Diarrheagenic Escherichia coli Infection in Baltimore, Maryland, and New Haven, Connecticut

Department of Microbiology and Immunology , University of Maryland, Baltimore, Baltimore, Maryland, United States
Clinical Infectious Diseases (Impact Factor: 8.89). 08/2006; 43(4):402-7. DOI: 10.1086/505867
Source: PubMed


Diarrhea remains a common complaint among US patients who seek medical attention.
We performed a prospective study to determine the etiology of diarrheal illness among patients and control subjects of all ages presenting to the emergency departments and outpatient clinics of 2 large academic hospitals in Baltimore, Maryland, and New Haven, Connecticut. We used molecular methods to detect the presence of diarrheagenic Escherichia coli pathotypes, including enteroaggregative E. coli (EAEC), as well as Shiga toxin-producing, cytodetaching, enterotoxigenic and enteropathogenic E. coli.
Of the pathotypes sought, only EAEC was found in an appreciable proportion (4.5%) of case patients, and it was found more frequently among case patients than control subjects (P<.02). Surprisingly, EAEC was the most common bacterial cause of diarrhea in our population. EAEC was common in all age strata and was not associated with foreign travel or immunodeficiency. EAEC infection is frequently accompanied by fever and abdominal pain, though this did not happen more frequently in patients with EAEC infection than in patients with diarrhea due to other causes.
Our data suggest that EAEC infection should be considered among persons with diarrhea that does not yield another known etiologic agent.

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    • "Early research on EAEC linked these strains to persistent diarrhoea in children in developing countries but EAEC have since been shown to be a significant cause of acute diarrhoea and important in the aetiology of intestinal infections in industrialized countries [10]. Two independent, large, prospective studies of diarrhoea aetiology conducted in the UK (1993–1996) and USA (2002–2004) reported a similar EAEC prevalence in patients with diarrhoea: 4.6% (160/3506) and 4.5% (37/823) in the UK and US studies, respectively, and 1.7% in control subjects from both studies [11], [12]. Clinical symptoms include watery diarrhoea, often with mucus, low grade fever, abdominal pain, nausea and vomiting [10]. "
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    ABSTRACT: Following a large outbreak of foodborne gastrointestinal (GI) disease, a multiplex PCR approach was used retrospectively to investigate faecal specimens from 88 of the 413 reported cases. Gene targets from a range of bacterial GI pathogens were detected, including Salmonella species, Shigella species and Shiga toxin-producing Escherichia coli, with the majority (75%) of faecal specimens being PCR positive for aggR associated with the Enteroaggregative E. coli (EAEC) group. The 20 isolates of EAEC recovered from the outbreak specimens exhibited a range of serotypes, the most frequent being O104:H4 and O131:H27. None of the EAEC isolates had the Shiga toxin (stx) genes. Multilocus sequence typing and single nucleotide polymorphism analysis of the core genome confirmed the diverse phylogeny of the strains. The analysis also revealed a close phylogenetic relationship between the EAEC O104:H4 strains in this outbreak and the strain of E. coli O104:H4 associated with a large outbreak of haemolytic ureamic syndrome in Germany in 2011. Further analysis of the EAEC plasmids, encoding the key enteroaggregative virulence genes, showed diversity with respect to FIB/FII type, gene content and genomic architecture. Known EAEC virulence genes, such as aggR, aat and aap, were present in all but one of the strains. A variety of fimbrial genes were observed, including genes encoding all five known fimbrial types, AAF/1 to AAF/V. The AAI operon was present in its entirety in 15 of the EAEC strains, absent in three and present, but incomplete, in two isolates. EAEC is known to be a diverse pathotype and this study demonstrates that a high level of diversity in strains recovered from cases associated with a single outbreak. Although the EAEC in this study did not carry the stx genes, this outbreak provides further evidence of the pathogenic potential of the EAEC O104:H4 serotype.
    PLoS ONE 05/2014; 9(5):e98103. DOI:10.1371/journal.pone.0098103 · 3.23 Impact Factor
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    • "The association of EAEC with diarrhea appears to vary geographically, and many studies have demonstrated the importance of EAEC in pediatric diarrhea. In studies carried out in Vietnam and the USA, EAEC was isolated at higher prevalence in children with diarrhea (11.6 and 4.5%, respectively) than in controls (7.2 and 1.7%, respectively) (1, 17, 18). Our findings, however, were in contrast to these studies. "
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    ABSTRACT: The aim of this study was to investigate the frequency of betalactamase producing EAEC isolates among young children with diarrhea in Zanjan, Iran. Entero aggregative Escherichia coli (EAEC) is an emerging enteric pathogen associated with acute and persistent diarrhea and the evolution and spread of acquired extended spectrum betalactamases (ESBLs) among these strains has become a serious problem in the management of infectious diseases in developing countries. During the period from March 2011 to January 2012, 140 isolates of E. coli from diarrheal children aged 0-60 months and 90 isolates from age-matched controls without diarrhea were investigated for EAEC using PCR. Antimicrobial susceptibility testing was performed as CLSI guidelines and betalactamase genes, including bla TEM, bla CTX-M, bla IMP, bla VIM and bla NDM-1 investigated in EAEC isolates. In this study, EAEC was detected with slightly higher frequency in children with (8%) than in children without (4.6%) diarrhea (P > 0.05). Diarrheagenic E. coli exhibited high level resistance to aztreonam (80.7%), amoxicillin (74.4%) and tetracycline (69.3%). Also, 86.4% of E. coli isolates were resistant to at least three different classes of antimicrobial agents and considered as multidrug resistance. Molecular characterization of betalactamase genes showed that bla TEM was the most frequently isolated betalactamase. It was detected in 78.9% of ESBL producing EAEC isolates. Also, the frequency of bla CTX-M was 63.1% (12/19) and 8 (42.1%) isolates carried the bla TEM and bla CTX-M, simultaneously. None MBL producing EAEC was detected in our study. Our results indicate that ESBLs especially bla TEM and bla CTX-M are widespread among EAEC isolates and appropriate surveillance and control measures are essential to prevent further dissemination of betalactamases in our country.
    Gastroenterology and hepatology from bed to bench 03/2014; 7(2):131-6.
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    • "In children, EAEC induced diarrhea is commonly associated with mucoid stool, which may sometimes contain blood and fecal leucocytes (FLCs) [4,5]. In USA, EAEC is the most common cause of diarrheal illness among all age groups [6]. Despite lots of information available on the virulence determinants of EAEC-mediated diarrhea, studies on the level of FLCs and associated histopathogenesis in gut mucosa are very less [7,8]. "
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    ABSTRACT: This study was conducted to determine the role of enteroaggregative Escherichia coli (EAEC) in inflammatory diarrhea among hospitalized patients in Kolkata. The inflammatory pathogenesis of EAEC was established in mice model and histopathological studies. Presence of fecal leucocytes (FLCs) can be suspected for EAEC infection solely or as a mixed with other enteric pathogens. Active surveillance was conducted for 2 years on 2 random days per week with every 5th patient admitted to the Infectious Diseases Hospital (IDH). Diarrheal samples were processed by conventional culture, microscopy, ELISA and molecular methods. Two EAEC isolated as sole pathogens were examined in mice after induced intestinal infection. The intestinal tissue samples were processed to analyze the histological changes. Of the 2519 samples screened, fecal leucocytes, erythrocytes and occult blood were detected in 1629 samples. Most of the patients had acute watery diarrhea (75%) and vomiting (78%). Vibrio cholerae O1 was the main pathogen in patients of 5--10 years age group (33%). Shigellosis was more in children from 2--5 years of age (19%), whereas children <2 years appeared to be susceptible for infection caused by EAEC (16%). When tested for the pathogenicity, the EAEC strains colonized well and caused inflammatory infection in the gut mucosa of BALB/C mice. This hospital-based surveillance revealed prevalence of large number of inflammatory diarrhea. EAEC was the suspected pathogen and <2 years children appeared to be the most susceptible age group. BALB/C mice may be a suitable animal model to study the EAEC-mediated pathogenesis.
    Gut Pathogens 12/2013; 5(1):36. DOI:10.1186/1757-4749-5-36 · 2.28 Impact Factor
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