A rare case of diffuse intracranial aspergillosis masquerading as skull base meningioma in an immunocompetent patient.

Intracranial aspergillosis is rare in immunocompetent patients. Its presentation is subtle, often without any diagnostic characteristics, and is frequently mistaken for tuberculous meningitis, pyogenic abscess, or a space-occupying lesion. The authors report a case of diffuse intracranial aspergillosis, in an immunocompetent 34-year-old male, that mimicked a meningioma on preoperative imaging. The origin, clinical course, radiological features, histopathological findings, and surgical treatment are discussed based on review of literature.
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Induced phytoremediation of metals from fly ash mediated by plant growth promoting rhizobacteria.

A study was carried out to observe the impact of a consortium of bacteria isolated from the fly ash on the metal accumulation by T. latifolia. When a consortium of bacteria Bacillus endophyticus NBRFT4 (MTCC 9021), Paenibacillus macerans NBRFTS (MTCC 8912) and Bacillus pumilus NBRFT9 (MTCC 8913) was bioaugmented into the rhizosphere of T. latifolia, it enhanced the metal concentration in root, stem and leaves of the plants through increased bioavailability of metals Fe, Cd, Pb, Cr, Ni, Cu and Zn in the fly ash. Besides, these bacteria also promoted the plant growth perhaps due to utilization of ACC, synthesis of phytoharmones and solubilisation of essential metals found in fly ash. As compared to fly ash alone, the accumulation of Fe was maximally enhanced by 164%, 196%, and 251%, followed by Ni by 92%, 44% and 56%, Zn by 82%, 57% and 91%, Cu by 71%, 53% and 60%, Cr by 96%, 80% and 105%, Pb by 119%, 87% and 140%, Cd by 80%, 109% and 115% in root, stem and leaves, respectively in fly ash with bacteria. Thus, an increased solubilisation of metals coupled with enhanced plant growth stimulated the phytoextraction of metals by T. latifolia from fly ash.

Stimulated phytoextraction of metals from fly ash by microbial interventions.

Various combinations of fly ash tolerant bacteria isolated from the rhizospheric zone of Typha latifolia naturally growing on a fly ash dump site were tested for enhanced metal uptake by Brassica juncea grown in fly ash amended with press mud. After enrichment of the bacteria in a nutrient broth, they were subsequently applied to the rhizospheric zone of B. juncea in different combinations. When the metal analysis was done in the plants at their maturity, it was revealed that out of 11 bacterial consortia prepared from the different combinations of four bacterial strains, Micrococcus roseus NBRFT2 (MTCC 9018), Bacillus endophyticus NBRFT4 (MTCC 9021), Paenibacillus macerans NBRFT5 (MTCC 8912) and Bacillus pumilus NBRFT9 (MTCC 8913), a combination of NBRFT5, NBRFT4 and NBRFT9 (ST3) was found to have induced the highest metal accumulations as compared to other consortia. The bioaugmentation of the ST3 consortium enhanced Fe accumulation by 247%, Ni by 231% and Zn by 223% in B. juncea as compared to control plants. These values were found to be significantly higher than the other bacterial consortia. Bacteria were also found to produce siderophores which could enhance the metal uptake by plants through metal mobilization. Besides siderophores, bacteria are also known to produce protons, organic acids and enzymes which enhance the metal mobilization and boost the phytoextraction process. The translocation of metals from root to stem was invariably higher than from stem to leaf. Hence, ST3 was adjudged the best consortium to be used in the field application to accelerate the phytoextraction of metals from fly ash by B. juncea.

In vitro degradation of fluoranthene by bacteria isolated from petroleum sludge.

An investigation was carried out for in vitro degradation of fluoranthene by four bacterial strains (PSM6, PSM7, PSM10 and PSM11) isolated from the petroleum sludge. Although all the strains registered their growth in MSM with 100 ppm fluoranthene, PSM11 growth was better than other strains. Growth of bacterial strains invariably corresponded to their degradation potential of fluoranthene. After 168 h of incubation, 61% fluoranthene was degraded by PSM11, followed by PSM10 (48%) and PSM6 (42%) and the least was recorded in PSM7 (41%). Besides, 11% loss in fluoranthene was attributed to abiotic factors. Thirty-eight times more activity of catechol 2,3-dioxygenase than catechol 1,2-dioxygenase showed that it played a significant role in fluoranthene degradation. Molecular weight of catechol 2,3-dioxygenase isolated from PSM11 was determined as ∼ 136 kDa by size exclusion chromatography and 34 kDa on denaturing SDS-PAGE, indicating tetrameric nature of the enzyme.

Microbe-induced changes in metal extractability from fly ash.

A low cost and eco-friendly technology to bioremediate toxic metals associated with fly ash dumps that contaminate ground and surface water in and around fly ash settling ponds, was investigated. The impact of augmentation of fly ash tolerant bacterial strains, isolated from Typha latifolia growing naturally on fly ash dumps, was studied for metal extractability. It was observed that most of the bacterial strains either induced the bioavailability of Fe, Zn and Ni or immobilized Pb, Cr, Cu, Cd in the fly ash. However, there were few exceptions also. In case of Ni, eight strains enhanced metal mobility, while others caused metal immobilization. The findings also suggest that metal solublization and immobilization are specific to bacterial strains. While induced bioavailability of metals by bacteria may be used to accelerate the phytoextraction of metals from fly ash by hyper accumulator plants, immobilization of metals can check their migration to water reservoirs and reduce the human suffering in affected areas. Thus, bacteria serve the dual purpose and may result in the microbe- assisted phytoremediation of contaminated sites.

Evaluation of metal mobility/immobility in fly ash induced by bacterial strains isolated from the rhizospheric zone of Typha latifolia growing on fly ash dumps.

In this investigation, 11 bacterial strains were isolated from the rhizospheric zone of Typha latifolia. All the strains were aerobic, showed positive result with indole production and were able to grow in MacConkey agar. However, four strains were gram positive and others gram negative. These strains were inoculated separately in the fly ash with additional source of carbon to test their ability to increase the bioavailability or immobilization of toxic metals like Cu, Zn, Pb, Cd and Mn. It was observed that most of the bacterial strains either enhanced the mobility of Zn, Fe and Mn or immobilized Cu and Cd. However, there were a few exceptions. For example, in contrast to other bacterial strains, NBRFT6 enhanced immobility of Zn and Fe and NBRFT2 of Mn. On the other hand, in place of immobility induced by most of the bacterial strains, NBRFT8 and NBRFT9 enhanced bioavailability of Cu. However, in case of Cd, all the strains without any exception immobilized this metal. The results also indicated that the mobility/immobility of trace metals from the exchangeable fractions was the specific function of bacterial strains depending upon the several edaphic and environmental factors. Based on the extractability of metals from fly ash, a consortium of high performer bacterial strains will be further used to enhance the phytoextraction of metals from fly ash by metal accumulating plants. On the other hand, bacterial strains responsible for immobilization of metals may be used for arresting their leaching to water bodies.