Pulmonary tuberculosis (PTB) is one of the major infectious diseases in developing countries. The objective of this study was to compare rapid diagnostics technique, GeneXpert MTB/RIF (GeneXpert) and Multiplex PCR assay (MPCR) targeting IS6110 segment and mpb64 gene for direct detection of Mycobacterium tuberculosis (MTB) in suspected PTB patients. A cross sectional study was carried among 105 sputum samples from suspected PTB patients to evaluate GeneXpert and Multiplex PCR who visited National Tuberculosis Center, Nepal. The patient's sputum samples were used directly for the GeneXpert whereas DNA extraction by CTAB method was followed to process the sample for MPCR. The sensitivity and specificity of GeneXpert and MPCR in smear positive cases was 78.6, 33.3, and 100.0%, 66.7%, respectively (P = 0.125). However, in smear negative cases sensitivity and specificity of both methods exhibited 90.9, 95.2, and 100.0%, 100.0% respectively (P = 0.625). Finally, the sensitivity and specificity of GeneXpert and MPCR were 82.9, 95.3 and 100.0%, 98.5% respectively, (P = 0.549) in pulmonary cases. Comparatively, we observed higher sensitivity and specificity for MPCR than GeneXpert for both smear positive and negative samples. Thus, we recommend MPCR alongside GeneXpert for the better diagnostic accuracy of PTB in a resource-limited country where tuberculosis is endemic.

Erosion resulting from landslides is a serious problem in mountainous countries such as Nepal. To restore such sites it is essential to establish plant cover that protects the soil and reduces surface erosion. Mycorrhizal fungi growing in symbiosis with plants are essential in this respect because they improve both plant nutrient uptake and soil structure. We investigated the influence of organic matter and P amendment on recently produced biomass of bacteria and arbuscular mycorrhizal (AM) fungi in eroded slopes in Nepal. Eroded soil mixed with different types of organic matter or P was placed in mesh bags, which were buried around trees of Bauhinia purpurea and Leucaena diversifolia between June 2003 and December 2003 (the wet season) or between December 2003 and June 2004 (the dry season). Signature fatty acids were used to determine bacterial and AM fungal biomass after the 6-month intervals. The amount and composition of AM fungal spores were analyzed in the mesh bags from the dry season. More microbial biomass was produced during the wet season than during the dry season. Furthermore, organic matter addition enhanced the production of AM fungal and bacterial biomass during both periods. The positive influence of organic matter addition on AM fungi could be an important contribution to plant survival in plantations on eroded slopes. Different AM spore communities and bacterial profiles were obtained with different organic amendments and this suggests a possible way of selecting for specific microbial communities in the management of eroded sites.

Water hyacinth (Eichhornia crassipes) is an invasive aquatic weed causing serious threats to water ecosystems throughout the world. Recently, considerable attention has been given at harvesting the plant for practical uses. An experiment on the bioactivity of water hyacinth was conducted using the soxhlet extraction (hot method) and cold percolation method in chloroform and ethanol in order to evaluate the antimicrobial properties of the plant. Plant samples were also analyzed for the presence of major pharmacologically active compounds. The antimicrobial assay was performed using well diffusion method against nine different clinical bacterial strains and six phytopathogenic fungal strains. The chloroform hot extract showed activity against 22.22% (Zone of Inhibition, ZOI < 13mm) bacteria and 66.66% (ZOI < 12mm) fungi; while the cold extract showed activity against 50% (ZOI < 13mm) fungi, but no activity against bacteria. Similarly, the ethanol hot extract showed activity against 77.77% (ZOI < 19mm) bacteria and 66.66% (ZOI < 20mm) fungi, while the cold extract showed activity against 77.77% (ZOI < 10mm) bacteria and 50% (ZOI < 14mm) fungi. The ethanolic hot and cold extract proved to be far better than the chloroform fraction showing more antibacterial activity, while they share the same value and possess same effectiveness against the different fungi. Chemical analysis indicated that the major components in these extracts were saponins, polyoses, alkaloid salts, and reducing compounds. The present study showed that the devastating aquatic weed, with strong antimicrobial potentials and presence of biologically active phytochemicals, may be useful for developing alternative compounds to treat infectious diseases caused by bacterial and fungal pathogens. doi: http://dx.doi.org/10.3126/botor.v8i0.5556 Botanica Orientalis – Journal of Plant Science (2011) 8: 33-39

The antimicrobial, chemical and allelopathical properties of invasive alien weed Mikania micrantha Kunth ex H.B.K were analyzed. The extraction was performed in different solvents by soxhlet extraction technique. Some bacteria (Acinetobacter sp. and Bacillus subtilis) were found to be highly inhibited, whereas the extract was found effective against Fusarium species (F. eridiforme) among the fungi. Of all the solvents used for extraction, methanolic hot extract showed good antimicrobial properties against tested pathogenic strains. The preliminary qualitative phytochemical assay divulged the presence of glycosides and quinones in the test plant. Germination rate was higher for all crops with control treatment. The germination rate decreased with the increase in the extract concentration and was found to be lowest at 5% concentration of extract. Generally, the radicle length of all bioassayed species decreased with increasing concentrations of Mikania, with Barley and Paddy being the most susceptible to the plant extract at full strength. The broad spectrum of activity of the extract indicated possibilities for wide use of M. micrantha for controlling the human pathogenic bacteria and phytopathogenic fungus that have been widely destroying crops.DOI: http://dx.doi.org/10.3126/njst.v12i0.6483 Nepal Journal of Science and Technology 12 (2011) 75-84

The biological and chemical properties of the medicinally important high altitudinal plant Rhododendron anthopogon D. Don were assayed. Extracts at a concentration of 100 mg-ml-1 from leaves and flowers were collectively obtained by employing hot extraction method with different solvents. The antibacterial and antifungal properties were assayed against different clinical bacteria (two Gram+ and six Gram-) and six phytopathogenic fungi. Klebsiella pneumoniae and Salmonella typhimurium were the most inhibited bacteria, while Fusarium eridiforme, a fungus, was highly inhibited. However, all the tested bacteria were resistant to n-hexane and chloroform extracts. Of all the extracts obtained, the ethyl acetate fraction, followed by the hot methanolic extract, was effective against all the pathogenic strains tested. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) values of ethyl acetate and aqueous extracts on bacteria ranged from 1.562 mg-ml” 1 to 25.0 mg-ml” 1, whereas MIC and MFC (minimum fungicidal concentration) values of n-hexane and ethyl acetate fractions on fungi varied from 1.562 mg-ml-1 to 12.50 mg-ml-1, which are slightly higher than expected. The extracts showed no activity against Exserohilum turticum and Stenophylum sp. There was a highly significant difference in the zone of inhibition between different extract fractions and bacterial or fungal strains. A preliminary qualitative phyto-chemical assay revealed the presence of polyphenols, reducing compounds, quinones, sterol, triterpenes and fatty acids in leaves and flowers of the test plant. The observed antimicrobial effects are believed to be due to the presence of these compounds. The broad spectrum of activity of the extracts would apparently explain the widespread use of this plant for controlling human pathogenic bacteria and phytopathogenic fungi that widely destroy crops in Nepal. This research reveals R. anthopogon to be a highly promising source of potent antimicrobial drugs that could be used to design therapeutic drugs in the pharmaceutical industry.