Hayashi I, Onuma K, Morohoshi T
Iwaki Kyoritsu General Hospital.
Kansenshogaku Zasshi. 1991 Apr;65(4):465-71. doi: 10.11150/kansenshogakuzasshi1970.65.465.
Though incident due to Serratia spp. has decreased with the use of third generation cephems, S. marcescens with multiple drug resistance are still clinically occasionally isolated S. marcescens strains 218, 219 and 220 we isolated clinically, were found to possess aminoglycoside inactivating enzyme activities which had not been expected to exist in Serratia spp. These isolates inactivated aminoglycoside antibiotics except strains 218 and 219 were sensitive to isepamicin whereas strain 220 was sensitive to isepamicin and gentamicin. It was found that strains 218 and 219 possessed aminoglycoside inactivating enzyme AAC(2'), and strain 220 AAC (6'). The genes coding for these inactivating enzymes were found to be on R-plasmid and transferred between bacterial cells. Frequencies of transfer of the R-plasmid from Serratia to Escherichia coli chi-1037 were be low, but the transfer definitely occurred as frequencies of 4.3 x 10(-7) from strain 218, 5.2 x 10(-7) from strain 219, and 8.3 x 10(-7) from 220 were determined. To prevent nosocomial infections, the eradication of multi-resistant Serratia strains is strongly recommended when they are isolated even apparent symptoms of infections are not observed.
尽管随着第三代头孢菌素的使用，沙雷氏菌属引起的感染有所减少，但多重耐药的粘质沙雷氏菌在临床上仍偶尔被分离出来。我们临床分离出的粘质沙雷氏菌菌株218、219和220，被发现具有氨基糖苷类灭活酶活性，而这在沙雷氏菌属中本不应存在。这些分离株能使氨基糖苷类抗生素失活，不过菌株218和219对异帕米星敏感，而菌株220对异帕米星和庆大霉素敏感。研究发现，菌株218和219具有氨基糖苷类灭活酶AAC(2')，菌株220具有AAC(6')。编码这些灭活酶的基因位于R质粒上，并在细菌细胞间转移。R质粒从沙雷氏菌向大肠杆菌chi - 1037的转移频率较低，但转移确实发生了，已确定菌株218的转移频率为4.3×10(-7)，菌株219为5.2×10(-7)，菌株220为8.3×10(-7)。为预防医院感染，强烈建议在分离出多重耐药沙雷氏菌菌株时将其根除，即便未观察到明显的感染症状。
