Objective To investigate the expression of mar operon in clinical isolates of Escherichia coli. Methods mar operon was amplified by polymerase chain reaction (PCR) and the PCR products were analyzed by restriction endonuclease and identified by Southern blot. The expression of mar operon was determined by reverse transcription polymerase chain reaction (RT PCR). Results No marO ,marR , marA deficiency was found in all clinical isolates of Escherichia coli. The level of expression of mar operon in Mar strain was significantly higher than those in other strains, and increased significantly when incubated with sodium salicylate or tetracycline.Conclusions High expression of mar operon is responsible for the Mar phenotype of clinical strains of Escherichia coli and some mutations leading to high expression of mar operon may exist in marR and/or marO. The expression of mar operon can be induced by salicylate and tetracycline.

Objective To determine the drug-resistance rates of bacteria isolated from 7 hospitals located at different areas of China.Methods 1 111 pathogenic strains were isolated for susceptibility test using agar dilution method from Sep 1,204 to Aug 3 1,2005.According to the criteria of guideline of CLSI (2007),MIC50 and MIC90 were detected for antibacterial activity of antimicrobial agents and resistant rate (R%),intermediate rate(I%)and sensitive rate(S%)were calculated based on susceptibility tests.Results The detectable rates of methiciltin-resistant Staphylococcus anreus(MRSA)and methicilllin- resistant Staphylococcus epidermidis(MRSE)were 39.3%and 74.0% respectively.The total resistant rate of penicillin resistant Streptococcus pneumoniae(R%+I%) was 33.3%(R%=5.6%,I%=27.7%). 91 strains of Enterococcus were isolated.The resistant rate of penicillin resistant E.faecalis Was 40.8%.and E.faecium Was 100%.Neither strains of S.aureus nor strains of S.epidemidis were found resistant to vancomycin.No strains of Enterococcus were found resistant to vancomycin.644 strains of gram-negative bacilli were isolated.The most common gram-negative bacilli were E.coli,k pneumoniae,Acinetobacter spp,P.aeruginosa,and E.cloacae,respectively.The ESBLs-producing strains accounted for 38.6% and 26.7% in E.coli and K. pneumoniae.respectively.Meropenem and imipenem were the most potent antimicrobial agents.Cefoperazone/sulbactam demonstrated excellent activity agent of gram-negative bacilli.Most of the gram-negative bacillus still susceptible to ceftazidime.The new fluroquinotones, moxifloxacin and levofloxacin showed strong and broad spectrum activity against the most gram-positive and gram-negative bacteria.Conclusions This surveillance in 2004-2005 together with the surveillance in 2002-2003,were similar in the bacterial resistance pattern and the trend of rising resistant rates for some pathogens.

In vitro synergistic activity of augmentin and amikacini sulfas, gentamicini sulfatis, cefazolinum natricum cloxacillinum natricum against 162 strains organism isolated from the clinical laboratories in Beijing were investigated. The results showed: At 8mg/L clavula-nic acid and 16mg/L amoxicillin of augmentin. Combined with 4 antibiotics against staphylococcus aureus, klebsiella pneumoniae shi-gella dysenteriae were showed 100% synergistic activity. The combination of augmentin and gentamicini sulfatis and amikacini sulfas against proteus vulgaris showed: Synergistic in 80% and 85%; against Escherichia coli synergistic in 93.33%; against Enterobacter cloacae synergistic in 17.86% and 42.86%, the combination of augmentin and cefazolinum natricum against Escherichia coli and proteus synergistic in all 100% and 85%.The combination of augmentin and cefazoliinum natricum against enterobacter cloacae in 100% antagonism.

AIM: To evaluate the safety and efficacy of cefetamet pivoxil vs cefixime in the treatment of acute bacterial infections. 　METHODS: A multicenter randomized controlled clinical trial was conducted. Ninety-eight patients (M 43, F 55; age 40 a±　s 13 a) with acute bacterial infections of cefetamet group were given cefetamet pivoxil 250-500 mg, po, bid, for 7-14 d, and ninty-five patients (M 44, F 51; age 42 a±14 a) of cefixime group were given cefixime 200 mg, po, bid, for 7-14 d.　RESULTS: The overall clinical efficacy rates were 95 % and 94 %, the bacterial clearance rates were 96 % and 94 %, the bacterial sensitive rates were 98 % and 96 %, the adverse reaction rates were 7 % and 6 %, respectively. There was no statistical significance between two groups (P>0.05).　CONCLUSION: Cefetamet pivoxil and cefixime are effective and safe in the treatment of acute bacterial infections.

Objective To determina the content of cucurbitacin B in cucurbitacins .Methods The highly effective liquid phase chromatography was used,with Waters Symmetry C18(250 mm ×4.6 mm 5μm) column.The mobile phase was acetonitrile-wa-ter (51:49), the flow rate was 1 ml/min, column temperature was 25 ℃, the detection wavelength was 228 nm.Results Cucurb-itacin B regression equation:Y=1 067.3C-0.508 4 (r=0.999 9), the average recovery rate was 99.39%(n=6), RSD was 0.56%, which showed that this method had a good recovery rate .Conclusion The HPLC method for the determination of content of cucurbitacin B in cucurbitacins was simple , reproducible , accurate .

Objective To compare the efficacy and safety of two β-lactam-β-lactamase inhibitor combinations, piperacillin/tazobactam and ticarcillin/clavulanic acid in the treatment of bacterial infections.Methods A randomized, open-labeled, controlled study was conducted for the treatment of 124 hospitalized patients with lower respiratory tract infection and urinary tract infections. Sixty-three patients received piperacillin (4 g)/tazobactam (500 mg) every 8 hours by intravenous infusion and 61 patients received ticarcillin (3 g)/clavulanic acid (200 mg) every 8 hours by intravenous infusion. The duration of treatment was 7-14 days in both groups. Results Sixty-three of 79 cases who received piperacillin/tazobactam and 61 of 84 cases who received ticarcillin/clavulanic acid were assessable for clinical efficacy. The overall efficacy rates were 90.5% for the piperacillin/tazobactam group and 88.5% for the ticarcillin/clavulanic acid group, whereas the bacterial eradication rates were 90.2% and 92.0%, respectively. 78 (77.2%) of 101 strains isolated from patients produced β-lactamases. The adverse reaction was evaluated in 65 cases of piperacillin/tazobactam group and 62 cases of ticarcillin/clavulanic acid group. The adverse drug reaction rates were 7.69% (5/65) and 8.06% (5/62), respectively. Conclusions Piperacillin/tazobactam and ticarcillin/clavulanic acid were effective and safe for the treatment of lower respiratory tract infections and urinary tract infections caused by β-lactamase-producing strains. The results showed that there was no statistical difference between these two groups (P>0.05).

OBJECTIVETo evaluate the efficacy and safety of meropenem in Chinese patients, we conducted a study for the treatment of patients with lower respiratory tract infections, urinary tract infections and other infections.

METHODSA total of 182 hospitalized patients were enrolled in the study. 90 patients received 500 mg meropenem every 12 hours (or 1 g every 12 hours if necessary) and 92 patients received imipenem/cilastatin 500 mg/500 mg every 12 hours (or 1 g every 12 hours if necessary) by intravenous infusion. The duration of treatment was 7 - 14 days for both groups.

RESULTSSeventy of 90 cases receiving meropenem and 70 of 92 cases receiving imipenem/cilastatin were assessable for clinical efficacy. The overall efficacy rates were 90% for the meropenem group and 87% for the imipenem/cilastatin group, and the bacterial eradication rates were 86% in both groups. 93 (76%) of 123 strains isolated from patients produced beta-lactamases. Adverse drug reactions were evaluated in 72 cases in the meropenem group and 70 cases in the imipenem/cilastatin group. The adverse drug reaction rates were 9.7% and 8.6%, respectively. The results showed that there were no statistical differences between these two groups (P > 0.05).

CONCLUSIONMeropenem is effective and safe for the treatment of bacterial infections caused mainly by beta-lactamase-producing strains.

Adult ; Aged ; Alanine Transaminase ; blood ; Aspartate Aminotransferases ; blood ; Cilastatin ; administration & dosage ; adverse effects ; therapeutic use ; Female ; Humans ; Imipenem ; administration & dosage ; adverse effects ; therapeutic use ; Male ; Middle Aged ; Respiratory Tract Infections ; drug therapy ; Thienamycins ; adverse effects ; therapeutic use ; Urinary Tract Infections ; drug therapy