医院感染葡萄球菌菌种变迁与耐药性近况

目的：了解近9年来医院感染葡萄球菌菌种的变迁与近3年来葡萄球菌药状况。方法：1993年1月至2001年12月我院传染病科等13科室住院病人的各种标本采用血琼脂培养，所分离的葡萄球菌采用美国DADE公司生产的MICROSCAN WALKAY-40全自动微生物分析仪鉴定到种及其亚种。药敏试验药物有青霉素、苯唑西林、氨苄西林、哌拉西林、阿莫西林／克拉维酸（阿莫仙）、头孢唑啉、头孢噻肟、头孢哌酮／舒巴坦（舒普深）、庆大霉素、复方新诺明、环丙沙星、氧氟沙星、利福平、万古霉素、红霉素、林可霉素、四环素、伊米配能／西司他丁（泰能）共18种。采用液体稀释法测定每株葡萄球菌对受试药物的最小抑菌浓度（MIC），操作按说明书进行。质控菌ATCC25923。依据新近NCCLS标准判读结果。结果：1993年至1998年分离的葡萄球菌中，金黄色葡萄球菌（金葡萄）占71.43%，凝固酶阴性葡萄球菌（CNS）占28.57%，包括表皮葡萄球菌（表葡菌）、腐生葡萄球菌、里昂葡萄球菌和头状葡萄球菌4种。1999年至2001年分离的424株葡萄球菌中，金葡菌仅占29.01%,CNS增至13种，占70.995，以表葡菌、溶血葡萄球菌、松鼠葡萄球菌为主。近3年来分离的各种葡萄球菌甲氧西林耐药率在73.03%-100%之间，除对舒普深、复方新诺明、利福平和万古霉素较敏感外，对其余抗菌药物的耐药率均超过60％，以金葡菌、溶血葡萄球菌、松鼠葡萄球菌的耐药率为最高。MRS耐药率普遍高于MSS，且均呈多重耐药。5.42%(23/424)菌株万古霉素MIC＞16mg/L，除1株为MSCNS外，其余22株均为MRS。结论：3年来医院感染葡萄球菌菌种构成比发生了显著变化，以CNS为主。对抗菌药物呈多重耐药，部分菌株对万古霉素敏感性降低，应予警惕。

CHANGES OF NOSOCOMIAL STAPHYLOCOCCAL SPECIES AND RECENT STATE OF RESISTANCE

Objective:To investigate changes of nosocomial staphylococcal species in nine years and state of staphylococcal resistance in recent three years.Methods: Staphylococci were cultured by blood plate Staphylococci isolated from Department of Infectious Diseases et al were identified by MICROSCAN WALKWAY 40 mede in American DADE Campany.There were 18 antimicrobials used to susceptibility test.MICs of antimicrobials to staphylococci were detected by dilute method of liquid.The results of drug susceptibility test were judged based on standard of NCCLS(1999) Results:Of staphylococcal strains from 1993 to 1998, Staphylococcus aureus accounted for 71 43%,coagulase negative staphylococcus (CNS) accounted for 28 57%,of them,there were staphylococcus epidermidis, Staphylococcus Saprophyticus,Staphylococcus lugdunensis and Staphylococcus capitis.Of 424 staphylococcus strains from 1999 to 2001,S.aureus accounted for 29 01%,CNS increased to 13 species The latter accounted for 70 99% S epidermidis,S.haemolyticus,S.sciuri were the most common strains.Rate of MRS was from 73 03% to 100% in recent three years.Susceptibilities of staphylococci to cefoperazole sulbactam,SMZ/TMP,rifampicin,and vancomycin were higher,However,resitant rates of staphylococi to other antimicrobials were the higher than 60%.Resistant rates of S.aureus,S.haemolyticus,S.sauri were the highest.Resistant rate fo MRS was higher than that MSS.MICs of vancomycin exceed 16 mg/L in 5 42% of staphlococcal strains.Conclusion:Of nosocomial staphylococci,CNS was the most common in recent three years.Most staphylococcal strains were multi drug resistance Susceptibilities of partal staphylococcal strains to vencomycin were reduced