Indranil Bhattacharjee

Biosorption of heavy metals from industrial waste water by Geobacillus thermodenitrificans.

The metal binding capacity of the thermophilic bacteria Geobacillus thermodenitrificans isolated from Damodar river, India was assessed using synthetic metal solutions and industrial waste water. Biosorption preference of dead biomass of G. thermodenitrificans for the synthetic metal solutions was in the following order Fe(+3)>Cr(+3)>Co(+2)>Cu(+2)>Zn(+2)>Cd(+2)>Ag(+)>Pb(+2). It reduced the concentration of Fe(+3) (91.31%), Cr(+3) (80.80%), Co(+2) (79.71%), Cu(+2) (57.14%), Zn(+2) (55.14%), Cd(+2) (49.02%), Ag(+) (43.25%) and Pb(+2) (36.86%) at different optimum pH within 720 min. When this strain was applied in the industrial waste water biosorption preference was in the following order Fe(+3)>Cr(+3)>Cd(+2)>Pb(+2)>Cu(+2)>Co(+2)>Zn(+2)>Ag(+) and concentrations reduced up to 43.94% for Fe(+3), 39.2% for Cr(+3), 35.88% for Cd(+2), 18.22% for Pb(+2), 13.03% for Cu(+2), 11.43% for Co(+2), 9.02% for Zn(+2) and 7.65% for Ag(+) within 120 min.

Antibacterial potentiality of Argemone mexicana solvent extracts against some pathogenic bacteria

The sensitivity of two Gram positive (Staphylococcus aureus and Bacillus subtilis) and two Gram negative (Escherichia coli and Pseudomonas aeruginosa) pathogenic multi-drug resistant bacteria was tested against the crude extracts (cold aqueous, hot aqueous, and methanol extracts) of leaves and seeds of Argemone mexicana L. (Papaveraceae) by agar well diffusion method. Though all the extracts were found effective, yet the methanol extract showed maximum inhibition against the test microorganisms followed by hot aqueous extract and cold aqueous extract.

Isolation and identification of bioactive antibacterial components in leaf extracts of Vangueria spinosa(Rubiaceae)

OBJECTIVE The column chromatographic fraction of ethyl acetate (EA1, EA2, EA3, EA4 and EA5) leaf extracts of Vangueria spinosa (V. spinosa) were screened for antibacterial activity and phytochemical analysis. METHODS EA3 fraction was isolated and identified by column chromatography, thin layer chromatography, spectral data analysis and phytochemical screening were used for analysis. RESULTS EA3 fraction was significantly active at 4 to 64 mg/L against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa with minimum inhibitory concentration of 1.5625 to 3.1250 mg/mL. The active fraction (EA3) revealed the presence of flavonoid with retention factor value (R(f)) of 0.39. The active antibacterial agent in the most potent fraction (EA3) was isolated and identified as flavonoid (-)-epicatechin-3-O-β-glucopyranoside by thin layer chromatography (TLC) and phytochemical screening. EA1 and EA2 show inhibitory activity at 4 to 64 mg/L against Staphylococcus aureus only where as fraction EA4 and EA5 do not shows any inhibitory activity within that range of concentration against any bacteria. CONCLUSIONS The results support the ethnomedicinal use of leaf of V. spinosa for the treatment of bacterial diseases.

A review on Anopheles subpictus Grassi--a biological vector.

Anopheles subpictus is a complex of four isomorphic sibling species A, B, C and D and is recognized as a primary vector of malaria, a disease of great socio-economic importance, in Australasian Zone, Celebes, Portuguese Timor and South East Asia and a secondary vector in Sri Lanka. This species is also a vector of some helminth and arboviruses. This species has been reported so far from nineteen countries of the Oriental and Australasian Zones. An. subpictus complex is the most abundant anopheline in most parts of the Indian subcontinent, with a widespread distribution eastwards and southwards to Papua New Guinea, westwards to Iran and northwards to China. Resistance to insecticide is alarming in many parts of the world. Different aspects of this important mosquito species including attempts related to its control have been discussed which will be highly useful to carry out further research.

Biocontrol efficiency of odonate nymphs against larvae of the mosquito, Culex quinquefasciatus Say, 1823.

An estimation of the predatory efficiency of the nymphs of five coexisting odonate species Aeshna flavifrons, Coenagrion kashmirum, Ischnura forcipata, Rhinocypha ignipennis and Sympetrum durum using the fourth-instar larvae of Culex quinquefasciatus as prey, was made under laboratory and semi-field conditions. The daily feeding rate varied among the odonate species, at laboratory conditions. The mean number of IV instars Cx. quinquefasciatus larvae killed per day, ranged between 14 and 64 (64 mosquito larvae for I. forcipata, 57 for A. flavifrons, 45 for R. ignipennis, 25 for S. durum and 14 for C. kashmirum). The prey consumption was linearly related to the number of predators and prey available but inversely related with space. It was also noted that the feeding rates varied significantly between dark and light conditions, in all the odonate species. The presence of nymphs in semi-field conditions significantly lowered the mosquito larval density in dipper samples after 15 days from the introduction, followed by a significant increase of larval mosquito density after 15 days from the withdrawal of the nymphs. The results of the present observations are suggestive of the use of odonate nymphs in temporary pools or larger habitats where they can be a potential biological resource in regulating the larval population of the vector and pest mosquitoes.

Isolation and identification of antibacterial components in seed extracts of Argemone mexicana L. (Papaveraceae)

Abstract Objective The column chromatographic fractions of chloroform (CH1, CH2, CH3) seed extracts of Argemone mexicana (A. mexicana) were screened for antibacterial activity and phytochemical analysis. Methods CH3 fraction was isolated and identified by column chromatography, thin layer chromatography, spectral data analysis and phytochemical screening were used for analysis. Results CH3 fraction was significantly active at 4 to 64 mg/mL against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa with minimum inhibitory concentration of 1.5625 to 3.125 mg/mL. The active fraction (CH3) revealed presence of alkaloid with retention factor value of 0.44. The active antibacterial agent in the most potent fraction (CH3) was isolated and identified as N-demethyloxysanguinarine by thin layer chromatography (TLC) and phytochemical screening. The CH1 and CH2 fractions did not show inhibitory activity. Conclusions The results support the ethnomedicinal use of seeds of A. mexicana for treatment of bacterial diseases.

Bactericidal Activities of Some Common Herbs in India

Abstract The bactericidal activities of the aqueous and methanol extracts of the leaves of three plants used as popular medicine in India were studied. The dried leaf extracts of Vangueria spinosa. B. (Rubiaceae), Cestrum nocturnum. L. (Solanaceae), and Nyctanthes arbortristis. L. (Oleaceae) were tested in vitro. by the disk diffusion method against four bacterial strains, namely, Staphylococcus aureus. (MTCC 2940), Bacillus subtilis. (MTCC 441), Escherichia coli. (MTCC 739), and Pseudomonas aeruginosa. (MTCC 2453). Both the aqueous and the methanol extracts of V. spinosa. showed the strongest activity, followed by C. nocturnum. and N. arbortristis.. The only exception was P. aeruginosa., which, in turn, was found to be resistant against the aqueous extract of N. arbortristis.. Aqueous extracts of the leaves of all the plants appeared to have less antibacterial activity than the methanol extracts.

Antibacterial activities of some plant extracts used in Indian traditional folk medicine

Objective To evaluate the antibacterial activity of the leaf extracts of Cestrum diurnum , Ocimum sanctum , Carcica papaya, Solanum villosum , Vitex negundo , and Clerodendron inerme against two gram positive bacteria ( Staphylococcus aureus MTCC 2940 and Bacillus subtilis MTCC 441) and two gram negative bacteria ( Escherichia coli MTCC 739 and Pseudomonas aeruginosa MTCC 2453). Methods The sensitivity of two gram positive and two gram negative pathogenic multi-drug resistant bacteria to extracts of leaves of six medicinal plants used as popular medicine in India was studied in vitro by the disk diffusion method and minimal inhibitory concentration (MIC). Results All the bacterial strains were found to be sensitive to aqueous, n-hexane and ethanol extracts. But, it is evident that the organic extracts were comparatively more effective than aqueous extracts. Conclusions It can be concluded that the leaf extracts of the six medicinal plants possess antibacterial activity against human pathogens.

Concurrent dengue and malaria in an area in Kolkata

OBJECTIVE To establish the nature and extent of dual dengue and malaria infections in an endemic area through a longitudinal study. METHODS A prospective study was conducted from August 2005 to December 2010 to document the nature and extent of concurrent dengue and malaria infections in an area in central Kolkata, endemic both for dengue and malaria. RESULTS Of 2 971 suspected cases of dengue fever, in 605 (20.36%) persons dengue infection was detected, of whom 46 (7.60%, 46/605) patients (40 and 6 suffered from secondary and primary dengue fever respectively) were simultaneously suffering from malaria (28 and 18 were infected with Plasmodium vivax (P.vivax) and Plasmodium falciparum (P. falciparum) respectively, such dual infections of dengue and malaria were detected in all the years of the study period, except 2007, indicating intense transmission of both dengue and malaria in the study area, and the phenomenon was not an isolated one, the rate of concomitant infections ranged from 25% in 2009 to 4.9% in 2005. Out of total population surveyed, 1.54% (46/2 971) had concurrent dengue and malaria infection. CONCLUSIONS These findings added a new dimension in diagnosis, treatment, epidemiology and control of dengue and malaria. The possible risk of concurrent dengue and malaria infections should always be kept in mind in endemic areas for early diagnosis employing modern technology and prompt and effective treatment to avoid serious complications.

Studies on breeding habitats and density of postembryonic immature filarial vector in a filarial endemic area

Abstract Objective To obtain a complete and systematic data about the breeding habitats and density of immature vector (larvae and pupae) in a filaria endemic area. Methods All the possible permanent and temporary water bodies were surveyed systematically. Four hundred samples were taken in each season from each type of habitats. Sampling was done with a 250 mL dipper and immature mosquito was identified following sdandered keys. Results In summer, rainy and winter seasons, overall 49.64%, 44.64% and 28.57% of the habitats were positive for immature vector Culex quinquefasciatus respectively; 36.93%, 35.11% and 21.18% of the samples were positive respectively. In the study year overall PDD were much higher in open cesspits (19.53) and drains (17.24) than in other habitats. Peak PDD of mosquito immature in Dobas (ditches), open cesspits and drains were in March; whereas in paddy fields and temporary water bodies peak PPD were in September and overall per dip densities (PDD) of immature were 10.29, 10.18 and 4.40 respectively. Conclusions Dobas , paddy fields, open cesspits, drains and temporary water bodies were found to be the main breeding sites of the vector in different months. Open cesspits and drains were most suitable almost throughout the year with peak in summer. Dobas also act as a steady breeding site throughout the year, whereas temporary water bodies immerge as strong breeding site during pre-monsoon to monsoon season. Information about the breeding habitats will be helpful to formulate filarial vector, Cx. quinquefasciatus control strategy and in turn to control the filarial diseases in the study area.