1204. Colonization Factors in Enterotoxigenic Escherichia coli (ETEC) Isolates from Travelers to Mexico, Guatemala and India Compared with Children in Houston, Texas; Evidence of the Importance of CS21
Session: Poster Abstract Session: Clinical Infectious Diseases: Enteric Infections
Friday, October 28, 2016
Room: Poster Hall
Posters
  • IDSA 2016 ETEC.pdf (237.8 kB)
  • Background:Enterotoxigenic E.coli(ETEC) can be attributed to around 200 million diarrheal episodes and 380,000 deaths in the developing regions. Travelers’ diarrhea occurs in 15-40% of travelers to developing regions with ETEC being the most important etiologic agent. A challenge to vaccine development is the temporal and regional variability in ETEC’s toxins and colonization factors (CFs). This study aims to describe the distribution of enterotoxins and CF profiles of ETEC isolates from stool samples of adult travelers acquiring diarrhea in Mexico, Guatemala and India and a group of children with acute diarrhea in Houston, Texas between 2007 and 2012.

    Methods:The LT/ST enterotoxins and CFs from 252 patients were determined using a published PCR assay

    Results:Among the 252 ETEC isolates, 15% were LT-only, 58% were ST-only and 28% produced both LT and ST. The distribution of LT-only (12-15%) and ST-only (55-56%) isolates was similar between Latin American and Indian sites. The most prevalent CF was CS21, expressed in 65% of the isolates followed by CS6 (25%) and CS3 (17%). Among the international travelers, 64% of the ETEC isolates expressed CS21. CS21 was expressed in 46% of isolates from Latin America compared to 96% of isolates from India (p< 0.0001). CS21 was expressed in 85% isolates from Houston children. CS21 was increasingly found in ST-only (p= 0.003) and ST/LT (p= 0.026) ETEC compared to LT-only ETEC.

    Table: Enterotoxin and CF profile of ETEC isolates obtained from adult travelers in developing regions and pediatric cases in Houston, 2007-2012

    Location

    ETEC n (%)

    LT-Only

    n=37

    (%)

    ST-Only

    n=145 (%)

    LT/ST

    n=70

    (%)

    CS1,

    n=25

    (%)

    CS2

    n=22

    (%)

    CS3

    n=44 (%)

    CS4

    n=4

    (%)

    CS5

    n=1

    (%)

    CS6

    n=63

    (%)

    CS7

    n=0

    (%)

    CS17/19

    n=1

    (%)

    CS21

    n=165

    (%)

    CFA1

    n=3

    (%)

    Guatemala & Mexico

    n=146 (57)

    22 (15)

    81 (55)

    43 (29)

    20 (14)

    19 (13)

    20 (14)

    0 (0)

    1 (0.7)

    47 (32)

    0 (0)

    1 (0.7)

    67 (46)

    3 (2)

    India n=73 (29)

    11 (15)

    41 (56)

    21 (29)

    5 (7)

    3 (4)

    24 (33)

    3 (4)

    0 (0)

    14 (19)

    0 (0)

    0 (0)

    70 (96)

    0 (0)

    U.S, n=33 (13)

    4 (12)

    23 (70)

    6 (18)

    0 (0)

    0 (0)

    0 (0)

    1 (3)

    0 (0)

    2 (6)

    0 (0)

    0 (0)

    28 (85)

    0 (0)

    Total ETEC n=252

    37 (15)

    145 (58)

    70 (28)

    25 (10)

    22 (9)

    44 (17)

    4 (2)

    1 (0.3)

    63 (25)

    0 (0)

    1 (0.3)

    165 (65)

    3 (1)

    Conclusion:High frequency of finding CS21 among recent isolates of ETEC over a wide geographic distribution warrants additional studies on this CF. Highly conserved CS21 is an important target for potential multivalent ETEC vaccines.

    Vineetkumar Kharat, PhD1, Makhdum Ahmed, MD, MPH1, Zhi-Dong Jiang, MD, DrPH2 and Herbert Dupont, MD, FIDSA2,3,4, (1)The University of Texas School of Public Health, Houston, TX, (2)Center for Infectious Diseases, The University of Texas, School of Public Health, Houston, TX, (3)Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, (4)The University of Texas Medical School, Houston, TX

    Disclosures:

    V. Kharat, None

    M. Ahmed, None

    Z. D. Jiang, None

    H. Dupont, None

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