Ovoic acid

A 39-year-old woman presented with a 4-year history of asymptomatic facial lesions that has progressively increased in number to become a cosmetic nuisance. These lesions have not responded to 6-months of topical 20% azelaic acid, 0.1% retinoic acid, and 20% vitamin C combination. She has had mild papulopustular acne. Her personal and family histories were unremarkable. On dermatologic examination, there were multiple flesh-colored to pigmented, firm ovoid to round papules, 2-5 mm in size, over the forehead and both cheeks (Figure 1). The dermatoscopic examination was nonspecific. Preliminary diagnoses were made of eccrine syringoma, steatocystoma multiplex, and papular elastorrhexis. A histopathologic examination from a punch biopsy displayed focal ossification within the dermis (Figure 2). Routine laboratory tests, including serum calcium, phosphorus, PTH, and vitamin D levels were within the normal ranges. A maxillofacial 3D CT scan, revealed multiple dermal and hypodermal ossifications, <3-5 mm in size-in the frontal, mandibular, and maxillary areas of the face (Figure 3). Scattered osteomas were also seen on the neck. A definitive diagnosis of multiple miliary osteoma cutis (MMOC) of the face and neck was firmly established based on clinical, histologic, and radiologic findings. Radiologically, the distribution and extent of the lesions were more pronounced than clinically anticipated. (SKINmed. 2022;20:469-471).

A Gram-stain-negative, cream-coloured, aerobic, motile and ovoid- to rod-shaped bacterium, designated as FT325T, was isolated from mangrove sediment collected in Shenzhen, PR China. The taxonomic position of strain FT325T was established by phylogenetic, physiological, biochemical and chemotaxonomic analyses. Strain FT325T grew optimally at 37-40 °C and pH 6.0 in the presence of 0 % (w/v) NaCl. Results of 16S rRNA gene sequence analysis showed that strain FT325T was most similarly related to Limibaculum halophilum CAU 1123T (96.2 %), Phaeovulum vinaykumarii DSM 18714T (93.9%) and Amaricoccus solimangrovi HB 172011T (93.7 %). The major fatty acids (>10 %) were C18 : 1 ω7c (60.0 %) and 11-methyl C18 : 1 ω7c (16.7 %). The sole respiratory quinone was Q-10. The polar lipids were phosphatidylglycerol, one unidentified glycolipid, three unidentified aminolipids and three unidentified phospholipids. Its estimated genome size was 4 318 768 bp and the genomic DNA G+C content was 69.6 mol%. Based on its distinct phenotypic, chemotaxonomic and phylogenetic characteristics, strain FT325T represents a novel species of the genus Limibaculum, for which the name Limibaculum sediminis sp. nov. is proposed (=MCCC 1K07397T=KCTC 92313T).

Rhamnose-rich cell wall polysaccharides (Rha-CWPSs) have emerged as crucial cell wall components of numerous Gram-positive, ovoid-shaped bacteria-including streptococci, enterococci, and lactococci-of which many are of clinical or biotechnological importance. Rha-CWPS are composed of a conserved polyrhamnose backbone with side-chain substituents of variable size and structure. Because these substituents contain phosphate groups, Rha-CWPS can also be classified as polyanionic glycopolymers, similar to wall teichoic acids, of which they appear to be functional homologs. Recent advances have highlighted the critical role of these side-chain substituents in bacterial cell growth and division, as well as in specific interactions between bacteria and infecting bacteriophages or eukaryotic hosts. Here, we review the current state of knowledge on the structure and biosynthesis of Rha-CWPS in several ovoid-shaped bacterial species. We emphasize the role played by multicomponent transmembrane glycosylation systems in the addition of side-chain substituents of various sizes as extracytoplasmic modifications of the polyrhamnose backbone. We provide an overview of the contribution of Rha-CWPS to cell wall architecture and biogenesis and discuss current hypotheses regarding their importance in the cell division process. Finally, we sum up the critical roles that Rha-CWPS can play as bacteriophage receptors or in escaping host defenses, roles that are mediated mainly through their side-chain substituents. From an applied perspective, increased knowledge of Rha-CWPS can lead to advancements in strategies for preventing phage infection of lactococci and streptococci in food fermentation and for combating pathogenic streptococci and enterococci.