new phenazinomycin antibiotic with a significant anti pseudomonas effect in chronic suppurative otitis media

ABSTRACT

A new henazinomycin-related antibiotic [H1] was isolated as a cultural product of Pseudomonas Aeruginosa. This antibiotic possesses antibacterial activity against certain Gram-positive bacteria and gram-negative bacteria including enteric bacteria and Ps. Aeruginosa. This minimum inhibitory concentration [MIC] as determined by the broth microdilution assay ranged between 25-65 micro g/ml. The product yield using a novel fermentation and purification technique was 100-605 micro g/ml, while by classical method a yield of only 10-50 micro g/ml was obtained. The physico-chemical properties of the antibiotic such as melting point, ionization constant and spectrophotometeric analysis were determined. Preliminary drug toxological studies [LD50] were determined in mice but did not show toxic or important undesirable effects even at relatively high concentrations of 400 mg/kg using the intraperitoneal route of administration. Clinically the H1 antibiotic in the form of ear drops [500 micro g/ml] proved effective in the eradication of 82.6% [71/86] gentamicin-resistant Ps. aeruginosa chronic middle ear infections with dramatic reduction in morbidity and negligible side effects