Phylogenetic background and virulence profile of Escherichia coli causing neonatal disease
Abstract number: P1294
Andreu A., Moreno-Pujol E., Tenedor M., Planes A.M., Molinos S., Ruiz de Gopegui E., Bosch J.
Objective: To determine the phylogenetic background and the virulence profile among E. coli strains causing neonatal disease, and compared with E. coli causing urinary bacteraemia.
Methods: Thirty-five E. coli strains, isolated in 4 hospitals within 1996 and 2007, 34 from blood and 1 from blood and CSF, of newborns within the first week of life. We compared them with 50 E. coli strains isolated from blood of patients with urinary bacteraemia (Moreno et al. 2005. Diag Microbiol Infect Dis: 53; 93). To these 85 epidemiologically unrelated strains, phylogenetic group and 15 virulence factors were determined by PCR
Results: Among the 35 E. coli causing neonatal disease, the highly pathogenic phylogenetic group B2 was the most frequent, 28 isolates (80%), followed by group D with 4 (11%) and group A with 3 (9%). These strains showed a high prevalence of proven virulent traits associated to extraintestinal infections, specially kpsMII (89%), malX (77%), fyuA (91%), and iutA (66%) and a relatively low prevalence of factors associated to P fimbriae: papA 43% and papG alelle II 34%. Factors associated to meningitis were ibeA 21%, and sfa/focDE 46%, but both were present in the strain isolated from CSF. In consequence, these strains showed a high aggregate virulence score with a mean of 6.8, and a range between 2 and 10 virulent factors/strain.
E. coli causing neonatal disease showed a similar distribution among phylogenetic groups than E. coli causing urinary bacteraemia (phylogenetic group B2 70%, group D 16%, group A 10%, and group B1 4%), a similar prevalence of virulent traits associated to extra-intestinal infections, kpsMII (76%), malX (70%), iutA (78%), and fyuA (88%), and a similar virulence score 7.2 (range, 1 to 10). However, papA and papG alelle II were statically associated to E. coli producing urinary bacteraemia (78% and 66%) in relation to E. coli producing neonatal septicaemia (P = 0.001 and P = 0.004; respectively).
Conclusions:E. coli producing neonatal disease derived mainly from the pathogenic phylogroup B2 and exhibited a great concentration virulent traits which inferred a virulent potential as high as E. coli causing urinary bacteraemia. However, P fimbriae, which enable bacteria to reach the kidney, was significant more prevalent in urinary bacteraemia.
The similarities between E. coli causing neonatal septicaemia, urinary bacteraemia and others, strongly suggest that all these E. coli should be classified as ``Extraintestinal Pathogenic E. coli (ExPEC)''
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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