Pseudomonas aeruginosa is the most common pathogen of burn wound infection. It can encode a variety of virulence factors and is highly pathogenic, which can lead to poor prognosis and high mortality. In order to research a new method to combat Pseudomonas aeruginosa infection, researchers have observed a wide range of interactions between the bacteriophages and the host. Bacteriophages influence and even dominate the structure, movement, and metabolism of host bacteria through a variety of mechanisms, catalyze the evolution of the host, and are also an important factor in host environmental adaptability and pathogenicity. In this paper, the interaction between Pseudomonas aeruginosa bacteriophages and the host is reviewed from the single cell level and the population level. Understanding these interactions could provide new idea for the treatment of Pseudomonas aeruginosa clinical infections, provides a basis for future development of antimicrobial agents and guides the treatment of burn infections.
Bacteriophages ; Burns/therapy* ; Humans ; Pseudomonas Infections/microbiology* ; Pseudomonas Phages ; Pseudomonas aeruginosa ; Virulence Factors

Ecthyma gangrenosum is a characteristic skin lesion of systemic infection due to Pseudomonas aeruginosa. It has a high incidence in patients with chronic disease and impaired defense mechanisms. Early diagnosis and appropriate systemic antibiotic therapy is crucial since its mortality rate is very high. We report a case of ecthyma gangrenosum in aplastic anemia.
Adult ; Anemia, Aplastic/*complications/pathology ; Case Report ; Female ; Human ; Opportunistic Infections/microbiology/pathology ; Pseudomonas Infections/*complications/microbiology/pathology ; Skin Diseases, Bacterial/drug therapy/*etiology/pathology

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

Anthracosis ; complications ; microbiology ; Anti-Bacterial Agents ; pharmacology ; Drug Resistance, Bacterial ; Humans ; Imipenem ; pharmacology ; Microbial Sensitivity Tests ; Pseudomonas Infections ; complications ; drug therapy ; microbiology ; Pseudomonas aeruginosa ; drug effects ; Pulmonary Heart Disease ; complications ; microbiology

OBJECTIVETo study changes in the drug-resistance of Pseudomonas aeruginosa (PA) and the use of antibiotics in burn wards so as to optimize the use of antibiotic in the future.

METHODSBacteria were isolated from specimens of blood, venous catheter, stool, sputum, urine, wound tissue from 5717 patients hospitalized in our burn wards within the duration of January 2005 to December 2009. The number of specimens examined and positive rates of bacteria were calculated. Changes in constituent ratio of cocci and bacilli, spectrum of bacteria, the drug-resistance rate of PA, and the usage of antibiotics were analyzed. The number of specimens examined, constituent ratio of cocci and bacilli, drug-resistance rate were processed with chi-square test. Bivariate correlation analysis was performed between the usage of antibiotics and the drug-resistance rate.

RESULTS(1) The number of specimens examined showed no statistical difference during the five years (with rates from 73.2% to 76.1%, χ(2) = 5.583, P > 0.05), while constituent ratio of cocci and bacilli showed statistical difference (with ratios from 105:134 to 169:126, χ(2) = 14.806, P < 0.01). The positive rates of bacteria were increasing in the five years. (2) One thousand six hundred and seventy-five strains were identified during the five years from different kinds of specimens, with 29 from blood, 39 from venous catheter, 3 from stool, 157 from sputum, 13 from urine, and 1434 from wound tissue. Among them, Staphylococcus aureus accounted for 28% to 42%, PA accounted for 10% to 25%, Acinetobacter baumannii accounted for 10% to 19%, and they were the predominant strains. (3) The difference among drug-resistance rates of PA to each kind of 12 antibiotics during the five years were statistically significant (with χ(2) values from 47.911 to 308.095, P values all below 0.01). The drug-resistance rates of PA to some antibiotics showed downward trend in the former four years, including amikacin, ceftazidime, and imipenem/cilastatin, but it rebounded in the fifth year. (4) There was descending trend in usage of cefoperazone/sulbactam and levofloxacin, but vancomycin was always used widely. (5) Drug-resistance rates of PA to 7 antibiotics, including amikacin, imipenem/cilastatin, and ciprofloxacin, etc., were positively correlated with usage of various antibiotics (with r values from 0.879 to 0.978, P < 0.05 or P < 0.01).

CONCLUSIONSIn our burn wards, drug-resistant PA was prevalent. Disinfection and isolation measures, appropriate use of antibiotics, etc. can reduce PA infection.

Anti-Bacterial Agents ; therapeutic use ; Burn Units ; Burns ; drug therapy ; microbiology ; Drug Resistance, Bacterial ; drug effects ; Female ; Humans ; Male ; Pseudomonas Infections ; drug therapy ; microbiology ; Pseudomonas aeruginosa ; drug effects ; isolation & purification

OBJECTIVETo study the therapeutical effects of the Chinese medicinal herb, Sophora flavescens (SFA) on a rat model of chronic Pseudomonas aeruginosa (PA) biofilm pneumonia.

METHODRats were challenged intratracheally with alginate embedded PA strain PAO579 at the concentration of 1 x 10(9) colony-forming units per milliliter (CFU x mL(-1)). After challeng on the second day, three different doses SFA or sterile normal saline (NS) were administered by gastric intubation once a day for two weeks. Two weeks post intratracheal challenge with P. aeruginosa, parameters were evaluated.

RESULTTwo weeks after challenge, a remarkable serum antibody response and significant infiltration of numerous polymorphonuclear leukocytes (PMN) with lower IFN-gamma production in the lungs were found in the model group. However, milder macroscopic and lower incidence of lung abscesses were found in all the three groups received different doses of SFA treatment compared to the model group (P < 0.001). Meanwhile, the microscopic lung pathology in all SFA-treated groups were characterized by chronic inflammation dominated by mononuclear leukocytes (MN). The rat number with acute inflammation in group II, III was significantly lower than that in the model group (P < 0.05). Furthermore, the serum level of anti-PA IgG was down-regulated in group II and III (P < 0.05 or P < 0.001), and serum IgG level was negatively correlated with the SFA doses (r = -0.95, P < 0.01). In all the SFA-treated groups higher IFN-gamma production in the lung was found compared to the model group (P < 0.001), and the lung IFN-gamma level was positively correlated with the SFA doses (r = 0.9, P < 0.02). These findings indicate that SFA has an effect on inducing Thl type of immune response. The anti-PA activity test of SFA was weakly positive whereas NS was negative.

CONCLUSIONSFA treatment significantly reduced pathology, which might be associated with a shift of local immune responding type from a Th2 like to Thl like that might provide a better protection to the rats with chronic P. aeruginosa lung infection. And these results also showed that the SFA dose of 12 g x kg(-1) was the best dosage in this present study.

Animals ; Biofilms ; drug effects ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; therapeutic use ; Female ; Male ; Pneumonia ; drug therapy ; microbiology ; pathology ; Pseudomonas Infections ; drug therapy ; microbiology ; pathology ; Pseudomonas aeruginosa ; pathogenicity ; Random Allocation ; Rats ; Rats, Wistar ; Sophora ; chemistry

To determine injection time and effective dose of ciprofloxacin in endophthalmitis and to evaluate the effectiveness of dexamethasone. In rabbits, Pseudomonas aeruginosa (2 x 10(4) CFU/0.1 ml) was inoculated intravitreally. At 6, 12, 18, 24 hours postinoculation, single intravitreal doses of ciprofloxacin (300 microgram/0.15 ml or 100 microgram/0.05 ml) alone or with dexamethasone (400 microgram) were given. Electrophysiological and histologic measures were utilized to rate drug effectiveness. 300 micrograms ciprofloxacin was effective in killing P. aeruginosa at 6 and 12 hours postinoculation, but one hundred ug ciprofloxacin was not effective. 300 ug ciprofloxacin had no significant effect in killing P. alphaeruginosa at 18 hrs and 24 hrs postinoculation. Eyes treated with dexamethasone (400 microgram) and ciprofloxacin (300 microgram) at 6 hours postinoculation did not differ from eyes treated with ciprofloxacin alone. Cultures from eyes treated with dexamethasone and ciprofloxacin at 12 hours postinoculation were positive. Cultures from eyes treated with ciprofloxacin alone were negative. The failure of treatment at 18 hrs and 24 hrs postinoculation may be due to either an increased rate of clearance of drugs from the eyes or a reduced bactericidal effect of ciprofloxacin which could be altered by acidic pH, degree of hypoxia or bacterial counts. Dexamethasone had no beneficial effect in the treatment of P. aeruginosa endophthalmitis in the early phase.
Animals ; Anti-Infective Agents/*administration & dosage ; Anti-Inflammatory Agents/*administration & dosage ; Ciprofloxacin/*administration & dosage ; Dexamethasone/*administration & dosage ; Disease Models, Animal ; Dose-Response Relationship, Drug ; Drug Therapy, Combination ; Electroretinography ; Endophthalmitis/*drug therapy/microbiology/pathology ; Eye Infections, Bacterial/*drug therapy/microbiology/pathology ; Pseudomonas Infections/*drug therapy/microbiology/pathology ; Pseudomonas aeruginosa/drug effects/isolation & purification ; Rabbits ; Time Factors ; Vitreous Body/microbiology

Although Pseudomonas aeruginosa is not generally considered as a cause of antibiotic-associated diarrhea, several cases of diarrhea caused by P. aeruginosa have been reported. We experienced seven cases of nosocomial diarrhea presumably caused by P. aeruginosa, which was the predominant organism isolated from stool cultures. Clostridium difficile toxin was also positive in one patient. No other potential or recognized enteropathogens were identified from stools. All patients had underlying diseases and had been receiving antibiotics before the diarrheal onset. All of the seven P. aeruginosa isolates were resistant to previously given antibiotics. Diarrhea stopped three days after withdrawal of probable offending antibiotics without specific treatment in two patients. The other five patients having continuous diarrhea despite withdrawal of probable offending antibiotics, were successfully treated with antipseudomonal agents. The median duration of diarrhea after the initiation of treatment was 6.3 days. These data suggest that P. aeruginosa can be a potential cause of antibiotic-associated diarrhea. Further investigations are warranted to evaluate the possible etiologic role of P. aeruginosa in antibiotic-associated diarrhea.
Adult ; Aged ; Antibiotics/*adverse effects ; Colitis/complications/drug therapy ; Cross Infection/complications ; Diarrhea/*chemically induced/*microbiology ; Feces/microbiology ; Female ; Human ; Male ; Middle Age ; Pseudomonas Infections/*complications ; *Pseudomonas aeruginosa ; Retrospective Studies

Scleral necrosis and infection are serious late complications of pterygium treatment and are difficult to manage. We describe a 70-year-old Chinese male who presented with scleral necrosis and Pseudomonas aeruginosa infection 15 years after the excision of a pterygium. The infection was treated early and aggressively with intensive topical and intravenous antibiotics and the thin necrotic sclera was reinforced with a donor scleral patch graft when the scleral infection was clinically controlled. The integrity of the globe was maintained by a thin layer of sclera anterior to the graft after the graft gradually shrunk in size and retracted posteriorly. The eye was saved from possible scleral perforation and endophthalmitis. This case is reported to highlight the importance of early aggressive treatment of infection and the value of prophylactic repair of scleral necrosis in the management of these late complications of pterygium treatment.
Administration, Topical ; Aged ; Anti-Bacterial Agents ; Drug Therapy, Combination ; administration & dosage ; therapeutic use ; Humans ; Injections, Intravenous ; Male ; Necrosis ; Pseudomonas Infections ; drug therapy ; Pseudomonas aeruginosa ; Pterygium ; surgery ; Sclera ; pathology ; transplantation ; Scleral Diseases ; drug therapy ; microbiology ; Surgical Wound Infection ; drug therapy ; etiology

OBJECTIVETo investigate the antibacterial effect of a particular antimicrobial peptide Cecropin B(CB) on Pseudomonas aeruginosa infection of wound in mice.

METHODSThirty ICR mice were enrolled in the study, and the Pseudomonas aeruginosa infection model was reproduced by excision of the full layer of dorsal skin with an area of 1 cm x 1 cm. Then they were randomly divided into C ( control, n = 10, with wet compress of isotonic saline at 3 postinjury hour( PIH) ) , M (with hydropathic compress of 100 g/L mafenide at 3 PIH), A (with wet compress of 1 000 mg/L Cecropin B at 3 PIH) groups. The changes in body temperature and hemogram in each group were determined before and 4 days after injury. Quantitative examination were used to detect the quantity of bacteria in muscular tissue of the wounds, and the survival of the mice were observed on 4 post-injury day( PID).

RESULTSThe wounds were moist with more exudation in C group,while that in other groups were dry without obvious exudation. The body temperature of the majority of the mice in each group were elevated, but the number of leucocytes in each group was lowered after operation. The quantity of bacteria in muscle in A group[ (42 +/- 50) CFU/g] was obviously lower than that in M group [(886+/-804) CFU/g, P <0.05] , and it was all obviously lower than that in C group[ (41 +/-28) x 10(5) CFU/g, P <0.01]. The number of surviving mice after 4 PID in C group was evidently smaller than that in A and M groups( P <0. 05).

CONCLUSIONThe cecropin B possesses obvious anti-bacterial effect on the Pseudomonas Aeruginosa infected wounds of ICR mice, and it can reduce the mortality.

Animals ; Antimicrobial Cationic Peptides ; therapeutic use ; Disease Models, Animal ; Insect Proteins ; therapeutic use ; Male ; Mice ; Mice, Inbred ICR ; Pseudomonas Infections ; drug therapy ; Wound Infection ; drug therapy ; microbiology