Lysobacter oculi sp. nov., isolated from human Meibomian gland secretions

Comparative Evaluation of Bandage Contact Lenses and Eye Patching after Bilateral Cataract Surgery

Purpose

To comparatively evaluate the safety and satisfaction of bandage contact lens (BCL) and eye patching in patients after cataract surgery.

Methods

Sixteen (32 eyes) patients who planned to undergo bilateral cataract surgery were recruited. The two eyes of each patient were randomly divided into 2 groups. Group A and Group B were instructed to wear BCLs immediately at the end of the surgery until one week and eye patch immediately after surgery until one day, respectively. Visual analog scales of ten specific symptoms, Visual Function Index (VF-14) questionnaire, and best-corrected visual acuity (BCVA) were conducted on the first day before the surgery and Day 1 and Day 7 after surgery. Oculus keratography was conducted on the first day before surgery and on Day 7. Patient satisfaction was determined on Day 1. Moreover, bacterial species in the conjunctival sac, meibomian gland secretions, and BCLs were subsequently identified using 16S rRNA gene sequencing.

Results

The patient satisfaction scores of Group A were higher than Group B. Group A were more motivated to choose the same treatment and were more likely to recommend BCLs to others. No statistically significant differences were found in bacterial culture positivity between the groups. The differences in ocular signs and symptoms between the two groups were not statistically significant. There were no significant differences in the BCVA and VF-14 between the groups at any time point.

Conclusions

BCLs could be safely and effectively used in patients after cataract surgery.

Exploring antibiotic resistance in environmental integron-cassettes through intI-attC amplicons deep sequencing

INTRODUCTION

Freshwater ecosystems provide propitious conditions for the acquisition and spread of antibiotic resistance genes (ARGs), and integrons play an important role in this process.

MATERIAL AND METHODS

In the present study, the diversity of putative environmental integron-cassettes, as well as their potential bacterial hosts in the Velhas River (Brazil), was explored through intI-attC and 16S rRNA amplicons deep sequencing. RESULTS AND DISCUSSION: ORFs related to different biological processes were observed, from DNA integration to oxidation-reduction. ARGs-cassettes were mainly associated with class 1 mobile integrons carried by pathogenic Gammaproteobacteria, and possibly sedentary chromosomal integrons hosted by Proteobacteria and Actinobacteria. Two putative novel ARG-cassettes homologs to fosB3 and novA were detected. Regarding 16SrRNA gene analysis, taxonomic and functional profiles unveiled Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria as dominant phyla. Betaproteobacteria, Alphaproteobacteria, and Actinobacteria classes were the main contributors for KEGG orthologs associated with resistance.

CONCLUSIONS

Overall, these results provide new information about environmental integrons as a source of resistance determinants outside clinical settings and the bacterial community in the Velhas River.

Lysobacter profundi sp. nov., isolated from freshwater sediment and reclassification of Lysobacter panaciterrae as Luteimonas panaciterrae comb. nov

A polyphasic taxonomic study was carried out on strains CHu50b-3-2T and CHu40b-3-1 isolated from a 67 cm-long sediment core collected from the Daechung Reservoir at a water depth of 17 m, Daejeon, Republic of Korea. The cells of the strains were Gram-stain-negative, non-spore-forming, non-motile and rod-shaped. Comparative 16S rRNA gene sequence studies showed a clear affiliation of two strains with γ-Proteobacteria, which showed the highest pairwise sequence similarities to Lysobacter hankyongensis KTce-2T (96.5 %), Lysobacter pocheonensis Gsoil193T (96.3 %), Lysobacter ginsengisoli Gsoil 357T (96.1 %), Lysobacter solanacearum T20R-70T (96.1 %), Lysobacter brunescens KCTC 12130T (95.4 %) and Lysobacter capsici YC5194T (95.3 %). The phylogenetic analysis based on 16S rRNA gene sequences showed that the strains formed a clear phylogenetic lineage with the genus Lysobacter . The major fatty acids were identified as summed feature 9 (iso-C17 : 1  ω9c and/or C18 : 1 10-methyl), iso-C15 : 0, iso-C16 : 0 and iso-C17 : 0. The respiratory quinone was identified as ubiquinone Q-8. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The genomic DNA G+C content was determined to be 66.8 mol% (genome) for strain CHu50b-3-2T and 66.4 mol% (HPLC) for strain CHu40b-3-1. Based on the combined genotypic and phenotypic data, we propose that strains CHu50b-3-2T and CHu40b-3-1 represent a novel species of the genus Lysobacter , for which the name Lysobacter profundi sp. nov. is proposed. The type strain is CHu50b-3-2T (=KCTC 72973T=CCTCC AB 2019129T). Besides Lysobacter panaciterrae Gsoil 068T formed a phylogenetic group together with strain Luteimonas aquatica RIB1-20T (EF626688) that is clearly separated from all other known Lysobacter strains. Based on the phylogenetic relationships together with fatty acid compositions, Lysobacter panaciterrae Gsoil 068T should be reclassified as a member of the genus Luteimonas: Luteimonas aquatica comb. nov. (type strain Gsoil 068T=KCTC 12601T=DSM 17927T).

Lysobacter alkalisoli sp. nov., a chitin-degrading strain isolated from saline-alkaline soil

Strains of Lysobacter, thought to play vital roles in the environment for their high enzyme production capacity, are ubiquitous in various ecosystems. During an analysis of bacterial diversity in saline soil, a Gram-stain-negative, aerobic, chitin-degrading bacterial strain, designated SJ-36^T, was isolated from saline-alkaline soil sampled at Tumd Right Banner, Inner Mongolia, PR China. Strain SJ-36^T grew at 4-40 °C (optimum, 30 °C), pH 5.0-10.0 (optimum, pH 7.0-8.0) and 0-6 % NaCl (optimum, 1.0 %). Oxidase and catalase activities were positive. A phylogenetic tree based on 16S rRNA gene sequences and the phylogenomic tree both showed that strain SJ-36^T formed a tight clade with Lysobacter maris KMU-14^T (sharing 97.6 % 16S rRNA gene similarity) and Lysobacter aestuarii S2-C^T (97.8 %). The major polar lipids of strain SJ-36^T were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, two unidentified lipids and one unidentified phospholipid. The major fatty acids were iso-C_15 : 0 (37.5 %), summed feature 9 (14.0 %; iso-C_17 : 1ω9c and/or C_16 : 0 10-methyl) and iso-C_11 : 0 (10.6 %). Q-8 was the predominant ubiquinone. Its genomic DNA G+C content was 66.6 mol%. The average nucleotide identity values of strain SJ-36^T to L. maris KMU-14^T, L. aestuarii S2-C^T and other type strains were 81.5, 79.1 and <79.0 %, respectively. The results of physiological, phenotypic and phylogenetic characterizations allowed the discrimination of strain SJ-36^T from its phylogenetic relatives. Lysobacter alkalisoli sp. nov. is therefore proposed with strain SJ-36^T (=CGMCC 1.16756^T=KCTC 43039^T) as the type strain.