[A clinical study of gastrointestinal flora in patients with, or without MRSA colonization in the upper-respiratory tract after introduction of preventive measures of hospital infection].

In early 1980's methicillin-resistant Staphylococcus aureus (MRSA) was reported as a major pathogenic organism of geriatric hospital infection in Japan. At the same time in the A geriatric hospital MRSA infection was prevalent. To decrease nosocomial infections some active preventive measures against hospital infection were taken since Oct. 1991. After introduction of preventive measures of hospital infection in geriatric ward (190 beds) nosocomial bacteremia and pneumonia were markedly decreased in comparison to the episode number before introduction of prevention. However several patients with MRSA colonization were observed every month. The aim of this clinical study was to clear how frequent MRSA was isolated from the gastric juice and stool. Any MRSA was not observed in 63 cultured stool, but just one MRSA was isolated in patients with MRSA colonization. On the other hand gram-negative organisms, which were E. coli, P. aeruginosa, P. mirabilis etc., were frequently observed in cultured stool. In conclusion, we considered frequency of MRSA colonization in gastrointestinal space was not so high but rather very low.