engleski

Pigeon ovalbumin glycans labeled with digoxin can be used for identification of uropathogenic E. coli (type-p).

E. coli’ s are by far the most common cause of urinary tract infections. Standard methods for identification of uropathogenic E. coli (UPEC) in urine are semi-quantitative and usually take 2-3 days, so development of a more rapid, molecular approach to detect UPEC may lead to earlier diagnosis and improve management of urinary tract infections. Attachment of UPEC to host cell receptors is mediated by interaction of the bacterial lectin (adhesin) localized at the top of fimbriae and specific carbohydrate moiety of the host membrane glycoconjugates. The most common type of UPEC causing pyelonephritis expresses type P adhesin (UPEC-P) that specifically recognizes P1 antigen (Galα (1-4)Gal moiety – galabiose). Pigeon glycoproteins are rich in galabiose sequences at the terminal positions of N-glycans that makes them potent ligands for UPEC-P adhesins. Oligosaccharides were purified from pigeon ovalbumin, reductively aminated with hydrazine and labeled with digoxin that was previously activated with CNBr. Microtiter plates were coated with purified pigeon ovalbumin and incubated with solution containing bacteria or a model lectin. Pigeon ovalbumin glycans conjugated with digoxin were added and detected with antibodies against digoxigenin (that also recognizes digoxin) conjugated with alkaline phosphatase. Linear response was observed in a wide range of concentration, indicating that this method might be useful for quantifying bacteria. As far as we know this is the first case of labelling glycans with digoxin as well as their application. Our preliminary study indicates that specific glycoproteins and glycans labeled with digoxin can be used for development of a rapid, species-specific molecular tool for detection of uropathogenic E. coli. Similar approach may be further utilized for the detection of other bacterial species, measurement of bacterial virulence and sensitivity to antibiotics.

pigeon ovalbumin glycans; digoxin; uropathogenic E. coli

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