Bacterial adherence is an important event in the initiation of many infectious processes, the ability of a given bacterial strain to adhere to a mucosal or endocardial surface or endovascular foreign body is an important factor determining localization of infection. Lipotoichoic acid has been found to mediate the adherence of gram- positive cocci to epithelial cells and mucosal surfaces and to mediate the adherence of gram-positive cocci to heart valves. Lipoteichoic acid has been found to bind to fibronectin and this protein has been postulated to be the adherence site on pharyngeal epithelial cells for Streptococcus pyogenes and on heart valves covered with platelets and fibrin for endocarditis strains of gram- positive cocci. The presence or absence of fibronectin has been associated with predominance of one microorganism or the other as a colonizer of the pharynx. There have been few studies on adherence of bacteria to endovascular devices and the mechanisms for such interaction await definition. The general hypothesis of this renewal proposal is that the bacterial strain receptor surface interaction is mediated by ligands and that there are receptor sites at the receptor surface which can be defined. Once the interaction is defined, measures can be taken to prevent it from happening. In the revised renewal we plan to: 1. Determine the role of lipoteichoic acid and fibronectin on the colonization (adherence) of bacterial endocarditis strains on the rabbit endocarditis model. Animals immunized with lipoteichoic acid, or with peptidoglycan (LTA free) or non-immunized animals will be challenged with different bacterial strains. The bacterial strains will be modified with anti-lipoteichoic acid antibody, antibiotics, etc. and adherence of bacteria surface with fibronectin will be studied. The quantitation of fibronectin at the adherence site will be expanded. 2. Study adherence of strains recovered from infections located at intravenous infussion sites, including S. aureus, S. epidermidis, E. coli, K. pneumoniae and P. aeruginosa to catheter segments of different chemical composition. To study adherence after surface modification with albumin, platelet rich plasma, antibodies bone cements, etc. To define the role of different ligands including lipoteichoic acid on such adherence and of possible receptors like fibronectin as the adherence site.

Project Start
Project End
Budget Start
Budget End
Support Year
17
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Puerto Rico Rio Piedras
Department
Type
DUNS #
City
San Juan
State
PR
Country
United States
Zip Code
00931
Rodriguez, A D; Ramirez, C; Shi, Y P (2000) The cumbiasins, structurally novel diterpenes possessing intricate carbocyclic skeletons from the West Indian sea whip Pseudopterogorgia elisabethae (Bayer). J Org Chem 65:6682-7
Rodriguez, A D; Ramirez, C (2000) A marine diterpene with a novel tetracyclic framework from the West Indian gorgonian octocoral Pseudopterogorgia elisabethae. Org Lett 2:507-10
Richardson, P L; Rodriguez, A D; Boulanger, A et al. (1998) Methoxyamericanolide B. Acta Crystallogr C 54 ( Pt 1):66-8
Figueroa, I D; el Baraka, M; Quinones, E et al. (1998) A fluorescent temperature probe based on the association between the excited states of 4-(N,N-dimethylamino)benzonitrile and beta-cyclodextrin. Anal Chem 70:3974-7
Rodriguez, A D; Soto, J J (1998) Pseudopterane and norcembrane diterpenoids from the Caribbean sea plume Pseudopterogorgia acerosa. J Nat Prod 61:401-4
Rodriguez, A D; Acosta, A L (1998) New cembranolides from the gorgonian Eunicea succinea. J Nat Prod 61:40-5
Rodriguez, A D; Cobar, O M; Padilla, O L et al. (1997) Calyxamines A and B, novel piperidine alkaloids from the Caribbean sea sponge Calyx podatypa. J Nat Prod 60:1331-3
Cobar, O M; Rodriguez, A D; Padilla, O L (1997) A new steroidal glycoside from a Caribbean gorgonian, Eunicea sp.1. J Nat Prod 60:1186-8
Rodriguez, A D; Gonzalez, E; Huang, S D (1997) Euniciniatin. Acta Crystallogr C 53 ( Pt 3):311-3
Rodriguez, A; Acosta, A L (1997) New cembranoid diterpenes and a geranylgeraniol derivative from the common Caribbean sea whip Eunicea succinea. J Nat Prod 60:1134-8

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