biostudies-literatureMilawati HNew York UniversityNCI NIH HHSNational Institute of General Medical SciencesNIGMS NIH HHS3414-3419https://www.ebi.ac.uk/biostudies/studies/S-EPMC12706776biostudies-literatureUnknown11(12)Bacterial strains are distinguished by surface glycans composed of defined sugar sequences that include "rare" monosaccharides, which are absent in human glycans and help to mediate host-microbe interactions. One of the most prevalent rare sugars is l-Rhamnose (l-Rha), and human sera are generally enriched in anti-l-Rha antibodies; however, the source of l-Rha antigens is unknown. Here, we synthesize a surface glycan l-Rha-<i>N</i>-acetyl glucosamine disaccharide sequence, which is found across many bacterial species, to evaluate binding motifs of human anti-glycan antibodies in clinical and commercial human sera. We find that sera are enriched in IgG antibodies that react with this disaccharide probe. Through capture of bound antibodies and analysis with surface glycan sequences from diffACS infectious diseasesMicrobial Surface Glycan Probe Isolates Anti-l-Rhamnose Antibodies from Human Serum for Bacterial Detection.PMC12706776P30 CA016087R35 GM1428875R35GM142887-02Lupoli TJJoo JMilawati HSheshova MfalseMicrobial Surface Glycan Probe Isolates Anti-l-Rhamnose Antibodies from Human Serum for Bacterial Detection.Bacterial strains are distinguished by surface glycans composed of defined sugar sequences that include "rare" monosaccharides, which are absent in human glycans and help to mediate host-microbe interactions. One of the most prevalent rare sugars is l-Rhamnose (l-Rha), and human sera are generally enriched in anti-l-Rha antibodies; however, the source of l-Rha antigens is unknown. Here, we synthesize a surface glycan l-Rha-<i>N</i>-acetyl glucosamine disaccharide sequence, which is found across many bacterial species, to evaluate binding motifs of human anti-glycan antibodies in clinical and commercial human sera. We find that sera are enriched in IgG antibodies that react with this disaccharide probe. Through capture of bound antibodies and analysis with surface glycan sequences from diff2025-01-01T00:00:00Z2025 Dec2026-06-06T03:59:37.143Z2026-05-25T03:11:57.032ZS-EPMC127067764128825310.1021/acsinfecdis.5c00757