Green synthesis of gold nanoparticles using extracellular metabolites of fish gut microbes and their antimicrobial properties.

In the present study, we synthesis nanoparticles using biosynthesis methods because of the eco-friendly approach. Gold nanoparticles were synthesized using extracellular metabolites of marine bacteria (Rastrelliger kanagurta, Selachimorpha sp., and Panna microdon). After the synthesis gold nanoparticles checked their antibacterial and antimycobacterial activities. Here we have few techniques that have been used for characterizing the gold nanoparticles followed by ultraviolet (UV)-visible spectrophotometer analysis, Fourier transform-infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscopy (TEM). We observed the formation of gold nanoparticles using UV-Vis spectroscopy (UV-Vis). FT-IR spectroscopy results of the extracellular metabolites showed that different characteristic functional groups are responsible for the bioreduction of gold ions. In the recent years, we used zebrafish for an animal model to estimate nanoparticle toxicity and biocompatibility. We tested toxicity of the gold nanoparticle using the zebrafish larvae that are growing exponentially. Sample 1 showed a good antimicrobial activity, and sample 5 showed a good antimycobacterial activity. Based on the UV spectrophotometer, sample 1 is used for further studies. Color change and UV spectrum confirmed gold nanoparticles. Based on the TEM and SEM particles, size was measured and ranged between 80 and 45 nm, and most of the particles are spherical and are in rod shape. XRD result showed the gold nanoparticles with crystalline nature. Toxicity studies in the zebrafish larvae showed that 50 µg ml-1 showed less toxicity. Based on the studies, gold nanoparticle has good antibacterial and antimycobacterial activities. The present was concluded that gold nanoparticles have potential biocompatibility and less toxicity. Gold nanoparticles will be used as a drug molecule in pharmaceutical company and biomedicine application.

Crystal structure of 2-amino-5-nitro-pyridinium sulfamate.

The title mol-ecular salt, C5H6N3O2 (+) ·H2NO3S(-), was obtained from the reaction of sulfamic acid with 2-amino-5-nitro-pyridine. A proton transfer from sulfamic acid to the pyridine N atom occurred, resulting in the formation of a salt. As expected, this protonation leads to the widening of the C-N-C angle of the pyridine ring, to 122.9 (3)°, with the pyridinium ring being essentially planar (r.m.s. deviation = 0.025 Å). In the crystal, the ion pairs are joined by three N-H⋯O and one N-H⋯N hydrogen bonds in which the pyridinium N atom and the amino N atom act as donors, and are hydrogen bonded to the carboxyl-ate O atoms and the N atom of the sulfamate anion, thus generating an R (3) 3(22) ring motif. These motifs are linked by further N-H⋯O hydrogen bonds enclosing R (3) 3(8) loops, forming sheets parallel to (100). The sheets are linked via weak C-H⋯O hydrogen bonds, forming a three-dimensional structure. The O atoms of the nitro group are disordered over two sets of sites with a refined occupancy ratio of 0.737 (19):0.263 (19).

2-Amino-5-nitro-pyridinium hydrogen oxalate.

In the cation of the title mol-ecular salt, C5H6N3O2 (+)·C2HO4 (-), the dihedral angle between the aromatic ring and the nitro group is 3.5 (3)°; in the anion, the dihedral angle between the CO2 and CO2H planes is 10.5 (2)°. In the crystal, the anions are linked into [100] chains by O-H⋯O hydrogen bonds. The cations cross-link the chains by way of N-H⋯O hydrogen bonds and the structure is consolidated by C-H⋯O inter-actions.

Assessment of panel slides prepared by phenol ammonium sulphate and NALC methods for proficiency testing.

BACKGROUND: Existing methods for the preparation of panel slides necessitate handling high-grade acid-fast bacilli positive sputum samples. OBJECTIVE: To compare panel slides prepared using the phenol ammonium sulphate sediment (PhAS) method with those prepared using the N-acetyl-L-cysteine (NALC) method in proficiency testing. METHODS: Pooled sputum specimens of known smear-positives and -negatives were divided into two parts: one part was used for preparing panel slides using the NALC method and the other using PhAS, a non-hazardous method. Respectively 413 and 384 smears of different grades were prepared in three batches using the PhAS and NALC methods. Smear grade and quality were recorded by 121 microscopists during proficiency testing in different states. Agreement between reference and reported results was analysed using the kappa test. RESULTS: The overall agreement was 96% for the PhAS method and 91% for the NALC method. There were 37 errors using the NALC method compared to 21 for the PhAS method (P < 0.223). Smear quality was equally good in both methods; however, the cell count was significantly higher in the PhAS than in the NALC method. CONCLUSION: The PhAS method, a non-hazardous procedure with good-quality smears, may be further explored for the preparation of panel slides.

Recovery of Mycobacterium tuberculosis from Löwenstein-Jensen media contaminated with other organisms.

Growth of contaminating organisms along with Mycobacterium tuberculosis on Löwenstein-Jensen (LJ) medium is common. However, there is no documented evidence on the decontamination procedure adopted in mycobacteriology laboratories to recover M. tuberculosis from the contaminants grown on LJ medium. At the National Institute for Research in Tuberculosis, of 1048 LJ slopes with M. tuberculosis received from intermediate reference laboratories, 98 (9%) were contaminated. Of these, 87 (89%) M. tuberculosis cultures were retrieved after decontamination with 1% cetrimide. The use of cetrimide as a decontaminating agent to retrieve M. tuberculosis cultures grown with contaminants is documented.

Quality indicators in a mycobacteriology laboratory supporting clinical trials for pulmonary tuberculosis.

BACKGROUND: Documentation of structured quality indicators for mycobacteriology laboratories supporting exclusively controlled clinical trials in pulmonary tuberculosis (PTB) is lacking. OBJECTIVE: To document laboratory indicators for a solid (Lowenstein-Jensen medium) culture system in a mycobacteriology laboratory for a period of 4years (2007-2010). METHODS: The sputum samples, collected from PTB suspects/patients enrolled in clinical trials, were subjected to fluorescence microscopy, culture and drug sensitivity testing (DST). Data was retrospectively collected from TB laboratory registers and computed using pre-formulated Microsoft Office Excel. Laboratory indicators were calculated and analyzed. RESULTS: The number of samples processed in a calendar year varied from 6261 to 10,710. Of the samples processed in a calendar year, specimen contamination (4.8-6.9%), culture positives (78.4-85.1%) among smear positives, smear positives (71.8-79.0%) among culture positive samples, smear negatives among culture negative samples (95.2-96.7%), and average time to report DST results (76-97days) varied as shown in parentheses. CONCLUSION: Values of quality indicators in mycobacteriology laboratories supporting exclusively clinical trials of PTB have to be defined and used for meaningful monitoring of laboratories.

Newer diagnostic tools in tuberculosis.

Tuberculosis (TB) is a global health problem. Multi Drug Resistant TB (MDR-TB) and Extensively Drug Resistant TB (XDR-TB) cause high mortality. There are obstacles to the diagnosis of TB due to lack of accurate, cost effective and rapid diagnostic tools. The delay in diagnostic process is an unresolved bottleneck impeding access to treatment. Presently available diagnostic tools for TB except some liquid culture and molecular tests take long time. TB culture and drug susceptibility test (DST) need specialized laboratory setup and are also very expensive. The New Diagnostics Working Group (NDWG) on TB is supporting development of new tools and also provides information to World Health Organization (WHO) for endorsement. Globally, TB control programmes need rapid and accurate diagnostic tools, which are to be implemented in peripheral health centers as well. In this review, we describe development of newer diagnostic tools, their endorsement status and usage in TB diagnosis.