济宁地区淋球菌对抗生素的敏感性测定分析

目的了解济宁地区淋球菌对青霉素、环丙沙星、头孢曲松、壮观霉素的敏感性。方法用纸片法和稀释琼脂法测定药物敏感性,测定β内酰胺酶。结果壮观霉素及头孢曲松药物敏感性无明显变化,4年间未发现耐药菌株;环丙沙星耐药性显著上升,由2000年的590%上升至2003年的679%,PPNG菌株在4年内上升96%。结论PPNG菌株的明显上升和喹诺酮类药物的高耐药性,表明淋球菌的耐药趋势逐渐增强。在济宁地区壮观霉素和头孢曲松为治疗淋病的首选药物。

Research on Bacteriostatic and Bactericidal Efficacy of Povidone Iodine on Aeromonas

[Objective] The aim of this study is to investigate the bacteriostatic and bactericidal efficacy of povidone iodine as one kind of disinfectants for aquaculture on Aeromonas.[Method] With the standard strain of Aeromonas ATCC7966 and the Aeromonas strains isolated from diseased fish or aquatic environment as the tested strains,the bacteriostatic and bactericidal efficacy of povidone iodine was studied by double broth dilution method.[Result] The povidone iodine could inhibit the growth of Aeromonas strains at lower concentration,and killed Aeromonas strains at higher concentration.The minimum bacteriostatic concentration（MIC） of povidone iodine on Aeromonas sp.T1,Aeromonas sp T2 and Aeromonas sp.T4 was 125.00 mg/L,and the minimum bactericidal concentration（MBC） was 4.00 g/L.Whereas,the minimum bacteriostatic concentration（MIC） of povidone iodine on ATCC7966,Aeromonas sp.T3,Aeromonas sp T5 and Aeromonas sp.T6 was 250.00 mg/L,and the minimum bactericidal concentration（MBC） was 8.00 g/L.[Conclusion] This study provides certain basis for reasonable application of povidone iodine.

Effects of Scutellaria Baicalensis on Activity and Biofilm Formation of Klebsiella Pneumoniae

Objective To explore the effects of Scutellaria baicalensis on activity and biofilm formation of Klebsiella pneumonia(Kp).Methods The broth and agar dilution methods were carried out to determine minimum inhibitory concentration and minimum bactericidal concentration of Scutellaria baicalensis for TW518.VITEK-32 system was used to assay TW518 susceptibility to antibiotics.Kp biofilms were formed in vitro and stained with Bac Light Live/Dead stain.The class integron geneⅠ1 m RNA expression was analyzed with RT-PCR.Results The minimum inhibitory concentration of Scutellaria baicalensis on TW518 identified as a Kp colony was 32 mg/ml,and minimum bactericidal concentration was 64 mg/ml.Scutellaria baicalensis and broad-spectrum penicillin,cephalosporin,quinolones,or beta-lactamase had synergistic bactericidal effects.Biofilm formation activity of Kp treated with Scutellaria baicalensis was significantly lower than that of the control group.And class integron geneⅠ1 m RNA expression of TW518 was significantly inhibited by Scutellaria baicalensis.Conclusions Scutellaria baicalensis has sterilization effect on Kp,and Scutellaria baicalensis could effectively inhibit Kp biofilm formation with prolonged treatment.Scutellaria baicalensis might inhibit Kp biofilm formation through down-regulating integron geneⅠ1 expression.

Extracts from Chinese Seabuckthorn Berry Have Antimicrobial Activity in vitro

Chinese seabuckthorn berry contains functional components. The berry was extracted by ethanol-water solution. MTT assay and growth rate method were applied to determine antibacterial ability in vitro of the extract solution. The antibacterial and antifungal assay indicated that the extract exhibited different degree of inhibitory activity. The result showed that the extract at a concentration of 1 250 mg/L had the maximum inhibitory effect against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Inhibitory effect against B. subtilis was much larger than that against the other two bacterial species. MIC values(minimum inhibitory concentration) of the extract on three bacterial species were 5 000, 1 250, and 1 000 mg/L respectively. IC_(50)(50% inhibiting concentration) evaluation of Trichoderma viride, Rhizopus stolonifer, Aspergillus niger, Penicillium expansum, and Vintage Red indicated that the berry had the strongest inhibitory effect against P. expansum(5 520 mg/L), while it had the weakest inhibitory effect against R. stolonifer(18 870 mg/L). The results proved that seabuckthorn berry had highly effective and comprehensive antimicrobial function.

Investigation of Argentinean Plant Extracts for Their Antibacterial Activity

Plants of Baccharis （Asteraceae） genus are commonly known in Argentina as ＂carqueja＂. The antimicrobial activity and minimal inhibitory concentration of B. articulata, B. trimera and B. crispa aqueous and ethanolic extracts were evaluated by using the micro-well dilution method. Previously, the components of extracts were analyzed by spectroscopial means. Gram-positive bacteria were more sensitive to Baccharis species extracts than Gram-negative bacteria. Out of 3 plant species, B. trimera showed significant antibacterial activity and aqueous and ethanolic extracts were active against Staphylococcus aureus （MIC = 2,500 μg/mL and 1,250 μg/mL, respectively） and Listeria monocytogenes （MIC = 625 μg/mL and 625 μg/mL, respectively）. All ethanolic extracts inhibited the growth of the selected Gram-positive （MIC values ranged between 625 μg/mL and 1,250 μg/mL）. Therefore, all Gram-negative bacteria were resistant to the ethanolic and aqueous extracts tested. One flavone, genkawanin, was identified from the three ethanolic extracts as the responsible of antibacterial activity. Two terpenes, hawtriwaic acid and bacrispine, were identified from ethanolic extract of B. crispa and B. trimera as the responsibles of antibacterial activity. These preliminary studies corroborated the antimicrobial activity of the selected plants used in folklore medicine. Therefore, they could be potential sources of new antimicrobial agents used in treatment of infectious diseases.

Nasal carriage of Streptococcus pneumoniae among children in Beijing

Objective To investigate the antimicrobial susceptibility of Streptococcus pneumoniae carried in the nose among children in Beijing and the distribution of serotypes,and to analyze the risk factors for nasal carriage of penicillin non-susceptible S.pneumoniae.Methods A disk diffusion test was applied to detect the antimicrobial susceptibilities of S.pneumoniae to erythromycin,trimethoprim-sulfamethoxazole,chloramphenicol and tetracycline.The E test was applied to determine the minimal inhibitory concentrations of penicillin,cefuroxime,cefotaxime,augmentin and imipenem.S.pneumoniae isolates were serotyped by the Quellung reaction.Results S.pneumoniae that was resistant to penicillin or cefuroxime was not found,but S.pneumoniae intermediate resistant to penicillin and cefuroxime accounted for 8.2% and 2.1%,respectively.All of the isolates were susceptible to cefotaxime,augmentin and imipenem.S.pneumonia that was resistant to erythromycin,trimethoprim-sulfamethoxazole and tetracycline were extremely numerous,accounting for 72%,70% and 79%,respectively.Five serotypes(19,6,14,23,17)accounted for 54.7%,and nontypables accounted for 20.6% of all the S.pneumoniae.Previous history of otitis media was a risk factor we found for nasal carriage of penicillin non-susceptible S.pneumoniae.Conclusions Continued surveillance of the antimicrobial susceptibilities of S.pneumoniae is necessary.A larger scale investigation is needed to identify if the 7 or 9-valent conjugate pneumococcal vaccine is appropriate for Chinese children.

Anti-infectious efficacy of essential oil from Caoguo(Fructus Tsaoko)

OBJECTIVE: To evaluate the anti-infectious efficacy of essential oil extracted from Caoguo(Fructus Tsaoko).METHODS: Minimum inhibitory concentrations(MICs) against clinical isolates of three extracts andthe essential oil from Caoguo(Fructus Tsaoko) were determined by the agar dilution method. The anti-infectious efficacy of the essential oil was evaluated using a mouse peritonitis model which was infected with Staphylococcus aureus or Escherichia coli. The chemical components of the essential oil were identified.RESULTS: The results showed that the essential oil exhibited strong antibacterial activity in vitro, with MICs ranging from 22.49 to 1438.91 μg/m L. The results of in vivo anti-infectious efficacy showed that the Caoguo(Fructus Tsaoko) essential oil can protect the mice from Staphylococcus aureus or Escherichia coli infection. The compositions of the essential oil and relative component percentages were examined. A total of 32 compounds, were identified. The major compounds of essential oil were 1,8-cineole(25.92%) and geraniol(13.69%).CONCLUSION: Our findings suggest that Caoguo(Fructus Tsaoko) essential oil has broad-spectrum antibacterial properties. It warrants further investigation as an antibacterial agent targeting some bacterium with multi-drug resistance.

Mechanisms,clinically curative effects,and antifungal activities of cinnamon oil and pogostemon oil complex against three species of Candida

The anti-fungus mechanisms and curative effects of cinnamon oil and pogostemon oil complexes to wards intestinal Candida infections were investigat ed.We measured the minimal inhibitory concentra tion(MIC) values of the complexes against Candida using proportionally-diluted test-tube medium and examined the evolution of the morphology and structures of Candida albicans using scanning electronic microscopy(SEM) and transmission elec tronic microscopy(TEM).We found that the aver age MIC values of the complexes against the fung were 0.064 mg/mL(cinnamon oil),0.032 mg/mL(pogostemon oil) for Candida albicans,0.129 mg/mL(cinnamon oil),0.064 mg/mL(pogostemon oil for Candida tropicalis,and 0.129 mg/mL(cinnamon oil),0.064 mg/mL(pogostemon oil),for Candida krusei.SEM examination over a 24-48 h period showed that the morphology of Candida albicans cells changed significantly.Irregular hollows ap peared on the surfaces,inside organelles were destroyed and the cells burst after treatment.TEM examination over a 48-72 h period indicated that the cell walls were damaged,organelles were destroyed and most cytoplasms became empty bubbles.Sixty intestinal Candida-infected patients were treated with a capsule containing cinnamon and pogostemon oil.The curative ratio was 71.67%(43/60),and the improvement ratio was 28.33%(17/60),giving a to talratio of 100%.Thus,the cinnamonoil and pogostemon oil complexes had strong anti-funguseffectsag ainst Candida albicans,Candidatropicalis,and Candidakrusei.They impacted the morphology and sub-micro structures of the fungus within48-72h,and eventually denatured and killed the cells.The complexes have also shown considerable curative effects to intestinal Candida infections.

Antimicrobial effect of sodium houttuyfonate on Staphylococcus epidermidis and Candida albicans biofilms

OBJECTIVE： To study antimicrobial effect of Sodi- um houttuyfonate （SH） on Staphylococcus epider- midis （SE） and Candida albicans （CA）. METHODS： The prepared strain broths （OD600=0.05） containing SE and CA were firstly used to test the minimal inhibitory concentrations （MICs） of SH, azithromycin （AZM） and fluconazole （FLU） by mi- cro-dilution method. Then the biofilms of SE and CA were matured in 96-well plates, and co-cultured with SH, AZM and FLU for 1, 2 and 3 days to assess the antibiofilm efficacies of the agents with differ- ent concentrations by crystal violet staining meth- od. At last, the treated biofilms of SE and CA by 2× MIC agents were observed by scanning electronic microscope. RESULTS： The MlCs of SE and CA were 256 and 1024 μg/mL, respectively. After the 1st, 2nd and3rd day of medications, the suppressions of biofilm were about 60% （P〈0.01）, 76% （P=0.000） and 75% （P=0.000） by 2×MIC SH, the suppressions of biofilm were about 90% （P=0.000）, 88% （P=0.000） and 90% （P=0.000） by 2×MIC SH, which could be testified by scanning electron microscope results. However, the inhibitions of biofilm attachment had no significant difference for SE by SH and azithromycin and CA by SH and fluconazole. CONCLUSION： SH had widely anti-pathogenic ef- fect on pathogenic biofilm formation of either bac- teria or fungus, had more influence on enclosed cells of SE and CA than the traditional antibiotics, revealing its target might be the extracellular poly- meric substances, and was more active to inhibit the growth of CA than SE.