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Journal of Clinical Microbiology, January 2002, p. 294-297, Vol. 40, No. 1
0095-1137/02/$04.00+0 DOI: 10.1128/JCM.40.1.294-297.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.
Characterization of Enteropathogenic and Enteroaggregative Escherichia coli Isolated from Diarrheal Outbreaks
Jun Yatsuyanagi,1* Shioko Saito,1 Hiroyasu Sato,1 Yoshimichi Miyajima,1 Ken-Ichi Amano,2 and Katsuhiko Enomoto3
Akita Prefectural Institute of Public Health, 6-6 Sensyu kubota-machi, Akita 010-0874,1
Central Research Laboratory,2
Department of Pathology, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan3
Received 9 July 2001/
Returned for modification 3 September 2001/
Accepted 21 October 2001

ABSTRACT
Virulence characteristics of diarrheal outbreak-associated
Escherichia coli O55:NM, O126:NM, and O111:NM were examined. The
E. coli O55:NM strains were atypical enteropathogenic
E. coli (EPEC),
while the
E. coli O126:NM and O111:NM strains should be classified
as enteroaggregative
E. coli (EAggEC). The contributions of
EPEC and EAggEC to the human disease burden in Japan might be
significantly greater than is currently appreciated.
TEXT
There are six categories of Escherichia coli that cause diarrhea: enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli, enteroaggregative E. coli (EAggEC), enteroinvasive E. coli, and diffusely adherent E. coli (21). EPEC causes characteristic attaching-and-effacing lesions (A/E), which can be observed by intestinal biopsy in both human patient (19) and animal (29) models. A/E is characterized by loss of microvilli, intimate adherence of bacteria between epithelial cell membranes (27, 30), and cytoskeletal changes such as actin polymerization directly beneath the adherent bacteria (15). Generally, EPEC causes infantile diarrhea in developing countries and sporadic diarrhea in developed countries (21). EAggEC, on the other hand, is an enteric pathogen defined by its distinctive aggregative or "stacked-brick" pattern of adherence to cultured human epithelial cells (22). EAggEC associates mainly with persistent diarrhea in developing countries (21). Only two reports in Japan have described diarrheal outbreaks caused by EAggEC or EPEC. Itoh et al. (11) reported the isolation of EAggEC from the stools of patients with severe diarrhea in elementary and junior high schools. Makino et al. (18) reported the isolation of EPEC from a mass outbreak. In this paper, we describe three cases of diarrheal outbreaks in Japan caused by E. coli belonging to the traditional EPEC serotype.
Chromosomal DNA-embedded agarose plugs for pulsed-field gel electrophoresis (PFGE) analysis were prepared by using the CHEF Bacterial DNA Plug Kit (Bio-Rad, Hercules, Calif.) and were digested with XbaI (Nippon gene; Osaka, Japan) at a concentration of 30 U/plug for 4 h at 37°C. The plugs were applied to a 1% PFC Grade Agarose (Bio-Rad) gel. Electrophoresis was performed in 0.5x Tris-Borate EDTA buffer at 14°C using a CHEF DR-II PFGE apparatus (Bio-Rad) under the following conditions: voltage, 6 V/cm; block 1, 11 h, with initial switching time of 4 s to final switching time of 8 s; block 2, 9 h, with initial switching time of 8 s to final switching time of 50 s. The HEp-2 cell assay was performed following the method described by Craviotto et al. (4), with modifications involving 3 or 6 h of incubation (15). The E. coli isolates were examined for the presence of the following virulence genes by PCR: stx1 (Shiga toxin) and stx2 (16), eaeA (E. coli attaching and effacing) (12), bfpA (bundle-forming pilus) (9), perA (EPEC plasmid-encoded regulatory region) (8), astA (EAggEC heat-stable enterotoxin) (28), aggR (transcriptional activator for EAggEC aggregative adherence fimbria I expression) (20), and pet (EAggEC plasmid-encoded heat-labile toxin) (6) using the primers listed in Table 1. EPEC E2348/69 and EAggEC 17-2 were kindly provided by James B. Kaper, and EAggEC 042 was kindly provided by James P. Nataro, University of Maryland School of Medicine, Baltimore, Md.
The diarrheal patients were junior high school students in case
1, adults who attended a party in case 2, and infants of a day
care center in case 3. The only diarrheagenic bacterial pathogens
isolated from the patients were three
E. coli O126:NM isolates
from four of nine patients in case 1, nine
E. coli O111:NM isolates
from 9 of 21 patients in case 2, and four
E. coli O55:NM isolates
from four of four patients in case 3. As shown in Fig.
1,
E. coli strains isolated within the same case showed identical
PFGE patterns, suggesting that the strains originated from the
common infectious sources in the respective cases. These results
indicated that these
E. coli strains were the causative agents
of the diarrheal outbreak cases. As shown in Fig.
2,
E. coli O55:NM possessed
eaeA and showed a localized HEp-2 cell adherence
pattern only in the 6-h assays but was negative for
bfpA and
perA, indicating that
E. coli O55:NM is an atypical EPEC. The
E. coli O55:NM isolate was negative for
aggR,
astA, and
pet.
On the other hand, both
E. coli O126:NM and O111:NM strains
were negative for the
eaeA,
bfpA, and
perA genes but positive
for the
aggR and
astA genes and showed an aggregative HEp-2
cell adherence pattern, indicating that they should be classified
as EAggEC, displaying features of the traditional EPEC serotypes.
The
E. coli O126:NM was
pet positive, while
E. coli O111:NM
was negative for this gene. All three
E. coli isolates were
negative for both
stx1 and
stx2 genes.
At the Second International Symposium on EPEC (
13), a consensus
on the basic characteristics of EPEC infection was reached,
identifying them as the presence of A/E histopathology and the
absence of Shiga toxin. The A/E phenotype is closely related
to the localized adherence phenomenon displayed by EPEC (
14).
DNA probes and PCR primers have been developed and used for
the evaluation of the three major characteristics of EPEC: A/E
(
12), the presence of a ca. 60-MDa plasmid designated EPEC adherence
factor plasmid (EAF) (
23), and lack of Shiga toxin (
16). Some
EPEC strains possess EAF-encoding bundle-forming pilus (BFP)
(
5). Typical EPEC strains possess the
eaeA for A/E and the EAF
or
bfpA, while atypical EPEC strains possess the
eaeA gene only,
and there is some controversy over whether atypical EPEC strains
are true diarrheagenic pathogens (
13). On the other hand, EAggEC
infection is diagnosed definitively by isolation from the stools
of patients of
E. coli showing the aggregative HEp-2 cell adherence
pattern (
21). EAggEC strains possess the
aggA gene that encodes
the aggregative adherent fimbria I (AAF/I) protein (
24), the
aggR gene for transcriptional activation of AAF/I expression
(
20), and the
astA gene that encodes the enteroaggregative
E. coli heat-stable enterotoxin I protein (
28). In this study,
we examined
E. coli isolated from patients with diarrhea from
three outbreak cases. Serotyping of
E. coli isolates showed
the pathogenic strains to be O55:NM, O111:NM, and O126:NM, representing
traditional EPEC serotypes. Based on phenotypic and genotypic
tests, the O55:NM strain was identified as an atypical EPEC;
it showed localized adherence and possessed the
eaeA without
the EAF. However,
E. coli isolates from the other two cases
were identified as EAggEC, because they showed aggregative adherence
and possessed
astA and
aggR but not
eaeA or EAF. In general,
EPEC infection is primarily a disease of infants younger than
two years old (
17), and EAggEC is associated with persistent
diarrhea (
1). Several outbreaks of diarrhea due to EPEC have
been reported in the United States, the United Kingdom, Finland,
and other developed countries. These outbreaks frequently occur
in day care centers (
2,
25) and occasionally occur in pediatric
wards (
10). However, reports of outbreaks due to atypical EPEC
are infrequent. Recently, Hedberg et al. (
10) reported an outbreak
caused by an atypical EPEC among adults who ate at a gourmet
buffet in the United States. This atypical EPEC strain was unique,
because its serotype was O39:NM, which did not belong to any
of the traditional EPEC serotypes, and it was positive for
astA along with
eaeA but negative for the EAF. Our present data,
along with Hedbergs observation, suggest that atypical
EPEC is a diarrheic pathogen. Furthermore, the number of reports
describing outbreaks due to EAggEC is increasing (
3,
7). In
Japan, there are only two reports describing outbreaks of diarrhea
involving EPEC and EAggEC (
11,
18). Based on our cases and the
two reports just mentioned, the contribution of EPEC and EAggEC
to the human disease burden in Japan might be significantly
greater than is currently appreciated.

FOOTNOTES
* Corresponding author. Mailing address: Akita Prefectural Institute of Public Health, 6-6 Sensyu kubota-machi, Akita 010-0874, Japan. Phone: 81-18-832-5005. Fax: 81-18-832-5938. E-mail:
jyatsu{at}spica.freemail.ne.jp.


REFERENCES
1 - Bahn, M. K., P. Raj, M. M. Levine, J. B. Kaper, N. Bhandari, R. Srivastava, R. Kumar, and S. Sazawal. 1989. Enteroaggregative Escherichia coli associated with persistent diarrhea in a cohort of rural children in India. J. Infect. Dis. 159:10611064.[Medline]
2 - Bower, J. R., B. L. Congeni, T. G. Cleary, R. T. Stone, A. Wanger, B. E. Murray, J. J. Mathewson, and L. K. Pickering. 1989. Escherichia coli O114:nonmotile as a pathogen in an outbreak of severe diarrhea associated with a day care center. J. Infect. Dis. 160:243247.[Medline]
3 - Cobeljic, M., B. Miljkovic-Selimovic, D. Paunovic-Todosijevic, Z. Velickovic, Z. Lepsanovic, D. Savic, R. Ilic, S. Konstantinovic, B. Jovanovic, and V. Kostic. 1996. Enteroaggregative Escherichia coli associated with an outbreak of diarrhoea in a neonatal nursery ward. Epidemiol. Infect. 117:1116.[Medline]
4 - Craviotto, 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. 3:9599.[CrossRef]
5 - Donnenberg, M. S., J. A. Girron, J. P. Nataro, and J. B. Kaper. 1992. A plasmid-encoded type IV fimbrial gene of enteropathogenic Escherichia coli associated with localized adherence. Mol. Microbiol. 6:34273437.[Medline]
6 - Eslava, C., F. Navarro-Garcia, J. R. Czeczulin, I. R. Henderson, A. Craviotto, and J. P. Nataro. 1998. Pet, as autotransporter enterotoxin from enteroaggregative Escherichia coli. Infect. Immun. 66:31553163.[Abstract/Free Full Text]
7 - Giron, J. A., F. Qadri, K. J. Jarvis, J. B. Kaper, and M. J. Albert. 1995. Monoclonal antibodies specific for the bundle-forming pilus of enteropathogenic Escherichia coli. Infect. Immun. 63:49494952.[Abstract]
8 - Gomez-Duarte, O. G., and J. B. Kaper. 1995. A plasmid-encoded regulatory region activates chromosomal eaeA expression in enteropathogenic Escherichia coli. Infect. Immun. 63:17671776.[Abstract]
9 - Gunzberg, 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. 33:13751377.[Abstract]
10 - Hedberg, C. W., S. J. Savarino, J. M. Besser, C. J. Paulus, V. M. Thelen, L. J. Myers, D. N. Cameron, T. J. Barrett, J. B. Kaper, and M. T. Osterholm. 1997. An outbreak of foodborne illness caused by Escherichia coli O39:NM: an agent that does not fit into the existing scheme for classifying diarrheagenic E. coli. J. Infect. Dis. 176:16251628.[Medline]
11 - Itoh, Y., I. Nagano, M. Kunishima, and T. Ezaki. 1997. Laboratory investigation of enteroaggregative Escherichia coli O untypeable:H10 associated with a massive outbreak of gastrointestinal illness. J. Clin. Microbiol. 35:25462550.[Abstract]
12 - Jerse, A. E., J. Yu, B. D. Tall, and J. B. Kaper. 1990. A genetic locus of enteropathogenic Escherichia coli necessary for the production of attaching and effacing lesions on tissue culture cells. Proc. Natl. Acad. Sci. USA 87:78397843.[Abstract/Free Full Text]
13 - Kaper, J. B. 1996. Defining EPEC. Rev. Microbiol. Sao Paulo 27:130133.
14 - Knutton, S., A. D. Phillips, H. R. Smith, R. J. Gross, R. Shaw, P. Watson, and E. Price. 1991. Screening for enteropathogenic Escherichia coli in infants with diarrhea by the fluorescent-actin staining test. Infect. Immun. 59:365371.[Abstract/Free Full Text]
15 - Knutton, S., P. H. Williams, and A. S. McNeish. 1989. Actin accumulation at sites of bacterial adhesion to tissue culture cells: basis of a new diagnostic test for enteropathogenic Escherichia coli. Infect. Immun. 57:12901298.[Abstract/Free Full Text]
16 - Kobayashi, K. 1991. Detection of enterohemorrhagic Escherichia coli using PCR. Rinsyo to Biseibutsu. 18:507513. (In Japanese.)
17 - Levine, M. M., and R. Edelman. 1984. Enteropathogenic Escherichia coli of classic serotypes associated with infant diarrhea: epidemiology and pathogenesis. Epidemiol. Rev. 6:3151.[Free Full Text]
18 - Makino, S., H. Asakura, T. Shirahata, T. Ikeda, K. Takeshi, K. Arai, M. Nagasawa, T. Abe, and T. Sadamoto. 1999. Molecular epidemiological study of a mass outbreak caused by enteropathogenic Escherichia coli O157:H45. Microbiol. Immunol. 43:381384.[Medline]
19 - Moon, H. W., S. C. Whipp, R. A. Argenzio, M. M. Levine, and R. A. Giannella. 1983. Attaching and effacing activities of rabbit and human enteropathogenic Escherichia coli in pig and rabbit intestines. Infect. Immun. 41:13401351.[Abstract/Free Full Text]
20 - Nataro, J. P., D. Yikang, D. Yingkang, and K. Walker. 1994. aggR, transcriptional activator of aggregative adherence fimbria I expression in enteroaggregative Escherichia coli. J. Bacteriol. 176:46914699.[Abstract/Free Full Text]
21 - Nataro, J. P., and J. B. Kaper. 1998. Diarrheagenic Escherichia coli. Clin. Microbiol. Rev. 11:142201.[Abstract/Free Full Text]
22 - Nataro, J. P., J. B. Kaper, R. Robins-Browne, V. Prado, P. Vial, and M. M. Levine. 1987. Patterns of adherence of diarrheagenic Escherichia coli to HEp-2 cells. Pediatr. Infect. Dis. J. 6:829831.[Medline]
23 - Nataro, J. P., M. M. Baldini, J. B. Kaper, R. E. Black, N. Bravo, and M. M. Levine. 1985. Detection of an adherence factor of enteropathogenic Escherichia coli with a DNA probe. J. Infect. Dis. 152:560565.[Medline]
24 - Nataro, J. P., Y. Deng, D. R. Maneval, A. L. German, W. C. Martin, and M. M. Levine. 1992. Aggregative adherence fimbriae I of enteroaggregative Escherichia coli mediate adherence to HEp-2 cells and hemagglutination of human erythrocytes. Infect. Immun. 60:22972304.[Abstract/Free Full Text]
25 - Paulozzi, L. J., K. E. Johnson, L. M. Kamahere, C. R. Clausen, L. W. Riley, and S. D. Helgerson. 1986. Diarrhea associated with adherent enteropathogenic Escherichia coli in an infant and toddler center, Seattle, Washington. Pediatrics 77:296300.[Abstract/Free Full Text]
26 - Ratchtrachenchai, O. A., S. Subpasu, and K. Ito. 1997. Investigation on enteroaggregative Escherichia coli infection by multiplex PCR. Bull. Dept. Med. Sci. 39:211220.
27 - Rothbaum, R., A. J. McAdams, R. Giannella, and J. C. Partin. 1982. A clinicopathological study of enterocyte-adherent Escherichia coli: a cause of protracted diarrhea in infants. Gastroenterology 83:441454.[Medline]
28 - Savarino, S. J., A. Fasano, J. Watson, B. M. Martin, M. M. Levine, S. Guandalini, and P. Guerry. 1993. Enteroaggregative Escherichia coli heat-stable enterotoxin 1 represents another subfamily of E. coli heat-stable toxin. Proc. Natl. Acad. Sci. USA 90:30933097.[Abstract/Free Full Text]
29 - Taylor, C. J., A. Hart, R. M. Batt, C. McDougall, and L. McLean. 1986. Ultrastructural and biochemical changes in human jejunal mucosa associated with enteropathogenic Escherichia coli (O111) infection. J. Pediatr. Gastroenterol. Nutr. 5:7073.[Medline]
30 - Ulshen, M. H., and J. L. Rallo. 1980. Pathogenesis of Escherichia coli gastroenteritis in mananother mechanism. N. Engl. J. Med. 302:99101.[Medline]
Journal of Clinical Microbiology, January 2002, p. 294-297, Vol. 40, No. 1
0095-1137/02/$04.00+0 DOI: 10.1128/JCM.40.1.294-297.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.
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