Sand Dune Streptomyces Jb66 Native To The Great Indian Thar Desert Inhibits Multidrug-Resistant Pathogens

The efficacy of an actinomycete strain JB66 recovered from a sand dune soil from the Bikaner district of the Thar desert in inhibiting the growth of various bacterial pathogens was studied. The type strains Staphylococcus aureus, Shigella flexneri, Klebsiella pneumoniae and the clinical isolates Escherichia coli, multidrug-resistant S. aureus and P. vulgaris were included in the antimicrobial assays. Polyphasic characterization of JB66 isolate revealed its identity as Streptomyces (MH762010). It showed 88.99-89.24% sequence similarity with the other members of this genus and share the maximum (88.89%) similarity with Streptomyces sp. ATSC13. The strain JB66 was found to produce a high amount of extracellular L-asparaginase, catalase, gelatinase, protease, tyrosinase and urease enzymes. The partial chemical categorization of the methanolic crude extract of the JB66 strain led to the preliminary identification of various metabolic compounds. The thin-layer chromatography fractionation revealed the presence of prodigiosin pigment or chandramycin, cephalosporin or zeatin, daidzein, demethoxy rapamycin, 4,6-dihydroxy-7-methoxyisoflavone, munumbicins and amiclenomycin like compounds. Bio-autography revealed that the metabolites localized at the Rf values of 0.40, 0.46 and 0.53 in TLC profile had the actual bioactive fractions. UV-VIS spectrum absorbance maxima at 288 nm revealed the presence of an aromatic nucleus.

Effect of critical medium components and culture conditions on antitubercular pigment production from novel Streptomyces sp D25 isolated from Thar desert, Rajasthan.

Effect of culture conditions and critical medium components on antitubercular pigment production from novel Streptomyces sp D25 isolated from Thar desert, Rajasthan was investigated. Antitubercular pigment from Streptomyces sp. D25 was produced by Agar Surface Fermentation (ASF) using yeast extract malt extract agar (YEME) as a basal medium. Effect of incubation period, temperature, carbon source, nitrogen source, minerals and sodium chloride concentration was studied by adopting one-variable-at-a-time method. Crude pigment produced under different conditions was extracted solid-liquid extraction method using ethyl acetate. Responses measured include the growth rate, quantity of crude extract and activity against S. aureus MTCC96 and M. tuberculosis H37Rv at 100 μg concentrations. Growth and pigment production was correlated with the bioactivity. Of the various conditions tested, maximum growth, pigmentation and bioactivity was observed on 6th day of incubation. Of the various medium components tested, 1% glucose, fructose and malt extract, pH 7 and 9, temperature 300C and 400C, 0.1% KNo3 and 0 – 5% NaCl was found to influence the growth, bioactive pigment production and antimicrobial bioactivity. Further statistical based optimization is in progress to prove the effect of interaction of the above variables on antitubercular pigment production from Streptomyces sp D25.

Isolation and characterization of osmotolerant bacteria from Thar Desert of Western Rajasthan (India)

The Thar Desert harsher environment harbors a limited diversity of life forms due to extreme conditions like low moisture of sandy soils and high soil temperature. In the present study, osmotolerant bacteria from the Thar soils were isolated and characterized. Bacteria were isolated from 20 soil samples (100g), collected from sand dunes, suspended in water and absolute alcohol. A total of 11 biochemical and morphological tests were carried out for generic identification of bacteria. Osmotic tolerance capacity of isolates was examined on glycerol, NaCl and alcohol; and sequencing of 16S rRNA gene was also performed for bacterial identification. 16S to 23S rRNA internal transcribed spacer analysis (RISA) was done for phylogenetic analysis of isolates. The soil suspended in water contained 2.5×10(6) bacteria/g of soil while alcohol suspended soil had 4.4×10(4) bacteria/g. The 24 bacterial isolates were found tolerant to 26% glycerol, 14% NaCl and 10% of alcohol, and 22 out of 24 isolates were found Gram positive. The results showed that 45.83% and 41.67% bacteria belong to Bacillus spp. and Corynebacterium spp., respectively, while Acinetobacter spp., Aeromonas spp. and Staphylococcus spp. were in equal proportion (4.16% each). Six isolates were selected for 16S rRNA gene sequencing and five were found 95% similar with Bacillus licheniformis whereas one isolate was identified as B. subtilis. All the isolates showed good growth up to 50°C with gradual reduction on subsequent increment of temperature. Out of 24 isolates, six could survive at 65°C while one isolate could grow at 63°C. Growth kinetic studies revealed that the reduction in generation time in solute(s) and temperature stress was more as compared to generation time in plain medium. This study suggests that virgin sand dunes may be a rich source of bacteria, tolerant to osmotrophic solutes, and can be examined for plant growth promotion activity in agriculture. Moreover, study might help to resolve the tactic adopted by microbes to defeat desiccation induced by various types of solutes.

El duro ambiente del desierto de Thar alberga una diversidad de formas de vida limitado debido a sus condiciones extremas, como el bajo contenido de humedad de los suelos arenosos y la alta temperatura del suelo. En el presente estudio, las bacterias osmotolerantes de los suelos de Thar, fueron aislados y caracterizados. Las bacterias fueron aisladas a partir de 20 muestras de suelo (100g), obtenidas de dunas de arena, suspendidas en agua y alcohol absoluto. Un total de 11 pruebas bioquímicas y morfológicas se llevaron a cabo para identificar géneros de bacterias: la capacidad de tolerancia osmótica de los aislados se examinó con glicerol, NaCl y alcohol, y la secuenciación de los genes 16S rRNA se realizó también para la identificación bacteriana. El análisis de espaciadores internos transcritos de 16S a 23S rRNA (RISA) se realizó para los aislamientos de análisis filogenéticos. El suelo suspendido en el agua contuvo 2.5×10(6) bacteria/g de suelo mientras que el suelo con alcohol suspendido presentó 4.4×104 bacteria/g. Los 24 aislados bacterianos se encontraron tolerantes a 26% glicerol, 14% NaCl y 10% de alcohol y 22 de los 24 aislados fueron grampositivas. Los resultados mostraron que 45.83% y 41.67% de las bacterias son Bacillus spp. y Corynebacterium spp., respectivamente, mientras que Acinetobacter spp., Aeromonas spp. y Staphylococcus spp. se presentaron en la misma proporción (4.16% cada uno). Seis aislamientos fueron seleccionados para secuenciación de genes 16S rRNA y 95% fueron similares a Bacillus licheniformis mientras que un aislamiento fue identificado como B. subtilis. Todos los aislamientos mostraron un buen crecimiento a 50º C con reducción gradual en el incremento subsiguiente de la temperatura. Fuera de 24 aislados, 6 podrían sobrevivir a 65ºC mientras que un aislado podría crecer a 63ºC. Estudios de crecimiento cinéticos revelaron que la reducción en el tiempo de generación en soluto (s) y estrés de temperatura fue mayor en comparación con el tiempo de generación en un medio simple. Este estudio sugiere que las dunas de arena virgen pueden ser una fuente rica de bacterias, tolerantes a los solutos osmotróficos y se pueden examinar para la promoción de crecimiento de plantas en la agricultura. Por otra parte, el estudio podría ayudar a resolver la táctica adoptada por los microorganismos para rechazar la desecación inducida por diversos tipos de solutos.

Isolation, characterization and growth kinetics of chaotrope induced water stress tolerant bacteria from soils of Thar Desert.

Chaotropic compounds that freely traverse biological membranes and do not affect turgor are powerful mediators of water stress. The present study was initiated to isolate, identify and characterize the Chaotrope tolerant bacteria from soil of Thar Desert. Bacteria were isolated from soil samples, collected from the surface of sand dunes, suspended in water contained 2.5 x 106 bacteria g-1 of soil while alcohol suspended soil had 4.4 x 104 bacteria g-1. The eleven bacterial isolates studied, for the tolerance was found tolerant to 10 % of alcohol, 14 % NaCl and 26 % glycerol and 9 out of 11 isolates were found to be gram positive. More than 50 % of isolates belonged to Bacillus species while Cornybacterium, Acinobacter, Aeromonas and Staphylococcus were also present. Growth kinetic studies revealed that under highly stressed conditions of alcohol and temperature, the generation time was reduced as compared to generation time in plain medium. A rise in incubation temperature and concentration of alcohol added in growth medium resulted in reduction in bacterial population. All Chaotropic solute tolerant bacteria were also tolerant to water stress induced by Halotropes and Kosmotrophes. This study suggests that non saline soil /sand dunes may be a common source for the isolation of bacteria tolerant to Chaotropic, Halotropic and Kosmotropic solutes up to a greater extent, and might help to resolve the general strategy adopted by microbes to thwart desiccation induced by various types of solutes.

A Study of Social Status of People with Disabilities due to Leprosy in Desert Part of Rajasthan, India.

Leprosy is a stigmatized disease in our society. Ninety-eight disabled leprosy patients were studied in areas of Pokaran CHC and Ramdeora PHC of Jaisalmer district. About ninety-five per cent (94.6%) leprosy patients were found discarded by their life partners due to disabilities. A positive relationship was found between social stigma and deformity due to disease. IEC need to be done at community level also for changing attitude and behaviour towards leprosy patients.

Investigation of the outbreak of typhoid in a village of Thar Desert Rajasthan, India.

Background & objectives: Outbreaks of typhoid have been reported from Maharashtra, Bangalore, West Bengal and Pondicherry in India but rarely from Rajasthan. We investigated an outbreak of typhoid in a village of Thar Desert of Rajasthan. Methods: A retrospective cohort study was carried out during May-July 2007 in Varkana village, Pali district, Rajasthan, to identify the risk factor for disease. The information on outbreak was collected and then described in time, place and person characteristics to arrive at aetiological hypotheses. Results: There were 219 cases of typhoid in village. Attack rate was 104 cases per 1000 population. Maximum attack rate of 276 cases per 1000 population was noted in persons of 10-14 yr age group. Forty three serum samples were reported positive for Widal agglutination test out of 70 tested. Drinking of water from government overhead tanks was associated with disease significantly (RR= 11.1, 95% CI= 3.7-33). Two of the three water samples from government tanks were found positive for faecal contamination. Interpretation & conclusion: The outbreak of typhoid in a village affected >200 persons of all age groups and both gender. Exposure to the drinking water from government tanks was found significantly associated with the disease. Preventive and control measures undertaken after analytical epidemiological study helped in terminating the outbreak.