Genetic diversity of the O antigens of Proteus species and the development of a suspension array for molecular serotyping

Abstract

Proteus species are well-known opportunistic pathogens frequently associated with skin wound and urinary tract infections in humans and animals. O antigen diversity is important for bacteria to adapt to different hosts and environments, and has been used to identify serotypes of Proteus isolates. At present, 80 Proteus O-serotypes have been reported. Although the O antigen structures of most Proteus serotypes have been identified, the genetic features of these O antigens have not been well characterized. The O antigen gene clusters of Proteus species are located between the cpxA and secB genes. In this study, we identified 55 O antigen gene clusters of different Proteus serotypes. All clusters contain both the wzx and wzy genes and exhibit a high degree of heterogeneity. Potential functions of O antigen-related genes were proposed based on their similarity to genes in available databases. The O antigen gene clusters and structures were compared, and a number of glycosyltransferases were assigned to glycosidic linkages. In addition, an O serotype-specific suspension array was developed for detecting 31 Proteus serotypes frequently isolated from clinical specimens. To our knowledge, this is the first comprehensive report to describe the genetic features of Proteus O antigens and to develop a molecular technique to identify different Proteus serotypes.

Cell Shape and Population Migration Are Distinct Steps of Proteus mirabilis Swarming That Are Decoupled on High-Percentage Agar

“…Another gene, BB2000_3206, encodes a predicted protein that has 21% pairwise identity to CmfA and is a putative glycosyltransferase family 4 protein. This locus is reportedly associated with the LPS biosynthesis pathway, specifically, the production of O antigen, and varies in the number and composition of genes among wild-type P. mirabilis strains (39,46). We opted to proceed with mutant strains KEL21 and KEL22.…”

Proteus spp. as Putative Gastrointestinal Pathogens

“…The genus is currently comprised of Proteus mirabilis, P. vulgaris, P. penneri, P. hauseri, P. terrae, and P. cibarius, along with the unnamed genomospecies 4, 5, and 6 (6)(7)(8)(9)(10). In humans, all current members of the genus, except for P. cibarius and P. terrae, have been isolated from clinical specimens (4,5,7,9,11). Typically, the human gut is colonized by various combinations of P. vulgaris, P. mirabilis, and P. penneri, but they comprise less than 0.05% of the gut microbiota of healthy subjects (Fig.…”

“…In addition to lipid A, Proteus species LPS includes O-antigens (polysaccharides that are repeating oligosaccharide units, each made up of 2 to 8 sugar residues) that are highly structurally diverse. Approximately 80 O-antigen serogroups have been reported, derived from a total of 60 O-antigen gene clusters (11,73). Antibodies to O-antigens are not uncommon in human sera, for example, 25% of blood donors have anti-P. mirabilis antibodies to the O36 serogroup, which is just one of the many serogroups (74).…”

O-Antigen Gene Clusters of Plesiomonas shigelloides Serogroups and Its Application in Development of a Molecular Serotyping Scheme

“…Three distinct pathways participated in the synthesis and translocation of OPS: the Wzx/Wzy pathway, the ATP-binding cassette (ABC) transporter pathway (Hu et al, 2013), and the synthase pathway. O-antigen serotyping, targeting the wzx and wzy genes, is able to detect distinct O-antigen forms, including E. coli , Shigella , Salmonella , Vibrio parahaemolyticus , Acinetobacter , Hafnia , and Proteus (Li et al, 2009, 2010; Guo et al, 2013; Hu et al, 2013; Chen et al, 2015; Duan et al, 2016; Yu et al, 2017). Our previous studies employed wzx and wzy for serotyping E. coli and Shigella by microarray (Li et al, 2006), wzx and wzy for serotyping Pseudomonas aeruginosa (Li et al, 2018) and wzm and wzt for serotyping 15 Legionella pneumophila serogroups by microarray (Cao et al, 2013).…”