부산대학교 도서관

In May 1979, a strain of Serratia marcescens was cultured from arterial and venous blood, sputum and urine of a patient who was admitted in the Iwaki Kyoritsu General Hospital. The strain showed low susceptibilities to almost all commercially available parenteral antibiotics (over than 100 mg/ml) except for gentamicin, amikacin and minocycline (50 mg/ml). The disease of the patient was diagnosed as septicemia due to multiple resistant Serratia marcescens and he was moved to an isolation ward. Soon after isolation of this patient, Serratia marcescens showing the same susceptibility pattern was cultured from the urine of another patient at the same ward who used the same bed that had been used by the isolated patient. At that time a possibility of a wide intrahospital spread of an opportunistic pathogen was suspected and thus retrospective study of microbiological laboratory records was conducted. It was found that emergence of infection caused by the epidemic strain could be traced back to November 1978, i.e. the epidemic strain had already cultured been from a patient who had died in November 1978 from uremia associated with severe urinary tract infection. Thus it was suspected that the epidemic spread originated in the urological ward. A retro- and pro-spective epidemiological and microbiological survey of prevalence of the epidemic strain was conducted from October 1978 through September 1979. The incidence increased from November 1978 to July 1979, when intensive control measures against the spread were instituted. Thereafter, the incidence became lower. During the period, from November 1978 to July 1979 a total of 132 patients were infected with the epidemic strain. The highest incidence was seen in the urological ward followed by that in the coronary care unit and that in the ward of obsterics and gynecology. Altogather 126 of the epidemic strains were isolated by October 1979. Most of them, 113 strains, were recovered from urine specimens and 5 were from the sputum. Three strains each were obtained from blood and pus of skin abscess respectively. One strain each was cultured from bile and an endometrial discharge. Thus it was known that the site of colonization of the epidemic strain was confined almost exclusively to urinary tract.A committee of doctors, nursing and paramedical staffs was organized and an active educational campaign against intrahospital spread of the epidemic strains of Serratia was started. This compaign, with the other intensive control measures, succeeded in decreasing the incidence of infection due to the epidemic strains.From the results of bacteriological examinations, the epidemic strain was shown to be distinctively different from the background strains of Serratia marcescens in the hospital. Twenty strains of Serratia marcescens isolated in the hospital were selected at random and the serological typing of them was made. All of the 16 strains, which showed the same antibiotic susceptibilities as those of the epidemic strain were grouped into serotype 04. Out of 4 strains, which showed a different susceptibility pattern from the epidemic strain, 2 belonged to serotype 04, and a strain did to serotype 01 and in a remaining strain serotype was not differentiable.