Publications by authors named "Y A Knirel"
Naturally occurring human antibodies against glycans recognize and quickly eliminate infectious bacteria, viruses and aberrantly glycosylated neoplastic malignant cells, and they often initiate processes that involve the complement system. Using a printed glycan array (PGA) containing 605 glycoligands (oligo- and polysaccharides, glycopeptides), we examined which of the glycan-binding antibodies are able to activate the complement system. Using this PGA, the specificities of antibodies of the IgM and IgG classes were determined in the blood serum of healthy donors (suggested as mostly natural), and, then, using the same array, it was determined which types of the bound immunoglobulins were also showing C3 deposition.
View Article and Find Full Text PDFStructure of the K58 capsular polysaccharide produced by Acinetobacter baumannii isolate MRSN 31468 includes Pse5Ac7Ac that is 4-O-acetylated by a phage-encoded acetyltransferase.
Carbohydr Res
January 2025
Article Synopsis
- Capsular polysaccharide (CPS) from the bacterial pathogen Acinetobacter baumannii is a key factor in its virulence, specifically the KL58 variant produced by the strain MRSN 31468.
- The CPS structure is characterized as a branched tetrasaccharide containing various sugar units, including glucose, galactose, N-acetyl-galactosamine, and a unique acid, indicating complex biosynthesis processes.
- The study identified specific genes responsible for synthesizing components of CPS, noting that an acetyltransferase linked to a prophage may influence its structural modifications, while a related CPS variant contains a different epimer not present in MRSN 31468.
Article Synopsis
- Unlabelled infections are a key global problem, with antibiotic resistance and capsular polysaccharide (CPS) playing significant roles in their virulence.
- A study identified an antibiotic-resistant isolate (48_n) from asymptomatic patients, revealing a unique CPS biosynthesis locus (KL71) and its structure using advanced spectroscopy techniques.
- Understanding diverse antibiotic resistance profiles, particularly from less common bacterial lineages, could offer insights into resistance spread and the development of new therapeutic interventions.
The K129 capsular polysaccharide produced by Acinetobacter baumannii MAR 15-4076 has the same composition as K84 but differs in the linkage between units altering the overall branching topology.
Carbohydr Res
November 2024
Capsular polysaccharide (CPS) is a heteroglycan that coats the cell surface of most isolates of the important Gram-negative bacterial pathogen, Acinetobacter baumannii. Strain MAR 15-4076, a clinical isolate recovered in Russia in 2015, was found to carry the KL129 sequence at the CPS biosynthesis K locus. The CPS was isolated from the strain and studied by sugar analysis, Smith degradation, one- and two-dimensional H and C NMR spectroscopy.
View Article and Find Full Text PDFThe carbapenem-resistant isolate BAL062 is a clinical reference isolate used in several recent experimental studies. It is from a ventilator-associated pneumonia (VAP) patient in an intensive care unit at the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam in 2009. Here, BAL062 was found to belong to the B sub-lineage of global clone 2 (GC2) isolates in the previously reported outbreak (2008 and 2012) of carbapenem-resistant VAP at the HTD.
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