1/14. Pyogenic bacterial infections in humans with IRAK-4 deficiency.Members of the Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) superfamily share an intracytoplasmic Toll-IL-1 receptor (TIR) domain, which mediates recruitment of the interleukin-1 receptor-associated kinase (IRAK) complex via TIR-containing adapter molecules. We describe three unrelated children with inherited IRAK-4 deficiency. Their blood and fibroblast cells did not activate nuclear factor kappaB and mitogen-activated protein kinase (MAPK) and failed to induce downstream cytokines in response to any of the known ligands of TIR-bearing receptors. The otherwise healthy children developed infections caused by pyogenic bacteria. These findings suggest that, in humans, the TIR-IRAK signaling pathway is crucial for protective immunity against specific bacteria but is redundant against most other microorganisms.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
2/14. Pneumococcemia as the presenting feature of multiple myeloma.multiple myeloma is associated with a susceptibility to bacterial infections, specifically for encapsulated organisms such as streptococcus pneumoniae. However, severe bacterial infection as the initial presentation of this disease has been rarely reported. The most common presenting features are anemia, lytic lesions, hypercalcemia, and renal failure. We report two cases of pneumococcal bacteremia as the initial manifestation of an underlying multiple myeloma. The first case is of a 68-year-old woman with pneumococcal pneumonia and bacteremia, presenting with a white blood cell count of 900/microL and mild anemia. Further work-up disclosed monoclonal IgG kappa and 50% plasma cells in bone marrow. Her course was complicated by acute renal failure requiring hemodialysis. The second patient is a 57-year-old man presenting with acute pneumococcal meningitis and bacteremia. Due to prior bacterial epiglottitis, further work-up disclosed IgG lambda monoclonal spike and 40% plasma cells in bone marrow. Both cases responded to antibiotic therapy without complications. These two cases add to the few patients described in the literature with pneumococcemia as the first sign of multiple myeloma. Features that were common in most of these cases, and that should lead to a suspicion of myeloma in an otherwise asymptomatic patient, are S. pneumoniae bacteremia, leukopenia, mild anemia, history of prior bacterial infections, and indirect evidence of a paraproteinemia, such as increased total protein levels with low albumin.- - - - - - - - - - ranking = 0.75keywords = bacterial infection (Clic here for more details about this article) |
3/14. A mixed bacterial infection of a bronchogenic lung cyst diagnosed by PCR.An unusual paediatric case of a bronchogenic cyst infected with both Haemophilus influenzae type b and streptococcus pneumoniae is described, which was detected not by culture of the purulent cyst fluid, but by real-time PCR amplification for several potential pathogens of dna extracted from the fluid.- - - - - - - - - - ranking = 1keywords = bacterial infection (Clic here for more details about this article) |
4/14. Overwhelming pneumococcal bacteraemia in systemic lupus erythematosus.An 18 year old woman presented with fulminant pneumococcal bacteraemia and subsequently died with multisystem organ failure. A search for diseases predisposing to overwhelming encapsulated bacterial infections was negative except for previously undiagnosed systemic lupus erythematosus (SLE). This case emphasises the severity of immune system dysfunction in some patients with SLE, regardless of immunosuppressive treatment. The possible relation between Fc receptor dysfunction and pneumococcal bacteraemia in SLE is discussed.- - - - - - - - - - ranking = 0.25keywords = bacterial infection (Clic here for more details about this article) |
5/14. Increased susceptibility to infection in hypothermic children: possible role of acquired neutrophil dysfunction.The addition of hypothermia to regimens to control cerebral edema in children at our institution has been associated with a substantial incidence of infectious complications. Of the 13 children maintained at 30 degrees C to prevent cerebral edema, 3 developed haemophilus influenzae pneumonia and 2 developed streptococcus pneumoniae sepsis (one with pneumonia). The importance of neutrophil (PMN) function for elimination of bacterial pathogens prompted in vitro studies of PMN function at clinically attainable hypothermic temperatures. neutrophils at 30 degrees C had significantly less ability to migrate towards a chemotactic stimulus (45 /- 10% inhibition; P less than 0.02), to ingest staphylococci (22 /- 5% inhibition; P less than 0.01) and to be metabolically activated as measured by superoxide production (35 /- 10% inhibition; P less than 0.01) or by chemiluminescence (18 /- 8% inhibition; P less than 0.05). These in vitro findings support the clinical observation that persons with decreased body temperature may be at an increased risk for bacterial infections secondary to PMN dysfunction.- - - - - - - - - - ranking = 0.25keywords = bacterial infection (Clic here for more details about this article) |
6/14. C2 deficiency, moderately low IgG2 concentrations and lack of the G2m(23) allotype marker in a child with repeated bacterial infections.C2 deficiency was demonstrated in an 11-year-old boy with a past history of recurrent purulent otitis media, pneumonia, H. influenzae meningitis and S. pneumoniae septicaemia. The major histocompatibility complex haplotypes present, A10, B18, DR2, BF*S, C2*QO, C4*A4, C4*B2 and A28, B18, DR2, BF*S, C2*Q0, C4*A4, C4*B2, were in accord with previous observations in C2 deficiency. The concentrations of C1q, C5, factor B and factor D were in the low normal range and the hemolytic activity of the alternative pathway was slightly decreased. In addition, the patient showed moderately low IgG2 concentrations and lacked the IgG2 subclass marker G2m(23). The findings indicate that the patient's susceptibility to bacterial infections may be due to C2 deficiency in combination with the presence of an IgG allotype associated with impaired antibody responses to carbohydrate antigens.- - - - - - - - - - ranking = 1.25keywords = bacterial infection (Clic here for more details about this article) |
7/14. Primary amyloidosis with diffuse splenic infiltration presenting as fulminant pneumococcal sepsis.This case illustrates a unique clinical presentation of primary systemic amyloidosis, namely, overwhelming pneumococcal sepsis. Although there exists a well-established association between hyposplenism and overwhelming bacterial infection, amyloid replacement of the spleen as a primary cause of the hyposplenism has not been reported. Functional hyposplenism in regard to the effect of the spleen on erythrocytes has been reported in cases of diffuse splenic amyloid infiltration. The patient described had a fulminant course and associated disseminated intravascular coagulation, two clinical features more commonly seen in pneumococcemia occurring in asplenic patients as opposed to patients with normal splenic function. He had no predisposing factors, other than amyloid replacement of the spleen, to account for the development of overwhelming pneumococcemia. The immunologic function of the spleen in protection against overwhelming bacterial infection is briefly discussed.- - - - - - - - - - ranking = 0.5keywords = bacterial infection (Clic here for more details about this article) |
8/14. Inherited deficiency of properdin and C2 in a patient with recurrent bacteremia.A nine-year-old white boy with recurrent pneumococcal bacteremia is described. His serum had no hemolytic activity in either the classic or alternative complement pathways. Absence of classic pathway activity was secondary to a homozygous deficiency of C2. The parents had half-normal levels of C2, compatible with an autosomal recessive mode of inheritance. Measurement of serum properdin levels by radial immunodiffusion and enzyme-linked immunoabsorbent assay revealed a profound deficiency in the patient, normal levels in the father, and half-normal levels in the mother, suggesting X-linked inheritance of the deficiency. Addition of purified properdin to the patient's serum fully reconstituted the alternative pathway function. This patient's unique combination of inherited deficiencies of properdin and C2 is a likely explanation for his susceptibility to bacterial infection.- - - - - - - - - - ranking = 0.25keywords = bacterial infection (Clic here for more details about this article) |
9/14. Pneumococcal cellulitis.A 42-year-old man with pneumonia was admitted for rhabdomyolysis. streptococcus pneumoniae was isolated from the cellulitis surrounding the muscular necrosis. Subcutaneous localisation of S. pneumoniae in the course of a septicemia has never been described, although rhabdomyolysis may be associated with bacterial infections.- - - - - - - - - - ranking = 0.25keywords = bacterial infection (Clic here for more details about this article) |
10/14. rhabdomyolysis associated with pneumococcal sepsis.A case of pneumococcal sepsis associated with rhabdomyolysis is reported. rhabdomyolysis is a rare complication of bacterial infections not directly involving muscle. Eleven cases of rhabdomyolysis associated with bacteremic infections were found in the literature and clinical data are summarized. The pathogenesis and frequency of this association remains unknown.- - - - - - - - - - ranking = 0.25keywords = bacterial infection (Clic here for more details about this article) |
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