Providencia stuartii: a search for its natural habitat.

A selective differential medium has been used to search for Providencia stuartii in sewage, sewage contaminated natural waters and the faeces and skin of a small population of healthy non-hospitalized males. Colonization of 12 male patients with long-term indwelling bladder catheters and the general environment of the spinal injury unit was also examined. Providencia stuartii was not isolated from the non-hospital samples, but colonization of the urine (two patients) faeces (five patients) and skin (eight patients) was observed. Apart from equipment that had been in contact with patients urine or skin there was no general contamination of the ward environment suggesting that colonized patients were the main reservoir of this multiply antibiotic-resistant nosocomial pathogen.