Virulence Factors ofEscherichia coliIsolated From FemaleReproductive Tract Infections and Neonatal Sepsis

[摘要] Objective:The presence of enterobacteria such asEscherichia coliin the vagina of normal women is not synonymouswith infection. However, vaginalE. colimay also cause symptomatic infections. We examined bacterialvirulenceproperties that may promote symptomatic female reproductive tract infections (RTI) and neonatal sepsis.Methods:E. coliisolated as the causative agent from cases of vaginitis (n = 50), tubo-ovarian abscess (n = 45) andneonatal sepsis (n = 45) was examined for selected phenotypic and genetic virulence properties. Results werecompared with the frequency of the same properties among fecalE. colinot associated with disease.Results:A significantly greater proportion of infectionE. coliexhibited D-mannose resistant hemagglutinationcompared with fecalE. coli(p< 0.01). This adherence phenotype was associated with the presence of P fimbriae(pap) genes which were also significantly more prevalent among isolates from all three infection sites (p< 0.01).The majority ofpap+isolates contained thepapG3allele (Class II) regardless of infection type. Increased frequencyof Type 1C genes among vaginitis and abscess isolates was also noted. No significant differences in frequency ofother bacterial adherence genes, fim, sfa, uca (gaf) or dra were observed.E. coli associated with vaginitis was significantly more likely to be hemolytic ( HIY+) than were fecal isolates(p< 0.05). The HIY+phenotype was also more prevalent among tubo-ovarian abscess and neonatal sepsis isolates(p< 0.08).Conclusions:E. coliisolated from female RTI and neonatal sepses possess unique properties that may enhancetheir virulence. These properties are similar to those associated with otherE. coliextra-intestinal infections,indicating that strategies such as vaccination or bacterial interference that may be developed against urinary tractinfections (UTI) and otherE. coliextra-intestinal infections may also prevent selected female RTI.

[学科分类] 妇产科学