Allelic variability of critical virulence genes (eae, bfpA and perA) in typical and atypical enteropathogenic Escherichia coli in Peruvian children.
Enteropathogenic Escherichia coli (EPEC) is a leading cause of infantile diarrhoea in developing countries. The aim of this study was to describe the allelic diversity of critical EPEC virulence genes and their association with clinical characteristics. One hundred and twenty EPEC strains isolated from a cohort diarrhoea study in Peruvian children were characterized for the allele type of eae (intimin), bfpA (bundlin pilin protein of bundle-forming pilus) and perA (plasmid encoded regulator) genes by PCR-RFLP. Atypical EPEC strains (eae+, bfp-) were the most common pathotype in diarrhoea (54/74, 73 %) and control samples from children without diarrhoea (40/46, 87 %). Overall, there were 13 eae alleles; the most common were beta (34/120, 28 %), theta (24/120, 20 %), kappa (14/120, 12 %) and mu (8/120, 7 %). There were five bfpA alleles; the most common were beta1/7 (10/26), alpha3 (7/26) and beta5 (3/26). There were three perA alleles: beta (8/16), alpha (7/16) and gamma (1/16). The strains belonged to 36 distinct serogroups; O55 was the most frequent. The gamma-intimin allele was more frequently found in diarrhoea episodes of longer duration (>7 days) than those of shorter duration (3/26, 12 % vs 0/48, 0 %, P<0.05). The kappa-intimin allele had the highest clinical severity score in comparison with other alleles (P<0.05). In Peruvian children, the virulence genes of EPEC strains are highly variable. Further studies are needed to evaluate additional virulence markers to determine whether relationships exist between specific variants and clinical features of disease.
Contreras
C A
CA
Instituto de Medicina Tropical 'Alexander von Humboldt', Universidad Peruana Cayetano Heredia, Lima, Peru.
Ochoa
T J
TJ
University of Texas School of Public Health, Houston, USA.|Instituto de Medicina Tropical 'Alexander von Humboldt', Universidad Peruana Cayetano Heredia, Lima, Peru.
Lacher
D W
DW
US Food and Drug Administration, Laurel, Maryland, USA.
DebRoy
C
C
E. coli Reference Center, Department of Veterinary and Biomedical Sciences, Pennsylvania State University, Pennsylvania, USA.
Navarro
A
A
Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de Mexico, Mexico.
Talledo
M
M
Department of Medical Genetics, University of Antwerp, Antwerp, Belgium.|Instituto de Medicina Tropical 'Alexander von Humboldt', Universidad Peruana Cayetano Heredia, Lima, Peru.
Donnenberg
M S
MS
University of Maryland School of Medicine, USA.
Ecker
L
L
Instituto de Investigación Nutricional, Lima, Peru.
Gil
A I
AI
Instituto de Investigación Nutricional, Lima, Peru.
Lanata
C F
CF
Universidad Peruana de Ciencias Aplicadas, Lima, Peru.|Instituto de Investigación Nutricional, Lima, Peru.
Cleary
T G
TG
University of Texas School of Public Health, Houston, USA.
D018829:Adhesins, Bacterial / Q000235:genetics* / Q000378:metabolism; D002648:Child; D015331:Cohort Studies; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology; D054308:Enteropathogenic Escherichia coli / Q000235:genetics / Q000378:metabolism*; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D036781:Fimbriae Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D010568:Peru / Q000453:epidemiology; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D014774:Virulence
D018829:Adhesins, Bacterial; C104901:BfpA protein, E coli; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; C120886:bfpT protein, E coli; C073819:eaeA protein, E coli; D036781:Fimbriae Proteins