epiglucan and Cross-Infection

Topics: Acinetobacter baumannii; Adhesins, Bacterial; Anti-Bacterial Agents; Bacterial Outer Membrane Proteins; Bacterial Proteins; beta-Glucans; Biofilms; Cell Wall; Cross Infection; Drug Resistance, Multiple, Bacterial; Fimbriae Proteins; Fimbriae, Bacterial; Genes, Bacterial; Glycolipids; Host Microbial Interactions; Humans; Immunity, Innate; Ion Channels; Lipopolysaccharides; Microbial Interactions; Polysaccharides, Bacterial; Porins; Type II Secretion Systems; Type VI Secretion Systems; Virulence

Acinetobacter baumannii has emerged as one of the leading bacteria for nosocomial infections, especially in burn wards and ICUs. The bacteria can easily form biofilm and readily attach to abiotic and biotic surfaces, resulting in persistent biofilm-mediated infections. Being surrounded by self-produced extracellular polymeric substance (EPS), the microorganisms in biofilm can acquire protective property against detrimental environment and their tolerance toward antibiotics is increased. Poly-β-1-6-N-acetylglucosamine (PNAG), the common constituent of EPS in Acinetobacter baumannii, acts as the key virulence factor and plays a crucial role in biofilm formation process. This review describes the properties and functions of the PNAG and its influence on biofilm formation and drug resistance of Acinetobacter baumannii.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Anti-Bacterial Agents; beta-Glucans; Biofilms; Burns; Cross Infection; Drug Resistance, Multiple, Bacterial

Topics: Anidulafungin; Antifungal Agents; beta-Glucans; Candida; Candidiasis; Caspofungin; Cross Infection; Echinocandins; Fungemia; Humans; Infusions, Intravenous; Lipopeptides; Lipoproteins; Male; Micafungin; Microbial Sensitivity Tests; Middle Aged; Neutropenia; Peptides, Cyclic; Practice Guidelines as Topic

In a effect to prevent nosocomial pneumonia and sepsis, we treated patients with severe multiple trauma with an immunomodulator--beta 1-3 polyglucose (glucan). Forty-one patients with no infection at admission were stratified using Trauma Score and included in a randomized double-blind controlled trial. They were divided into a control group (n = 20) and a glucan group (n = 21). Pneumonia occurred in 11 of 20 patients in the control group and in two of 21 recipients of glucan (p < 0.01). Sepsis occurred in seven of 20 patients in the control group and in two of 21 patients treated with glucan (p < 0.05). Considering patients with pneumonia and sepsis, a decrease was observed in nosocomial infection from 65.0 to 14.4 percent (p < 0.001). The mortality rate related to infection was 30.0 percent in patients in the control group and 4.8 percent in the group treated with glucan (p < 0.05). The general mortality rate, cerebral deaths excluded, was 42.1 percent in the control group and 23.5 percent in the glucan group.

Topics: Adjuvants, Immunologic; Adult; Bacterial Infections; beta-Glucans; Craniocerebral Trauma; Cross Infection; Double-Blind Method; Female; Glucans; Humans; Incidence; Male; Multiple Trauma; Pneumonia

Nosocomial infections and increasing multi-drug resistance caused by Acinetobacter baumannii have been recognized as emerging problems worldwide. Moreover, A. baumannii is able to colonize various abiotic materials and medical devices, making it difficult to eradicate and leading to ventilator-associated pneumonia, and bacteremia. Development of novel molecules that inhibit bacterial biofilm formation may be an alternative prophylactic option for the treatment of biofilm-associated A. baumannii infections. Marine environments, which are unlike their terrestrial counterparts, harbor an abundant biodiversity of marine organisms that produce novel bioactive natural products with pharmaceutical potential. In this study, we identified 5-episinuleptolide, which was isolated from Sinularia leptoclados, as an inhibitor of biofilm formation in ATCC 19606 and three multi-drug resistant A. baumannii strains. In addition, the anti-biofilm activities of 5-episinuleptolide were observed for Gram-negative bacteria but not for Gram-positive bacteria, indicating that the inhibition mechanism of 5-episinuleptolide is effective against only Gram-negative bacteria. The mechanism of biofilm inhibition was demonstrated to correlate to decreased gene expression from the pgaABCD locus, which encodes the extracellular polysaccharide poly-β-(1,6)-N-acetylglucosamine (PNAG). Scanning electron microscopy (SEM) indicated that extracellular matrix of the biofilm was dramatically decreased by treatment with 5-episinuleptolide. Our study showed potentially synergistic activity of combination therapy with 5-episinuleptolide and levofloxacin against biofilm formation and biofilm cells. These data indicate that inhibition of biofilm formation via 5-episinuleptolide may represent another prophylactic option for solving the persistent problem of biofilm-associated A. baumannii infections.

Topics: Acinetobacter baumannii; Acinetobacter Infections; Animals; Anthozoa; Anti-Bacterial Agents; beta-Glucans; Biofilms; Biological Products; Cross Infection; Diterpenes; Drug Resistance, Multiple, Bacterial; Drug Synergism; Equipment Contamination; Extracellular Matrix; Genes, Bacterial; Humans; Levofloxacin; Microscopy, Electron, Scanning

Microbiological diagnosis of nosocomial candidemia is negatively affected by suboptimal culture yield. Alternative methods are not fully reliable as an aid in candidemia diagnosis. Recently, the detection of (1,3)-β-D-glucan (BG) has been shown to be very promising in this setting. We carried out a prospective study on the clinical usefulness of BG detection in early diagnosis of candidemia. BG detection was performed in patients with fever unresponsive to antibacterial agents and risk factors for candidemia. BG detection was done with the Fungitell test. A total of 152 patients were included in the study; 53 were proven to have candidemia, while in 52 patients candidemia was excluded on microbiological and clinical bases. The remaining 47 patients were considered to have possible candidemia. In summary, 41 of 53 candidemia patients (77.3%), 9 of 52 patients without candidemia (17.3%), and 38 of 47 patients with possible candidemia (80.8%) were positive in the BG assay. With these results, the sensitivity and the specificity of the assay were 77% and 83%, respectively. BG levels of >160 pg/ml were highly predictive of candidemia. In 36 of 41 patients with candidemia and positive BG testing, the BG assay was performed within 48 h from when the first Candida-positive blood sample for culture was drawn, thus allowing a possible earlier start of antifungal therapy. Based on these results, the BG assay may be used as an aid in the diagnosis of nosocomial candidemia. The timing of assay performance is critical for collecting clinically useful information. However, the test results should be associated with clinical data.

Topics: Antigens, Fungal; beta-Glucans; Candidemia; Clinical Laboratory Techniques; Cross Infection; Early Diagnosis; Humans; Immunoassay; Prospective Studies; Sensitivity and Specificity