EXTRACELLULAR ENZYMES OF PSEUDOMONAS-AERU GINOSA AS VIRULENCE FACTORS

Pseudomonas aeruginosa is an opportunistic pathogen causing a variety of diseases, es pecially in immunocompromised patients like those suff ering from cystic fibrosis (CF) where these bacteria preferentially co lonize the bronchopulmonary tract. A high intrinsic antibiotic resista nce and its ability to synthesize and secrete numerous different virul ence factors are regarded as biological properties contributing to the pathogenicity of P. aeruginosa. Among the virulence factors are many enzymes which have been characterized in detail with respect to their molecular properties. Environmental factors regulating the synthesis a nd release of extracellular enzymes have been identified as e.g. the c oncentration of Fe- and PO4-ions, choline, pH, and osmolarity. In addi tion, low molecular weight substances named autoinducers were identifi ed as regulators which are synthesized by the bacteria. Therefore, P. aeruginosa represents an example for the remarkably complex relationsh ip between pathogenic bacteria and their human host.