4. Discussion
Microbiologyintwenty-firstcenturybeginswithabundanceof the articles concerning resistance, superbugs and the pros- pects of a post-antibiotic era. In addition, the threat of bio- terrorism with multi-drug resistant pathogens emphasized the need for continued development of new antibiotics.
Currently, the ongoing battle against bacteria prevails cer- taintyofevolvingresistance.Ontheotherhand,advancement in medical sciences results in more patients in critical and immune suppressed states, thus creating a perpetual need for new antibiotics. But unfortunately, there is a subsequent decline in both academic and industrial research in this field. As a result, current rate of discovery of new antibiotics is far lower than in the golden age of antibiotics in the (1940se1960s).8 Medicinal plants and their extracts were used as first medicines since ancient times. Medicinal plants may be defined as any plant that has medicinal use such as foxglove, opium, garlic, turmeric, etc. Plants may be an important source of potentially useful structures for the development of new chemotherapeutic agents.9 The first step towards this goal is the in vitro screening of plant extracts for their bioac- tivity. In the present study, leaf extracts of three different plants have tested against clinical pathogens. In our preliminary screening, the number of bacterial strains was determined in accordance with their cell wall structure. Sensitive strains of Gram negative and Gram posi- tive bacteria were chosen assuming that one strain each of Gram positive and Gram negative bacteria is enough for the screening of antibacterial activityoftheextracts.S. aureusand E. coli were used in this antimicrobial testing because of their medicalsignificanceincausingcommonproblemsofbacterial infections in hospitals. Based on this screening, out of three different extracts tested, only methanol extract of A. pan- iculata exhibited the antibacterial activity. Despite of reports