引发医院感染表皮葡萄球菌生物被膜的检测

为了解引发医院感染的表皮葡萄球菌中ica操纵元的存在与生物被膜的产生的关系及其对抗生素敏感性的影响，收集了引发医院感染的表葡萄球菌106株，采用定量和定性法检测生物被膜的产生，PCR法检测ica操纵元基因的存在以及测量细菌对红霉素（ERY）、氨苄青霉素（AMP）、头孢西丁（FOX）、头孢曲松（CRO）、替考拉宁（TEC）、环丙沙星（CIP）、四环素（TCY）、复方新诺明（SXT）、万古霉素（VAN）的最小抑菌浓度（MIC）；106株表皮葡萄球菌分离株中，有33株检测出icaABC（31．1％）；ica^＋菌中产膜菌的检出率高于ica^＋菌（P=0．001）；葡萄糖和NaCl可提高产膜菌的检出率；ica^＋浮游菌对红霉素，头孢西丁和头孢曲松的耐药率高于ica^＋浮游菌株，但对氨苄青霉素，环丙沙星，四环素和复方新诺明的耐药率与ica^＋菌相似；ica位点基因的存在与引发表葡菌医院感染密切相关，但生物被膜内菌耐药机制还需进一步研究。

Biofilm Production in Staphylococcus epidermidis Isolated from Hosocomial Infection

To determine the relationship between the intercellular adhesion operon (ica) and the biofilm production in Staphylococcus epidennidis isolates from nosocomial infection, and the affection of ica on the antibiotic susceptibility of the isolates, we collected 106 strains, epidermidis isolates from nosocomial infection specimen to detect their biofilm production by quantitative and qualitative method and investigate the existence of ica operon by PCR. The minimal inhibitory concentration (MIC) to erythromycin, ampicillin, cefoxitin, ceftriaxone, teco-planin, ciprofloxacin, tetracycline, trimethoprim-sulfamethoxazole and vancomycin were tested. Among the isolates, 33 (31. 1% ) of them were detected out carrying ica operon. The rate of biofilm production of the ica-posi-tive isolates was higher than that of the ica-negative (P =0. 001) . By adding glucose and NaCl into the culture the detection rate of biofilm production could be increased. The antibiotic susceptibility of the plankton cells of ica-positive isolates to erythromycin, cefoxitin and ceftriaxone , except ampicillin, ciprofloxacin, tetracycline and tremethoprim-sulfamethoxazole, were lower than those of ica-negative isolates. This study showed that the existence of ica operon was close related to the biofilm formation in 5. epidermidis isolates from nosocomial infection. However, the mechanism of antibiotic resistance of the strains inside the biofilm still needed to be illustrated.