Determination of antibacterial activity of polyenzyme preparations Gumseb using in vitro methods

A novel polyenzyme formulation Gumseb developed by Advanced Enzyme Technologies Ltd, Thane and Speciality Biochemicals Co., USA, was tested for antibacterial properties using ATCC strains and clinical isolates of Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae. A modified antibiotic susceptibility test was used for the purpose. S. aureus, S. pyogenes and S. pneumoniae were found to be sensitive to the formulation at the chosen concentration. Next, to study the interaction between Gumseb and currently used antibiotic, a checkerboard Minimum Inhibitory Concentrations (MIC) was carried out for each organism. The assay was carried out with the aim of establishing whether the polyenzyme formulation had any potentiating effect on the antibiotic of choice. Synergistic effect was established when Gumseb was used in conjunction with penicillin against S. pyogenes. Partial synergy was established when it was used in conduction with Ceftazidime against P. aeruginosa and with Ciprofloxacin against methicillin sensitive, coagulase positive S. aureus. Antagonism was established when it was used in conjunction with Ampicillin against E. coli, with Ciprofloxacin against S. typhi and coagulase negative staphylococcal strain. The results indicate that Gumseb can be used in conjunction with those antibiotics with which a synergistic or a partially synergistic effect could be shown, as in the case of P. aerugionosa and S. aureus. These findings have particular importance since these organisms are responsible for hospital based infections and are notorious for antibiotic resistance. In cases where antagonism was established, it should not be used in combination with that particular antibiotic. However, it can be used individually since it has proved to have antibacterial activity and MIC could be determined for all five commonly encountered pathogens. Therefore, it has the potential of being a novel broad range antibacterial drug. These findings are significant given the alarming rise in incidence of antibiotic resistance in most clinically important pathogens.