Bacterial strains used in this study are obtained from King George Hospital, Visakhapatnam, A.P, India. Pure strains were isolated and maintained on nutrient agar slants for bioassays. Reference strain ATCC 43300 is obtained from Himedia laboratories, Mumbai and used as a positive control. The minimum inhibitory concentrations were determined by using agar dilution click here method, following the standard protocol of the European committee for antimicrobial susceptibility testing (EUCAST-2000). The methods implemented in the present study helped to find
out the least MIC exhibited by crude plant extract combined with antibiotics and is further useful in the study of its phytocomponents. Around 30 nocosomial isolates collected from the health care workers of King George Hospital,
Visakhapatnam and isolated for pure strains of S. aureus. Resistant and Sensitive isolates were determined by treating the pure isolates with different concentrations http://www.selleckchem.com/products/17-AAG(Geldanamycin).html of stock methicillin 1 mg/ml. MIC values for clinical as well as reference strains was observed ( Table 1). The strains are tested with other antibiotics ( Fig. 2) and MIC’s of the synergistic combination of antibiotics and plant extracts were determined. The minimum inhibitory concentrations of the synergistic combinations of antibiotics and plant extracts are shown in (Table 2), (Fig. 1). There is a half fold drop of MIC observed with the tested combinations. The combination of Plumbago extract with various antibiotics yielded low MIC’s compared to P. granatum, Ocimum and Vitis seed. S. aureus, when tested with plant extracts, yielded low MIC GPX6 values for Plumbago compared to P. granatum, Ocimum and Vitis seed. This may be attributed due to the presence of plumbagin and
naphthoquinones which showed interesting biological activity. 9, 10 and 11 Obviously irrespective of the class of antibiotic used, there is half fold drop in the MIC values, when a combination of antibiotics and extracts were tested against S. aureus. 12 This could be referred that the crude extracts have many different phytochemicals, 9 which inhibit S. aureus by different mechanisms. This double attack of both the agents on different target sites of the bacteria could theoretically lead to either an additive or synergistic effect. 13 Combined antibiotic therapy has been shown ( Fig. 1) to delay the emergence of bacterial resistance and produce desirable synergistic effects. The results were consistent with previous invitro studies, which reported synergistic effects with significant reduction in MIC’s of the antibiotics due to combination of different antimicrobial agents with crude plant extracts against Staphylococcus aureus strains. 14, 13, 15 and 12 Natural products had proven medicinal importance in Ayurvedic and Homeopathy. Large amounts of natural products are required to fight MDR organisms.