Antibacterial and anti-biofilm activities of crude extracts of Lawsonia inermis against Methicillin Resistant Staphylococcus aureus

 Objective:The continuous rise in the prevalence of multi drug resistance pathogens globally is threatening the treatment and management of infectious diseases. Ethno medicine plays a key role in the exploration for novel bioactive compounds. The present study evaluates the antibacterial and antibiofilm activities of the crude extracts of Lawsonia inermis against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA).Materials and methods: Shade dried and finely powdered leaves of the plant were extracted by maceration method using six solvents methanol, acetone, ethyl acetate, chloroform, petroleum ether and n-hexane. Antibacterial and antibiofilm activities of the extracts against MDR MRSA by agar cup diffusion and tube method respectively.Results: Methanol extract showed the highest antibacterial activity of 18mm compared to other extracts. Similarly, petroleum ether extract showed highest biofilm inhibition of 84.7%. Other solvent extracts also exhibited significant biofilm inhibition [n-Hexane-83.6%, Ethyl acetate -79.5%, Chloroform-79.2%, Acetone -77% and Methanol-77%].Conclusion: The leaf extracts of L. inermis have shown promising biofilm inhibitory activity and good antibacterial activity, which can be explored for the development of new drugs for the MDR pathogens. Keywords: Antibioticacivity, Antibiofilm activity, L.inermis, MRS

ISOLATION, SCREENING AND CHARACTERIZATION OF L-ASPARAGINASE PRODUCING FUNGI FROM MEDICINAL PLANTS

Objective: To isolate and characterize of L-asparaginase producing fungi from medicinal plants.Methods: Fungal strains were isolated on standard media, characterized and were screened for their ability to produce L-asparginase, used in the treatment of certain types of cancers, using modified Czapek-Dox medium supplemented with L-asparagine.Results: A total of 10 fungal isolates were obtained from 3 plant leaf samples and two isolates exhibited significant L-aspargniase production. Fusarium sp. (SMGR-F1) isolated from the papaya leaves showed the maximum activity. The organism was grown under submerged fermentation conditions at 30 °C produced 111.07±1.53 IU/ml of L-asparaginase at 120 h.Conclusion: L-asparaginase is being effectively used for the treatment of acute lymphoblastic leukemia and tumor cells. Fusarium sp. was isolated from the papaya plant leaves showing significant L-asparaginase activity and thus can be further exploited for the commercial production of L-asparaginase.Â

Biofilm formation by clinically isolated Staphylococcus Aureus from India

Introduction: Staphylococcal biofilms are prominent cause for acute and chronic infection both in hospital and community settings across the world. Current study explores biofilm formation by Staphylococcus aureus isolates from clinical samples by different methods. Methodology: Standard techniques used for the characterization of S.aureus. Qualitative and quantitative biofilm formation was assessed by Congo red Agar, Tube and Microtiter plate methods. Results: A total of 188 clinical isolates of S.aureus were screened for biofilm formation and 72 (38.29%) of them were found to be biofilm producers, 34 (18.08%) strong, 38 (20.21%) moderate. The remaining 116 (61.7%) were weak/ non biofilm producers. Maximum biofilm formers were recorded in pus samples (39.06%), followed by isolates from blood (38.23%) and urine (34.61%). Statistical analysis for the formation of biofilm indicated that Microtiter plate method is the most sensitive and specific method for screening biofilm production. Conclusions: Biofilm formation is one of the influential virulence factor in staphylococcal pathogenesis and persistence. Microtiter plate and Congo red agar remain as reliable methods for the qualitative and quantitative estimation of biofilm formation. Monitoring of biofilm formation in various etiological agents will help in determining the severity of infection

Bioleaching of copper from chalcopyrite ore by fungi

319-324Microorganisms have been geologically active in mineral formation, mineral diagenesis and sedimentation via direct action of their enzymes or indirectly through chemical action of their metabolic products. This property of microorganisms is being harnessed during the recent years for extraction of metals from their ores, especially from low-grade ores. In the present study bioleaching of copper from its low-grade chalcopyrite ore using 26 isolates of acidophilic fungi is reported. Most of these fungal strains belonged to the genera Aspergillus, Penicillium and Rhizopus. The leaching experiments were conducted in Czepek Dox minimal medium containing 1% (100 mesh) ore with shaking at room temperature for 20 days. Out of these, 4 isolates exhibited significant bioleaching activities. Maximum leaching of copper (78 mg/L) was observed with Aspergillus flavus (DSF-8) and Aspergillus niger (DOF-1). Nutritional and environmental conditions for optimum bioleaching were standardized. Present study indicates the usefulness of acidophilic fungi in bioleaching of copper from its low-grade ores.</span