OBJECTIVETo observe the biofilm (BF) formation of Staphylococcus aureus (SA), Acinetobacter baumannii (AB) and Pseudomonas aeruginosa (PA) on the surface of deep vein catheters in burn patients after infection.

METHODSThe bacteria from deep vein catheters in 20 patients hospitalized from November 2008 to August 2009 were isolated, and were compared with their respective standard stains. Catheters tips were examined with scanning electron microscope (SEM). The semi-quantitative adhesion assay of bacterial BF was performed with modified microtiter-plate test, and the thickness of BF was scanned and measured by confocal laser scanning microscopy (CLSM) after double fluorescence staining, after being cultured in vitro for 12, 24, 48, 72 hours and 5 days, respectively. Data were processed with grouped t test.

RESULTSSix strains of SA, 8 strains of AB, and 6 strains of PA, all drug resistant, were isolated from the deep vein catheters. SEM showed that the BF structures on the inner surfaces of catheters were in diverse in their shape and degree, characterized by adherence and flake formation, and embedded in polysaccharide matrix. BF gathered in clusters, forming three-dimensional structure, in which small amount of red blood cells were found. A small number of bacteria were incompletely embedded, with some bacteria adhered to them. The absorbance values for SA after 24, 48 and 72 hours of culture (PCH) were above the cut-off value, the same for AB at PCH 12, 24, 48 and 72, and PA after PCH 48. Except for PA standard strain, CLSM showed scattered green fluorescence, mainly close to the bottom of plate, while the red fluorescence was observed in full scope at PCH 24 for each strain. At PCH 48 green fluorescence increased obviously and extended upward from the bottom, overlapping partly with red fluorescence, forming yellow fluorescence, and among the bacteria it was most obvious in AB culture, with SA the next. Compared with those of the standard stains, the intensity and quantity of fluorescence from the clinical strains were stronger; at PCH 72 the green fluorescence increased obviously especially for PA and its standard strain, while the yellow fluorescence was full of the scope for other strains. On in vitro culture day 5, the green fluorescence was dispersed and was obvious on the bottom of the plate. BF mature time for AB and SA was PCH 48, and for PA was PCH 72. The BF thickness of AB was (18.2 +/- 3.6) microm at PCH 72, which was thicker than that [(9.4 +/- 2.6) microm] of its standard strain (t = 5.42, P < 0.05), and was also the thickest among the three clinically found strains.

CONCLUSIONSSA, AB and PA, which are commonly found bacteria in burn patients, can form BF in deep vein catheters. Their ability to form BF seems to be stronger than other usually pathogenic strains, especially AB, which is the important pathogen leading to catheter related infection.

Acinetobacter Infections ; microbiology ; Acinetobacter baumannii ; growth & development ; Bacterial Adhesion ; Biofilms ; Burns ; microbiology ; Catheters ; microbiology ; Humans ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa ; growth & development ; Staphylococcal Infections ; microbiology ; Veins ; microbiology

OBJECTIVE: To observe the effect of biyuanshu oral liquid on the formation of pseudomonas aeruginosa biofilms in vitro. METHOD: Pseudomonas aeruginosa biofilm was established by plate culture and detected by Scanning electron microscopy and AgNO3 staining. After treated with different dosages of biyuanshu oral liquid and erythromycin, the pseudomonas aeruginosa biofilms were observed by AgNO3 staining and the number of viable bacteria were measured by serial dilution. RESULT: The pseudomonas aeruginosa biofilms could be detected by SEM at the seventh culture day and it was consistent with the detection of AgNO3 staining. The biyuanshu oral liquid and erythromycin have the effect on inhibiting the formation of pseudomonas aeruginosa biofilms. But with the already formed pseudomonas aeruginosa biofilms the inhibition was not significant. The serial dilution method showed that the viable counts of bacteria of biyuanshu oral liquid and erythromycin treated groups were significantly lower than those untreated groups (P < 0.05). CONCLUSION The biyuanshu oral liquid and erythromycin can inhibit the formation of pseudomonas aeruginosa biofilms in vitro.
Anti-Bacterial Agents ; pharmacology ; Biofilms ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Erythromycin ; pharmacology ; Pseudomonas aeruginosa ; drug effects ; growth & development

OBJECTIVE: To establish the rat model of chronic suppurative otitis media and observe the formation of bacterial biofilm in middle ear mucosa of animal models and discuss the role of bacterial biofilm in the pathogenesis of chronic suppurative otitis media. METHOD: Twenty-eight rats were divided into six experimental groups and a control group evenly. All rats in experimental groups were infected with pseudomonas aeruginosa solution in 1 X 10(6) cfu/ml concentration through the tympanic membrane puncture approach to bilateral middle ear cavity. On the first, sixth, tenth, fifteenth and twenty-first st day after inoculation respectively, four rats in one experimental group were narcotized, then two-sided tympanic membrane of each rat were observed by using electric otoscope. We rated on the severity of the inflammation from the general pathology level (0 for normal, four for the most serious). After the execution, the two-sided otocysts were obtained. The left was made to SEM specimen and the shape of bacterial biofilm in middle ear mucous was observed. The right was observed by CLSM. Control group were executed at the beginning of the experiment. RESULT: (1) Bacterial biofilm in line with their respective criteria were found at the six days after the inoculation, and were more typical in shape after ten days. Then the states maintained stably within three weeks. (2) By observing tympanic membrane under electric otoscope, it can be seen that the inflammation severity of otitis media aggravated gradually in the first ten days and achieved the peak, then the state continued to the third week. The differences of tympanic membrane rating between one day group and six day group, six day group and ten day group were statistically significant (P < 0.05, P < 0.01). CONCLUSION (1) In this experiment, the process of bacterial biofilm development in rats model is: from beginning to the five days, the bacteria adhere and accumulates. After six days, the 3D structure of bacterial biofilm preliminary formatted. After ten days, the bacterial biofilm achieves the mature and steady state. (2) With the growth and maturity of bacterial biofilm in middle ear mucosa, the inflammation of otitis media is gradually increasing, which suggests that the inflammation severity of otitis media and the maturation of bacterial biofilm in middle ear mucosa are closely related.
Animals ; Biofilms ; growth & development ; Disease Models, Animal ; Mucous Membrane ; microbiology ; Otitis Media, Suppurative ; microbiology ; Pseudomonas aeruginosa ; Rats ; Rats, Wistar

Pseudomonas aeruginosa is an important pathogenic bacterium of nosocomial infections. The microbe easily produce biofilm which brings us much difficulties in clinical treatment. The formation processes of biofilm, including the stages of early bacteria planting, mushroom-like structure forming and extracellular matrix producing, are regulated by a series of molecules and genes. And quorum sensing system of the microbe is responsible for regulation of the whole process of biofilm formation. According to the process of biofilm formation and the mimitat associated regulation mechanism, several anti-biofilm therapeutic strategies have been applied in clinical medicine, and some novel drugs and methods are developed.
Biofilms ; growth & development ; Gene Expression Regulation, Bacterial ; Polysaccharides, Bacterial ; metabolism ; Pseudomonas Infections ; drug therapy ; microbiology ; Pseudomonas aeruginosa ; genetics ; physiology ; Quorum Sensing ; genetics ; physiology

BACKGROUND: Delayed entry of blood culture bottles is inevitable when microbiological laboratories do not operate for 24 hr. There are few studies reported for prestorage of these bottles. The growth dynamics of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were investigated with respect to various preincubation conditions. METHODS: Fifteen or 150 colony-forming units (CFU) of bacteria were inoculated into standard aerobic or anaerobic blood culture bottles. Bottles were preincubated at 25degrees C or 37degrees C for 0, 2, 4, 8, 12, 24, or 48 hr. The time to detection (TTD) then was monitored using the BacT/Alert 3D system (bioMerieux Inc., USA). RESULTS: Significant difference in TTD was observed following preincubation for 8 hr at 25degrees C vs. 4 hr at 37degrees C for S. aureus, 4 hr at 25degrees C vs. 4 hr at 37degrees C for E. coli, 12 hr at 25degrees C vs. 4 hr at 37degrees C for P. aeruginosa, compared to no preincubation (P<0.005). TTD values did not vary significantly with bacterial CFU or with aerobic or anaerobic bottle type. The BacT/Alert 3D system returned false negatives following preincubation of P. aeruginosa for 48 hr at 25degrees C or 24 hr at 37degrees C. CONCLUSIONS: TTD was mainly affected by preincubation temperature and duration rather than by input CFU quantity or bottle type for the 3 experimental bacteria.
Bacteriological Techniques/instrumentation/*methods ; Culture Media ; Escherichia coli/growth & development/*isolation & purification ; Pseudomonas aeruginosa/growth & development/*isolation & purification ; Staphylococcus aureus/growth & development/*isolation & purification ; Temperature ; Time Factors

OBJECTIVETo explore the relationship of bacteria identified in cholesterol gallstones and gallstone formation.

METHODSObserve the bacteria activity in model bile and the influence of bacteria on the cholesterol nucleation time (NT).

RESULTS(1) Model bile were suitable for the growth of E. coli, Pseudomonas aeruginosa, staphylococcus aureus, enterococcus faecalis, clostridium difficile and Clostridium. Propionibacterium acne grew weakly and the growth of Bacteroides fragilis was restrained in model bile. (2) Only pseudomonas aeruginosa and enTerococcus faecalis could ly shorten the cholesterol nucleation time. (3) With pseudomonas aeruginosa or enTerococcus faecalis added in model bile, the formation of cholesterol crystals presented a progressive course of evolution.

CONCLUSIONSPseudomonas aeruginosa and enterococcus faecalis, not propionibacterium acne, have pro-nucleating ability in model bile.

Bile ; metabolism ; microbiology ; Cholelithiasis ; microbiology ; Cholesterol ; metabolism ; Crystallization ; Enterococcus faecalis ; growth & development ; Models, Biological ; Propionibacterium acnes ; growth & development ; Pseudomonas aeruginosa ; growth & development

OBJECTIVETo investigate the resistant effect of houttuyfonate sodium (SH) combined with imipenem (IMP) against Pseudomonas aeruginosa (Pa) biofilms.

METHODThe two-fold dilution method was used to examine the minimum inhibitory concentration (MIC) of the tested drug. The crystal violet staining was applied to detect the effect of the combination of 1/2MIC, 1MIC, 2MIC of SH, single IMP, 1/2MIC of SH and IMP of various concentrations on the clearance rate of adherent bacteria, growth of biofilms and alginate production. Fluorescein diacetate (FDA)-propidium iodide (PI) doubling staining assay was employed to observe the bacterial viability and morphological changes after membrane dispersion of each drug group.

RESULTSodium houttuyfonate could enhance the effect of IMP against pseudomonas aeruginosa biofilms. Particularly, the combination group with the concentration of 2MIC showed the highest effect, with P < 0.001 compared with the negative control group. The above results were proved by the bacterial viability and biofilm morphology under fluorescence microscope.

CONCLUSIONAfter being combined with imipenem, sodium houttuyfonate shows a higher effect against biofilms. It is expected that the combination of the two drugs could improve the clinical efficacy of associated infections.

Alkanes ; pharmacology ; Biofilms ; drug effects ; growth & development ; Drug Synergism ; Imipenem ; pharmacology ; Microbial Sensitivity Tests ; Microbial Viability ; drug effects ; Pseudomonas aeruginosa ; drug effects ; physiology ; Sulfites ; pharmacology

OBJECTIVETo explore the different expression of TGF-beta1 and collagen during the healing process of wound infected by Pseudomonas aeruginosa (PAO1).

METHODS24 female Wistar rats were randomly divided into pure wound group (group A) and wound + PAO1 group (group B). The re-epithelial rate, shrinkage rate and neutrophils number on the wounds were observed on the 1st, 3rd, 7th and 10th day after operation. The expression of TGF-beta1 and collage I, Ill was also detected.

RESULTSOn the 7th day, the re-epithelial rate in group A was higher than that in group B, while the shrinkage rate in group A was lower than that in group B. The neutrophils number increased to peak on the 1st day in group B, but on the 3rd day in group A. The TGF-beta1 expression increased after operation in both groups, but it decreased in group B on the 3rd day and re-increased after that. The TGF-beta1 expression was significantly different between the two groups on the 7th day (P < 0.05). The expression of collagen I and III decreased during healing. The expression of collagen III in group A was higher on the 3rd day and was lower on the 7th and 10th day than that in group B, showing a significant difference (P < 0.05).

CONCLUSIONSPAO1 infection could delay the expression of TGF-beta1 and collagen I, III on wound, which may interfere the healing process of wound.

Animals ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Female ; Pseudomonas Infections ; pathology ; Pseudomonas aeruginosa ; Rats ; Rats, Wistar ; Skin Transplantation ; Surgical Wound Infection ; metabolism ; microbiology ; Transforming Growth Factor beta1 ; metabolism ; Wound Healing

OBJECTIVE: To analyze the factors and biological characteristics of infection after cochlear implantation so as to control the risk factors and improve the treatment of postoperative infection. METHOD: A retrospective study was conducted to analyze the clinical data of 316 patients receiving cochlear implantation from July 2001 to October 2011. RESULT: Postoperative infection was found in five of the 316 cases and one transferred case. The six cases recovered after clinical therapy without explantation. One case underwent explantation due to recurrent meningitis after implantation of 8 years later. CONCLUSION The pathogens of infection after cochlear implantation are staphylococcus aureus, pseudomonas aeruginosa, etc. The key infectious factor is the formation of bacterial biofilm, which can be removal by chemical agents to control the postoperative infection, especially the flap infection. It is not necessary to remove the artificial cochlea when the postoperative infection occurs. Positive perioperative interventions and postoperative infection control can improve the outcome of cochlear implantation.
Adolescent ; Aged ; Biofilms ; growth & development ; Cochlea ; Cochlear Implantation ; adverse effects ; Humans ; Postoperative Complications ; microbiology ; Pseudomonas Infections ; etiology ; Pseudomonas aeruginosa ; physiology ; Retrospective Studies ; Risk Factors ; Staphylococcal Infections ; etiology ; Staphylococcus aureus ; physiology

OBJECTIVETo evaluate the free radical generation and antioxidant enzymes status in murine peritoneal macrophage during in vitro amikacin resistant Pseudomonas aeruginosa (ARPA) treatment with different time interval.

METHODSPeritoneal macrophages were treated with 1×10(8) CFU/mL ARPA cell suspension in vitro for different time interval (1, 2, 3, 6, 12, and 24 h) and super oxide anion generation, NO generation, reduced glutathione level and antioxidant enzymes status were analyzed.

RESULTSSuper oxide anion generation and NO generation got peak at 12 h, indicating maximal free radical generation through activation of NADPH oxidase in murine peritoneal macrophages during ARPA transfection. Reduced glutathione level and antioxidant enzymes status were decreased significantly (P<0.05) with increasing time of ARPA transfection. All the changes in peritoneal macrophages after 12 h in vitro ARPA transfection had significant difference (P<0.05).

CONCLUSIONSFrom this study, it may be summarized that in vitro ARPA infection not only generates excess free radical but also affects the antioxidant system and glutathione cycle in murine peritoneal macrophage.

Amikacin ; pharmacology ; Animals ; Anti-Bacterial Agents ; pharmacology ; Antioxidants ; analysis ; Cells, Cultured ; Drug Resistance, Bacterial ; Free Radicals ; analysis ; Glutathione ; analysis ; Macrophages, Peritoneal ; immunology ; microbiology ; physiology ; Male ; Mice ; Oxidative Stress ; Pseudomonas aeruginosa ; growth & development ; immunology ; Time Factors