Objective To evaluate the clinical efficacy and safety of domestic sparfloxacin in the treatment of acute bacterial infections. Methods A multicenter randomized controlled clinical trial was conducted. 117 patients were treated with domestic sparfloxacin 200-300 mg qd for 5-14 days and 114 patients were treated with domestic lomefloxacin 300 mg bid for 5-14 days. Results The cure rates and the efficacy rates in each group were 84.62%, 74.56% and 94.87%, 92.98%, respectively. The bacterial clearance rates were 94.28% and 92.02%, respectively. Adverse drug reactions rates were 7.69% and 11.40%, most of them were mild. There were no significant differences of above results between the two groups (Pgt;0.05). Conclusions The results suggest that sparfloxacin with wide antibacterial spectrum, satisfactory activity, is an effective and safe antibacterial agent in treatment of mild to moderate acute bacterial infections.
Objective To evaluate the efficacy and safety of amoxicillin/sulbactam (AMX/SBT) in the treatment of acute bacterial infections. Method A multicentre randomized controlled clinical trial was conducted. Ampicillin/sulbactam (AMP/SBT) was chosen as the control drug. 113 patients were enrolled in the study (58 cases in test group and 55 cases in control group). AMX/SUL and AMP/SUL were administered 4.5-6.0 g and 4.5-12.0 g every day respectively. Both drugs were given intravenously for 7-14 days. Results The cure rates and the efficacy rates of the two groups were 75.86%, 80.0% and 94.83%, 98.18% respectively. The β-lactamase producing rates were 67.35% , 69.57% and the bacterial clearance rates were 93.88%, 95.65%.There were no significant differences of the above results between the two groups (Pgt;0.05). There was no serious adverse drug reaction in AMX/SBT groups. Conclusion This study suggests that AMX/SBT is an effective and safe drug for treating acute bacterial infections.
Objective To study endotoxin release induced by differential antibiotics in gram negative bacterial infection. Methods Thirty critical patients accompanied with gram negative bacterial infection were divided into group A (imipenem group, n=15) and group B (ceftazidine group, n=15). Imipenem (0.5 g iv q8h) and ceftazidine (1.0 g iv q8h) were given respectively. White blood cell (WBC), systolic blood pressure (SBP), lipopoly sacchride (LPS), tumor necrosis factor alpha (TNFα) and high density lipoprotein (HDL) were determined in 0, 1, 2, 3, 5 and 7 day. Results There was no difference in the change of WBC between two groups. Group A had a more stable SBP than group B. There was lower endotoxin release in group A than in group B and so were the cytokines release. HDL level was lower in group B than in group A. Conclusion Imipenem has lower endotoxinliberating potential than ceftazidine and mediate lower cytokines release. HDL may protect the patients from LPS damage.
Objective To investigate nosocomial non-fermented bacterial infection in lower respiratory tract and the risk factors for multi-drug resistant bacterial infection. Methods 229 patients with nosocomial nonfermented bacterial infection in lower respiratory tract from January to December in 2007 in Xiangya Hospital were analyzed retrospectively. The distribution and drug sensitivity of pathogens were recorded. Of those 229 patients,183 cases were infected by non-fermented multi-drug resistant bacteria( MDRB) . The risk factors for non-fermented MDRB infection in lower respiratory tract were analyzed by multi-factor logistic multiple regression analysis.Results The top four non-fermented bacteria isolated were Pseudomonas aeruginosa( 47.6%) , Acinetobacter baumannii( 36. 3% ) , Acinetobacter spp( 8. 6% ) , and Stenotrophomonas maltophilia( 5. 1%) . Higher isolatated rate was found in neurosurgery ( 25. 7% ) and central ICU( 22. 9% ) . The isolated non-fermented bacteria except Stenotrophomonas maltophilia were resistant to all antibiotics except cefoperazone-sulbactam and meropenem. ICU stay( P lt; 0. 001) , tracheotomy or tracheal intubation( P = 0. 001) , and previous use of carbapenemantibiotics( P =0. 032) were independent risk factors for non-fermented MDRB infection. Conclusion Non-fermented bacillus were important pathogens of nosocomial infection in lower respiratory tract with high rates of antibiotic resistance. It is important to prevent non-fermented MDRB infection by strict limitation on the indication of ICU stay,tracheotomy and use of carbapenem.
Objective To investigate the antibiotic resistance distribution and profiles of multidrug resistant bacteria in respiratory intensive care unit ( RICU) , and to analyze the related risk factors for multidrug resistant bacterial infections. Methods Pathogens from79 patients in RICU from April 2008 to May 2009 were analyzed retrospectively. Meanwhile the risk factors were analyzed by multi-factor logistic analysis among three groups of patients with non-multidrug, multidrug and pandrug-resistant bacterialinfection. Results The top three in 129 isolated pathogenic bacteria were Pseudomonas aeruginosa ( 24. 0% ) , Staphylococcus aureus( 22. 5% ) , and Acinetobacter baumannii( 15. 5% ) . The top three in 76 isolated multidrug-resistant bacteria were Staphylococcus aureus ( 38. 9% ) , Pseudomonas aeruginosa ( 25. 0% ) , and Acinetobacter baumannii( 19. 4% ) . And the two main strains in 29 isolated pandrug-resistant bacteria were Pseudomonas aeruginosa ( 48. 3% ) and Acinetobacter baumannii ( 44. 8% ) . Multi-factor logistic analysis revealed that the frequency of admition to RICU, the use of carbapenem antibiotics, the time of mechanical ventilation, the time of urethral catheterization, and complicated diabetes mellitus were independent risk factors for multidrug-resistant bacterial infection( all P lt; 0. 05) . Conclusions There is a high frequency of multidrug-resistant bacterial infection in RICU. Frequency of admition in RICU, use of carbapenem antibiotics, time of mechanical ventilation, time of urethral catheterization, and complicated diabetes mellitus were closely related withmultidrug-resistant bacterial infection.
Objective To investigate the effects and mechanisms of lactic acid bacteria on MAPK signaling in immune response of dust mite sensitized mice. Methods Forty C57BL/6 mice in Group M, P and L, were sensitized and challenged with mite extract while then the animals in Group N were treated with saline as control. The mice in Group L and P were fed with Lactococcus lactis or Lactobacillus respectively.Three days after the last challenge, all mice were sacrificed for lung pathological examination. IL-10 level in culture supernatant of splenocytes stimulated with mite extract was detected by ELISA. The expression of IL-4/ IFN-γon CD3 +CD4 + cells was detected by flow cytometry. Western blot were performed for detection of MAPK signaling ( P38, ERK, and JNK) from mice’s spleen cells stimulated with mite extract. Results The mice fed with Lactococcus lactis ( Group L) had lower rate of eosinophilic airway inflammation and higher level of IL-10 in the culture supernatant of splenocytes than Group P. Meanwhile, the number of CD4 + T cell with IL-4 expression was decreased revealed by the analysis of flow cytometry. P38 signaling inspleen cells was activated in the mice of Group M, similarly in the mice of Group P, but not of Group L.Conclusion Oral treatment of Lactococcus lactis can induce an immune tolerance in response to mite by up-regulating the level of Tr cells secreting IL-10, thus inhibiting activation of P38 signaling.
Objective To investigate the value of bronchial mucosa biopsy and quantitative culture in the differential diagnosis of lower airway bacterial colonization and infection. Methods A prospective observational cohort survey onMDR Pseudomonas aeruginosa and Acinetobacter baumannii was carried out in intubed or tracheotomized patients with invasive ventilation in respiratory intensive care unite ( RICU) . A total of 50 ICU patients were followed for the detection of MDR pathogen colonization or infection from June 2008 to October 2009. All subjects were divided into an infection group and a colonization group according to the outcome of patients discharged fromthe RICU. Baseline information, APACHEⅡ scores, and CPIS scores were recorded on individual forms for each patient untill discharge or death. Bronchial mucosa biopsy was conducted on appropriate time to identify whether the patient was comfirmed as infection. Microbiological diagnosis was performed with quantitative culture. Results Fifty patients were enrolled in this study, of which infected in 23 cases and colonized in 27 cases. The time of invasive mechanical ventilation, length ofICU stay, catheter indwelling time, and the kinds of disease were significantly different between the two groups( P lt; 0. 05) . The kinds of using antibiotics before onset of multi-drug resistance of bacteria showed that cefoxitin/ cefmetazole and mezlocillin also had significant difference between the infection group and the colonization group. The results of dynamic CPIS score of the infection group showed that scores at each timepoint were higher than those in the colonization group. However, the results of t-test showed that there was higher score in the infection group than that in the colonization group on 14 days after intubation ( P lt;0. 05) . The bronchial mucosa biopsy showed that airway inflammation was detected in 19 cases in the infection group and 9 cases in colonization group. The positive rate in the infection and the colonization group were 55. 6% and 25. 0% , respectively assessed by traditional threshold of 103 cfu/mL for PSB in quantitative bacterial culture. In addition, there was more inflammatory cells in the patients with drug-resistant pathogens infection than that in the patients without nosocomial infection. The combination of bronchial mucosa biopsy and microorganism quantitative cultures had the highest sensitivity and specificity and the highest diagnostic accuracy. Conclusions Bronchial mucosa biopsy combining microorganism quantitative culture is feasible in identifying colonized or infected bacteria. Invasive mechanical ventilation time, length of ICU stay and the catheter indwelling time extending are risk factors for bacterial colonization.
Objective Platelet-rich plasma (PRP) contains high concentrations of platelets and leucocytes, which play a key role in antimicrobial host defense system. To evaluate the antimicrobial efficacy of autologous PRP in vitro and in vivo and to explore the mechanism of action so as to provide the experimental basis for the prevention and treatment of bone infection. Methods PRP was prepared with the method of two centrifugation from 15 health volunteers. Platelet-leukocytegel (PLG) was obtained after activation of PRP with bovine thrombin. Next, PLG was incubated with Staphylococcus aureus (1 × 106 cfu/mL) in vitro compared with PRP, platelet-poor plasma (PPP) and PBS. Samples were taken out after 2, 4, 6, 8, 12, and 24 hours for bacterial culture and colony count. Thirty-six New Zealand adult rabbits, weighing (2.85 ± 0.11) kg, were divided into 4 groups: PLG (n=10), antibiotic (n=10), infection (n=10), and PBS (n=6) groups. The osteomyel itis models were made by injecting 0.1 mL Staphylococcus aureus suspension (1 × 106 cfu/mL) into the tibial canal in PLG group, antibiotic group, and infection group; equal volumes of PBS was injected in PBS group as a control. Autologous PLG was injected immediately after operation in PLG group. Cefazol in (30 mg/kg) was injected through the auricular vein from 1 hour before operation to 72 hours after operation in antibiotic group, once per 8 hours. No treatment was given in infection and PBS groups. The efficacy of PLG for osteomyel itis prophylaxis was evaluated by microbiological, X-ray and histological observation within 28 days. Results The contents of leucocyte and platelet of PRP were 6.2 times and 5.5 times of whole blood, showing signficant differences ((P lt; 0.05); the contents of leucocyte and platelet of PPP were significantly lower than those of whole blood and PRP ((P lt; 0.05). In vitro test showed that PLG had the most obvious bacteriostasis effect. The bacterial count reached a minimum value at 4 hours after incubation in PLG and at 6 hours after incubation in PRP. PPP had slow and no obvious bacteriostasis effect and PBS had no bacteriostasis effect. At 2, 4, 6, 8, 12, and 24 hours of incubation, the bacterial count reduced significantly when compared PLG with PRP and PPP (P lt; 0.05), when compared PRP with PPP (P lt; 0.05). In PLG group and antibiotic group, 1 rabbit died, respectively; 34 rabbits survived to the end of the experiment. There was no significant difference (P gt; 0.05) in temperature, body weight, erythrocyte sedimentation rate and content of leucocyte between 28 days after operation andbefore operation in 4 groups. After 28 days, the X-ray scores were 2.78 ± 1.39, 1.55 ± 1.48, 4.17 ± 1.25, and 0 in PLG, antibiotic,infection, and PBS groups, respectively, which was significantly higher in infection group than in other 3 groups ((P lt; 0.05). Also, the histological scores were 5.89 ± 3.92, 3.00 ± 2.31, 10.33 ± 4.03, and 0, respectively, which was significantly higher in infection group than in other 3 groups (P lt; 0.05), and was significantly lower in antibiotic group than in PLG group ((P lt; 0.05). The results of bacterial culture showed that the infection rates of PLG group (44.4%) and antibiotic group (20.0%) were significantly lower ((P lt; 0.05) than that of infection group (88.9%). The quantitative analysis of bacteria showed that the number of bacteria was signifcantly lower ((P lt; 0.05) in PLG and antibiotic groups than in infection group. Conclusion PRP forms into PLG after activating, it can inhibit Staphylococcus aureus reproduction in vitro and can effectively prevent bone infection in vivo.
Objective Titania and Ag containing nano-hydroxyapatite/polyamide 66 (TiO2-Ag-nHA/PA66) composite bone fill ing material has good biocompatibil ity and biological safety. To investigate the antibacterial effect and Ag+ release characteristics of TiO2-Ag-nHA/PA66 composite bone fill ing material containing different concentrations of Ag+ in vitro. Methods The n-HA/PA66 composite bone fill ing material A1 (material A1) was prepared by co-polymerization method, and TiO2-Ag-nHA/PA66 composite bone fill ing materials A2 and A3 (materials A2 and A3) were prepared by thesame way containing Ag+ of 0.22wt% and 0.64wt%, respectively, and the TiO2 content was 2.35wt%. The materials A2 and A3 were respectively immersed in 50 mL simulated body fluid (SBF), and Ag+ concentration was measured by atomic absorption spectrometry at 1, 3, 7, 14, 21, and 49 days. The inhibition ring test and colony count method were used to evaluate antibiotic effect against Staphylococcus aureus and Escherichia coli, the anti-adhesion capacity of Staphylococcus aureus and Escherichia coli was observed by scanning electron microscope (SEM). Results There was no significant difference in the Ag+ concentration between materials A2 and A3 at 1 day and 3 days (P gt; 0.05); and there were significant differences in the Ag+ concentration between materials A2 and A3 after 7 days (P lt; 0.05). The inhibition ring diameters of materials A2 and A3 to Staphylococcus aureus and Escherichia coli reached the maximum at 1 day, which were (13.40 ± 2.88), (9.40 ± 1.14) mm and (23.60 ± 1.14), (18.80 ± 0.84) mm, showing significant difference (P lt; 0.05) between materials A2 and A3 respectively; and then, the diameter of inhibition ring reduced with the time. The antibacterial effect of materials A2 and A3 against Staphylococcus aureus and Escherichia coli lasted 15, 33 days and 9, 24 days, respectively. No inhibition ring was observed around material A1 all the time. And the inhibitory rates of materials A2 and A3 were 89.74% ± 3.62%, 94.18% ± 2.05% and 78.65% ± 5.64%, 85.96% ± 2.50%; showing significant differences (P lt; 0.05) among materials A1, A2, and A3. SEM showed that bacterial adhesion of materials A2 and A3 was obviously fewer than that of material A1. Conclusion TiO2-Ag-nHA/PA66 composite bone fill ing material has antibacterial property against Staphylococcus aureus and Escherichia coli, and it has a good release effect in SBF.
Objective To prepare silver-containing hydroxyapatite coating (hydroxyapatite/Ag, HA/Ag) and investigate its antibacterial property and biocompatibil ity in vitro. Methods Vacuum plasma spraying technique was adopted to prepare HA/Ag coating on titanium alloy substrate (3% Ag). After incubating the HA/Ag and the HA coating under staphylococcus aureus and pseudomonas aeruginosa suspensions of 2% tryptic soy broth (TBS) medium for 2, 4 and 7 days, respectively, the biofilm on the coatings was examined by confocal laser scanning microscope, and the bacterial density and viable bacterial percentage of bacterial biofilm were calculated. Meanwhile, the micro-morphology of bacterial biofilm was observed by SEM, the cytotoxicity was detected via MTT and the biocompatibil ity of biofilm was evaluated by acute aemolysis test. Results Compared with HA coating, the bacterial biofilm’s thickness on the surface of HA/Ag coating witnessed no significant difference at 2 days after culture (Pgt; 0.05), but decreased obviously at 4 and 7 days after culture (P lt; 0.01). The bacterial density of the biofilm increased with time, but there was no significant difference between two coatings (P gt; 0.05) at 2, 4 and 7 days after culture. The viable bacterial percentage of the biofilms on the surface of HA/Ag coating decreased obviously compared with that of HA coating at 2, 4 and 7 days after cultureP lt; 0.01). The MTT notified the cytotoxic grade of both coatings was zero. The acute haemolysis assay showed that the hemolytic rate of HA/Ag and HA coating was 0.19% and 0.12%, respectively. Conclusion With good biocompatibil ity, significant antibacterial property against staphylococcus aureus and pseudomonas aeruginosa, no obvious cytotoxicity and no erythrocyte destruction, the vacuum plasma sprayed HA/Ag coating is a promising candidate for the surface of orthopedic metal implants to improve their osseointegration and antibacterial property.