Disease relevance of Pneumococcal Infections

• The ability of antibodies present in normal serum to support pneumococcus-induced serotonin release suggests that the thrombocytopenia seen in pneumococcal infection may at least in part be caused by pneumococcal antigen-antibody complexes [1].
• Because secondary pneumococcal infections occurring shortly after recovery from influenza are associated with enhanced inflammatory responses, we hypothesized that IDO activity contributes to the enhanced response to bacterial challenges in mice previously infected with influenza virus [2].
• Intranasal immunization with pneumococcal polysaccharide conjugate vaccines with nontoxic mutants of Escherichia coli heat-labile enterotoxins as adjuvants protects mice against invasive pneumococcal infections [3].
• Use of polymerase chain reaction to identify pneumococcal infection associated with hemorrhage and shock in two previously healthy young children [4].
• The recombinant PspA in this phage lysate elicited protection against pneumococcal infections with three strains of two different capsular serotypes [5].

High impact information on Pneumococcal Infections

• Although the protective efficacy of pneumococcal polysaccharide vaccine has been demonstrated in randomized trials in young African gold miners, there has been controversy about its efficacy in older Americans at risk for serious pneumococcal infections [6].
• We used MARCO-deficient mice to directly test the in vivo role of AM MARCO in innate defense against pneumococcal infection and environmental particles [7].
• SIGN-R1 contributes to protection against lethal pneumococcal infection in mice [8].
• Protective humoral response against pneumococcal infection in mice elicited by recombinant bacille Calmette-Guérin vaccines expressing pneumococcal surface protein A [9].
• Thus the opsonic properties of CRP previously described may be related to protection against pneumococcal infection [10].

Chemical compound and disease context of Pneumococcal Infections

• Infection of a subcutaneous air pouch with penumococci produced eosinopenia within 6 h after inoculation, but there was no rise in serum corticosterone during the first 12 h of the pneumococcal infection [11].
• At present, the most useful drugs for the management of resistant pneumococcal infections are cefotaxime, ceftriaxone, vancomycin, and rifampin [12].
• These results support the newly established ceftriaxone/cefotaxime MIC breakpoints (cutoffs) for nonmeningeal pneumococcal infections [13].
• The effect of cephalosporin resistance on mortality in adult patients with nonmeningeal systemic pneumococcal infections [13].
• In the case of other laboratory abnormalities, such as albumin, creatinine, and bilirubin, it was difficult to determine which abnormality might have predisposed to pneumococcal infection and which might have resulted from it [14].

Biological context of Pneumococcal Infections

• In our present report we have produced insertional inactivation mutants that lack PspA and have used these mutants to demonstrate that PspA can play a role in pneumococcal virulence and that anti-PspA immunity can lead to protection against pneumococcal infection [15].
• Mannose-binding lectin genotype as a risk factor for invasive pneumococcal infection [16].
• The combined results confirm earlier conclusions that the alternative pathway of complement activation is indispensable for innate immunity against pneumococcal infection and that PspA interferes with the protective role of the alternative pathway [17].
• This study provides the first unequivocal evidence that CRP plays an important role in vivo in host defense against pneumococcal infections, and shows that sex hormones can affect expression of the human CRP transgene in mice [18].
• Bacterial clearance and antibody response were studied in young mice from mothers injected with pneumococcal type 9V polysaccharide (PS) conjugated with the inactivated pneumolysin to examine the protective immunity of young mice to pneumococcal infection [19].

Anatomical context of Pneumococcal Infections

• We have previously shown that in mice CRP increases splenic clearance of PnC-coated autologous erythrocytes and S. pneumoniae, and increases survival after pneumococcal infection [20].
• These data demonstrate that a complex chemokine network is activated in response to pulmonary pneumococcal infection, and also suggest an important role for fMLP receptor in monocyte/macrophage recruitment in that model [21].
• We finally demonstrate that in C57BL/6 mouse lung tissue in vivo as well as in the bronchial epithelial cell line BEAS-2B, Nod1 and Nod2 mRNA expressions were up-regulated after pneumococcal infection [22].
• CONCLUSION: Reduced interleukin-8 production may result in decreased neutrophil recruitment, and hence increased susceptibility to pneumococcal infection in HIV-infected subjects [23].
• Does naturally acquired IgG antibody to cell wall polysaccharide protect human subjects against pneumococcal infection [24]?

Gene context of Pneumococcal Infections

• Pneumococcal infection of mice caused a significant increase in brain TLR2 mRNA expression at both 4 and 24 h postchallenge [25].
• Recognition of pneumolysin by Toll-like receptor 4 confers resistance to pneumococcal infection [26].
• Matrix-driven delivery pellets that contained 70 mg of the IDO inhibitor 1-methyl-DL-tryptophan (MeTrp) released over a period of 7 days were subcutaneously implanted 48 h before pneumococcal infection [2].
• Our new results suggest that complement receptors CR1/2, CR3, and CR4 all play important roles in host defense against pneumococcal infection [17].
• The properdin or alternate complement pathway may function as a heat-labile opsonin for pneumococci, and evidence has been sought for its activation in pneumococcal infections [27].

Analytical, diagnostic and therapeutic context of Pneumococcal Infections

• These results show that intranasal administration of PspA together with mCT S61F is an effective mucosal vaccine against pneumococcal infection and induces CD4+ Th2-type cells, which provide help for both mucosal and systemic Ab responses [28].
• Improved utilization of the pneumococcal polysaccharide vaccine and continued development of improved vaccines are essential, and the emergence of drug-resistant strains of S. pneumoniae highlights the importance of preventing pneumococcal infections by vaccination [29].
• Detection of pneumococcal polysaccharide in sputum by counterimmunoelectrophoresis (CIE) or isolation of pneumococci from blood or pleural fluid (BPF-positive) was considered indicative of definite pneumococcal infection [30].
• Immunotherapy with antibodies to PspA may have some utility in treating pneumococcal infections in humans [31].
• Blood-based pneumolysin PCR was compared to blood culture and detection of pneumolysin immune complexes, as well as to detection of antibodies to pneumolysin and to C polysaccharide, in the diagnosis of pneumococcal infection in 75 febrile children [32].

References