Identification of infectious Pseudomonas aeruginosa strains in an occupational saturation diving environment

Abstract

Objectives: Occupational saturation divers have various skin disorders, of which skin infections are the most serious and frequent. Pseudomonas aeruginosa is the microbe most often isolated from skin infections in divers. The purpose of the present work was (a) to report the occurrence of P aeruginosa in skin infections in operational saturation diving in the North Sea from 1987 to 1995; (b) to report the environmental occurrence of P aeruginosa in saturation diving systems, and finally (c) to identify possible relations between infection related to strains of P aeruginosa and environmental isolates of the microbe.

Results: During the period 1987-95, P aeruginosa was isolated from 257 skin infections in operational saturation divers. Most of the isolates related to infection by P aeruginosa show a unique growth inhibition pattern towards the normal skin flora, and the serotype pattern of P aeruginosa from skin infections is limited compared with similar infections in non-divers. In a mini-epidemiological study on board one diving vessel during one operational diving period, five significantly different DNA fragment profiles were found among the 12 isolates related to infection by P aeruginosa obtained from the saturation system. In two cases the infectious genotypes were detected in the fresh water for the saturation chambers weeks before the arrival of the infected diver.

Conclusions: The most commonly used epidemiological marker for P aeruginosa world wide, also used in earlier studies, is serotyping, but with pulsed field gel electrophoresis (PFGE) miniepidemiology it was shown to be insufficient for epidemiological purposes in saturation environments. PFGE analyses were shown to be superior both to antibacterial factor and to serotyping in epidemiological analyses of P aeruginosa infections in saturation diving.