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Encapsulated Organisms (encapsulated + organism)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Induction of a protective capsular polysaccharide antibody response to a multiepitope DNA vaccine encoding a peptide mimic of meningococcal serogroup C capsular polysaccharide

IMMUNOLOGY, Issue 2 2003
Deborah M. Prinz
Summary Systemic infection by encapsulated organisms, such as Neisseria meningitidis, is a major cause of morbidity and mortality worldwide, especially in individuals less than 2 years of age. Antibodies directed at the capsular polysaccharide are shown to be protective against disease by inducing complement-dependent bactericidal activity. The current polysaccharide vaccine has been shown to be poorly immunogenic in high-risk groups and this is probably related to its T-independent properties. An alternative approach to eliciting a T-dependent serum immunoglobulin G (IgG) antibody response to encapsulated pathogens is DNA vaccination. We assessed the immunogenicity of a multiepitope DNA vaccine encoding a T-cell helper epitope and a peptide mimic of N. meningitidis serogroup C. The DNA construct induced a significant anti-polysaccharide antibody response that was bactericidal. Mice immunized with the DNA construct were subsequently protected against challenge with a lethal dose of N. meningitidis serogroup C. [source]

Cryptococcal infection in sarcoidosis

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 11 2002
Khosrow Mehrany MD
A 48-year-old man with a history of sarcoidosis was transferred to the Mayo Clinic for evaluation and management of progressive neurologic decline. Two years before admission, he was admitted to a local hospital with mental status changes accompanied by ataxia and severe headache. A diagnosis of pulmonary and central nervous system sarcoidosis was made based on computed tomography of the head, lumbar puncture, and chest radiography. A mediastinoscopy with lymph node biopsy exhibited noncaseating granulomas and negative stains for microorganisms. Prednisone therapy was initiated at 80 mg/day. Clinical improvement was apparent for 13 months during steroid therapy until the slow taper reached a dosage of 20 mg/day. At that time, the patient was readmitted to the local hospital with severe confusion and skin lesions. When intravenous methylprednisolone therapy for presumed central nervous system sarcoidosis did not improve the patient's mental status, he was transferred to the Mayo Clinic. Physical examination of the thighs revealed large, well-marginated, indurated, irregularly bordered, violaceous plaques and rare, umbilicated, satellite papules with central hemorrhagic crusts (Fig. 1A). Superficially ulcerated plaques with a similar appearance to the thigh lesions were coalescing around the lower legs (Fig. 1B). A skin biopsy specimen of the thigh demonstrated abundant numbers of encapsulated organisms and minimal inflammatory response (Fig. 2). Skin, blood, and cerebrospinal fluid cultures confirmed the presence of Cryptococcus neoformans. Amphotericin and flucytosine combination therapy was initiated, and steroid dosages were gradually tapered. A test for human immunodeficiency virus was negative. The patient was dismissed from hospital after a complicated 2-month course resulting in improved mental status but progression of the lower extremity ulcerations as a result of polymicrobial infection. Figure 1. (A) Violaceous plaque with satellite papules on thigh. (B) Ulcerating plaques coalescing around leg Figure 2. (A) Sparse inflammatory infiltrate and abundant encapsulated organisms (hematoxylin and eosin; × 20). (B) Cryptococcal organisms (Gomori's methenamine silver; × 40) [source]

Bloodstream infections in hospitalized adults with sickle cell disease: A retrospective analysis

AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2006
Lalita Chulamokha
Abstract Bloodstream infections (BSI) are a common cause of morbidity and mortality in people with sickle cell disease (SCD). In children with SCD, BSI are most often caused by encapsulated organisms. There is a surprising paucity of medical literature that is focused on evaluating SCD adults with BSI. We reviewed the charts of adults with SCD and BSI who were admitted to our hospital between April 1999 and August 2003. During this period a total of 1,692 hospital admissions for 193 adults with SCD were identified and 28% of these patients had at least 1 episode of positive blood cultures, with 69 episodes (17%) considered true BSI. Nosocomial BSI occurred in 34 episodes (49%). Among community BSI, in contrast to BSI in children with SCD, Streptococcus pneumoniae was rarely encountered. A high incidence of staphylococcal BSI in adults with SCD was noted. Twenty-eight percent of all BSI were caused by Staphylococcus aureus, and 15 of 22 isolates (68%) of these were methicillin-resistant. Gram-negative organisms, anaerobes, and yeast were found in 21 (27%), 3 (4%), and 4 isolates (5%) of BSI, respectively. Since over 80% of BSI were considered catheter-related, the higher incidence of gram-positive bacterial infections was likely due to the presence of indwelling central venous catheters. Empiric therapy for adults with SCD suspected of having BSI, especially in the presence of indwelling central venous catheters, should include antimicrobial therapy targeted at gram-positive bacteria (especially MRSA) and gram-negative bacteria. Also, if patients are critically ill, consideration should be made to include antifungal agents. Additional research into the adult SCD population appears necessary to further define this problem. Am. J. Hematol., 2006. © 2006 Wiley-Liss, Inc. [source]