[Enteropathogenic yersinias: pathogenicity factors and new diagnostic methods]

Area of Science:

• Microbiology
• Molecular Biology
• Immunology

Background:

• Certain Yersinia enterocolitica and Y. pseudotuberculosis serotypes cause human enteropathogenic infections.
• Molecular biology has significantly advanced the understanding of Yersinia pathogenicity in the last decade.

Purpose of the Study:

• To elucidate the role of plasmid-encoded factors in Yersinia pathogenicity.
• To identify suitable antigens for serologic diagnosis of yersiniosis.

Main Methods:

• Identification of plasmid-encoded polypeptides.
• Characterization of plasmid-mediated pathogenic functions.
• Analysis of chromosomal determinants including invasion factors, enterotoxin, and iron-utilization systems.
• Serologic diagnosis using immunoblotting and indirect immunofluorescence.

Main Results:

• Human pathogenic Yersiniae possess a 70-kilobase virulence plasmid.
• Thirteen plasmid-encoded polypeptides identified; two are outer membrane proteins, ten are secreted.
• Plasmid functions include serum survival, phagocytosis resistance, cell adhesion, and cytotoxicity.
• Chromosomal factors include invasion determinants, heat-stable enterotoxin, and an iron-utilization system.
• Iron-uptake system contributes to mouse lethality.
• Plasmid-encoded proteins are superior antigens for diagnosing yersiniosis compared to whole bacterial antigens.

Conclusions:

• The 70-kilobase plasmid is essential for virulence in pathogenic Yersinia species.
• Plasmid-encoded proteins are crucial for Yersinia pathogenesis and serve as effective diagnostic targets.
• Molecular insights into Yersinia pathogenicity enhance diagnostic strategies for yersiniosis.