oxyfedrine and Salmonella-Infections--Animal

The cardiovascular drug oxyfedrine HCl revealed noteworthy in vitro antibacterial action against 501 strains of Gram positive and Gram negative bacteria. It also offered significant protection to mice challenged with a mouse-virulent bacterial strain. Prompted by such results, the present study was carried out to ascertain whether this drug could augment the efficiency of an antibiotic when used in combination with it. For this purpose, ten bacterial strains were selected, which were sensitive to oxyfedrine as well as to six antibiotics, like benzyl penicillin, chloramphenicol, ciprofloxacin, erythromycin, streptomycin and tetracycline. Distinct and statistically significant (p<0.01) synergism was observed between oxyfedrine and tetracycline by disc diffusion tests, compared with their individual effects. The fractional inhibitory concentration (FIC) index of this combination, evaluated by checkerboard analysis, was 0.37, which confirmed synergism between the pair. This synergistic drug duo was further dispensed to infected mice. The results of the mouse-protection tests advocated that the combination was significantly synergistic (p<0.0001), according to Student's 't' test. Hence, the capacity of extended antibiotic therapy in several microbial diseases may be improved with the help of this synergistic drug pair, and the study might throw light on newer directions to contest drug-resistant bacterial infections.

Topics: Animals; Anti-Bacterial Agents; Bacteria; Drug Synergism; Drug Therapy, Combination; Male; Mice; Microbial Sensitivity Tests; Oxyfedrine; Salmonella Infections, Animal; Salmonella typhimurium; Tetracycline

Ten cardiovascular drugs, having diverse pharmacological action, were screened for possible antimicrobial property against known eight sensitive bacteria, belonging to Gram positive and Gram negative types. Although five drugs failed to show antimicrobial activity and three had moderate antimicrobial action, oxyfedrine HCl and dobutamine were seen to possess pronounced antimicrobial property. Oxyfedrine was further tested in vitro against 471 strains of bacteria from two Gram positive and fourteen Gram negative genera. The minimum inhibitory concentration (MIC) of oxyfedrine was determined by agar dilution method, which ranged from 50-200 microg/ml in most of the strains, while some strains were inhibited at even lower concentrations. In animal experiments, this compound was capable of offering significant protection to Swiss strain of white mice, challenged with 50 median lethal dose (MLD) of a virulent strain of Salmonella typhimurium at concentrations of 15, 30 and 60 microg/mouse. The in vivo results were highly significant according to chi-square test.

Topics: Animals; Anti-Bacterial Agents; Cardiotonic Agents; Cardiovascular Agents; Gram-Negative Bacteria; Gram-Positive Bacteria; Male; Mice; Microbial Sensitivity Tests; Oxyfedrine; Salmonella Infections, Animal; Salmonella typhimurium