Ply PCR, in particular, is not specific and shows cross-reactions with other streptococcal species. In addition, not only is the gene target important, but exactly which segment of this gene is targeted is apparently also important, owing to allelic variation in the target gene between closely related species. Serotype-specific real-time PCR assays are also showing promise for low-concentration DNA extracts prepared from whole blood and other clinical specimens [4,54] (Carvalho, Mda G. et?al., unpublished data). Moreover, when positive, a high bacterial DNA load has been associated with increased mortality and higher risk of septic shock [14,61]. The properties of the antigen pneumococcal choline-binding protein?A (PcpA) could be used to design and validate an antigen assay in blood that could be specific <a href="https://en.wikipedia.org/wiki/Oxyclozanide">oxyclozanide</a>
for pneumococcal pneumonia. PcpA is expressed only in the presence of a low manganese <a href="http://www.selleckchem.com/products/sorafenib.html">Sorafenib
price</a> concentration, which is the case in blood (<0.1?��M Mn2+) as compared with nasopharyngeal specimens (40?��M Mn2+) . In addition, studies have shown that PcpA is expressed in the lungs, but not in the nasopharynx , which makes this target promising for distinguishing pneumococci causing carriage from those causing pneumonia. Antigen detection in urine.? Extensive efforts to validate the BinaxNOW assay have shown the assay to be more sensitive than blood culture, and to be able to identify more cases of pneumococcal pneumonia than traditional methods in both inpatient and outpatient settings [2,17,25,28,31,39,80]. It is easy to use and non-invasive, but the assay lacks specificity in children, because it can give positive results in healthy children with carriage of pneumococci and of other closely related Streptococcus species. Increasing the cut-off at which the assay result is determined to be positive could improve the specificity, but doing so would require extensive validation to determine the impact on sensitivity. Although there is an enormous literature on the use of BinaxNOW in urine specimens, little is known about its use in serum. Assays based on other antigens, including proteins (PpmA, Ply, or PcpA) or polysaccharides <a href="http://www.selleckchem.com/HIF.html">HIF
cancer</a> that may also allow typing, are less sensitive or specific than BinaxNOW, but this approach warrants further research to search for better antigens and methodologies. Proteome profiling in urine could help to identify new antigens that could be useful in the development of new diagnostic assays. Serotype-specific antigen detection in urine might be a promising approach to detect serotype-specific pneumonia in adults , but may also be confounded by carriage in children. Plasmodium and mycobacterial DNA can be detected in urine and inform diagnoses, possibly making it worthwhile to look for S.