Microbial Biomass and Activity in Relation to Accessibility of Organic Carbon in Saline Soils of Coastal Agro-Ecosystem

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - In coastal agro-ecosystems, soil salinity follows a decreasing gradient from coastal margin towards inland...     

Plant Growth Promoting and Metal Bioadsorption Activity of Metal Tolerant Pseudomonas aeruginosa Isolate Characterized from Uranium Ore Deposit

In the present study, a metal-tolerant fluorescent pseudomonad isolated from uranium ore rich deposit of Domiasiat in North-East India was identified as Pseudomonas aeruginosa DPs-13 based on morphological, biochemical and molecular analysis. The isolate showed higher tolerance to uranium and other metals like copper, cadmium, zinc and lead when compared with the reference strain P. aeruginosa MTCC2474. When checked for uranyl bioadsorption potential, the isolate showed 94 % (22.5 mg/L) and 72 % (342.7 mg/L) removal of uranium (VI) when challenged with 100 μM (23.8 mg/L) and 2 mM (476 mg/L) uranyl nitrate solutions within 1 h of incubation as compared to 68 % (16.18 mg/L) and 25 % (119 mg/L) when challenged with above concentrations respectively of uranyl nitrate by the reference strain. The isolate was resistant to most of the commonly used antibiotics like Ampicillin, Kanamycin, Chloramphenicol, Erythromycin, Aztreonam, Tetracycline, Ciprofloxin and Streptomycin. The isolate had no phytotoxic effect, produced siderophores, possessed phosphate solubilising ability as well as two antibiotic producing genes, and had antagonistic activity against plant pathogens. Plasmid occurrence was also noticed in the isolate. The isolate from the uranium ore rich site besides being a promising metal tolerant bacterium had potent plant growth promoting activity and can be used to promote plant growth in bioremediation approaches in metal contaminated sites.     

Evaluation of Plant Growth Promoting Rhizobacterial Activity in Soil Samples of Arid Zone Plants

In the present investigation, soil samples of Capparis decidua L., Calligonum polygonoides L., Cuminum cyminum Gmel. were taken from different areas of Rajasthan. The bacterial isolates were evaluated for their plant growth promoting rhizobacterial (PGPR) activity, by nitrogen fixation and phosphate solubilization activity. K3, P40, C63, and C79 were the isolates that showed both activities and C63 and C79 showed very good response among all the isolates selected for each plant species. These PGPR may serve as bioinoculants to increase availability and uptake of mineral nutrients for plants and stimulate growth of plants in arid soils of Rajasthan. Rhizobacterial isolates from C. cyminum C63, C68, and C60 showed positive PGPR activity i.e., increased root and shoot length, mean wet biomass, and percent germination.     

Growth Properties of Mecillinam-Resistant Bacterial Variants in Urine

Resistant variants are often formed when susceptible Enterobacteriaceae are grown in media containing mecillinam. These variants have not yet been detected in patients or identified as a cause of treatment failure in limited clinical trials. Mecillinam-resistant organisms were formed by 5 out of 13 urinary isolates of Enterobacteriaceae incubated in urine containing mecillinam. The mean generation time of these five variants in urine containing therapeutic concentrations of mecillinam was 3.2 times that of normal organisms in antibiotic-free urine. When three of these five resistant variants were subcultured in antibiotic-free urine, the generation time, morphology, and antibiotic susceptibility returned to normal. On antibiotic-free agar medium, all five mecillinam-resistant variants readily reverted to the "susceptible" form and were therefore more likely to be phenotypic rather than genotypic mutants. In a second series of experiments, the flushing effect of the bladder on the clearance of organisms was partly simulated by frequent subculture in urine. Under these conditions, the cell density of cultures of all bacteria remained high during 10 subcultures over 52 h. However, bacterial populations progressively decreased in urine containing mecillinam until none could be detected at 28 h or thereafter. The slow growth rate of mecillinam-resistant variants may explain why detectable numbers of these organisms fail to colonize the urinary tract during treatment. Other factors may reinforce the postulated effect of the reduced growth rate in vivo.     

Antagonism between Epidermal Growth Factor and Phorbol Ester Tumor Promoters in Human Breast Cancer Cells

It has been suggested that the phorbol ester tumor promoters act via the receptor-effector system for epidermal growth factor (EGF), since they interact with the EGF receptor system and mimic many of the effects of EGF in cultured cells. We have studied the interaction of phorbol esters with the EGF-responsive MCF-7 human breast cancer cell line. Similar to other systems, phorbol esters inhibit EGF binding in MCF-7 cells in a manner paralleling their potency as tumor promoters in mice. The effect is specific for EGF since the membrane binding of insulin is unaffected. Like EGF, the potent phorbol ester 12-O-tetradecanoyl-13-phorbol acetate (TPA) stimulates protein synthesis as indicated by a twofold increase in [(3)H]leucine incorporation into protein after 24 h in TPA. Cell morphology, however, is significantly different with TPA treatment. After 24-48 h in TPA, cells become markedly enlarged with increased cytoplasmic vacuolization and increased membrane microvilli. This is reflected in a fourfold increase in the protein/DNA ratio (control 13.1; TPA 55.9). Furthermore, TPA inhibits cell division in media with or without serum, and prevents growth stimulation by EGF. Low TPA concentrations (1.0 ng/ml) are active, and 10 ng/ml results in maximal inhibition of cell replication. Other phorbol esters inhibit MCF-7 cells relative to their tumor promoting activity in vivo and their ability to inhibit EGF binding in these cells. After 24 h in TPA, incorporation of [(3)H]thymidine into DNA is markedly reduced and the thymidine labeling index falls (33% to 2%) indicating very few S-phase cells. Growth inhibition is reversible by removing TPA from the medium. Similar inhibitory effects are seen with the two other human breast cancer cell lines studied, ZR75-1 and MDA-MB-231. In conclusion, phorbol esters may interact with the EGF receptor domain in MCF-7 human breast cancer cells, but they have distinct effects on cell morphology and growth suggesting alternative pathways of action. The antineoplastic activity of these compounds needs further investigation.     

术中浸血盐水含菌量与切口感染关系的研究

目的通过对术中清洗浸血纱布和器械的生理盐水细菌含量的动态观察与分析,了解术后切口感染与术中生理盐水含菌的关系。方法将层流手术室中,100例Ⅰ、Ⅱ类手术中浸血盐水,分别于手术开始(0min)至结束每隔30min采样计数盐水含菌量,并同期随访观察100例病人切口情况,对所得数据运用SPSS11.0统计软件进行统计学处理。结果Ⅰ、Ⅱ类手术盐水含菌量90min前各时间点对比,差异无统计学意义(P>0.05);90min与120min的盐水含菌量差异有统计学意义(P<0.05);同一时间点Ⅱ类手术浸血盐水含菌量高于Ⅰ类手术。Ⅰ类手术切口无感染,Ⅱ类手术切口感染组和未感染组比较,盐水含菌量差异有统计学意义,P<0.05,感染组盐水含菌量明显高于未感染组。结论Ⅰ、Ⅱ类手术开始后90min均应更换盐水和盛装盐水的容器;Ⅱ类手术中清洗浸血纱布和器械的生理盐水含菌量与术后切口感染有关。     

术中浸血盐水含菌量与切口感染关系的研究

目的通过对术中清洗浸血纱布和器械的生理盐水细菌含量的动态观察与分析,了解术后切口感染与术中生理盐水含菌的关系.方法将层流手术室中,100例Ⅰ、Ⅱ类手术中浸血盐水,分别于手术开始(0 min)至结束每隔30 min采样计数盐水含菌量,并同期随访观察100例病人切口情况,对所得数据运用SPSS 11.0统计软件进行统计学处理.结果Ⅰ、Ⅱ类手术盐水含菌量90 min前各时间点对比,差异无统计学意义(P＞0.05);90 min与120 min的盐水含菌量差异有统计学意义(P＜0.05);同一时间点Ⅱ类手术浸血盐水含菌量高于Ⅰ类手术.Ⅰ类手术切口无感染,Ⅱ类手术切口感染组和未感染组比较,盐水含菌量差异有统计学意义,P＜0.05,感染组盐水含菌量明显高于未感染组.结论Ⅰ、Ⅱ类手术开始后90 min均应更换盐水和盛装盐水的容器;Ⅱ类手术中清洗浸血纱布和器械的生理盐水含菌量与术后切口感染有关.     

Effect of Engineered Nanoparticles of Fe and Zn Oxides on Enzyme Activity and Bacterial Abundance in Soil at Ambient and Elevated Atmospheric CO2

Nanomaterials are finding widespread applications in industry, agriculture and environment due to their unique properties. But, before these materials are widely in use, their impact on soil ecology needs to be thoroughly investigated. In addition, how the nanoparticles behave in soil under elevated CO₂ is unknown. A pot culture experiment was conducted under controlled conditions in phytotron to study the effect of nanoparticles on microbial biomass and enzyme activity in soil under rice crop at ambient and elevated atmospheric CO₂. Manufactured nanoparticles of Fe and Zn (n-Fe₂O₃ and n-ZnO) were added to soil at concentrations of 100, 500 and 1,000 mg kg^?1. FeSO₄ (11.1 mg kg^?1), ZnSO₄ (5.33 mg kg^?1) and ‘control’ treatments were also included for comparison. Results showed highest bacterial population at 100 mg kg^?1 n-Fe₂O₃, which significantly decreased at 500 and 1,000 mg kg^?1 n-Fe₂O₃ or n-ZnO. Similarly the dehydrogenase activity is significantly higher with 100 mg kg^?1 n-Fe₂O₃ as compared to control and FeSO₄ or ZnSO₄. As compared to 100 mg kg^?1 concentration, there was twofold to fivefold decrease in fluorescein diacetate activity at 500 and 1,000 mg kg^?1 of nano-Fe₂O₃ treatment. At elevated CO₂, the microbial biomass and activities were higher at tillering than panicle initiation of rice crop over ambient CO₂ with 100 mg kg^?1 n-Fe₂O₃ and ZnO than other treatments. It is concluded that n-Fe₂O₃ and n-ZnO at 100 mg kg^?1 is effective to maintain various soil microbiological process but at higher concentrations (e.g., 500 and 1,000 mg kg^?1) negative impacts on soil ecology can be expected.     

Improvement of Growth,Photosynthesis and Antioxidant Defense in Rice (Oryza sativa L.) Grown in Fly Ash-Amended Soil

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Due to the hostile conditions created by fly ash, its utilization in vegetation is restricted. Therefore, fly...     

Comparative Activity of Amoxycillin and Ampicillin in an Experimental Bacterial Infection in Mice

Against experimental infections in mice with strains of Escherichia coli and with Proteus mirabilis, amoxycillin was found to be more active than ampicillin both by the oral and the subcutaneous routes of administration. With the bacteria used in these experiments, ampicillin and amoxycillin showed the same minimal inhibitory concentrations and, after subcutaneous administration, the levels of ampicillin and amoxycillin in the plasma and tissue homogenate were also similar. However, counts of the number of viable bacteria present in the infected tissue showed that amoxycillin exerted a more rapid and a more marked bactericidal effect than did ampicillin, and this could be correlated with the difference in therapeutic effect. When given by mouth, amoxycillin was more completely absorbed than ampicillin and gave rise to higher levels of antibiotic in the plasma. This may have accounted in part for the difference in therapeutic activity seen when these penicillins were given by the oral route. However, when appropriate oral dosages of ampicillin and amoxycillin were used so as to achieve similar levels of antibiotic in the plasma and tissue homogenate, amoxycillin was again found to exert a more marked bactericidal effect than did ampicillin, and this was accompanied by greater therapeutic activity. In experiments in vitro, amoxycillin also showed a more rapid bactericidal effect than did ampicillin against the bacteria which were used to produce the experimental infections.     

Evaluation of Antitumor Activity of Glutaminase-Free Periplasmic Asparaginase from Indigenous Bacterial Isolates as Candidates for Cancer Therapy

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Asparaginase is a very important antineoplastic drug extensively used for the treatment of acute...     

Impact of Tree Leaf Application on Microbial Biomass and Productivity in Tropical Dryland Rice Microcosm

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - The present study shows the positive impact of application of tree leaves on soil microbial biomass and rice...     

Effects of Dietary Sodium and of Acute Saline Infusion on the Interrelationship between Dopamine Excretion and Adrenergic Activity in Man

The effects of dietary sodium and of saline infusion on urinary dopamine and norepinephrine and on the relationship of these catecholamines to adrenergic activity were determined. In seven normal subjects on a 9-meq sodium intake, urinary dopamine and norepinephrine were 136+/-18 (SE) and 37.4+/-5.3 mug/day, respectively. When sodium intake was increased to 209 or 259 meq/day, urinary dopamine increased to 195+/-20 mug/day (P<0.01) whereas urinary norepinephrine decreased to 21.1+/-3.0 mug/day (P<0.01). Infusion of saline in seven subjects increased sodium excretion and urinary dopamine (from 2.18+/-0.22 to 2.79+/-0.19 mug/20 min, P<0.01), but decreased plasma dopamine-beta-hydroxylase by 33% and urinary norepinephrine insignificantly. The clearance of inulin and p-aminohippurate did not change significantly and filtration fraction was the same. The data indicate that an increase in dietary sodium or infusion of saline results in an apparent decrease in adrenergic activity and an increase in urinary dopamine. Dopamine excretion would thus appear to relate inversely to adrenergic activity and to parallel sodium excretion. These findings suggest a possible role for dopamine and norepinephrine in the regulation of renal sodium excretion.     

Safety and Efficacy of Moxifloxacin-Dexamethasone Eyedrops as Treatment for Bacterial Ocular Infection Associated with Bacterial Blepharitis

Introduction

Treatments that offer two medications in a fixed combination have the potential to offer efficacious and safe treatment with advantages such as a regimen that is simpler than administering two separate solutions. This study evaluated the safety and efficacy of fixed-combination versus concomitant moxifloxacin 0.5% and dexamethasone 0.1% ocular solutions for the treatment of bacterial ocular inflammation and infection.

Methods

The clinical study design was a randomized, double-masked, active-controlled, parallel-group trial of 102 subjects with bacterial blepharitis in which two patients also had bacterial conjunctivitis. All subjects received two bottles of study medication: either a fixed combination of moxifloxacin 0.5%/dexamethasone 0.1% ophthalmic solution and placebo eye drops (fixed-dose group), or moxifloxacin 0.5% ophthalmic solution and dexamethasone 0.1% (concomitant group). One drop of each study medication was instilled bilaterally four times per day for 7 days. Clinical resolution, signs, symptoms, and safety were assessed. Microbiological specimens were collected from the eyelid margin and conjunctivae of each eye from each patient at the time of enrollment and at the exit visit.

Results

Clinical resolution occurred similarly in both groups (81.6% of eyes, fixed-dose group; 82.3% of eyes, concomitant group). Moreover, the microbiological efficacy of the treatment was also similar for both the fixed-dose group (84%) and the concomitant group (83%). Ocular symptoms and signs improved over time, with no significant differences between groups after 7 days of treatment, except the fixed-dose group had significantly more eyes with clinical resolution in eyelid erythema (100%, n = 98/98, fixed-dose group; 92.7%, n = 89/96, concomitant group; P = 0.0194) and eyelid scaling/crusting (98%, n = 96/98, fixed-dose group; 89.6%; n = 86/96 eyes, concomitant group; P = 0.0337). Both regimens were safe and well tolerated.

Conclusion

The fixed-dose combination of moxifloxacin, 0.5% and dexamethasone, 0.1% was therapeutically equivalent and as well tolerated as the concomitant dosage.     

The Papain Inhibitor (SPI) of Streptomyces mobaraensis Inhibits Bacterial Cysteine Proteases and Is an Antagonist of Bacterial Growth

A novel papain inhibitory protein (SPI) from Streptomyces mobaraensis was studied to measure its inhibitory effect on bacterial cysteine protease activity (Staphylococcus aureus SspB) and culture supernatants (Porphyromonas gingivalis, Bacillus anthracis). Further, growth of Bacillus anthracis, Staphylococcus aureus, Pseudomonas aeruginosa, and Vibrio cholerae was completely inhibited by 10 μM SPI. At this concentration of SPI, no cytotoxicity was observed. We conclude that SPI inhibits bacterial virulence factors and has the potential to become a novel therapeutic treatment against a range of unrelated pathogenic bacteria.     

Inoculation with Microbial Consortium Promotes Growth of Tomato and Capsicum Seedlings Raised in Pro Trays

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Tomato and capsicum are important vegetable crops with wide usage in culinary. Inoculation of the planting...