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Anaerobic Organisms (anaerobic + organism)

Distribution by Scientific Domains

Medical Sciences	60%

Selected Abstracts

A Comparative Study of Community- and Nursing Home-Acquired Empyema Thoracis

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 11 2007
Ali A. El Solh MD
OBJECTIVES: To compare the clinical presentation, microbiological features, and outcomes of patients with community-acquired empyema (CAE) with those of patients with nursing home-acquired empyema (NHAE). DESIGN: A retrospective observational study. SETTING: Three tertiary care centers. PARTICIPANTS: One hundred fourteen patients admitted from the community and 55 patients transferred from nursing homes. MEASUREMENTS: Baseline sociodemographic information, activities of daily living, Charlson Comorbidity Index score, and clinica, and microbiologic data were obtained. Outcome was assessed at hospital discharge and 6 months postdischarge. RESULTS: Patients admitted from nursing homes had a delayed presentation, with dyspnea, weight loss, and anemia as the predominant manifestation. Patients with CAE presented more acutely, with fever, cough, and chest pain. Anaerobic organisms were more commonly isolated from patients with NHAE. The success rate of nonsurgical intervention was significantly lower for the NHAE patients than for the CAE group (39% vs 63; P=.01). In-hospital mortality was not significantly different between the two groups (NHAE, 18%; CAE, 8%; P=.09). In a Cox regression analysis, preadmission functional status (hazard ratio (HR)=1.26, 95% confidence interval (CI)=1.19,1.4; P<.001) and surgical intervention (HR=0.47, 95% CI=0.24,0.92; P=.03) were the only variables highly correlated with long-term outcome. CONCLUSION: Patients admitted with NHAE have distinctly different clinical and microbiological presentation from that of patients with CAE. Because of the delayed presentation in patients with NHAE, medical treatment alone may be associated with higher rate of failure. Surgical therapy should be considered for selected cases, with the aim of improving long-term survival. [source]

Microbiology of Stents in Laryngotracheal Reconstruction,

THE LARYNGOSCOPE, Issue 2 2004
Payman Simoni MD
Abstract Objectives: Granulation tissue often forms around a laryngotracheal stent, tracheostomy tube, or other airway prosthesis, especially if infection occurs. We studied the types and frequency of organisms colonizing stents used in pediatric laryngotracheal reconstruction. Study Design: This prospective study included 21 patients undergoing 23 consecutive laryngotracheal reconstructions with stents between 1991 and 1999. Methods: After endoscopic removal, each laryngotracheal stent was placed immediately in a sterile container and transported to the laboratory. Specimens for culture were obtained from biofilms on the stents and plated on agars for growth of aerobic, anaerobic, and fungal organisms. Culture results were analyzed with regard to patient age, duration of stenting, and graft type. Results: All stents were colonized with more than one pathogen (range 2,7). The most frequent aerobic isolates were Streptococcus viridians, Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenza, and Neisseria species. Anaerobic organisms were isolated in 26% of cases. Candida species were isolated in 57% of the cases; patients whose stents were colonized with Candida were significantly (P = .007) older (mean 77.5 months) than those not colonized with this organism (mean 26.1 months) Conclusions: The antibiotic agents currently used for children undergoing laryngotracheal reconstruction target mainly aerobic organisms. Despite prophylactic measures, the incidence of granulation tissue formation is clinically significant, and the prevalence of anaerobic, including fungal, pathogens is high. Antibiotic therapy directed toward controlling anaerobic and fungal organisms could help in controlling local inflammation and thus granulation tissue formation. [source]

Purification, crystallization and X-ray crystallographic analysis of Archaeoglobus fulgidus neelaredoxin

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010
Tiago M. Bandeiras
Neelaredoxins are a type of superoxide reductase (SOR), which are blue 14,kDa metalloproteins with a catalytic nonhaem iron centre coordinated by four histidines and one cysteine in the ferrous form. Anaerobic organisms such as Archaeoglobus fulgidus, a hyperthermophilic sulfate-reducing archaeon, have developed defence mechanisms against toxic oxygen species in which superoxide reductases play a key role. SOR is responsible for scavenging toxic superoxide anion radicals (O2·,), catalysing the one-electron reduction of superoxide to hydrogen peroxide. Crystals of recombinant A. fulgidus neelaredoxin in the oxidized form (13.7,kDa, 125 residues) were obtained using polyethylene glycol and ammonium sulfate. These crystals diffracted to 1.9,Å resolution and belonged to the tetragonal space group P41212, with unit-cell parameters a = b = 75.72, c = 185.44,Å. Cell-content analysis indicated the presence of a tetramer in the asymmetric unit, with a Matthews coefficient (VM) of 2.36,Å3,Da,1 and an estimated solvent content of 48%. The three-dimensional structure was determined by the MAD method and is currently under refinement. [source]

Bacterial translocation in a non-lethal rat model of peritonitis

COLORECTAL DISEASE, Issue 5 2001
V. Yao
Background Bacterial translocation from the gut may occur under a variety of different clinical circumstances and has been implicated in the development of multiple organ failure. The aim of this study was to determine the distribution of bacterial translocation occurring in a model of chemically induced peritonitis. We also sought to document the degree of the associated immune and inflammatory response. Methods Though a midline laparotomy, rats were injected with 5 mg of zymosan (in 0.2 ml of saline) into the subomental space. After 4, 18, 24, 48 and 96 h, a number of endpoints evaluated: intraperitoneal cellular influx, TNF-, and interleukin-6 concentrations and myeloperoxidase activity. Bacterial cultures were initiated from the free peritoneal fluid, mesenteric lymph nodes, liver, lung, and kidney. Imprints were also made of the peritoneal mesothelial surface to determine its integrity. Results When comparing rats injected with zymosan with the controls, there was evidence of a peritoneal inflammatory response within 4 hours. Facultative gram negative bacteria were found to be growing in the mesenteric lymph nodes and in the peritoneal fluid at 48 h. Anaerobic organisms were also cultured from the peritoneal fluid at 48 h. No organisms were cultured from the liver, lung or kidneys. In addition there was a significant increase in intraperitoneal cell numbers (predominantly neutrophils, P < 0.05), myeloperoxidase activity (P < 0.05) and TNF-, and IL-6 concentrations (P < 0.05). There was extensive loss of the peritoneal mesothelial cells. The peritoneal inflammatory changes and bacterial translocation had resolved by 96 h. Conclusion Bacterial translocation can be induced by the presence of an acute inflammatory focus in the peritoneal cavity. The translocation and inflammatory changes were associated with extensive loss of mesothelial cells. Nonetheless, these changes all resolved, indicating that the peritoneal cavity has a significant capacity to deal with such insults. A clearer understanding of the cellular and molecular events involved in the resolution phase could lead to improvements in the treatment of peritonotis. [source]

Production, characterization and determination of the real catalytic properties of the putative ,succinate dehydrogenase' from Wolinella succinogenes

MOLECULAR MICROBIOLOGY, Issue 5 2009
Hanno D. Juhnke
Summary Both the genomes of the epsilonproteobacteria Wolinella succinogenes and Campylobacter jejuni contain operons (sdhABE) that encode for so far uncharacterized enzyme complexes annotated as ,non-classical' succinate:quinone reductases (SQRs). However, the role of such an enzyme ostensibly involved in aerobic respiration in an anaerobic organism such as W. succinogenes has hitherto been unknown. We have established the first genetic system for the manipulation and production of a member of the non-classical succinate:quinone oxidoreductase family. Biochemical characterization of the W. succinogenes enzyme reveals that the putative SQR is in fact a novel methylmenaquinol:fumarate reductase (MFR) with no detectable succinate oxidation activity, clearly indicative of its involvement in anaerobic metabolism. We demonstrate that the hydrophilic subunits of the MFR complex are, in contrast to all other previously characterized members of the superfamily, exported into the periplasm via the twin-arginine translocation (tat)-pathway. Furthermore we show that a single amino acid exchange (Ala86,His) in the flavoprotein of that enzyme complex is the only additional requirement for the covalent binding of the otherwise non-covalently bound FAD. Our results provide an explanation for the previously published puzzling observation that the C. jejuni sdhABE operon is upregulated in an oxygen-limited environment as compared with microaerophilic laboratory conditions. [source]