Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ampicillin resistance among strains of Hemophilus is usually due to production of beta-lactamase. This paper reports the isolation of a strain of H. parainfluenzae resistant to ampicillin with no detectable beta-lactamase or amidase activity. The organism, isolated from the blood of a patient who had aortic valve endocarditis, gave a zone diameter consistent with ampicillin sensitivity when tested by disc diffusion in Mueller-Hinton agar supplemented with 1% IsoVitaleX and 1% hemoglobin. Broth dilution testing in Levinthal medium, however, revealed the following minimal inhibitory cencentrations: ampicillin, 32 micrograms/ml; penicillin, 256 micrograms/ml; methicillin, 128 micrograms/ml; carbenicillin, 128 micrograms/ml; and cephalothin and chloramphenicol, 1.0 micrograms/ml. The results of acidimetric, iodometric, and chromogenic cephalosporin methods for detection of beta-lactamase were negative. Beta-lactamase activity could not be demonstrated in cell sonicates or induced by growth of the cells in antibiotic-containing medium. In addition, no extracellular degradation of either ampicillin or penicillin could be demonstrated.
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PMID:Ampicillin resistance in Hemophilus parainfluenzae. 696 94

The importance of viridans streptococci as agents of serious extra-oral diseases, including endocarditis, is now recognized. We have tested the hypothesis that the ability to utilize sialic acid as a nutrient source may play a role in the proliferation of these organisms. The type strains of the 15 presently recognized species of viridans streptococci and two clinical isolates-S. oralis (AR3), isolated from a patient with infective endocarditis, and S. intermedius (UNS35), a brain abscess isolate-were studied for their ability to utilize sialic acid. Only S. oralis, S. sanguis, S. gordonii, S. mitis ("oralis group") S. intermedius, S. anginosus, S. constellatus ("milleri group"), and S. defectivus ("nutritionally variant group") were able to use sialic acid (N-acetylneuraminic acid) efficiently as a sole carbon source. Formate, acetate, and ethanol were produced as the major metabolic end-products of sialic acid metabolism, while corresponding glucose-grown cultures produced lactate as the major metabolic end-product. Utilization of sialic acid was independent of the production of sialidase. Cell-free extracts of sialic acid-grown cultures expressed elevated levels of N-acetylneuraminate pyruvate-lyase (NPL; the first enzyme in the intracellular catabolism of sialic acid) and N-acetylglucosamine-6-phosphate (GlcNAc-6-P) deacetylase and glucosamine-6-phosphate (GlcN-6-P) deaminase (enzymes involved in the intracellular catabolism of N-acetylglucosamine). These activities were repressed by growth in the presence of glucose. The intracellular fate of sialic acid, after cleavage by NPL into N-acetylmannosamine (ManNAc) and pyruvate, is uncertain, but the elevated levels of GlcNAc-6-P deacetylase and GlcN-6-P deaminase in sialic acid-grown cells suggest that phosphorylation and isomerization are possible steps in the metabolism of ManNAc to generate an intermediate common to the pathway of N-acetylglucosamine metabolism. The species of viridans streptococci that have the ability to utilize sialic acid are those most commonly associated with extra-oral diseases, and this ability is likely to play a role in the persistence and survival of these infecting organisms in vivo.
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PMID:Utilization of sialic acid by viridans streptococci. 890 24

Staphylococcus aureus can cause bloodstream infections associated with infective endocarditis (IE) and disseminated intravascular coagulopathy (DIC). Both complications involve platelets. In view of an increasing number of antibiotic-resistant strains, new approaches to control systemic S. aureus infection are gaining importance. Using a repertoire of 52 recombinant S. aureus proteins in flow cytometry-based platelet activation and aggregation assays, we identified, in addition to the extracellular adherence protein Eap, three secreted staphylococcal proteins as novel platelet activating proteins. Eap and the chemotaxis inhibitory protein of S. aureus (CHIPS), the formyl peptide receptor-like 1 inhibitory protein (FLIPr) and the major autolysin Atl induced P-selectin expression in washed platelets and platelet-rich plasma. Similarly, AtlA, CHIPS and Eap induced platelet aggregation in whole blood. Fluorescence microscopy illustrated that P-selectin expression is associated with calcium mobilization and re-organization of the platelet actin cytoskeleton. Characterization of the functionally active domains of the major autolysin AtlA and Eap indicates that the amidase domain of Atl and the tandem repeats 3 and 4 of Eap are crucial for platelet activation. These results provide new insights in S. aureus protein interactions with platelets and identify secreted proteins as potential treatment targets in case of antibiotic-resistant S. aureus infection.
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PMID:Secreted Immunomodulatory Proteins of Staphylococcus aureus Activate Platelets and Induce Platelet Aggregation. 2955 97

Peptidoglycan (PGN) recognition proteins (PGLYRPs) are a highly conserved group of host defense proteins in insects and mammals that sense bacterial cell wall PGN and act bactericidally or cleave PGN by amidase function. Streptococcus (S.) pneumoniae is one of the top five killers worldwide and causes, e.g., pneumonia, endocarditis, meningitis and sepsis. S. pneumoniae accounts for approximately 1.5-2 million deaths every year. The risk of antibiotic resistance and a general poor prognosis in young children and elderly people have led to the need for new treatment approaches. To the best of our knowledge, there is no report on the relevance of PGLYRP2 in lung infections. Therefore, we infected mice deficient for PGLYRP2 transnasally with S. pneumoniae and examined the innate immune response in comparison to WT animals. As expected, PGLYRP2-KO animals had to be sacrificed earlier than their WT counterparts, and this was due to higher bacteremia. The higher bacterial load in the PGLYRP2-KO mice was accomplished with lower amounts of proinflammatory cytokines in the lungs. This led to an abolished recruitment of neutrophils into the lungs, the spread of bacteria and the subsequent aggravated course of the disease and early mortality of the PGLYRP2-KO mice. These data suggest a substantial role of PGLYRP2 in the early defense against S. pneumoniae infection, and PGLYRP2 might also affect other infections in the lungs.
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PMID:Peptidoglycan Recognition Protein 2 Regulates Neutrophil Recruitment Into the Lungs After Streptococcus pneumoniae Infection. 3083 60