The Role of Pili and Capsule in the Pathogenesis of Neonatal Infection with Escherichia coli K1

• Published in: The Journal of infectious diseases Vol. 148; no. 3; pp. 395 - 405
• Main Authors: Guerina, N. G., Kessler, T. W., Guerina, V. J., Neutra, M. R., Clegg, H. W., Langermann, S., Scannapieco, F. A., Goldmann, D. A.
• Format: Journal Article
• Language: English
• Published: Chicago, IL University of Chicago Press 01-09-1983
• Subjects: Adhesiveness; Animals; Animals, Newborn; Bacteremia; Bacteria; Bacterial colonization; Bacteriology; Biological and medical sciences; Capsules; Epithelial cells; Escherichia coli; Escherichia coli - analysis; Escherichia coli - physiology; Escherichia coli - ultrastructure; Escherichia coli Infections - microbiology; Fimbriae, Bacterial - physiology; Fundamental and applied biological sciences. Psychology; Ileum - microbiology; Infections; Intestinal Mucosa - microbiology; Microbial colonization; Microbiology; Mouth; Mouth - microbiology; Oropharynx - microbiology; Pathogenesis of Infection; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Polysaccharides, Bacterial - physiology; Rats; Rats, Inbred Strains; Sepsis - microbiology; Microorganism capsule; Pathogenicity; Bacteria; Pilus
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/148.3.395

The role of pili and capsule was studied in neonatal infection with Escherichia coli K1. E coli strains were selectively cultured into three phases: mannose-sensitive (MS) piliated, non-mannose-sensitive (NMS) piliated, and nonpiliated. A high percentage of neonatal rats fed each phase of K1 strains developed bacteremia; there was no bacteremia with non-K1 strains or an acapsular mutant of K1 strain C94 (C94K⁻). Oral cavity colonization was noted in nearly 100% of rats fed K1 strains, non-K1 strains, or C94K⁻, regardless of the phase of piliation at feeding. Only MS piliated bacteria were found on oral cavity culture, indicating a rapid shift of NMS piliated and nonpiliated bacteria to the MS piliated phase. Conversely, only nonpiliated bacteria were found on blood culture when neonatal rats were fed piliated bacteria. Colonization of ileal epithelium was not observed. Thus, in vivo phase variation may be important in colonization and bacteremia with E coli K1.