Comparison of Changes in Tensile Strength in Three Different Flexible Epidural Catheters Under Various Conditions.

BACKGROUND: Rarely, epidural catheters may fracture upon removal or insertion. Understanding some of the mechanical properties of epidural catheters, such as their tensile strength and how external factors (including temperature) can influence their strength, will aid physicians in making decisions if faced with an entrapped catheter. In the present study, we evaluated the impact in tensile strength when catheters are exposed to 37 ± 1°C, after the removal of the inner metal coil and after the injection of sterile saline through the catheter. METHODS: We analyzed the tensile strength of a total of 120 catheters (19-gauge) from 3 different brands and materials. The reinforced epidural catheters were affixed to opposing, specially designed tensile test fixtures and then installed in an Applied Test System tensile test apparatus. We evaluated the strength of 10 catheters from different brands and materials for each of the following variables: at room temperature (control group), after the removal of the inner wire present in all the flexible catheters tested, injection of normal saline, and at 37 ± 1°C. RESULTS: When compared with their control groups, the Arrow catheter (2.85 kg) was shown to be superior to B-Braun (2.17 kg; P < 0.0001) and Smith catheters (2.33 kg; P < 0.0005). No statistical difference was noted between the Smith and B-Braun catheters (P = 0.39). When comparing catheters after wire removal against their respective control group, no statistical difference was noted. A decrease in tensile strength was noted in the B-Braun catheters (1.53 kg) when tested at 37°C (P ≤ 0.0001). In contrast, the Smith and the Arrow catheters did not show a statistically significant change when tested at 37°C (P = 1.0 and P = 0.063, respectively). After the injection of normal saline, the Arrow (2.33 kg) and the B-Braun (1.58 kg) catheters showed a decrease in tensile strength (P = 0.0010 and P = 0.0001, respectively). CONCLUSIONS: The current recommendation of injecting saline through an entrapped catheter resulted in a decrease in tensile strength of the Arrow and B-Braun catheters. A decrease in tensile strength also was noted in the B-Braun catheters when tested at 37°C. There is no benefit, at least in terms of tensile strength, in removing the wire or inner coil from any of the tested brands. The Smith catheter was the most resilient, showing no decrease in tensile strength at 37°C and after the injection of normal saline when compared with control.

Description of Domibacillus indicus sp. nov., isolated from ocean sediments and emended description of the genus Domibacillus.

A novel Gram-stain-positive, spore-forming, aerobic, non-motile, rod-shaped bacterium designated strain SD111(T) that forms red-pigmented colonies was isolated from a marine sediment sample (collected from 5 m depth) from Lakshadweep, India. Strain SD111(T) grew well on seawater agar at pH 6-10 (optimum pH 7.5±0.2). It showed maximum (97.6 %) 16S rRNA gene sequence similarity and formed a monophyletic clade with Domibacillus robiginosus WS 4628(T) ( = DSM 25058(T)). The genomic DNA G+C content was 37.4 mol% and the strain showed 37.7 % DNA-DNA relatedness to D. robiginosus DSM 25058(T). The major fatty acids were anteiso-C15 : 0, C16 : 0, iso-C15 : 0 and iso-C16 : 0 and MK-6 was the predominant quinone. The polar lipid profile of strain SD111(T) consisted of unidentified phospholipids (PL1 and PL2), phosphatidylglycerol (PG) and diphosphatidylglycerol (DPG). The cell wall contained meso-diaminopimelic acid and the peptidoglycan was of A1γ type. Glucose and ribose were detected as major cell-wall sugars. Results from polyphasic studies indicated that SD111(T) represents a novel species of the genus Domibacillus for which the name Domibacillus indicus sp. nov. is proposed. The type strain is SD111(T) ( = MCC 2255(T) = DSM 28032(T)).

Biology and survival of extremely halophilic archaeon Haloarcula marismortui RR12 isolated from Mumbai salterns, India in response to salinity stress.

Haloarchaea are unique microorganism's resistant to environmental and osmotic stresses and thrive in their habitats despite extreme fluctuating salinities. In the present study, haloarchaea were isolated from hypersaline thalossohaline salterns of Bhandup, Mumbai, India and were identified as Haloferax prahovense, Haloferax alexandrines, Haloferax lucentense, Haloarcula tradensis, Haloarcula marismortui and Haloarcula argentinensis. The mechanism of adaptation to contrasting salinities (1.5 M and 4.5 M) was investigated in the extreme haloarchaeon, Hal. marismortui RR12. Hal. marismortui RR12 increased the intracellular sequestration of K(+) and Cl(-) ions in hypo salinity and hyper salinity respectively as detected by Energy-dispersive X-ray spectroscopy microanalysis (EDAX) and Inductively Coupled Plasma- atomic Emission Spectroscopy (ICP-AES) indicating the presence of 'salt-in' strategy of osmoadaptation. As a cellular response to salinity stress, it produced small heat shock like proteins (sHSP) identified using MALDI-TOF MS and increased the production of protective red carotenoid pigment. This is the first report on the study of the concomitant cellular, molecular and physiological mechanism adapted by Hal. marismortui RR12 when exposed to contrasting salinities in external environment.

Insights into Diversity and Imputed Metabolic Potential of Bacterial Communities in the Continental Shelf of Agatti Island.

Marine microbes play a key role and contribute largely to the global biogeochemical cycles. This study aims to explore microbial diversity from one such ecological hotspot, the continental shelf of Agatti Island. Sediment samples from various depths of the continental shelf were analyzed for bacterial diversity using deep sequencing technology along with the culturable approach. Additionally, imputed metagenomic approach was carried out to understand the functional aspects of microbial community especially for microbial genes important in nutrient uptake, survival and biogeochemical cycling in the marine environment. Using culturable approach, 28 bacterial strains representing 9 genera were isolated from various depths of continental shelf. The microbial community structure throughout the samples was dominated by phylum Proteobacteria and harbored various bacterioplanktons as well. Significant differences were observed in bacterial diversity within a short region of the continental shelf (1-40 meters) i.e. between upper continental shelf samples (UCS) with lesser depths (i.e. 1-20 meters) and lower continental shelf samples (LCS) with greater depths (i.e. 25-40 meters). By using imputed metagenomic approach, this study also discusses several adaptive mechanisms which enable microbes to survive in nutritionally deprived conditions, and also help to understand the influence of nutrition availability on bacterial diversity.