Microalgae as a Source of Mycosporine-like Amino Acids (MAAs); Advances and Future Prospects.

Mycosporine-like amino acids (MAAs), are secondary metabolites, first reported in 1960 and found to be associated with the light-stimulated sporulation in terrestrial fungi. MAAs are nitrogenous, low molecular weight, water soluble compounds, which are highly stable with cyclohexenone or cycloheximine rings to store the free radicals. Microalgae are considered as a good source of different kinds of MAAs, which in turn, has its own applications in various industries due to its UV absorbing, anti-oxidant and therapeutic properties. Microalgae can be easily cultivated and requires a very short generation time, which makes them environment friendly source of biomolecules such as mycosporine-like amino acids. Modifying the cultural conditions along withmanipulation of genes associated with mycosporine-like amino acids biosynthesis can help to enhance MAAs synthesis and, in turn, can make microalgae suitable bio-refinery for large scale MAAs production. This review focuses on properties and therapeutic applications of mycosporine like amino acids derived from microalgae. Further attention is drawn on various culture and genetic engineering approaches to enhance the MAAs production in microalgae.

Whole genome global insight of antibiotic resistance gene repertoire and virulome of high - risk multidrug-resistant Uropathogenic Escherichiacoli.

Elucidation of genetic determinants via whole genome sequence (WGS) analyses can help understand the high risk multidrug-resistant (MDR) Uropathogenic Escherichia coli (UPEC) associated with urinary tract infections (UTI) and its evasion strategies from treatment. We investigated the WGS of 30 UPEC strains from UTI samples across the world (2016-2019) and found 25 UPEC strains carrying 2-23 antibiotic resistance genes (ARGs) scattered across 1-3 plasmids per strain. Different ARGs (blaTEM, blaCTXM, blaNDM, blaOXA, blaCMY) encoding extended-spectrum beta-lactamases (TEM, CTXM, CMY) and carbapenemases (NDM, OXA) were found in 24/30, ARGs encoding aminoglycoside modifying enzymes (AAC, APH, AAD) variants in 23/30, trimethoprim ARGs (dfrA17, dfrA12, dfrA5, dfrB4 variants) encoding dihydrofolate reductase in 19/30 and sulfonamide ARGs (sul1, sul2, sul3) encoding dihydropteroate synthase and macrolide ARGs (mph1) encoding macrolide 2' phosphotransferase in 15/30 UPEC strains. Collectively the ARGs were distributed in different combinations in 40 plasmids across UPEC strains with 20 plasmids displaying co-occurrence of multiple ARGs conferring resistance to beta lactam, aminoglycoside, sulfonamide, trimethoprim and macrolide antibiotics. These resistance plasmids belonged to seven incompatibility groups (IncF, IncI, IncC, IncH, IncN, IncB and Col), with IncFI and IncFII being the predominant resistance plasmids. Additionally, we observed co-occurrence of specific mutation pattern in quinolone resistance determining region (QRDR) viz., DNA gyrase (gyrA: S83L, D87N), and topoisomerase IV (parC: S80I, E84V; parE: I529L) in 18/30 strains. The strains also harbored diverse virulence genes, such as fimH, gad, iss, iha, ireA, iroN, cnf1 and san. Multilocus sequence typing (MLST) reconfirmed ST131(n = 10) as the predominant global high-risk clonal strain causing UTI. In summary, our findings contribute to better understand the plasmid mediated ARGs and its encoded enzymes that may contribute in antibiotic inactivation/modification or alteration in the antibiotic target site in high risk MDR hypervirulent UPEC strains causing UTI. The study reinforces the need to characterize and design appropriate inhibitors to counterattack different enzymes and devise strategies to curtail resistance plasmid.

Pigmented villonodular synovitis in a child: A missed diagnosis.

Paediatric joint pain and swelling is a frequent presentation. The clinical profile and relevant laboratory investigations often lead to the correct diagnosis; however some patients present a diagnostic conundrum. Pigmented villonodular synovitis (PVNS) is a rare entity that may afflict children and be easily missed.