OBJECTIVE To investigate the antimicrobial resistance of nosocomial infection pathogens and to provide the reference for the clinical treatment and infection control in hospital. METHODS Bacteria were isolated from patients in our hospital from Jan 2000 to Dec 2004 and animicrobial susceptibility was tested by disc diffusion method(K-B method). RESULTS A total of 7016 strain pathogens were isolated,among them 2250 strains were Gram-positive cocci.The most common pathogens of them were Staphylococcus.Meticillin resistant strains of S.aureus and coagulase negative Staphylococcus(CNS) accounted for 62.1% and 76.0%,respectively.There were 4766 strains of Gram-negative bacilli.The most common pathogens of them were Pseudomonas aeruginosa,Klebsiella pneumoniae,Escherichia coli,Acinetobacter and Enterobacter cloacae.The most common ESBLs producing strains were K.pneumoniae and E.coli.In our data,no vancomycin resistant Staphlococcus was isolated.The imipenem resistant P.aeruginosa was growing by year. CONCLUSIONS Coagulase negative Staphylococcus and meticillin resistant Staphylococcus are growing,imipenem resistance of P.aeruginosa is a serious problem.

BACKGROUND: It is recently found that some kinds of antibiotics can aggravate the obstruction of neuromuscular junction(NM J) transmission,exacerbate myasthenia gravis (MG). Hitherto, there are few reports about the effect of antibiotics on transitive function on animal models. Along with the appearance of new antibiotics, the effects of the antibiotics on NMJ transitive function need to be further observed.OBJECTIVE: To investigate the effect of aminoglycoside antibiotics, fluoroquinolone antibiotics and cephalosporin antibiotics on the transitive function of NMJ in MG, and to provide an experimental basis for using those antibiotics securely in clinic and for selecting those antibiotics to treat MG properly.DESIGN: Randomized controlled study based on experimental animals.SETTING: Department of nosocomial infection, neurology and pharmacy in a university hospital.MATERIALS: The experiment was conducted at the Neurological Institute of Tongji Medical College, Huazhong University of Science and Technology from March 2002 to January 2003. Totally 150 healthy female C57BL/6mice, 6 - 8 weeks old, weighting 18 - 20 g, were divided randomly into 4groups: normal group( n = 10), MG group( n = 10), saline group( n = 10)and antibiotics group( n = 120) . Mice in antibiotics group were divided randomly again into gentamicin group, etimicin group, ciprofloxacin group,fleroxacin group, cefuroxime group and cephradine group, with 20 mice in each group.INTERVENTIONS: C57BL/6 mice were immunized with the acetylcholine receptor(AChR) protein in complete Fruend' s adjuvant(CFA) to establish experimental autoimmune myasthenia gravis(EAMG) . Mice in saline group were injected normal saline and mice in antibiotics group were injected antibiotics(10 mg/kg), lasted 14 days. Mice in MG group were without any treatments. On the 7th day after the last immunization and the 14th day after the antibiotics treatments, MG scores was evaluated, repetitive nerve stimulation(RNS) and the levels of acetylcholine receptor antibody(AChRab)were tested at the same time.RESULTS; The mean symptom scores on the 14th day after the antibiotics treatment with gentamicin, etimicin, ciprofloxacin and fleroxacin were higher than that in MG group, and there was no significant difference in the mean symptom scores among cefuroxime group, cephradine group and MG group. The decrement percent of RNS in gentamicin group [ (21.22 ± 4.63)% ], etimicin group[ (19.08 ±4. 25)% ], ciprofloxacin group[ (22.25 ±4.95)% ] and fleroxacin group[ (21.71 ±4.99)% ] were higher than that in MG group[(15.75 ±2.22)% ], but no difference was found in the attenuation rate among cefuroxime group[(15.25 ±2. 87)% ],cephradine group[ ( 15.25 ± 3.30)% ] and MG group. The levels of AChRab in gentamicin, etimicin, ciprofloxacin and fleroxacin groups were also higher than that in MG group, but no difference was found among cefuroxime group, cephradine group and MG group.CONCLUSOIN: Aminoglycoside and fluoroquinolone antibiotics can aggravate the obstruction of NMJ transmission, and cephalosporin antibiotics have no obvious effect on the obstruction of NMJ transmission function in MG.