the introduction of said undergraduates and researchers into cryoEM in the future.

Author(s): Mukkamala, Lekha K; Avaylon, Jaycob; Welch, R Joel; Yazdanyar, Amirfarbod; Emami-Naeini, Parisa; Wong, Sophia; Storkersen, Jordan; Loo, Jessica; Cunefare, David; Farsiu, Sina; Moshiri, Ala; Park, Susanna S; Yiu, Glenn | Abstract: PurposeTo investigate whether intraoperative retinal changes during epiretinal membrane (ERM) peeling affect anatomic or functional outcomes after surgery.MethodsWe measured retinal thickness using an intraoperative optical coherence tomography (iOCT) device in patients undergoing pars plana vitrectomy with membrane peeling for idiopathic ERM. Changes in intraoperative central macular thickness (iCMT) were compared with postoperative improvements in CMT and best-corrected visual acuity (VA).ResultsTwenty-seven eyes from 27 patients (mean age 68 years) underwent iOCT-assisted ERM peeling surgery. Before surgery, mean VA was logMAR 0.50 ± 0.36 (Snellen 20/63), and mean baseline CMT was 489 ± 82 µm. Mean iCMT before peeling was 477 ± 87 µm, which correlated well with preoperative CMT (P l 0.001). Mean change in iCMT was -39.6 ± 37 µm (range -116 to +77 µm). After surgery, VA improved to logMAR 0.40 ± 0.38 (Snellen 20/50) at month 1 and logMAR 0.27 ± 0.23 (Snellen 20/37) at month 3, whereas CMT decreased to 397 ± 44 µm and 396 ± 51 µm at months 1 and 3. Eyes that underwent greater amount of iCMT change (absolute value of iCMT change) were associated with greater CMT reduction at month 1 (P l 0.001) and month 3 (P = 0.010), whereas those with greater intraoperative thinning (actual iCMT change) showed a trend toward better VA outcomes at months 1 (P = 0.054) and 3 (P = 0.036).ConclusionsIntraoperative changes in retinal thickness may predict anatomic and visual outcomes after idiopathic ERM peeling surgery.Translational relevanceOur study suggests that intraoperative retinal tissue response to ERM peeling surgery measured by iOCT may be a prognostic indicator for restoration of retinal architecture and for visual acuity outcomes.