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Journal of Clinical Microbiology, March 2004, p. 1388-1389, Vol. 42, No. 3
0095-1137/04/$08.00+0 DOI: 10.1128/JCM.42.3.1388-1389.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
Concurrent Infection in a Dog and Colonization in a Child with a Human Enteropathogenic Escherichia coli Clone

LETTER
Pets can be natural reservoirs of several organisms potentially
able to cause disease to humans, who, in turn, may also be carriers
of countless infectious agents specific for animals. Children
are central players in this cross-transfer game in view of their
frequent nonobservance of proper hygiene habits. Human adults
and animals are immune to enteritis caused by enteropathogenic
Escherichia coli (EPEC), a common agent of infantile diarrhea
in some developing countries (
10). EPEC hallmarks are the abilities
to express localized adhesion (LA) to epithelial cells and to
induce cytoskeletal rearrangements resulting in histopathological
alterations known as attaching and effacing in these cells (
9).
The LA is dependent on the expression of multiple adhesins,
among which the plasmid-encoded bundle-forming pilus (BFP) is
the best characterized. EPEC identification can be performed
by the detection of the gene for the structural subunit of BFP
(
bfpA) and the
E. coli attaching and effacing (
eae) gene. Typical
EPEC strains belong to a restricted number of O:H serotypes
representing natural
E. coli clones (
3). Although the above
features have been identified in clinical isolates of
E. coli from dogs, the association of typical EPEC with canine enteritis
and the recognition of pet dogs as reservoirs of the organism
are still controversial (
10,
12). Here we report an observed
similarity between
E. coli isolates from a 3-year-old healthy
child and her 3-month-old diarrheic pet dog which tested negative
for parvovirus, rotavirus, and
Cryptosporidium,
Salmonella,
and
Shigella organisms. Three isolates out of five bacterial
colonies picked on MacConkey agar from both the dog and the
child's stool culture were identified as
E. coli. The six isolates
were nonmotile, did not produce gas from glucose, and were unable
to decarboxylate lysine. When submitted to serotyping (
4) with
antisera specific for classical EPEC O serogroups (
14), assays
for adhesion to HEp-2 cells (
2), PCR for
eae (
6) and
bfpA (
8),
and assessment of their genetic relationship by enterobacterial
repetitive intergenic consensus-PCR (ERIC-PCR) (
13), they showed
complete identity. They were all serotyped with the O111 antiserum,
displayed LA to HEp-2 cells, were PCR positive for
eae and
bfpA,
and displayed similar ERIC-PCR fingerprints.
EPEC is a human-specific enteropathogen affecting infants in their first year of life, whose significance was questioned in the past (5) because of the failure of many investigators to identify known virulence markers among clinical isolates of the organism (11). However, studies conducted particularly in the 1980s and 1990s on several aspects of its pathogenesis generated sufficient data to dissipate the doubts about EPEC's relevance as a human enteropathogen. The recent detection of EPEC markers among E. coli isolates from diarrheic dogs (1, 7) raised the question of its supposed association with enteritis in animals as well. In this report we show both that the dog's and the child's E. coli isolates are closely related and that they represent a typical human EPEC clone. Since they were phenotypic and genetically similar, belonged to the same O:H serotype (O111:H-), and showed identical EPEC markers, they certainly represent a single E. coli clone. In addition, because the diarrheic dog was negative for common viral, parasitic, and bacterial agents, the EPEC strains that it shed may well have been the cause of its symptoms of diarrhea. Concerning the child, the absence of these symptoms associated with a positive result for EPEC is not a surprise, since she belongs to an age group in which humans are immune to EPEC infections. Although this is a single case report, the results presented seem to suggest that pet dogs may be not only carriers but also susceptible hosts of typical EPEC strains. Yet, in order to validate this hypothesis, the study should be expanded, with the survey of a larger number of animals, which must also be evaluated for symptoms of diarrhea and whose stools should be tested periodically for the presence of EPEC.

ACKNOWLEDGMENTS
This work was supported by grant 1997/07733-9 from the Fundação
de Amparo à Pesquisa do Estado de São Paulo awarded
to J.R.

REFERENCES
1 - Beaudry, M., C. Zhu, J. M. Fairbrother, and J. Harel. 1996. Genotypic and phenotypic characterization of Escherichia coli isolates from dogs manifesting attaching and effacing lesions. J. Clin. Microbiol. 34:144-148.[Abstract]
2 - Cravioto, A., R. J. Gross, S. M. Scotland, and B. Rowe. 1979. An adhesive factor found in strains of Escherichia coli belonging to the traditional infantile enteropathogenic serotypes. Curr. Microbiol. 3:95-99.[CrossRef]
3 - Dalla-Costa, L. M., K. Irino, J. Rodrigues, I. N. G. Rivera, and L. R. Trabulsi. 1998. Characterisation of diarrhoeagenic Escherichia coli clones by ribotyping and ERIC-PCR. J. Med. Microbiol. 47:227-234.[Abstract/Free Full Text]
4 - Ewing, W. H. 1986. The genus Escherichia, p. 93-134. In W. H. Ewing (ed.), Identification of Enterobacteriaceae, 4th ed. Elsevier Science Publishing Co., Inc., New York, N.Y.
5 - Gangarosa, E. J., and M. H. Merson. 1977. Epidemiologic assessment of the relevance of the so-called enteropathogenic serogroups of Escherichia coli in diarrhea. N. Engl. J. Med. 296:1210-1213.[Medline]
6 - Gannon, V. P. J., M. Rashed, R. K. King, and E. J. Thomas. 1993. Detection and characterization of the eae gene of Shiga-like toxin-producing Escherichia coli using the polymerase chain reaction. J. Clin. Microbiol. 31:1268-1274.[Abstract/Free Full Text]
7 - Goffaux, F., B. China, L. Janssen, and J. Mainil. 2000. Genotypic characterization of enteropathogenic Escherichia coli (EPEC) isolated in Belgium from dogs and cats. Res. Microbiol. 151:865-871.[Medline]
8 - Gunzburg, S. T., N. G. Tornieporth, and L. W. Riley. 1995. Identification of enteropathogenic Escherichia coli by PCR-based detection of the bundle-forming pilus gene. J. Clin. Microbiol. 33:1375-1377.[Abstract]
9 - Kaper, J. B. 1996. Defining EPEC. Rev. Microbiol. 27(Suppl. 1):130-133.
10 - Nataro, J. P., and J. B. Kaper. 1998. Diarrheagenic Escherichia coli. Clin. Microbiol. Rev. 11:142-201.[Abstract/Free Full Text]
11 - Robins-Browne, R. M., M. M. Levine, B. Rowe, and E. M. Gabriel. 1982. Failure to detect conventional enterotoxins in classical enteropathogenic (serotyped) Escherichia coli strains of proven pathogenicity. Infect. Immun. 38:798-801.[Abstract/Free Full Text]
12 - Trabulsi, L. R., R. Keller, and T. A. T. Gomes. 2002. Typical and atypical enteropathogenic Escherichia coli. Emerg. Infect. Dis. 8:508-513.[Medline]
13 - Versalovic, J., M. Schneider, F. J. Bruijn, and J. R. Lupski. 1994. Genomic fingerprinting of bacteria using repetitive sequence-based polymerase chain reaction. Methods Mol. Cell. Biol. 40:5-25.
14 - World Health Organization. 1987. Programme for control of diarrhoeal diseases. Manual for laboratory investigations of acute enteric infections. World Health Organization, Geneva, Switzerland.
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Josias Rodrigues* Cristiane M. Thomazini Carlos A. M. Lopes Liliane O. Dantas
Departamento de Microbiologia e Imunologia, Instituto de Biociências da UNESP em Botucatu, Campus de Rubião Júnior, CEP 18.618-000, Botucatu, São Paulo, Brazil
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* Phone: 055 (14) 3811-6058, Fax: 055 (14) 3815-3744, E-mail: josias{at}ibb.unesp.br |
Journal of Clinical Microbiology, March 2004, p. 1388-1389, Vol. 42, No. 3
0095-1137/04/$08.00+0 DOI: 10.1128/JCM.42.3.1388-1389.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
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