Article Figures & Data
Figures
- FIG 1
Phylogenetic tree showing the species from the Enterobacteriaceae family that colonize the human gastrointestinal tract. GenBank accession numbers of the16S rRNA gene sequences are provided for each species, and the family names are indicated. E. coli is highlighted in green, and the Proteus genus is shown in blue. (Reproduced from reference 133.)
- FIG 2
(Top) Strain of P. mirabilis inoculated twice, 1 h apart, demonstrating the macroscopic characteristic bull's-eye pattern produced by periodic swarming. (Reproduced with permission from reference 134.) (Bottom left) Interacting P. mirabilis swarmer cells; (bottom right) combination of swimmer and swarmer cells within a biofilm. (Both panels reproduced from reference 135 with permission from Elsevier.)
- FIG 3
Potentially important Proteus-related virulence factors in relation to anatomical disease location and disease. *, immune evasion includes the production of the ZapA metalloprotease, O-antigens, and flagellin variation.
Tables
- TABLE 1
Fimbriae and pili expressed by Proteus speciesa
Fimbrial type Structure Characteristic(s) Contribution(s) to gastrointestinal pathogenicity Reference(s) MR/P 7-nm–8-nm, “thick” channeled fimbriae Important for epithelial cell adhesion Expression may allow mucosal cell adhesion in the gastrointestinal tract and contribute to intestinal persistence 38, 39, 69, 136 MR/P expression undergoes phase variation, allowing for a molecular “switch” that turns on/off the expression of the mrp operon depending on the environment and oxygen availability, e.g., on in bladder colonization and off in kidney colonization The repeating structures of flagellin proteins contribute to immunogenicity in the gut MR/P fimbriae are potent immunogens and potential vaccine candidates MR/P+ Proteus strains are more genotoxic and cytotoxic to bladder/kidney-derived epithelial cells than MR/P− mutants MR/P+ Proteus strains are also likely more cytotoxic to intestinal epithelial cells MR/K 4-nm–5-nm, “thin” nonchanneled fimbriae Expression is more common in P. penneri strains than in P. mirabilis strains P. penneri has not been linked to gastrointestinal pathogenicity 42, 137 NAF/UCA 4-nm, “thin” nonchanneled fimbriae Recognizes glycolipids, including asialo-GM1, asialo-GM2, lactosyl ceramide, and galectin-3 40, 41, 138 Important for epithelial cell adhesion and colonization Not present in P. vulgaris ATF Highly expressed at 23°C, moderately expressed at 37°C The structural subunit AtfA has significant homology with the major subunit of type 1 fimbriae from other enteric pathogens, such as S. enterica serovar Typhi 37, 40, 139–141 Not considered to contribute to UTI or biofilm formation; may be more important for enteric colonization and environmental survival Believed to be important for survival and persistence outside a mammalian host, at room temp PMP Identified in uropathogenic P. mirabilis strains isolated from dogs 142 Not present in P. vulgaris PmpA fimbrial subunits show high homology to P-fimbriae from uropathogenic Escherichia coli Cell surface assembly has not been confirmed PMF Important in biofilms and responsible for the formation of higher-volume biofilms 37 ↵a UTI, urinary tract infection.
- TABLE 2
Cell culture lines capable of intracellular uptake of Proteus mirabilis
Cell line Cell type Reference(s) CaCo-2a/CaCo-2BBea Colorectal adenocarcinoma/C2BBe1 (brush border-expressing cells) 60, 62, 132, 143, 144 Models for apical microvilli and tight junctions HT29a Enterocytes, undifferentiated or differentiated (polarized, in the absence of glucose) 60, 62, 132, 143, 145 HT29-18N2a Mucus-secreting differentiated cells 60, 132 HT29-FUa Mucus-secreting differentiated cells HT29-MTXa Mucus-secreting differentiated cells INT407a Embryonic intestinal epithelial cells (possibly HeLa-contaminated line) 61 HCT-8a Ileocecal colorectal adenocarcinoma T24 Transitional cell bladder carcinoma HeLa Cervical carcinoma 146 Vero African green monkey kidney cells L-929 Mouse fibroblasts Human blood lymphocytes ↵a Gastrointestinal cell line.
- TABLE 3
Substrates degraded by Proteus mirabilis ZapA metalloprotease
Substrate Locations Reference(s) Structural cell components Actin, β-tubulin, fibronectin, collagen, laminin All cells 21 Innate immune components Immunoglobulins (IgA1, IgA2, IgG) 21, 147 Complement proteins (C1q, C3) 21 Defensins (human beta defensin 1) Epithelial surfaces, small bowel, and large bowel 21, 148, 149 Cathelicidin peptide LL-37 Epithelial surfaces, wounds 21, 150
