Amphotericin B Loaded Polymeric Nanoparticles for Treatment of Leishmania Infections.

Fungal infections in immune-compromised patients are an important cause of mortality and morbidity. Amphotericin B (Amp B) is considered a powerful fungicidal drug but its clinical usage has certain limitations when administered intravenously due to its toxicity and poor solubility. In consideration of such challenges, in cutaneous leishmaniasis, the topical application of Amp B can be a safer option in many aspects. Thus, herein, biopolymer of polycaprolactone (PCL) nanoparticles (NPs) were developed with the loading of Amp B by nanoprecipitation for the treatment of topical leishmanial infections. Various parameters, such as concentration of PCL and surfactant Poloxamer 407, were varied in order to optimize the formation of nanoparticles for the loading of Amp B. The optimized formulation exhibited a mean hydrodynamic particle size of 183 nm with a spherical morphology and an encapsulation efficiency of 85%. The applications of various kinetic models reveal that drug release from nanoformulation follows Korsmeyer-Peppas kinetics and has a high diffusion exponent at a physiological pH of 7.4 as well a skin relevant pH = 5.5. The activity of the prepared nanoparticles was also demonstrated in Leishmania infected macrophages. The measured IC50 of the prepared nanoparticle formulation was observed to be significantly lower when compared to control free Amp B and AmBisome® for both L. tropica KWH23 and L. donovani amastigotes in order to demonstrate maximum parasite inhibition. The prepared topical nanoformulations are capable of providing novel options for the treatment of leishmaniasis, which can be possible after in vivo assays as well as the establishment of safety profiles.

Gimesia chilikensis sp. nov., a haloalkali-tolerant planctomycete isolated from Chilika lagoon and emended description of the genus Gimesia.

A Gram-stain-negative, aerobic, non-motile, salt- and alkali-tolerant, pear to oval shaped, rosette-forming, white coloured, bacterium, designated as strain JC646T, was isolated from a sediment sample collected from Chilika lagoon, India. Strain JC646T reproduced through budding, grew well at up to pH 9.0 and tolerated up to 7 % NaCl. Strain JC 646T utilized α-d-glucose, fumarate, lactose, sucrose, fructose, d-galactose, mannose, maltose and d-xylose as carbon sources. Peptone, l-isoleucine, l-serine, l-lysine, l-glutamic acid, l-aspartic acid, dl-threonine and l-glycine were used by the strain as nitrogen sources for growth. The respiratory quinone was MK6. Major fatty acids were C16 : 1 ω7c/C16 : 1 ω6c and C16 : 0. The polar lipids of strain JC646T comprised phosphatidyl-dimethylethanolamine, phosphatidylcholine, diphosphatidylglycerol, an unidentified amino lipid and two unidentified lipids. Strain JC646T had highest (97.3 %) 16S rRNA gene sequence identity to the only species of the genus Gimesia, Gimesia maris DSM 8797T. The genome of strain JC646T was 7.64 Mbp with a DNA G+C content of 53.2 mol%. For the resolution of the phylogenetic congruence of the novel strain, the phylogeny was also reconstructed with the sequences of 92 housekeeping genes. Based on phylogenetic analyses, digital DNA-DNA hybridization (19.0 %), genome average nucleotide identity (74.5 %) and average amino acid identity/percentageof conserved proteins (77 %) results, chemotaxonomic characteristics, and differential physiological properties, strain JC646T is recognized as representing a new species of the genus Gimesia, for which we propose the name Gimesia chilikensis sp. nov. The type strain is JC646T (=KCTC 72175T=NBRC 113881T).

Paracoccus aeridis sp. nov., an indole-producing bacterium isolated from the rhizosphere of an orchid, Aerides maculosa.

A Gram-stain-negative, non-motile, coccoid-shaped, catalase- and oxidase-positive, non-denitrifying, neutrophilic bacterium designated as strain JC501T was isolated from an epiphytic rhizosphere of an orchid, Aerides maculosa, growing in the Western Ghats of India. Phylogenetic analyses based on the 16S rRNA gene sequence indicated that strain JC501T belonged to the genus Paracoccus and had the highest levels of sequence identity with Paracoccus marinus KKL-A5T (98.9 %), Paracoccus contaminans WPAn02T (97.3 %) and other members of the genus Paracoccus (<97.3 %). Strain JC501T produced indole-3 acetic acid and other indole derivatives from tryptophan. The dominant respiratory quinone was Q-10 and the major fatty acid was C18 : 1ω7c/C18 : 1ω6c, with significant quantities of C18 : 1ω9c, C17 : 0 and C16 : 0. The polar lipids of strain JC501T comprised phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, an unidentified glycolipid, two unidentified aminolipids, two unidentified lipids and four unidentified phospholipids. The genome of strain JC501T was 3.3 Mbp with G+C content of 69.4 mol%. For the resolution of the phylogenetic congruence of the novel strain, the phylogeny was also reconstructed with the sequences of eight housekeeping genes. Based on the results of phylogenetic analyses, low (<85.9 %) average nucleotide identity, digital DNA-DNA hybridization (<29.8 %), chemotaxonomic analysis and physiological properties, strain JC501T could not be classified into any of the recognized species of the genus Paracoccus. Strain JC501T represents a novel species, for which the name Paracoccus aeridis sp. nov. is proposed. The type strain is JC501T (=LMG 30532T=NBRC 113644T).

Chryseobacterium candidae sp. nov., isolated from a yeast (Candida tropicalis).

A Gram-stain-negative, rod shaped, non-motile, aerobic bacterium (strain JC507T) was isolated from a yeast (Candida tropicalis JY101). Strain JC507T was oxidase- and catalase-positive. Complete 16S rRNA gene sequence comparison data indicated that strain JC507T was a member of the genus Chryseobacterium and was closely related to Chryseobacterium indologenes NBRC 14944T (98.7 %), followed by Chryseobacterium arthrosphaerae CC-VM-7T (98.6 %), Chryseobacterium gleum ATCC 35910T (98.5 %) and less than 98.5 % to other species of the genus Chryseobacterium.The genomic DNA G+C content of strain JC507T was 36.0 mol%. Strain JC507T had phosphatidylethanolamine, four unidentified amino lipids and four unidentified lipids. MK-6 was the only respiratory quinone. The major fatty acids (>10 %) were anteiso-C11 : 0, iso-C15 : 0 and iso-C17 : 03OH. The average nucleotide identity and in silico DNA-DNA hybridization values between strain JC507T and C. indologenes NBRC 14944T, C. arthrosphaerae CC-VM-7T and C. gleum ATCC 35910T were 80.2, 83.0 and 87.0 % and 24, 26.7 and 32.7 %, respectively. The results of phenotypic, phylogenetic and chemotaxonomic analyses support the inclusion of strain JC507T as a representative of a new species of the genus Chryseobacterium, for which the name Chryseobacteriumcandidae sp. nov. is proposed. The type strain is JC507T (=KCTC 52928T=MCC 4072T=NBRC 113872T).