Sanchez M L, Flint K K, Jones R N
Department of Pathology, University of Iowa College of Medicine, Iowa City 52242.
Diagn Microbiol Infect Dis. 1993 Mar-Apr;16(3):205-13. doi: 10.1016/0732-8893(93)90111-j.
A total of 2189 staphylococcal strains at the University of Iowa Hospitals and Clinics (Iowa City, IA) were initially screened to determine the incidence of constitutive (29.8%) and potential inducible macrolide-lincosamide-streptogramin (MLS) resistance (11.3%). Staphylococcus haemolyticus and S. epidermidis (62.5% and 55.3%) showed the highest incidence of constitutive resistance. Staphylococcus hominis had the highest incidence of inducible resistance (40.6%), while S. aureus had the lowest rate for both resistance types. The overall ratio of constitutive-inducible MLS resistance was 4:1. Among strains initially speciated using the Vitek System GPI card, there was only a 69% species identification reproducibility, and 78% accuracy versus a reference identification method. A random sample of 105 Staphylococcus spp. isolates with discordant macrolide (erythromycin resistant) and lincosamide (clindamycin susceptible) susceptibility patterns were tested against 16 antimicrobial agents by using a reference broth microdilution method. All erythromycin-resistant Staphylococcus spp. were also resistant to other 14-member macrolides and azithromycin, while all organisms remained susceptible to clindamycin, rifampin, vancomycin, and the streptogramin compounds (RP59500 and virginiamycin). Resistance to teicoplanin was identified among some oxacillin-resistant S. haemolyticus strains. Of 105 isolates, 65 (62%) showed inducible MLS resistance, 28 (27%) were noninducible, and 12 (11%) were either fully susceptible or resistant to the MLS drugs (Vitek System interpretation errors). MLS disk induction tests revealed two inducible resistance phenotypes: ML and MLS. Staphylococcus aureus showed the highest inducible resistance rate at 95% with an MLS-predominant pattern. In contrast, endemic S. haemolyticus isolates did not demonstrate inducible resistance that is, efflux-mediated erythromycin resistance.(ABSTRACT TRUNCATED AT 250 WORDS)
对爱荷华大学医院及诊所（爱荷华市，爱荷华州）的总共2189株葡萄球菌菌株进行了初步筛查，以确定组成型（29.8%）和潜在诱导型大环内酯-林可酰胺-链阳菌素（MLS）耐药性的发生率（11.3%）。溶血葡萄球菌和表皮葡萄球菌（分别为62.5%和55.3%）的组成型耐药发生率最高。人葡萄球菌的诱导型耐药发生率最高（40.6%），而金黄色葡萄球菌在两种耐药类型中的发生率最低。组成型-诱导型MLS耐药的总体比例为4:1。在最初使用Vitek系统GPI卡进行菌种鉴定的菌株中，菌种鉴定的重现性仅为69%，与参考鉴定方法相比准确率为78%。通过参考肉汤微量稀释法，对105株大环内酯类（对红霉素耐药）和林可酰胺类（对克林霉素敏感）药敏模式不一致的葡萄球菌属分离株随机样本进行了16种抗菌药物的测试。所有对红霉素耐药的葡萄球菌属菌株也对其他14元大环内酯类和阿奇霉素耐药，而所有菌株对克林霉素、利福平、万古霉素和链阳菌素类化合物（RP59500和维吉尼亚霉素）仍敏感。在一些对苯唑西林耐药的溶血葡萄球菌菌株中发现了对替考拉宁的耐药性。在105株分离株中，65株（62%）表现出诱导型MLS耐药，28株（27%）为非诱导型，12株（11%）对MLS药物完全敏感或耐药（Vitek系统解释错误）。MLS纸片诱导试验揭示了两种诱导型耐药表型：ML和MLS型。金黄色葡萄球菌的诱导型耐药率最高，为95%，以MLS型为主。相比之下，地方性溶血葡萄球菌分离株未表现出诱导型耐药，即外排介导的红霉素耐药。（摘要截短于250字）
