Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Occult bacteremia, which precedes many serious infections in children, is most often due Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, or Salmonella species. Diagnosis on the basis of clinical judgment is unreliable, although the presence of certain risk factors may suggest the diagnosis. These risk factors include an age of 3 months to 3 years, a temperature of greater than or equal to 39.0 degrees C, and a white blood cell count of greater than or equal to 15,000/mm3. Although results are delayed, a culture of blood is the only definitive test. Studies suggest that treatment with various antibiotics may be helpful, but that some drugs, particularly orally administered amoxicillin, should not be relied on to eliminate occult bacteremia or prevent its most serious sequela, meningitis.
 ...
PMID:Management of children with occult bacteremia who are treated in the emergency department. 201 44

The phagocytosis of Haemophilus influenzae type b (Hib) by rat macrophages and the intracellular fate of ingested organisms was investigated using an acridine orange-crystal violet assay. There was a correlation between the ability of organisms to survive in macrophages in vitro and their ability to cause invasive disease. Encapsulated Hib survived and replicated within macrophages, whereas capsule-deficient mutants, although more susceptible to phagocytosis, were killed after ingestion. Differences in lipopolysaccharide also affected the ability of encapsulated Hib to survive in macrophages. The presence of viable intracellular organisms in macrophages in vivo may enhance the persistence of bacteremia and may also be important in mediating the entry of Hib into the central nervous system.
 ...
PMID:Relationship between intracellular survival in macrophages and virulence of Haemophilus influenzae type b. 203 2

An isogenic mutant of Haemophilus influenzae type b (Hib) lacking the ability to express the P2 major outer membrane (porin) protein was constructed and characterized in various model systems. Linker insertion mutagenesis of a cloned Hib DNA insert containing the P2 structural gene was used in conjunction with a genetic transformation system to obtain a transformant unreactive with a P2-specific monoclonal antibody. This transformant was shown to lack detectable P2 protein by both protein staining and immunoblot methods. The P2 mutant exhibited a generation time in complex broth medium that was significantly longer than that of the wild-type parent strain. The P2 mutant was also unable to produce detectable bacteremia in infant rats after intraperitoneal challenge, while the wild-type parent strain produced bacteremia in all animals challenged with this strain. Reintroduction of a wild-type copy of the P2 gene into this mutant yielded a transformant strain that had a generation time in vitro identical to that of the wild-type parent strain and that was also fully virulent in the infant rat model. These findings suggest that the ability to synthesize the P2 protein may be necessary but not sufficient for full expression of virulence by this pathogen.
 ...
PMID:Characterization of a mutant of Haemophilus influenzae type b lacking the P2 major outer membrane protein. 216 63

An Escherichia coli clone producing a high-molecular-weight surface antigen of Haemophilus influenzae type b (Hib) was isolated from a library of Hib DNA fragments cloned as lysogens in a lambda replacement vector. The antigen is found in sarcosyl-insoluble outer membrane protein preparations and was produced by all 36 H. influenzae isolates tested. Absorption studies indicated that the antigen is a surface determinant on all isolates tested. Antibodies to the antigen (D15) were found in eight of nine convalescent-phase sera from children with invasive Hib infection. Affinity-purified antibodies prepared against the cloned antigen gave protection against the development of bacteremia in a rat pup model.
 ...
PMID:Expression in Escherichia coli of a high-molecular-weight protective surface antigen found in nontypeable and type b Haemophilus influenzae. 218 12

Haemophilus influenzae is a common pathogen in infections of the head and neck. Although most mucosal infections (otitis media, sinusitis) are caused by non-encapsulated organisms, invasive disease (meningitis, periorbital cellulitis, epiglottis) is caused by type B encapsulated organisms. Bacteremia is common with H. influenzae type B infections and therapy with parenteral antibiotics is indicated. A vaccine against H. influenzae type B given at 18 months of age is now part of the routine childhood immunization schedule. Chemoprophylaxis with rifampin is recommended for at-risk contacts of patients with invasive type B disease. This review examines the bacteriology, pathogenesis, immunity, and disease manifestations of H. influenzae. Appropriate diagnostic methods, antimicrobial therapy, and recommended chemoprophylaxis and immunoprophylaxis are presented.
 ...
PMID:Haemophilus influenzae type B and its role in diseases of the head and neck. 219 72

Haemophilus influenzae type b is a major cause of bacterial meningitis and other invasive diseases in children under four years of age. One surface antigen, the type b capsular polysaccharide, polyribosylribitol phosphate (PRP), is a primary virulence factor of the organism. Antibody directed against PRP is protective; however, the purified polysaccharide is poorly immunogenic in young children. Polysaccharide-protein conjugate vaccines have been prepared which are significantly more immunogenic and efficacious in young children compared to the plain polysaccharide vaccine. Noncapsular surface antigens may also play a role in the virulence of H. influenzae. Some mutants (or phase variants) which differ in lipooligosaccharide (LOS) structure exhibit decreased virulence in the infant rat model of bacteremia. Proteins including the IgA protease, pili, a 98K outer membrane protein (OMP) as well as OMPs P1, P2 and P6 have also been examined in considerable detail, but whether they have a role in the virulence of the organism remains to be determined. However, antibody directed against the 98K OMP as well as P1, P2 and P6 is protective in the infant rat model of bacteremia. The role of antibody directed against LOS epitopes in protection is less clear, due at least in part, to phase variation in LOS antigens. Characterization of one surface antigen of H. influenzae type b, the capsular polysaccharide, already has led to the prevention of many cases of Haemophilus disease. Characterization of the noncapsular antigens together with a more detailed understanding of the mechanisms of virulence, most likely will permit development of even better vaccines, and possibly better treatment modalities, in the future.
 ...
PMID:Haemophilus influenzae: surface antigens and aspects of virulence. 219 7

Five cases of bacteremic infections due to Haemophilus influenzae type f in adults are described, and previous reports of type f disease in nonpediatric patients are reviewed. Respiratory tract infections were most common in our series (two cases of pneumonia, one of epiglottitis, and one of nosocomial septicemia probably resulting from aspiration pneumonitis). All of these patients had factors predisposing them to respiratory tract infections, e.g., neurologic disease, congestive heart failure, or cigarette smoking. A fifth patient, who was bacteremic without an apparent primary focus, had dysgammaglobulinemia. Six episodes of bacteremia occurred in five patients; 11 of 13 cultures of blood obtained before parenteral antibiotic therapy were positive. All isolates were biotype I and susceptible to ampicillin. Antibiotic therapy was curative in cases of proved respiratory tract infection but failed in the setting of nosocomial septicemia, perhaps because of delayed initiation. The brevity of antibiotic treatment of the cryptogenic bacteremia permitted infection of a prosthetic vascular graft and recurrent bacteremia. Graft removal and repeated antibiotic therapy were curative.
 ...
PMID:Bacteremic disease due to Haemophilus influenzae capsular type f in adults: report of five cases and review. 220 Oct 66

Buccal cellulitis (BC) is an innocuous appearing infection of the cheek that is found in children and has a high incidence of concomitant bacteremia. Typically, the child is younger than 12 months and has a 2 to 8 hour prodrome of coryza and fever before developing the cellulitis on the cheek. A purplish hue on the cellulitic region is highly suggestive of Hemophilus influenzae bacteremia. The differential diagnosis is reviewed. A complete blood count, blood culture, and cellulitis aspirate culture, should be obtained on all patients with BC. Meningitis may be present despite the lack of meningeal signs. A lumbar puncture should be performed on all children at risk for bacteremic BC. The vast majority of these children are bacteremic and require parenteral antibiotics. A typical case of BC is presented and its management is reviewed.
 ...
PMID:Buccal cellulitis. 222 2

We undertook a study of 414 bacteremic patients (167 with Haemophilus influenzae and 247 with Streptococcus pneumoniae bacteremia) to evaluate their clinical presentation, laboratory and clinical results, and subsequent outcomes. Patients with H influenzae bacteremia were more likely to have soft-tissue foci, poorer clinical appearance at presentation, and be at higher risk for subsequent serious focal infections, persistent bacteremia, and subsequent hospital admissions than patients with S pneumoniae. Patients with H influenzae bacteremia had a 21.1-fold increase in risk of meningitis (95% confidence interval [CI] of 3.8 to 78.0) compared with those with S pneumoniae. The odds ratio for initial lumbar puncture was 5.25 (95% CI [1.1-23.6]). Ambulatory patients treated with antibiotics at presentation were less likely to develop new serious soft-tissue infections, persistent bacteremia, or to require subsequent hospital admissions than untreated patients. The effect of treatment was greater for patients with S pneumoniae than those with H influenzae. Careful follow-up and reevaluation of patients with presumptive bacteremia is essential because treated and untreated patients can still develop serious soft-tissue infections.
 ...
PMID:Bacteremia in an ambulatory setting. Improved outcome in children treated with antibiotics. 223 57

Hemoglobinopathies are a major public health problem in Saudi Arabia. We studied the effect of splenectomy in 16 Saudi Arabian children with compound hemoglobinopathies. Seven patients no longer require regular blood transfusions, and transfusion requirements were decreased by 30 to 60% in the other eight patients. Three patients whose heights and weights were below the 5th percentile before splenectomy reached the 25th percentile 1 year after the surgery. In spite of preoperative pneumococcal vaccination and the penicillin prophylaxis after the surgery, one patient died of Haemophilus influenzae Group B bacteremia, and three others had six episodes of pneumonia.
 ...
PMID:Splenectomy in compound heterozygous hemoglobinopathies in Saudi Arabia. 224 Apr 76


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>