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P Ferrieri

Publications and source records attributed to P Ferrieri.

At least 37 records · Page 2Linked to original sources
PubMed1997

Prevention of bacterial endocarditis. Recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Antibiotic Prophylaxis↗
PubMed1997

Surface protein expression in group B streptococcal invasive isolates.

Results from characterization of 211 GBS isolates from early-onset disease indicated that serotypes Ia, III and V accounted for almost 80% of the isolates, and that alpha was the protein most often expressed. Each of the common polysaccharide types had a characteristic predominant protein expression pattern: alpha for Ia, R4 for type III and R1+R4 for type V isolates. Expression of alpha protein was always mutually exclusive of R proteins. The presence of more than one species of R by a given isolate was confirmed by IEP. In addition, PAGE/WB studies verified the multiple MW forms of R1, and the variation from strain to strain in the highest form of R4 that we had previously reported. Our data not only showed the great complexity of the GBS cell surface but also demonstrated the advantage of using both type polysaccharides and surface-localized proteins as markers for characterization of GBS strains.

Bacteremia↗
PubMed1997

Prevention of bacterial endocarditis: recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the Infectious Diseases Society of America, the American Academy of Pediatrics, and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis, and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using the root words endocarditis, bacteremia, and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the US Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate-, and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered; and (6) for gastrointestinal or genitourinary procedures, the prophylactic regimens have been simplified. These changes were instituted to more clearly define when prophylaxis is or is not recommended, improve practitioner and patient compliance, reduce cost and potential gastrointestinal adverse effects, and approach more uniform worldwide recommendations.

Anti-Bacterial Agents↗
PubMed1997

Cloning of the glutamine synthetase gene from group B streptococci.

The glnA gene from the human pathogen Streptococcus agalactiae was cloned from a genomic library prepared with the lambda phage vector lambdaDASHII. A 4.6-kb DNA fragment of one of the recombinant phages was subcloned in pUC18. This Escherichia coli clone expressed a 52-kDa protein encoded by a 1,341-bp open reading frame. The nucleotide sequence of the open reading frame and the deduced amino acid sequence shared a significant degree of homology with the sequences of other glutamine synthetases (GS). The highest homology was between our deduced protein and GS of gram-positive bacteria such as Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus. Plasmids with the cloned streptococcal glnA were able to complement E. coli glnA mutants grown on minimal media. Rabbit antisera to streptococcal GS recombinant protein recognized not only the recombinant protein but also a similar-sized band in mutanolysin extracts of all group B streptococcal strains tested, regardless of polysaccharide type or surface protein profile. The amino acid sequence of the deduced protein had similarities to other streptococcal cell-surface-bound proteins. The possible functional role of the immunological features of streptococcal GS is discussed.

Amino Acid Sequence↗
PubMed1997

Prevention of bacterial endocarditis: recommendations by the American Heart Association.

OBJECTIVE: To update recommendations issued by the American Heart Association last published in 1990 for the prevention of bacterial endocarditis in individuals at risk for this disease. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association for their expertise in endocarditis and treatment with liaison members representing the American Dental Association, the infectious Diseases Society of America, the American Academy of Pediatrics and the American Society for Gastrointestinal Endoscopy. EVIDENCE: The recommendations in this article reflect analyses of relevant literature regarding procedure-related endocarditis, in vitro susceptibility data of pathogens causing endocarditis, results of prophylactic studies in animal models of endocarditis and retrospective analyses of human endocarditis cases in terms of antibiotic prophylaxis usage patterns and apparent prophylaxis failures. MEDLINE database searches from 1936 through 1996 were done using root words endocarditis, bacteremia and antibiotic prophylaxis. Recommendations in this document fall into evidence level III of the U.S. Preventive Services Task Force categories of evidence. CONSENSUS PROCESS: The recommendations were formulated by the writing group after specific therapeutic regimens were discussed. The consensus statement was subsequently reviewed by outside experts not affiliated with the writing group and by the Science Advisory and Coordinating Committee of the American Heart Association. These guidelines are meant to aid practitioners but are not intended as the standard of care or as a substitute for clinical judgment. CONCLUSIONS: Major changes in the updated recommendations include the following: (1) emphasis that most cases of endocarditis are not attributable to an invasive procedure; (2) cardiac conditions are stratified into high-, moderate- and negligible-risk categories based on potential outcome if endocarditis develops; (3) procedures that may cause bacteremia and for which prophylaxis is recommended are more clearly specified; (4) an algorithm was developed to more clearly define when prophylaxis is recommended for patients with mitral valve prolapse; (5) for oral or dental procedures the initial amoxicillin dose is reduced to 2 g, a follow-up antibiotic dose is no longer recommended, erythromycin is no longer recommended for penicillin-allergic individuals, but clindamycin and other alternatives are offered.

Algorithms↗
PubMed1997

Laboratory evaluation of compomers in Class V restorations.

PURPOSE: To evaluate the in vitro microleakage, marginal morphology and resin tags configuration of a compomer restorative material (Dyract) alternatively used with two different bonding systems (Dyract-PSA and Prime & Bond 2.0). A hybrid resin composite (Prisma TPH) used with two different bonding systems (Universal Bond 3 and ProBond) was evaluated as control material. MATERIALS AND METHODS: Class V non-retentive restorations were made in vitro at CEJ and divided at random in four groups: Dyract/PSA, Dyract/P&B 2.0, Prisma TPH/UB3, and Prisma TPH/ProBond. The latter two groups were as controls. After finishing the restorations, an impression material was used to obtain an epoxy resin replica for SEM analysis of margin alterations. Percentage of perfect margin was evaluated under SEM and calculated comparing it with the width/length of restoration margin. The presence of gaps, enamel fractures and other marginal alterations was also recorded inspecting under SEM replicas. Each tooth was then immersed for 24 hours in erythrosin B dye solution at room temperature and evaluated at superficial margins as marginal leakage (ML) for dye penetration. Each sample was then longitudinally sectioned, and leakage was expressed as % dye penetration of the total cavity wall, longitudinal leakage (LL). Finally, each tooth was dissolved (10%H3PO4 for 48 hours and NaOCl solution for additional 24 hours) to leave only the resin restoration. The internal walls of each restoration were then inspected by SEM at x1,000-15,000 to evaluate the presence of resin-dentin infiltrated layer (hybrid layer) and to calculate the ability of primer/bonding to infiltrate peritubular dentin and to form resin tags. RESULTS: Gap widths were 2-6 microns at dentin and lower at enamel. Several enamel fractures along the margin were observed. Resin tags were observed only in deeper dentin. Only Prime & Bond 2.0/Dyract formed resin tags at medium-superficial dentin. The length of resin tags ranged from 1-6 microns for Dyract-PSA primer to 100 microns for Prime & Bond 2.0. Marginal and longitudinal leakage was observed both at dentin and enamel levels. The best dentin seal was obtained with Prime & Bond 2.0/Dyract, while enamel seals were equivalent with both bonding systems (P > 0.05). No correlations were demonstrated between leakage and SEM observations.

Adult↗
PubMed1996

Diagnosis of microsporidial keratitis by confocal microscopy and the chromatrope stain.

PURPOSE: To illustrate the value of confocal microscopy and chromatrope stain in the diagnosis of microsporidial keratitis. METHODS: In vivo confocal microscopy was performed on a man with the human immunodeficiency virus who had severe bilateral epithelial keratitis refractory to topical antibacterial medications. The results were compared to conjunctival scrapings stained with the chromatrope-based Weber stain. RESULTS: Confocal microscopy demonstrated many small, intraepithelial opacities of the corneal epithelium, which were suggestive of Microsporidia. Results of the chromatrope stain of conjunctival scrapings confirmed the diagnosis of microsporidial keratitis. CONCLUSIONS: Rapid diagnosis allowed prompt initiation of topical fumagillin, which permitted rapid, long-term control of the symptoms of microsporidial keratitis.

AIDS-Related Opportunistic Infections↗
PubMed1996

Molecular diversity among the trypsin resistant surface proteins of group B streptococci.

The alpha (alpha) component of the c protein and R proteins are trypsin resistant, but antigenically distinct, proteins on the cell surface of some but not all strains of group B streptococci (GBS). These two classes of proteins, along with the group and type polysaccharide, can be used to characterize strains of GBS. Four species of R protein (R1 through R4) have been described. We studied trypsin extracts from numerous strains of GBS by immunodiffusion in agarose and polyacrylamide gel electrophoresis/Western blot. Sera monospecific for alpha, R1 and R4 were used to immunoprecipitate/blot the proteins. The molecular weight of the blotted proteins was determined. Although by immunodiffusion the proteins within a class were identical to each other, great heterogeneity in size and blotting pattern was found within each class. Variation was independent of the polysaccharide serotype. Multiple molecular weight species were seen for alpha, R1 and R4 proteins. For a given strain, the various forms of alpha or R1 appeared to form a multiple size ladder; those of R4 were fewer and closer in size. The highest form of alpha ranged from 85 to 170 kDa, with 45 kDa being the highest form for some rare GBS strains. For R4 the predominant and highest form varied from 84 to 197 kDa, whereas some strains with R1 had the highest form over 200 kDa. Our results indicated that despite similarities, there is great diversity among the alpha, R1 and R4 trypsin resistant proteins of GBS.

Animals↗
PubMed1996

Immune responses to the R4 protein antigen of group B streptococci and its relationship to other streptococcal R4 proteins.

The R antigen, a trypsin-resistant protein observed in group A, C, F, G, and L streptococci, has also been found in group B streptococci (GBS). Although four species of the R antigen have been described for GBS, the R4 protein is the most prevalent in GBS isolates recovered from humans. This study examined the prevalence of antibodies against the R4 antigen by Western blot (immunoblot) (WB) in sera from 40 mothers colonized with GBS serotype II and III and from 26 noncolonized mothers; 92.5% of the colonized mothers had anti-R4 antibodies, compared with 54% of the noncolonized mothers (P < 0.001). Findings of antibodies in neonatal cord sera (n = 14) were concordant with maternal results by WB analysis for 71% of mother-infant pairs colonized with serotype II and for 57% of pairs colonized with serotype III. Of mothers known to be colonized with type II/R4 or III/R4, 100% (n = 12) had antibody against R4 by WB. This study also evaluated the prevalence of antibody to the GBS R4 antigen in 48 sera from individuals with high and low group A streptococcal anti-DNase B titers. Of those individuals with an anti-DNase B titer of > 640, 64% had a positive WB for anti-R4 antibody, compared with 30% of individuals with low anti-DNase B titers (P < 0.05). The R4 antigen of GBS had immunologic identity to the R4 antigen of group A streptococci. Overall, the findings suggested that antibodies to the streptococcal R4 antigen were commonly present in GBS-colonized mothers and that transplacental passage of these antibodies occurred. The presence of antibody to R4 in non-GBS-colonized individuals may be due to immunologic responses to past exposure to the R antigen present in GBS or other streptococcal groups.

Antigens, Bacterial↗
PubMed1996

Conservation of the C5a peptidase genes in group A and B streptococci.

The chromosome of group B streptococci (GBS) contains a gene which is related to the C5a peptidase gene (scpA) of group A streptococci (GAS). scpA encodes a surface-associated peptidase (group A streptococcal C5a peptidase [SCPA]) which specifically cleaves C5a, a major chemoattractant generated in serum by activation of complement. The entire scpA-like gene (scpB) was cloned from a GBS strain and sequenced. The gene encodes an open reading frame of 3,450 bp, which corresponds to a deduced protein (SCPB) of 1,150 amino acids with a molecular weight of 126,237 Da. Nucleotide and deduced amino acid sequences of SCPB were found to be highly homologous to those of SCPAs from GAS. Unexpectedly, scpA12 is more similar to scpB than to another GAS gene, scpA49. The sequence 5' of the open reading frame, including transcription start and a termination site in the signal sequence, is also similar to that of scpA, although less conserved than the coding sequences. The near identity of GBS and GAS peptidases is consistent with horizontal transmission of the scp gene between these species. Recombinant SCPB was expressed in Escherichia coli by using the expression vector plasmid pGEX-4T-1 and was shown to be identical in size to the enzyme extracted from the parental GBS strain 78-471.

Adhesins, Bacterial↗
PubMed1995

Antibiotic treatment of adults with infective endocarditis due to streptococci, enterococci, staphylococci, and HACEK microorganisms. American Heart Association.

OBJECTIVE: To provide guidelines for the treatment of endocarditis in adults caused by the following microorganisms: viridans streptococci and other streptococci, enterococci, staphylococci, and fastidious gram-negative bacilli of the HACEK group. PARTICIPANTS: An ad hoc writing group appointed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young. EVIDENCE: Published studies of the treatment of patients with endocarditis and the collective clinical experience of this group of experts. CONSENSUS PROCESS: The recommendations were formulated during meetings of the working group and were prepared by a writing committee after the group had agreed on the specific therapeutic regimens. The consensus statement was subsequently reviewed by standing committees of the American Heart Association and by a group of experts not affiliated with the working group. CONCLUSIONS: Sufficient evidence has been published that recommendations regarding treatment of the most common microbiological causes of endocarditis (viridans streptococci, enterococci, Streptococcus bovis, staphylococci, and the HACEK organisms) are justified. There are insufficient published data to make a strong statement regarding the efficacy of specific therapeutic regimens for cases of endocarditis due to microorganisms that uncommonly cause endocarditis. As a useful aid to the practicing clinician, the writing group developed a consensus opinion regarding management of endocarditis caused by the most commonly encountered microorganisms and regarding those cases due to infrequent causes of endocarditis.

Adult↗
PubMed1995

Dentine permeability and bond quality as affected by new bonding systems.

OBJECTIVES AND METHODS: The relationship between dentine bonding and the condition of dentine for four dentine bonding systems (All Bond 2, Clearfil Liner Bond, Scotchbond MP and XR Bond) has been examined. Different dentine conditions were evaluated and correlated with adhesion values. Dentine permeability was calculated using a hydraulic pressure apparatus working under physiological pulpal pressure (6.9 kPa), while remaining dentine thickness (RDT) was measured using pincer calipers. Scanning electron microscopic (SEM) examinations were effected to analyse dentine morphology. These evaluations were considered as an index of the condition of dentine. Shear bond strength tests were used to evaluate adhesion. Dentine samples after the bonding systems application were stored for 24 h under pulpal pressure before bond strength was tested. RESULTS: Scanning electron microscopy examinations indicated that the application of bonding system conditioners caused the removal of smear layer, the demineralization of dentine and the formation of a layer of collapsed collagen fibrils in the intertubular and peritubular dentine. Primers were able to infiltrate the collagen fibrils. A layer of resin infiltrated/reinforced dentine (the so-called 'hybrid layer') was observed for All Bond 2, Clearfil Linear Bond and Schotchbond MP. CONCLUSIONS: Significant correlations were observed only for XR Bond, which proved very sensitive to RDT and dentine permeability despite the presence of smear layer. The other three materials did not show any correlation with dentine conditions. By contrast they showed the highest bond values.

Acid Etching, Dental↗
PubMed1995

Stool carriage, clinical isolation, and mortality during an outbreak of vancomycin-resistant enterococci in hospitalized medical and/or surgical patients.

During a nosocomial outbreak of infection due to vancomycin-resistant enterococci (VRE), rectal swabs that were collected weekly were used to identify and isolate VRE carriers. Over 6 months, 1,458 stool specimens from 724 high-risk patients were cultured, and 187 VRE isolates were recovered from 61 patients; 96% of the isolates were Enterococcus faecium. VRE tended to be isolated from clinical specimens from patients identified as VRE carriers by stool surveillance (P < .01). However, isolation of VRE from surveillance cultures preceded clinical isolation for only approximately 50% of the patients from whom a clinical VRE isolate was recovered. Mortality was greater (P < .05) among patients from whom a clinical VRE isolate was recovered than among patients from whom VRE was isolated only by stool surveillance. The mortality (1[17%] of 6) among patients for whom VRE was isolated from blood was similar to that (10 [27%] of 37) among patients for whom vancomycin-susceptible enterococcus was isolated from blood (P = .97). Despite prompt initiation of contact precautions for VRE carriers, the incidence of fecal carriage of VRE remained approximately 8% among this patient population for the 6-month period of the study.

Adult↗
PubMed1995

Treatment of acute streptococcal pharyngitis and prevention of rheumatic fever: a statement for health professionals. Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young, the American Heart Association.

Primary prevention of acute rheumatic fever is accomplished by proper identification and adequate antibiotic treatment of group A beta-hemolytic streptococcal (GAS) tonsillopharyngitis. Diagnosis of GAS pharyngitis is best accomplished by a throat culture. Penicillin (either oral penicillin V or injectable benzathine penicillin) remains the treatment of choice, because it is cost effective, has a narrow spectrum of activity, has long-standing proven efficacy, and GAS resistant to penicillin have not been documented. Various macrolides, oral cephalosporins, and other beta-lactam agents are acceptable alternatives, particularly in penicillin-allergic individuals. The individual who has had an attack of rheumatic fever is at very high risk of developing recurrences after subsequent GAS pharyngitis and needs continuous antimicrobial prophylaxis to prevent such recurrences (secondary prevention). The duration of prophylaxis depends on the number of previous attacks, the time lapsed since the last attack, the risk of exposure to streptococcal infections, the age of the patient, and the presence or absence of cardiac involvement. Penicillin is again the agent of choice for secondary prophylaxis, but sulfadiazine or erythromycin are acceptable alternatives in penicillin-allergic individuals. This report is an update of a 1988 statement by this committee. It expands on the previous statement, includes more recent therapeutic modalities, and makes more specific recommendations for the duration of secondary prophylaxis.

Acute Disease↗
PubMed1995

[A morphological analysis and assessment of the dentinal permeability of detergents and liners].

In this study we evaluated the morphological aspect at scanning electron microscopy (SEM) and the degree of permeability of the dentinal surface after treatment with different detergent solutions, liners and cleansers. In particular we tested new potassium oxalate products. The results obtained with in vitro tests showed that many detergents, liners and cleansers are able to maintain almost unaltered the smear layer, causing small modifications for the diameter and the number of dentinal tubules which are partially exposed. The materials we used were able to deterge the dentinal surface, as demonstrated by SEM analysis, but one of them was able to stabilize and to protect the surface. All tested products, except potassium oxalate, caused an increase in dentinal permeability, proving to exercise a potential by damaging action towards the dentine and the pulpal tissue. Only DDS was able to reduce the dentinal permeability, causing the formation of calcium oxalate precipitates which occlude the dentinal tubules.

Dentin↗