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

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

Community prevalence of methicillin and vancomycin resistant Staphylococcus aureus in and around Bangalore, southern India

INTRODUCTION: Staphylococcus aureus is a known colonizer in humans and has been implicated in community acquired soft tissue infections. However emergence of methicillin resistant S. aureus (MRSA) has aroused great concern worldwide. This study aimed to determine the prevalence of MRSA in the community of Bangalore, southern India. METHODS: Swabs were collected from anterior nares, forearm, dorsum and palm of the hands of 1,000 healthy individuals residing in and around Bangalore, belonging to different socioeconomic strata and age groups. RESULTS: Analysis verified that 22.5% and 16.6% of the individuals presented Staphylococcus aureus and MRSA, respectively, at any of the three sites. Vancomycin resistance was observed in 1.4% of the S. aureus isolates, which was confirmed by detection of the vanA gene. It was interesting to note that 58.8% of the children in the age group 1-5 years-old presented MRSA, the highest percentage compared to other age groups of < 1 (44.4%) year-old, 5-20 (21.7%) years-old, &gt; 40 (11%) years-old and 20-40 (9.9%) years-old. Among the population of various socioeconomic strata, maximum MRSA colonization was observed among doctors (22.2%), followed by upper economic class (18.8%), lower economic class (17.7%), apparently healthy hospital in-patients (16.5%), nurses (16%) and middle economic class (12.5%). Most of the MRSA isolates were capsular polysaccharide antigen type 8 (57.1%). CONCLUSIONS: There is a need for continuous surveillance and monitoring of the presence of MRSA in the community and a clearer understanding of the dynamics of the spread of MRSA will assist in controlling its dissemination